Dr. Salem Neuromuscular Disorders Lecture

Dr. Salem Neuromuscular Disorders Lecture


hello everyone today we will be talking
about neuromuscular disorders this is a very big topic obviously because anytime
we say neuromuscular disorders we are referring to all these disorders that
affect the peripheral nervous system as opposed to the central nervous system so
that would include you know the motor neuron disease and the muscles and
nerves and and roots we’ll try to have an organized approach based on
localization so we’ll start with a definition of the motor unit and then
we’ll start to take the important disorders or diseases that affect
different parts of the peripheral nervous system and collectively or
together that’s what we refer to as in your muscular disorder so a peripheral nervous system obviously
consists of the two main types of neurons the sensory neurons and the
motor neurons anytime we talk about weakness of prefer nervous system
etiology meaning weakness in any neuromuscular disorder that means that
we’re talking about lower motor neuron condition and lower motor neurons
obviously the cell bodies are located in the anterior horns and from that from
there the roots will come out and they will be joined with the sensory neurons
in the spinal nerve in the road that come out of the spinal cord and then go
and the roots will join together and form plexus and and go to their muscles
it’s a very important concept to keep in mind that the motor neurons or no one
would especially lower motor neurons are not just the ones that originate from
the spinal cord there are also lower motor neurons that generate from the
brainstem they come out of the model nuclei in the brain stem so for example
the facial nerve the seventh cranial nerve consists primarily of lower motor
neuron that come out of the brainstem and to go in a rate different muscles in
the face see for the hypoglossal nerve which is the 12th cranial nerve same for
the third fourth and sixth cranial nerves that innervate the extraocular
muscles while at the same time within the same nerve itself you may have other
fibers in addition to the motor fibers or motor neurons and the example would
be the the third cranial nerve will in addition to the motor neurons or motor
fibers you have parasympathetic fibers also or for
example the trigeminal nerve which is primarily sensory neurons but in
addition to that there are some motor neurons that would go to the Masters now
it’s so so that’s important anytime we talk about lower motor neuron we need to
always imagine three and two horn cells sending out these lower motor neurons in
all these different spinal cord segments from the cervical all the way to the
lumbar spine and in addition to that the lower motor neurons that come out of the
motor nuclei in the brainstem an important concept in peripheral nervous
system or renewal muscular field is something called the motor unit the
motor unit is simply the motor neuron itself consisting of the cell body and
the action and the Milan and the neuromuscular Junction in addition to
these muscle fibers that are innervated by this specific in neuron so the muscle
contains many many much different muscle fibers the same muscle will receive
multiple neurons that are coming or together in in one nerve each neuron
would control a group of muscle fibers if that neuron is diseased these muscle
fibers will be affected or what we called innervated however if they
address a neuron that goes to different muscle fibers is a still intact then the
conductivity through that neuron will still be working and these muscle fibers
will still contract and do their job completely normal so in that case we
have two motor units one of them is impaired and the other one is intact
although the neurons are both of them are coming within the same now this here we try to refresh our
memory and remember the different parts of the nervous system I think many of
you are probably familiar with the with this graph here the peripheral nervous
system consists of anterior horn cell or or talking primarily about the lower
motor neuron here it consists of an two horn cells and if you have anything that
goes wrong with them to your horn cells then we call it motor neuron disease
that’s kind of the umbrella that will include different types of diseases and
conditions and then the root and if you have anything goes wrong with the root
then that we call that condition radiculopathy and then these multiple
roots and different levels they get together and they form the tree of
multiple connections of different roots that tree of nerves we call it flexible
plexus and anything that it’s wrong with the plexus we call it flex property and
then from the plexus you get multiple different nerves that run from the
plexus all the way to the muscles we call nerves the nerves are connected to
the master it’s through junction and anything goes it goes wrong there we
call it you know muscular Junction disorder and that is different from the
general term of the neuromuscular disorder you know we’ll talk about
specifically the neuromuscular Junction disorder and then the muscle itself
would they all with all the muscle fibers and anything goes wrong with the
muscle we call it myopathy just like if anything goes wrong with a nerve we call
it inner apathy so those terms are very well defined and
each of them refers to a part of the peripheral nervous system
now also in the peripheral nervous system we have the sensory nerves you
know starting with the receptors in the skin and then going through the sensory
nerves that are commonly combined within the same nerve so median or
Aradia they contain both motor fibers and sensory fibers where the signals are
going both way so these signals and the sensory nerves are coming out from the
periphery going through the nerves through the plexuses through the roots
but instead of the anterior they’ll go through the posterior horns and from
there they’re they synapse with their order they continue actually or they may
cross to the other side and then they put in of their tracks or corresponding
tracks based on what sensation is that all the way to the brain to the thalamus
primarily this is the sensory relay station and from there to the sensory
cortex or other types of the cortex now we is a very important concept to to
remind ourselves with before we start this lecture is the difference between a
central nervous system and peripheral nervous system one of the best ways to
differentiate between them is obviously the upper versus lower motor neuron
signs with the upper motor neuron we have a hyper reflex eeeh and hypertonia
and with the suspect isset II with the lower motor neuron or peripheral nervous
system we have hyporeflexia and hypotonia acidity in addition to that
with the central nervous system problems in upper motor neuron disorders we have
the bins pisang and we have clonus wild with the prefer nervous system lower
motor neuron conditions or sources we have atrophy and we have fasciculations
anytime we see one of these features it simply suggests that we’re dealing with
the lower motor neuron and that means a peripheral nervous system and then from
there we just need to further localized within the peripheral nervous system we
do not have to have all the features so if someone has a neuropathy or or
myopathy or radiculopathy they don’t have to have
decreased reflexes plus decreased tone plus atrophy plus
fasciculations any one of those is enough the more the
better of course and the more secure that they ignore this will be the few
things here that I added to this slide that are of extreme importance to help
us localized within the peripheral nervous system some of them are not
absolutely reliable but they are fairly reliable for example if someone has if
we have a case of someone describing some symptoms in one extremity only and
does not involve you know upper and lower extremities it does not involve
both sides of it it’s just one extreme one arm on one leg obviously naturally
you’re gonna be considering things like very cooperative flex apathy and mono
neuropathy just one nerve deal it logically speaking it makes the
possibility of myopathy for example or polyneuropathy it just becomes almost
impossible it’s it’s extremely rare for in myopathy there are few but it’s
extremely rare for myopathy to affect just one extremity strictly and doesn’t
cause any other problems if we have pain in the spine for example and more
importantly radiating pain down the arm or the leg with some symptoms whether
they are sensory only or motor only or both then that pain itself obviously is
going to make you think more of radiculopathy anytime we have upper and
