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Dr. Derrick Cheng joins us today for an approach to acute onset weakness!

Join us as on our treatment journey from onset to treatment, and think about what you might do if encountering the same clinical situation.

Important points we discuss in this episode:

  • The tempo of the disease onset
  • Where can we localize the symptoms?
  • Fatigue vs weakness
  • Triaging patients with acute onset weakness
  • Stabilization and management of acute weakness


Follow Dr. Cheng at x.com/dlchengmd

& so much more
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The views expressed do not necessarily represent those of any associated organizations. The information in this podcast is for educational and informational purposes only and does not represent specific medical/health advice. Please consult with an appropriate health care professional for any medical/health advice.

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Transcript

Episode Transcript

Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Michael Kentris (00:02):
Hello and welcome back to the
Neurotransmitters, your sourcefor everything related to
clinical neurology.
I'm joined today for ahopefully new and continuing
segment with Dr Derek Chang.
Thanks for joining us today.

Derrick Cheng (00:16):
Thanks so much for having me.

Michael Kentris (00:17):
So Derek reached out to me online, as so
many things.
We meet a lot of our folksonline through either email or
Twitter, so always happy to meetnew people coming to me all the
way from the West Coast at UCSF.
So thank you for waking uppost-call, dealing with the time
difference today.
So Derek reached out and thisis a concept that I've been

(00:38):
wanting to work with a while iskind of the chief complaint
oriented way to organize yourthoughts, and so Derek did all
this heavy lifting on writing upa kind of a schema, if you will
.
So we're going to kind of gothrough some exercises today and
talk about how we couldapproach in real time some chief

(01:01):
complaints and kind of givesome little pauses throughout.
You know, let the listener you,our dear listeners listen and
think and hopefully come to someconclusions on your own and
then see if you agree with us.
Does that sound about right,dirk?

Derrick Cheng (01:14):
That sounds exactly right.
One of my goals for puttingthis together was to put some
more listeners in the driver'sseat and let them think through
a resident's thought process aswe approach some of these
consults at different stages ofthe consult, whether it's the
initial page, when we'reapproaching our patients to talk
about a history and exam, andhow we formulate the question
and think about our next stepsin terms of diagnostics and

(01:35):
treatment.

Michael Kentris (01:36):
Excellent.
Yes, and this is something that, for those who maybe are more
junior in their medical journey,that neurologists love to do,
whether they are teaching on thewards or in morning report or
in a hundred other settings.
I think this is a prettystandard neurology fair.
So this is kind of how we learnand then subsequently teach as

(01:58):
we get more senior down the road.
So I think this is a great ideaand I'm looking forward to it.
So Derek has been generousenough to put me in the driver's
seat, at least initially, soI'm going to crib off of his
work here.
So we start off by getting apage because we still use in
medicine in some areas, and itsays new neuro consult

(02:22):
57-year-old female with newweakness.
And it says new neuro consult57 year old female with new
weakness.
So with nothing else, what arethe first?

Derrick Cheng (02:31):
things that, uh, that your mind goes to.
So I feel like I've gotten thispage 10 times in the past
couple of weeks, um at minimum,and we hear this console
question all the time.
One of the first things that Ialways wonder about when I hear
this question of new weaknessesis this even a neurologic
problem?
A lot of folks come in withsepsis and have generalized
weakness, or they have a heartfailure exacerbation and have

(02:52):
fatigue and shortness of breath,though our ED medicine, other
consulting colleagues are prettygood about parsing these things
out early on.
So other questions that I'd bethinking about early on are time
course.
When did this start?

(03:14):
How quickly did it progress?
Because their tempo can reallyhelp triage and really help us
with our diagnosis.
As we go forward, I want to knowabout what things they're
actually having difficulty doing.
Are there particular musclegroups that are affected?
Is this a symmetric issue?
Can they walk?
Are they having issues standingup from a chair or reaching up
over their head, or are therecertain times during the day

(03:35):
where I feel like this is worse?
This all helps me put thispatient together into a
different illness script.
And then, finally, I'd want toknow about what other symptoms
are going on.
The presence of kind of some ofthese other symptoms or the
absence of other symptoms canreally help me localize this to
different parts of the interaxis.
Are they having blurry vision,diplopia?
Are they having bulbar symptomsand respiratory issues?

(03:58):
Are they having new numbness,tingling or sensory changes?
All of these can really help meshape what I ask the patient
and how I approach them when Igo down to do my physical exam I
think that's.