lower motor neuron signs in the same patient in a non localizing pattern
meaning in a pattern that cannot be explained by spinal cord condition or or
something else then that’s obviously the indicator of a motor neuron disease if
someone has bilateral symptoms really symmetric and there are sensory symptoms
mostly distal for example in the the feet then that’s how neuropathy
starts versus if someone has only motor symptoms no sensor symptoms whatsoever
then you certainly would exclude things like critical appetit or neuropathy even
though there are pure motor neuropathy but that is relatively uncommon what’s
more common actually is that or more likely I would say is that you’re
dealing with myopathy neuromuscular Junction disorder and motor neuron
disease because those conditions obviously they will have motor symptoms
only and the other way around if someone has some sensory symptoms in their
complaint then that by itself would exclude the possibility of motor neuron
disease like ALS for example why would an als patient have any sensory symptoms
as part of their ALS it’s purely motor neuron disease same for myopathy muscles
have do not cause any numbness or tingling so now again we’re always
talking about a one etiology behind the symptoms in the real life you’re gonna
have cases where you know people may have two different things going on at
the same time like some diabetic neuropathy that’s developing and on top
of that they’re having some myopathy so of course you know things can may not be
straight forward in in real life but generally speaking most of the time even
in real life and always in the exam you can have the you have to consider that
this is only the most important test that you do in
any time we suspect peripheral nervous system problem is EMG nerve conduction
study so this is kind of the equivalent to getting brain or spinal or the
imaging when we’re dealing with the central nervous system now it’s
important to keep in mind that nerve conduction studies do not and and even
EMG do not become abnormal right after a lesion in the peripheral nervous system
there is some delay and that is variable but generally speaking at least five to
seven days after the onset of the légion need to pass before we start to
see abnormalities on the nerve conduction study and EMG so that will
need to be kept in mind if we’re dealing with the situation where we need
information right away to help us with the diagnosis or guide the management
then and the symptoms just started within a day or two then EMG nerve
conduction study obviously is not the test that we can rely on at that point
now the this test consists of two separate parts because they’re
completely separate and nerve conduction study assesses the nerves and the
electromyography is when you put the needle in in the muscles the Nerf nature
study can be performed alone without an EMG and you would still be able to get
helpful information in in certain scenarios
neither electromyography alone is almost never done before the information will
not be complete and it’s hard to interpret the medium do without presence
of nerve conduction study there is a technique called repetitive stimulation
test that’s not a routine a part of the EMG nerve potential study so this
part needs to be specified when we want wanted to be performed repetative
simulation test is than for only one reason which is to investigate for a
neuromuscular Junction disorder very briefly the nephron after study simply
is based on stimulating one point of the nerve and recording from another point
usually that recording point is disturbed to the stimulating point and
we always do a pre-measured distance between the
recording point and the stimulating point and if we know the distance then
we can calculate or obviously the Machine the study machine will calculate
the conduction velocity the amplitude and latency of the electric signal the Neph could I should study will help us
know a lot of information about the conductivity of the nerves from the
point of stimulation and more distally it does not help with anything that or
any lesions that could be more proximal to the stimulating point if we’re
stimulating at the wrist and someone has a lesion at the elbow level then the
nerve conduction study will be completely normal because we’re
stimulating at the wrist and recording from the fingertip for example the
needle electromyography helps a lot in learning about the muscle the motor unit
action potentials and there’s any muscle disease in addition to that it’s very
important and critical in assessing the roots disorders radiculopathy and the
anterior horn cells motor neuron disease keep in mind that those two parts even
plug hoppitty to a large degree they cannot be as
test by nerve conduction study we cannot stimulate these structures because you
know plexus and roots are very deep buried inside the neck and inside the
chest or pelvis and and children cells obviously cannot be stimulated so the
when we do the nefud I should study and that the study is normal meaning the
nerves themselves in the arm of the lake are normal but the neither
electromyography still shows signs of denervation
in the muscle that the muscle is not acting properly the these muscle fibers
are innervated that indirectly confirms that this denervation source must be
coming from a proximal structure which is the root or the plexus or the motor
in it the the the internal home cell another important concept in the nerve
conduction study is which muscles are affected and which nerves are affected
so for example if the need electromyography of multiple muscles if
is performed in the extremity and two of these multiple muscles show signs of
denervation both muscles are let’s say one muscle is innervated by the median
nerve the other muscle is innervated by the ulnar nerve both of them are
abnormal then this could mean that median and ulnar nerves both of them are
affected however if both muscles are innervated by let’s say c7 or c8 for
example radiculopathy or whatever root is that then that would be the more
logical explanation that this must be radiculopathy rather than both median
and ulnar neuropathy at the same time and the best way to confirm it is to
test a muscle that is innervated by a median nerve also but not by that
specific root its not by c8 Mossad has innovated by V
Turner and c6 if this was a median nerve then this muscle must be abnormal if
this was c8 then this muscle must be completely normal and that’s how we can
tell with absolute accuracy through the EMG nerve conduction study where is a
problem in the peripheral nervous so we start with the motor neuron
disease and again motor neuron disease the hallmark is that you have an
involvement of the anterior horn cells it’s whether it’s an infectious or
degeneration sometimes on top of that you may have involvement in the
corticospinal tract and that’s typically in the degenerative cases and which is
ALS obviously Lou Gehrig’s disease and that’s why we have an ALS upper and
lower motor neuron symptoms but in any type of motor neuron disease the
anterior horn cells are or must be involved and affected it’s very
important to keep in mind that the sensation is normal fasciculations are
extremely important in motor neuron disease physicians are a feature of any
lower motor neuron disorder so you can see it with neuropathy myopathy and
radiculopathy however it’s mostly prominent in motor neuron disease so in
exam if you see someone talk about fasciculations keep in mind things like
ALS or polio or at your horse of disorders is very likely possibility you
know if they are referring to tongue fasciculation specifically then the then
they’re certainly referring to ALS all motor neuron disease don’t have any
effective treatments one thing to keep in mind when we’re testing when doing
the nerve conduction study an EMG again as we said this is a the most important
test that you do to evaluate the proffering of the system in motor neuron
disease in Africa study will be normal again not absolutely but but largely
speaking we can say it will be normal it’s the needle electromyography that
will show you some dinner vation features and some fasciculation
the potentials so we’ll start with amyotrophic lateral sclerosis AMS or
what many people refer to as Lou Gehrig’s disease this is a
neurodegenerative disorder so the exact etiology and why does it happen in
certain people or not in others is unclear als hallmark is upper and lower
motor neuron signs in an and oka lysing pattern the disease general speaking is
progressive in a subacute to even slow fashion sometimes when it starts or it’s
somewhat in relatively in its early stages people may not have the upper and
lower motor and strengthen your own science yet both existing so that might
be a little confusing however soon in a few months probably when the exams
repeated and obviously with the symptoms progressing we’re gonna find some other
features once we have both upper and lower motor neuron features then this
must be motor neuron this degenerate ‘iv motor neuron disease affecting both
corticospinal tract giving the upper motor neuron signs and anterior horn
cells whether in the spinal cord or in the brain stem in the motor cleaner
nerves giving the lower motor neuron features
the the ALS a lot of times will start in one extremity so someone would have you
know weakness in an arm or a leg and some atrophy in it and then later on
another extremity might be involved with let’s say you know the bin ski sign and
and the cloners and maybe some weakness sometimes both operand or motor and so
on it sighs me both of them in the same extremity
generally speaking the involvement is not symmetric it can be obviously but
that’s but that’s not necessarily the typical presentation a lot of times the
ALS patients will have bulbar symptoms meaning symptoms have been coming from
involvement or damage or problems with the lower part of the brain stem
functions motor functions so things like this are 3n dysphagia through
involvement of the 12th and 10th ninth cranial nerves and commonly people may
have official weakness also because of the involvement of the facial nerves the
seventh cranial nerve so bulbar symptoms are common
anytime someone presents with dysphagia this are three especially if they have
no other symptoms whatsoever ALS in addition to my Sinha gravis those must
be the top two differential diagnoses for this are three and dysphagia that is
slowly progressive obviously without any Legion that is seen on a brain MRI in
the brainstem generally speaking in ALS extractor movements they tend to be
intact the propia is not an issue that is one feature that distinguishes ALS
from Mycenae gravis generally speaking ALS is not confused
easily by Mycenae gravis those are really separate and different but
sometimes in early stages of both of them they may present with similar
features however diplopia it is a very typical and common presentation in mice
and gravis is rare in Ellis as we mentioned before if you see tank
atrophied or fasciculations there’s particular Manik for ALS generally
speaking no cognitive deficit in ALS although recently the study suggests
that there are some minor changes in fact actually and those changes tend to
have a lot of frontal and temporal features almost sometimes in severe
cases like frontal temporal dementia obviously there’s no cure for ALS it’s
mostly supportive treatment typically they will need pick a trach at some
point there is survivor is usually short almost 50% of patients with ALS will die
within three years of the ignosi’s so that’s kind of a number that we always
look at however survivor can be up to five years and there are some uncommon
or infrequent cases where people survived more than that however when we
talk about survival a lot of this time will be spent what the patient is
extremely weak probably bedridden on the ventilator and it would affect you the
only available medication is called the rivers old and it’s FDA approved it’s an
expensive medication we need to console the patient and clarify that
expectations are low this medicine show that it can delay the need for
tracheostomy and it prolongs the survival of the patient by few months
while again the patient is most likely bedridden and on their another condition
that affects at your home selves is polio myelitis so polio is a virus that
was common in the past now polio is largely almost completely
eradicated not just in the US but in vast parts of the world including in
developing countries so it is not that important issue anymore however we we
need to keep it in mind especially if we’re facing a case of
people who are refugees they were born and lived their childhood in in parts of
the world where access to health care is very limited specially
in war-torn countries and these places so a refugee coming from this area was
developing a pure motor neurone lower motor neuron weakness with the features
of door motor neurone it’s something that we have to consider the the big
example is is what happened in Syria recently the polio has been eradicated
for more than two decades and in the last two to three years there have been
proven cases that started to show up again because of the lack of vaccination
polio starts typically or all affects the human body as a viral infection most
of the time it does not cause any neurologic problems however if it does
it will start as a meningitis a picture headache fever body aches and neck
stiffness and injeel’ features and then followed by this diffused weakness it
can affect some parts of the of the body or it can affect the entire body
obviously the weakness has low motor neuron features it is accompanied by a
trophy remember a trophy does not happen right away it takes time sometimes
several weeks before the atrophy develops the generally speaking even
when we have polio myelitis the prognosis is overall is not bad people
tend to recover reasonably well however there are severe cases where there will
be permanent paralysis a natural feel the if we do CSF the CSF will be
consistent with viral meningitis and the polio antibodies will be positive both
in the blood or in the CSF or sometimes even in a Ferengi swab polio is spread
through droplets transmission and or Africa and transmission currently we
only use the the killed virus vaccine because there’s
been rare reports of the oral life at nuit vaccine and causing polio the
treatment is mostly supportive now this might be actually more important than
polio West Nile virus causing acute flaccid paralysis this is a very rare
complication of West Nile virus however because was not virus infection is
relatively common especially I mean obviously only during summer time so
that’s something that we need to keep in mind again just like polio West Nile
virus causes a viral syndrome it doesn’t necessarily affect the
nervous system however if it does affect the nervous system it that would cause
meningitis and all encephalitis a patient would present will present with
the meningitis picture CS air full of viral meningitis West Nile virus
antibodies are present the CSF a lot of times within a few days this patient
very rapidly will develop weakness diffuse weakness flaccidity all over
decreased to absent reflexes and that’s what we call acute flaccid paralysis it
commonly involves the diaphragm and causes respiratory failure it generally
speaking this condition has poor prognosis the last example of motor neuron disease
will be a group of conditions we called spinal muscular atrophy SMAS there are
multiple types of SMAS and they’re mostly hereditary disorders we will not
go in depth in in these different types however one of them is very important to
keep in mind or know something about it is the learning hoffman disease this is
an autosomal recessive condition like most of the spinal muscular atrophy it
is the most common SMA and also it’s a more severe SMA it’s actually probably
about half of all different SMAS that are reported the they are welding
Kaufman’s disease the the reason to suspect that is we have a floppy baby
the floppy baby syndrome has a lot of different causes a floppy baby simply
means that there is hypotonia decreased own and that can be seen in many
different types of neuromuscular disorders that affect newborns but of
course that’s not the only depression diagnosis some central nervous system
disorders actually can present with probably maybe a lot of genetic problems
what one of the issues or the fresher diagnose will be very puffed man’s
disease symptoms usually are present by age of six months and most children will
die at the age of two with lot of complications obviously there is no
treatment so if you want to know anything about SMA
spinal muscular atrophy think of holding Hoffman’s disease autosomal recessive
floppy baby no treatment it is a motor neuron disease
now we move to radiculopathy and this is something that’s encountered very
frequently all the time the problem here is obviously the spinal
nerve roots before we talk about with the cloppety I want to clarify a couple
different points here there’s something called the central canal and the neural
foramina I’m sure you’re very familiar with that but let’s make sure that this
is clear again refresh it both of them can be comes to nosed or narrowed and