Michael Kentris (04:09):
That's very, very well put um and to.
If I, if I may try and condensethe, the general thought process
, right, we talk about the tempoor the, the timing of the onset
, as well as the where of it,and then what's the associated.
So I always had one attendingwho was like you, got to be like
a reporter who, what, when,where and why.

(04:31):
The why is usually up to you,but the rest of it it guides you
there, and so I do find that alot of times the localization,
the where, and then the timing,the when, tend to be the two
questions that we usually startwith in neurology and those
really do guide a lot of ourespecially in the initial acute
phase, kind of a lot of ourmanagement and triaging.

(04:54):
So next up you get a littlemore history.
You talk to the ED provider andthe story's a little thin to
start.
So they say the weaknessstarted two to three days ago,
mostly in the proximal muscles,now impairing their ability to
walk, some shortness of breathalso noted and nothing obviously
precipitating it.

(05:14):
No recent trauma, afebrile,normal vital signs and initial
labs, including CBC BMP, areunremarkable.

Derrick Cheng (05:22):
Perfect.
So this is often where we arewhen we first talk to our ET
colleagues, and there's a littlebit of a story, but some of the
details aren't so clear.
Just hearing this brief snippet, though, there are a few things
that jump out at me as being alittle concerning.
You know, this patient ishaving new shortness of breath.
They've got this new whatsounds like a muscular weakness

(05:42):
with this proximal muscleinvolvement, and it sounds like
it's relatively quick onset.
So I would start putting theminto a bucket at least in my
head as I'm getting ready to godown and see them of rapidly
progressive weakness.

Michael Kentris (05:55):
Yeah, and I think you'll probably mention
this more as we go on, but thewhere of the weakness and, as
you said, the what are theyunable to do?
One thing that I think we oftenrun into is is this is like the
difference between fatigueversus weakness, right, when
very often you know, as you saidearlier, if someone has sepsis

(06:17):
or some other acute like heartfailure or a kidney injury or
some other metabolic processgoing on, they may seem
quote-unquote weak, but it'smore related to they're more
fatigued or feeling unwell, moregenerally speaking, rather than
true muscular weakness.
They can still generate theforce, just they become more
fatigued more easily, whichsometimes can be, especially in

(06:39):
some diagnoses, a bit of a fineline to walk.
But it's something that we runinto a lot, especially with some
of our patients with neurologicdisorders who are on the more
chronic side, so like peoplewith, like myasthenia gravis or
multiple sclerosis or kind ofthese chronic diseases where
weakness is certainly a veryconcerning symptom.
So you always have to parsethat out very clearly.

Derrick Cheng (07:00):
Absolutely.

Michael Kentris (07:02):
So you get in there, you're talking with the
patient.
So otherwise, no significantpast medical history related to
these types of symptoms.
Overall, fairly healthy recenttreatment for UTI and they've
noted this sudden onset andprogressive proximally
predominant weakness.
Initially they thought this wasjust fatigue.

(07:22):
I might have given the gameaway when getting up out of a
chair over the past several days.
Now they're noticing some otherthings, such as slurred speech
and a little shortness of breathwhen you ask them specifically
and I think this emphasizes theimportance between open versus
closed-ended questions they alsonote some double vision before
bed.
So, again, more in the eveningthan in the morning and that's

(07:45):
not something that patientsnormally will volunteer.
So being very direct with someof these questions when you are
building your illness script inyour head For sure.
So, all that being said, whatare you thinking and what are
the most important exam findingsthat you're looking for in this
patient?

Derrick Cheng (08:02):
Sure.
So there are a few highlightsout of this that I'm picking up
on.
Just like you said, some ofthis proximal, predominant stuff
.
When you hear about difficultygetting out of a chair, you're
thinking about some of theirproximal or extremity strength,
and then some of this slurredspeech and the shortness of
breath is cueing me in towards.
Could there be a bulbarsymptoms?