just like in the first picture at a certain picture that you have on your
left lower corner the the central canal is where the spinal cord goes and
surrounded by CSF obviously and to have a central canal stenosis either the
pedicles or the ligament in in behind or the disc in the front is going to bulge
or ligament is thickened or something and this would cause compression on the
spinal cord this is what we call spinal cord compression because of central
canal stenosis and if this central canal stenosis happens in the lower part of
the spine in the lumbar vertebrae in the lumbar discs are talking below l2 simply
that means that there is no more spinal cord at that level spinal cord ends
around l1 l2 so if I have central canal stenosis and
l3 four or five s 1 this will compress not the spinal cord obviously but the
roots the lumbar and sacral boots that are still traveling in the cistern down
there and that’s what we do refer to as cauda equina those roots is the cauda
equina so if you have central canal stenosis at the lower level of the
number spine then you can have you do not have spinal cord compression you
have code equina syndrome that’s one type central canal stenosis
the other type would be neural foramen st noses the neural foramen is the space
where the the nerve the spinal nerve or the root comes out of of the spine and
like what we see in the second picture again I’m starting from the left going
to the right so if you have stenosis there this is what’s gonna give you
ready kalapa the– because we’re pushing on a root that’s what the protocol
operty happens spinal cord compression does not cause a lot of pain while
radiculopathy it causes a lot of pain and when you have neural foraminal
stenosis it will push on one root only now if you have stenosis at more than
one level obviously you’re gonna have more than one root pushed and so it’s
either mono radiculopathy which is usually most of the times that’s what it
is when we say radiculopathy we means we mean like it’s one one root however we
can have probably radiculopathy so multiple roots either on the same side
or on both sides sometimes you have bilateral neural foraminal stenosis at
the same level so people may have let’s say c7 radiculopathy on both sides
Europe foramina stenosis is less concerning than spinal cord as sorry
then central canal stenosis because the central canal stenosis we have spinal
cord compression people will have symptoms from that level all the way
down even with cauda equina when you have the stenosis that will compress
multiple roots at the same time that the roots that are traveling down rather
than just one root another obvious point is that almost always
radiculopathy is a mechanical etiology there’s compression the thoracic spine
and the sacral part of the spine except probably for s1 and de rarely is too
those areas you will really have radical operty in them it’s mostly cervical and
lumbar a few other things about radiculopathy
of course typically it’s one extremity or it almost always it’s one extremity
however if it’s bilateral that that certainly can happen there is always
radical radicular pain radiates from the neck or from the lower back should Stan
commonly described as an electric like a pain or sharp shooting pain it’s very
important to remember that the specific reflexes of that route if that route has
corresponding reflexes those would be decreased or absent because this is a
lower motor neuron condition the route again itself will contain both motor and
sensory fibers but as long as it’s damaged obviously the motor fibers will
be damaged and that will affect the reflexes and that would cause a trophy
and so on the nerve conduction study in ready
property is normal while EMG as we mentioned which showed innervation in
any muscle that is sampled that is innervated by that specific route while
when you sample the other muscles that are innervated by different routes those
muscles will be the EMG where those muscles will be completely normal down
in this couple illustrating pictures here on the left side you will see what
do we mean by central canal stenosis where the spinal cord itself is
compressed either from the back the sides or from the front the the next one
to your right it will show you again in down there there the three red points
are how would the nerve or spinal cord can be injured so you may have second
ligament that is pushing on the spinal cord itself and that would be the
countless cord compression and central canal stenosis however the
routes themselves those green structures can be compressed either because of a
herniated disc compressing of the under root or because of bone spurs that are
compressing with the road on the right side I just want you to refresh your
memory of different terms or conditions that you might read sometimes on x-ray
reports or MRI or CT reports or as diagnosis so we have degeneration or
degenerative discs we have bulging discs but not necessarily herniated we have a
herniated disc where there is rupture of the fibrous tissue the periphery of the
disc sometimes we have thinning in the disc itself without any bulging or
herniated and sometimes we have degeneration the desk with osteophyte
formation on top of that so now let’s discuss the important radiculopathy
starting with a cervical radiculopathy if you have c5 radiculopathy biceps
reflux will be decreased or absent and commonly but not necessarily the
brachioradialis reflex the sensory distribution is usually the
anterolateral shoulder it’s only in the shoulder area it never go be below the
elbow and to be on the lateral side a very important muscle that is involved
is the deltoid because no other really cooperative would have filled the
deltoid other than c5 now looking at c6 brachioradialis typically is decrease or
absent however you may have also biceps so in a sense both c5 and c6 both of
them they would affect the reflexes of biceps and brachioradialis – to some
degree again you have the decree decrees
reflexes and the sensory distribution is the lateral forearm while the c5 is
lateral shoulder area that c6 is lateral but it’s in the forearm itself and
there’s typically weakness with the biceps and weakness with the wrist
extensors with c7 you will have problems with the triceps reflex c7 sensory
distribution is the posterior of forearm so that’s that’s really important
anytime you have sensory deficit in the posterior side of the arm forearm and
we’ll talk about the quality then what then this must be c7 or probably we’ll
talk about what else are in the exam then it must be decrease or absent
triceps reflexes again the the triceps muscle itself will be weak now going
down to a lumbar and sacral radiculopathy l1 and l2 are extremely
rare and we’re not gonna talk about the L 3 L 3 is also not very common just
remember that if you have pain and sensory deficit in the knee area that is
coming because of ready cooperative then this must be l3 l4 is very important
because we have a patellar reflex and if you have problems with l4 then you’ll
have decreased or absent patellar reflex the sensory distribution of l4 is the
medial side of the leg and typically what’s most important with l4 is that we
have foot drop witness in the photos reflection anterior tibialis the foot drop happens either because of
elf already property or common peroneal or fibula neuropathy now l5 and s1 those are the by far the
most common the two lumber ready cooperatives l5 the lateral leg and the
big toe are evolved as far as station and there is usually weakness of two or
dorsiflexion s1 we have problems with the Achilles reflects and it affects
them lateral side of the foot there is also commonly problems with
aversion and plantar flexion we we talked about cauda equina syndrome again
here the lumbar roots that are traveling down out of the spinal cord segments
those roots are traveling down in order to reach the corresponding newer
foramina to exit from there that’s what forms the cauda equina and if there is
compression in on this group of roots centrally that causes the symptoms the
typical symptoms would be bilateral involvement in both lower extremities so
it is political apathy and again it’s usually bilateral typically there will
be what we refer to as saddle anesthesia so proximal bilateral lower extremities
in addition to the pineal area the that’s innervated by the sacral nerves
there’s commonly urinary involvement typically with the urinary retention and
there’s decrease director tone again that’s all because of the involvement of
them s1 is too and sometimes it’s three
routes the treatment typically is surgical decompression if someone has
significant symptoms and the surgery must be done urgently now we’re moving
to the plexus and as well refer to as property again we have four flex our
path is a possible work surface we have two plexuses on both sides of the upper
chest below the clavicle those are the brachial plexus and we have to number
circular plexuses in the pelvic area cause the groin and typically plexippus
II would be only one plexus involvement bilateral symptoms are extremely
unlikely and uncommon because by far the most common reason for blocks apathy is
mechanical compression and to have bilateral brachial by that’s what
lumbosacral that’s kind of unusual it affects one extremity and typically the
symptoms are mixed we just cannot have a pure sensor or pure motor presentation
if someone has flex apathy because all these trunks and roots and I mean and
then divisions and court those are all mixed sensory motor fibers when do we
suspect blocks apathy so if someone has some sort of motor and sensory deficits
maybe a loss of some reflexes some atrophy in one extremity this could be a
radiculopathy this could be modern neuropathy like carpal tunnel or or
owner or something so when do I suspect that this
Black Sabbath II the reason we suspect Black Sabbath II is based on the
physical exam if we feel that the sensory deficit does not follow its
specific dermatome or a specific nerve distribution it doesn’t fit with the
median distribution it doesn’t fit with the radial distribution of sensory
deficit the muscles that are weak some of them are Alan are innervated some of
them are radial innervated and some of them are median innervated then maybe
all of these nerves are affected but that’s kind of odd what seems more
likely in this case that it must be the plexus and that’s why multiple different
muscles are affected a nerve conduction study commonly is normal EMG will show
the innervation in multiple muscles but different from what we saw with the
radiculopathy and what we will see with more neuropathies those muscles again
they do not belong to a specific route or specific no the a lot of these Black
Sabbath is especially if they are non mechanical not compression related they
start usually by severe pain in the plexus area whether in the groin or in
the armpit that is followed soon within a day or two sometimes with sensory
deficit and/or motor deficit so remember this severe pain that precedes the onset
of property especially in inflammatory or autoimmune cases those charts just to refresh our memory
of the brachial plexus and their number and the sacral plexus remember a few
important things a femoral nerve comes from the upper lumbar roots mostly l2 l3
and l4 the tibial and peroneal or fibular in your name nerves they both
are the two components of the sciatic nerve and the sciatic nerve originates primarily from the lower lumbar and the
upper sacral roots so those are the two biggest nerves in the lower extremity
the femoral nerve and the sciatic nerve think of femoral as relatively speaking
upper lumbar roots and the sciatic nerve is lower lumbar / sacral roots and here
are some etiology of plexippus is starting with a breakup let’s hop
a–they banquets to human very important a patient who is a smoker for example
and our patients have you been weightless and they present with one
extremity right or left arm having sensory deficit motor weakness and on
top of that there must be lower motor neuron science to tell you that this is
a profile nervous system condition then you have to consider Pancoast tumor you
do chest x-ray or see this kind of the chest using crutches sometimes that can
cause breaker clicks apathy on the long term
another very important one is thoracic outlet syndrome when you have the
cervical thoracic outlet syndrome has two types vascular which is more common
and less common neurogenic thoracic outlet syndrome is a type of apathy any
compression because of a mass in the upper chest whether it’s an abscess a
lymph node scar tissue anything trauma especially if the arm is hyper extended
and that can cause property and of course difficult vaginal deliveries
which will then talk about in the next slide
– just remember clamp case and machines hoppity’s
the lumbosacral except it is perfect tumors especially the very end or cervix
or bladder tumors those can push on the lumbosacral plexus retroperitoneal
hematomas that’s also a possible etiology to cause compression
post-surgical especially the guy in surgeries sometimes even because of the
position or because of some complications from
the surgery just because of the anatomical proximity of the number
sacral plexus to we will not go in depth in these two
types of properties both of them happen as a result of delivery complication
Comcast palsy is big because when the baby is born the arm is hyper a be
ducted during the delivery Arab to shin-soo Ponzi it’s actually the
opposite the arm is hyper adducted during delivery
there’s dystocia basically shoulder dystocia that is happens here the herbs
to Sheen a palsy it’s a superior plexus injury versus comp is positive it’s a
lower plexus injury calm case flex apathy very important to remember that
it commonly happens with the Horner’s syndrome because of injury to the
sympathetic chain the pattern of muscle weakness in each one leads to a
deformity or abnormal position of the hand that will give this unique
description claw hand we see it with compass palsy versus the waiter step
hand and we see it with the non-mechanical causes applix
operatives are less common however they’re very important diabetic etiology
that’s one of the important ones it’s referred to as diabetic radicular click
so neuropathy so multiple parts of the peripheral nervous system are involved
in diabetes used to be called davidic my trophy the it usually happens in the
lower extremities the etiology can be autoimmune it can be post radiation
sometimes however out of the non mechanical properties the most common
one would be the idiopathic we’re moving now to neuropathy and that’s a very
important topic I want to think of neuropathy as three different groups
it’s either that one nerve is affected and that’s what we call mono neuropathy
or multiple nerves that are affected in different parts of the body arms and
legs and that’s what we refer to as polyneuropathy the third type is
multiple mono neuropathies so instead of all the nerves are affected in legs and
arms it is one nerve affected here and there in a random way but not all of
them and that’s what we refer to as multiple multiple neuropathies or
mononeuritis multiplex mostly because the etiology most of them is
inflammatory mono neuropathies again it’s usually one nerve involved almost
always it’s a mechanical compression on that nerve and each nerve has certain
spots or areas where it can commonly get entrapped but the Legion or trampin does
not always have to be in that point so median nerve for example almost very
commonly I would say it is interact at the level of the wrist but it does not
have to be there it can happen anywhere so we need
to keep this in mind in case things do not fit well fit well peripheral
polyneuropathy the involvement of the nurse is diffused and symmetric in both
arms both legs together the geologists are usually systemic things like
diabetes alcohol and thyroid disorders and all the autoimmune conditions and
rheumatologic conditions pärnu plastic vitamin deficiencies medication and use
all these different etiologies multiple monitor neuropathy or mononeuritis
multiplex as we mentioned it’s commonly inflammatory etiology and the
involvement here is not related to is that the length dependent so it does not
follow a certain pattern this would be a case of someone who developed all known
neuropathy for example last year and then this year few months ago comes with renewed neuropathy and then a couple
months later he is developing the other side femoral neuropathy and now is
developing carpal tunnel syndrome so within several months is just having
one mono neuropathy after the other and that’s obviously either that’s what we
refer to as mononeuritis multiplex every neuropathy that can be classified
in multiple ways so the same neuropathy is it acute versus chronic did it
develop within a few days or a week or two versus it’s been gradual over
several months is it excellent or demyelinating or mixed a lot of
neuropathies are mixed actually is it’s sensory pure sensory or pure model or is
it mixed and again a lot of neuropathies are mixed a sensory motor is it large
fiber neuropathy or small fiber neuropathy large fiber neuropathies are
usually neuropathy that were we’re talking about right now we can prove
them they ignore them or exclude their diagnosis based on the novel that you
study at the EMG the small fiber neuropathy are the ones that affect that
the small fibers the C fibers are myelinated fibers the last way to
classify and look at the same neuropathy is is it acquired or is it inherited so
in some examples for example when we talk about her editor in neuropathy we
have to think of about charcot-marie-tooth that’s a B this
example of a hereditary neuropathy charcot-marie-tooth obviously has
different types however generally speaking we think about it as a demon in
a timothy although it has some excellent types a small fiber neuropathy it refers
to the unmyelinated neuropathy or C fibers and marinated them in fibers or C
fibers and those are heavily involved in a pain signal so small fiber neuropathy
is commonly referred to as painful neuropathy
an acute neuropathy the the biggest differential would be guillain-barré
syndrome and toxic neuropathies when there is an
exposure to a medication or chemotherapy or toxin the neuropathy progresses
rapidly otherwise most other neuropathies are sub acute to chronic as
far as sensory versus motor and the mixed type is by far the most common
type of all neuropathies the general speaking if you have damage to the
myelin sheath but the axon is still intact then you’re better off and have
better chance of recovery then when you have an excellent opportunity the axon
small fiber neuropathy is a mg no flashes to this completely normal
the diagnosis is usually through skin biopsy to check the density of the small
fibers in the skin large fiber neuropathy is obviously the EMG study is
abnormal and in axon owner apathy what we have is reduced amplitude and reduced
conduction velocity so the signal is amplitude decreases when in examiner
operty not the whole signal is being conducted because the axon is damaged
when indy marinating neuropathies what we have is specifically prolonged
latency so there is delay in conducting the signal EMG and both types eggs and
the magnetic will show denervation signs the abetik polyneuropathy is typically
length dependent it starts in the distal parts of the feet and then gradually
progresses symmetrically approximately toward the ankles and then about the
ankles or the knees and then it can continue above the knees in in severe
cases usually once it arrives to the knees level the neuropathy will start to
show up in the hands and progresses toward the wrists
obviously there’s weakness hyperreflexia and some atrophy in addition to the
sensory and motor symptoms gait ataxia what you refer to as sensory ataxia is a
very common symptom sometimes even the main complaint can be the off balance
feeling which turns out to be due to the loss of proposition sense because of the
neuropathy with diabetes you can have large fiber neuropathy but also patients
can have the autonomic neuropathy which symptom wise can cause gi motility
problems can cause sweating problems and orthostatic blood pressure problems
because those are all innovated through the or control through the autonomic
nervous system so remember is syndrome or what’s
officially called acute inflammatory demyelinating polyneuropathy this is a
very important condition that presents as an acute neuropathy I know it is
typical to think about guillain-barre syndrome as an ascending
paralysis and that that kind of feature is very important but what’s more
important than that actually is to simply understand that it is in
neuropathy so you would expect some weakness and or sensory deficit like
numbness tingling loss of sensation or even pain and because it’s neuropathy
you would certainly expect decreased or absent reflexes in in the lower
extremities because it’s a neuropathy you would expect it to start
distally and progress approximately and that’s what the ascending feature comes
from and what’s unique about it it’s an acute neuropathy acute mean means it
progresses fairly quickly so over over a few days so that’s where that that
feature of a sending weakness or numbness or tingling come from if things
are not clearly ascending but it’s more of a progressive rapidly progressive
sort of neuropathy then guillain-barré a still must be considered as very
likely possibility commonly happens after the viral infection or
Campylobacter gastroenteritis it is a Damali nating neuropathy that’s
very important and it has generally a very good prognosis most cases recover
well unless you know the the case was permanent and severe the diagnosis you
can do pmdf connection study and that will show that the magnetic features but
remember that when become abnormal before probably five to
seven or even 10 days after onset so the best way is if we want to increase our
suspicion but the Ignace is mostly clinical but if we want to increase the
suspicion and and feel more comfortable that this is GPS we need to do spinal
tap and the spinal tap will show the inflammatory pattern in the CSF which is
usually elevated protein with a slight little bit white blood cells if not
completely normal sometimes and those white blood cells if they are elevated
they will be lymphocytes the treatment is IVIG or plasmapheresis always
remember steroids have no role in treatment of guillain-barré syndrome
very important to monitor negative inspiratory force and vital capacity as
part of the promoter function tests every sometimes 12 hours or even every
six hours especially if the patient’s having some respiratory symptoms because
the respiratory failure can progress very quickly sometimes the chronic form
of this inflammatory demyelinating polyneuropathy we call it syidp chronic
inflammatory demanding eating polyneuropathy and the difference is
simply remember it is a monophasic condition so it happens once and it
recovers and it should not happen again if someone comes with another
guillain-barré a few months a few years after the onset of the first one it
comes with another attack or on the other hand if someone had calimary and
it’s been more than eight weeks and there has not been clear significant
improvement does it have to be back to normal but just clear improvement after
eight weeks if we do not see that that’s when we start to suspect
syidp so recurrent sort of guillain-barre presentations or remember
representation that is not improving after eight weeks here in addition
during the IVIG and plasma exchange and the steroids which can be used in syidp
patient will need to be on immune suppressant chronically now we will
quickly go over some of the common mono neuropathies and starting with the
median nerve man and rapidly carpal tunnel syndrome very common median nerve
can be compressed anywhere in its course however compression at the wrist is the
most common when it goes through the carpal tunnel this is the most common
location it typically happens because of overuse of the wrist so typing for
example lifting things even if they’re not very heavy but if we do that all the
time pushing things you know working with machines or or sometimes you know
people if they use wheelchair for example any repetitive trauma to to the
wrist even if it’s minor diabetes increases the chance of all for comin on
dropper tees so the ability will have are at higher risk of having things like median neuropathy the carpal tunnel
syndrome or unknown neuropathy and and so on and it also happens in pregnancy
so pregnant women started to have you know symptoms in their hand we think
carpal tunnel syndrome commonly you have the thinner atrophy because of the in
modesto pollicis brevis atrophy and this a trophy again only happens after
several weeks of a significant Legion that is affecting the nerve so mild
cases certainly do not expect any to see any atrophy
if you see an atrophy ii in this picture here that means even before you do the
nerve conduction study that means this is a severe advanced case of of carpal
tunnel the sensory distribution of the median nerve is obviously the first
three digits falen sign and tea no sign can be done
clinically try to elicit the symptoms commonly people they would say if they
are driving for a long distance they may feel the symptoms coming on if they are
holding their hands on the steering wheel or while they’re asleep they wake
up from sleep because their hand is is numb tingly and is hurting any
hyperextension or reflection of the wrist would trigger the symptoms again
these clinical signs are not always reliable treatment trying to avoid you
know the hyper extension flexion that’s why you know wrist brace is commonly the
first step if that doesn’t help steroid injection and the last step obviously
would be the surgical release now on neuropathy is also become type of
neuropathy the other nerve at the elbow goes through the cubital tunnel so the
most common location of onion wrap compression is at the elbow level the
sensory deficit is on the other side of of the hand so we said median nerve is
the first three digits as we three-and-half exactly the unknown nerve
is the fourth and fifth digits sensor distribution so on the medial side of
the hand again remember the sensor distribution can vary sometimes of odd
so this is we’re going with the most common sensor distribution but there’s
always some variability in advanced cases you see you do not see the thinner
atrophy you would see the hypothenar atrophy which is on the other side of
the hand and again that’s in advanced cases as far as the weakness you see
what we refer to as a claw hand because of involvement of different types of
muscles in the hand so as you see as you see
in the in the picture down the the fingers fourth and fifth fingers are
extended at the initially and then they’re flexed
distal is approximately if they are extended and distally they’re flexed
simply because of the weakness of the extensors of this fourth and fifth
fingers claw hand we see it also in laxity in clamp case example T but this
claw hand and that claw hand are slightly different actually as well as
the shape but both of them they will give you that kind of impression it’s
it’s like a claw what’s common also is a trophy not just in the high post senior
area but in the first dorsal interosseous as we see in the picture
the biggest differential diagnosis for unknown Robert E is medial epicondylitis
where people would have pain at the elbow just like with unanimity the pain
could radiate on the medial side of the forearm and that’s also coming with
unknown or apathy and there could be also some numbness tingling with it so
everything would would be suggestive on neuropathy but in these cases EMG nerve
conduction studies will be completely normal and suggesting that this must be
a tennis elbow rather than I’m not neuropathy radial neuropathy is also an
important neuropathy it can happen whenever there is compression on the
radial nerve that runs our loops around the humerus and when it goes through the
spiral groove in the mid humerus this is the most common location of compression
of the radial nerve but obviously that’s not the only compression side at this is
the most the most common one the sensory deficit is on the posterior side of the
arm and hand so that’s what this which is radial neuropathy from all other
neuropathies median and ulnar you’re talking only in the hand
and either for three digits or last two digits with your neuropathy everything
we’re talking about as far as sensation is on the dorsum of the hand and on the
posterior aspect of the arm and forearm and from as far as weakness you get
wrist a drop extensors there is extensors weakness and also the finger
extensors so whenever we see a wrist drop then we’re thinking radial
neuropathy femoral neuropathy it can happen because of trauma or pelvic mass
that push on the femoral nerve which is more of an anterior nerve in the pelvis
and it can happen after surgery especially the GYN surgeries the sensory
deficit is in the anterior thigh always think of femoral nerve as anterior
sciatic nerve is posterior as far as sensation so the anterior aspect of the
thigh is mostly femoral nerve and that’s when you have already have numbness
tingling and and pain the weakness is related to the quads weakness plus – the
iliopsoas so both of these are flexors hip flexors and I mean the horses hip
flexor the quadriceps are knee extensors but both of them what they do is they
basically help us bend the knee and go up stairs so if someone is having
problems going up stairs and if they feel like their knees buckling one of
the first thing to to question is possibility of femoral neuropathies
femoral nerve is involved in the petiole patellar reflex and that’s very
important because we lose the knee reflex here so anytime remember any time
we have a loss of the knee reflex patellar reflex you see in either l4
radiculopathy or femoral neuropathy now this is not uncommon
manraja porous etiquette as a fancy name the lateral femoral cutaneous nerve runs
underneath the inguinal ligament and it is a pure sensory nerve it goes to the
anterior lateral aspect of the thigh between the hip all the way to the knee
and people may have numbness tingling and pain in in that area and that’s what
we call a geopolitical compression on the lateral cutaneous lateral femoral
contains nerve the it happens in in patients who have horribly especially if
they have central obesity so there’s a lot of fat that’s when they said even
wonder stand it’s pushing on the groin area or if they have if they tend to
wear you know tight belts or or pants can happen after trauma treatment is
either medication to help out there with the symptoms of their mild or you know
block to the lateral femoral cutaneous nerve sciatica neuropathy or what’s
referred to as sciatica when I clarify one confusing picture here commonly
sciatica is referred to mistakenly always used mistakenly as a term to
describe someone who has lumbar or sacral radiculopathy like five or s1
radiculopathy and we say that this patient has a attica and the reason is
because in this radiculopathy is people will have this radiating shooting pain
from the back down if it’s more on the posterior aspect of them
sigh and laid it really sounds like sciatica so so we need to be a little
careful when you use that term what do we mean exactly sciatica neuropathy the
problem is not at the level the roots it is not really cooperative
this is a neuropathy so the sciatic nerve which is outside
the spine in the posterior aspect of the pelvis the there’s a problem with the
sciatic nerve the sciatic nerve is the origin of both the tibial nerve and the
fibular nerve which is the common peroneal nerve however the symptoms that
people have with sciatica neuropathy are predominantly fibular symptoms or
company symptoms the the pain radiates from around the hip area sometimes close
to the low back that’s what creates some confusion between Lombardy cloppety and
sciatica neuropathy and it reduced down through the leg tends to be more on the
posterior aspect of the thigh and leg rather than anterior or lateral like
what we talked about in the femoral and lateral femoral cutaneous nerves the
patients may have a foot drop it is not uncommon so keep this in mind foot drop
will always think of perineal neuropathy fibular nerve
neuropathy but avian remember society neuropathy that’s the origin of the
Pyrenean nerve it can give a foot rub and sometimes they may have achilles
reflexes I gone or absent it is commonly caused by prolonged sitting on hard
surfaces you know prolonged compression to the to the sciatic nerve a pro-union neuropathy or fibula
neuropathy that’s will receive foot job typically remember foot drop you think
new neuropathy elf already kalapa the– and occasionally sciatica neuropathy and
remember with l4 radiculopathy you would lose reflects the the knee reflexes
versus with fibular upon your neuropathy the knee reflex is intact that’s how you
can tell the difference clinically it commonly happens because of crossing
legs as a habit you know one time after the other day after day for a long time
then there will be some damage to the peroneal nerve or because of knee
injuries because the compression is at the head of the fibula and the patients
will develop weakness in the photos reflection which isn’t irritability and
that leads to foot drop the sensory deficit is on the lateral aspect of the
leg rather than the thigh so it’s all from the knee and down to the foot so disorders of the neuromuscular
Junction they cause obviously only motor symptoms there’s only weakness there’s
no sensory deficit or pain the enormous conjunction is where an electric signal
coming through the nerve the neuron would be transferred into a chemical
signal with the s T of Colleen being released in the synaptic cleft to bind
to the esthetically receptors in the neuromuscular Junction in the muscle and
that will trigger an electric signal again the action potential in the muscle
fibers so a vector signal transformed to chemical signal to trigger another
electric signal fatigability of the muscles is the hallmark of a
neuromuscular Junction disorder and it does not have to be just that toward the
end of the day that the muscles get weak but it could be even within a few
minutes of the use of the muscle or you know frequent use of the muscle the
muscle gets week and then after rest for a while it may improve some EMG and
nerve but I should study both of them would be normal in these disorders
that’s what we need the repetitive stimulation test to make the ignores
there’s another technique called single fiber EMG that’s also very helpful to
make a diagnosis of a neuromuscular Junction disorder but that’s a very
specific type of technique Mycenae gravis lambert-eaton syndrome
and botulism those of the common enormous color Junction disorders so
I’ll talk about the important ones Mycenae gravis it’s an autoimmune
condition and there are antibodies against the asti of choline receptors
whether these are blocking antibodies biting antibodies the the other type is
called anti mask antibodies in the past there were about 15-20 percent of the
Mycenaean gravis cases where they were considered seronegative because the acid
calling antibodies were absent in them however it was found that there is
another type of antibody so both together we refer to commonly as Mycenae
gravis antibodies panel it is very common that maizena gravis patient have
thymoma and which is a growth in the thymus gland a client in the in the
upper chest and a lot of times sign next to me alone will significantly improve
if not cure the symptoms of Mycenae gravis so it’s very important to look
for time on there are different types for my senior gravis we all think of the
generalized type however the ocular meisinger gravis is a very important
type and we see it frequently that’s when people present with droopiness of
the eyelid double vision this conjugate gaze the eyes movements are not right
and that’s what gives them obviously double vision so there’s really no other
symptoms in in their in their body no weakness in the arms or legs nothing
else that’s the ocular missing in gravis it certainly can remain ocular a type
forever and never progress to generalized type but there’s certainly
chance that it may progress later on this doses and diplopia
again we’ll have the fatigability features that things might be a little
better in the morning but then they get worse toward
you know no one an afternoon the other type is the bulbar so these people may
or may not have a lot of diplopia and ptosis but their main symptoms actually
are this artery a dysphagia and facial weakness which means an involvement of
the levels of the seventh cranial nerve and the ninth tenth and twelfth cranial
nerves now remember the problem here is not the nerves themselves this is not a
cranial neuropathy for example the problem is those nerves are taking the
signals but the muscles that are innervated by those nerves they are not
triggering any action potential because the acid choline is is not working in
the synaptic cleft so that’s the bulbar type the generalized type is obviously
when different parts of the extremity muscles are involved and typically you
will have proximal more than distal muscles involvement and the generalized
step you commonly also will have diplopia and families and ptosis also
dyspnea shortness of breath and sometimes even respiratory failure can
be seen in this type or obviously in any other type so those types are not very
distinct from each other it’s kind of a spectrum but we’re talking about the
initial presentation it can be mostly in the eye problems or mouse face
swallowing speech problems or generalized weakness the the ignores of Mycenae gravis relies
on checking the antibodies in the serum and they are highly sensitive and
specific the only problem it takes time takes few days if not even a week the if
we need a more a sooner confirmation of the diagnosis then we can do the 10-7
test at your phone IAM a test at the phoneme is a short-acting anti
cholinergic and the once we give it through the IV instantly within half a
minute to a minute you’re gonna see clear improvement and the muscles become
much stronger symptoms improve and that may last for a few minutes and then
would go away and the symptoms come back the way they were and so if we see that
that’s very confirming now when you when you want to do a tensile test you want
to make sure that you have some objective findings that will likely
improve and can be and the problem can be measured easily so someone has ptosis
you can easily see that the eyelid is not a droopy anymore someone had a cyst
double and then within a minute of administering the medication now the
double vision is gone or it’s much better
you know this contains but if you have someone who has profound weakness in the
arms and legs and you give them a dose or two of the Interphone IAM it’s very
unlikely it will be strong enough to show you clear improvement in in their
weakness and in this case not seeing improvement doesn’t mean that the
patient does not have mice in a crevasse so we need to be careful in when to
choose using this test another method would be doing repetitive stimulation
test and you will stimulate a nerve let’s say the median nerve and record
from a muscle record the action potential from a muscle that is
innervated by this nerve let’s say the AP doctor pollicis brevis so when you
give the first stimulation you’re going to get a motor in
you’ll get a compound action potential you give a second one right away after
and a third one and a fourth one and fifth one so you keep stimulating the
muscle again and again and again normally the compound action motor
action potential the CMAP should always remain about the same the muscle should
be able to generate contractions over and over ten times let’s say in ten
seconds in in people with Mycenae gravis that’s not going to be the case you
start with a bigger CMAP bigger amplitude of the motor action potential
and then the more you stimulate the smaller the amplitude gets that’s what
we call decrement and if we see that pattern that is definitely a confirming
of Mycenae gravis again we want to make sure we choose the test in the right
cases so if someone has diplopia and ptosis well those muscles cannot be
stimulated and and recorded from so if you order a repetitive stimulation test
on the left or right upper extremity in someone who has ocular maizena gravis
that test can certainly be completely normal that does not rule out my Sinha
gravis the last thing that’s very important to do is CT of the chest to
look for thymoma the treatment for my senior gravis the
three main things you need to strengthen the muscle through a paralytic mean or
neostigmine any of those medications that will increase are still Colleen in
the synaptic cleft you want to treat the root cause of the problem which is an
autoimmune process so you wanna use immune suppression with whatever
medication that you will pick and you want to look for time moment if there is
time MoMA or thymus hyperplasia you would you wanna remove the thymus
because that commonly is a trigger of the autoimmune process so every patient
will have to these three approaches at the same time
when people come with my Cinna gravis crisis or exacerbation when things are
really severe then the treatment will be any of the plasmapheresis or IVIG or
high dose of IV steroids until we we get rid of this excessive attack of
antibodies and then you try to focus on strengthening the muscles with maybe
adjusting the dose or adjusting mean with Mussina gravis crisis just like
with any neuromuscular condition you wanna be very careful monitoring the
immune function as the Neph and better capacity to ensure that they are not
deteriorating and if they are they will need elective intubation lambert-eaton
syndrome is another type of my ceiling of Junction disorders
it’s a brand-new plastic syndrome so anytime we reach this diagnosis or was
suspected and we need to look for lung cancer specifically small cell lung
cancer so we do a CT of the chest and on the other way around if you have someone
with a smoker for example or history of cancer and they’re developing weakness
then you have to suspect lambert-eaton syndrome as a differential diagnosis
there again the fatigue ability of the muscles is a very important feature now
we want to be careful with with lambert-eaton syndrome presentation
because we know that frequent stimulation of the muscle will improve
the aesthetic Alim function and the synaptic cleft and give you a better
compound motor is an action potential but that entirely depends on the
frequency of that stimulation so overall in from a clinical standpoint the people
the patient will be getting weaker with the further use of of their
muscles not necessarily they get stronger with that the diagnosis is
based on simulation test and that would show an increment in the compound
moderate action potential when we use it at a certain frequency the treatment is obviously immune
suppressant with medications you could also use a gauge you

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