(08:23):
Could there be some kind ofrespiratory involvement,
something that might make metriage them differently when I'm
starting to staff them with myattendant?
The double vision before bed isreally interesting.
I definitely want to dig alittle bit more into that,
especially when I'm doing myphysical exam, seeing if there's
a fatigability component inthis, whether this is something
else.
So when I go downstairs to domy neurologic exam or to do my

(08:46):
exam in general, I'd be lookingat a few things in particular.
In addition to doing a kind ofa basic neuro exam, I'd be
wanting to kind of get a betterunderstanding of what muscles
are involved.
I also feel like acardiorespiratory exam is a
little bit of a lost art inneurology sometimes, but I still
carry around my stethoscope andI encourage everyone to listen

(09:08):
to heart and lungs and make surethere's nothing crazy going on.
But outside of that, there area few more specific things that
I want to do.
First, looking at the patient.
How do they look?
Do they look like they're usingtheir accessory muscles to
breathe?
Do they look really ill?
That can always help push youin one direction or another.
And then some more specifictesting that I might look at as

(09:31):
a neurology resident includethings like their cranial nerves
.
So you've mentioned theirdiplopia.
I'd want to make sure there'sno new cranial nerve palsy.
Make sure their eyes are movingin all the correct directions.
See if they have any diplopiaon end, gaze in any direction,
things like that.
See if they have any diplopiaand gaze in any direction,
things like that.
I'd be looking for ptosis ifthey have drooping of their
eyelids, if they have dysarthriasome of these patients can

(09:51):
start having a very nasal speechor they might have a very
guttural dysarthria wherethey're having difficulty with
sounds from the back of theirthroat.
And I'd be looking at thingslike facial strength.
So putting this together, allof the different cranial nerves.
One little tidbit I heard onceis that you can get a good
understanding of facial strengthby having some of these
patients whistle or seeing ifthey can whistle Other things

(10:13):
that I'd be looking for reallyhone in on this respiratory
component.
So one thing I like to test inall of my patients with new
onset weakness is somethingcalled a breath count, where I
have them take a deep breath andcount as high as they can.
You and I should be able to getup above 25.
When patients start to getlower and lower, we start

(10:36):
wondering if they haverespiratory compromise, whether
there's someone who's going toneed additional respiratory
support, going to needadditional respiratory support.
And on the same vein, I like totext their neck flexion and
their neck extension.
Neck flexion is when we havethem take their chin, try to
touch their chest, push forwardwith their head while you
provide resistance.
Neck extension is the exactopposite, where they bring their
head back into the bed or thechair and you provide resistance

(10:59):
and you really shouldn't beable to overcome them.
Folks with neck flexion weaknessin particular are some of the
people who we might be moreworried, have a respiratory
involvement or might be needingto go to an ICU or at least need
some additional respiratorysupport.
Similarly, in terms of themotor exam, I'm looking to test
their proximal muscles, lookingspecifically at things like

(11:20):
their shoulder girdle, their hipgirdle, looking at things like
fatigability If I'm pushing onone side multiple times, are
they going to be more weak onthat side?
As well as sustained up gaze.
That's a test where we have thepatient look up and keep
looking up and look for kind ofa drift downwards in their eyes
or their eyelids specifically.
Some of us carry around icepacks because it's a test that

(11:44):
we can use to parse outmyasthenia.
I don't do this often, but acouple of times over the course
of my residency.
So that's kind of the moremuscular and the cranial nerve
components.

Michael Kentris (11:55):
And I will say just a life hack for the
residents out there that I'vedone and maybe some other folks
have come to the same idea Ifyou don't have an ice pack on
hand is getting an exam gloveand filling it at the nurse's
station with some ice water andthen tying that off like a water

(12:16):
balloon can sometimes be adecent improvised test,
especially in the middle of thenight if you're on call.
So I've definitely done thatmore than a few times myself.

Derrick Cheng (12:25):
That's a great idea.
It's something that I've nevertried before, but it's
definitely something I'm goingto do.
I spend a decent amount of timerunning around looking for ice
packs.

Michael Kentris (12:33):
Right, anyway, sorry to interrupt.

Derrick Cheng (12:36):
No, no, thank you so much.
There are a couple of otherfinal things closing out.
I know we talked about theircranial nerve exam, their motor
exam.
Other things that I like tolook for in these patients are
paying special attention ifthere's any sensory involvement,
if I'm thinking about amuscular problem or a
neuromuscular junction problem,these should really spare your
sensation, whereas a problem.

(12:59):
A lot of these patients willpresent with new sensory
deficits, new numbness, andwould push you away from a
muscle problem, for example.
So that can really help youdifferentiate between a couple
of causes of weakness.
And, as always, we carry aroundour trusty reflex hammers.
So I often, or always, checktheir reflexes and see if
there's areflexia orhyporeflexia, things that might

(13:22):
be making me more concerned forthings like GBS or demyelinating
polyneuropathies.

Michael Kentris (13:28):
Excellent.
No, I think those are all greatthings, especially when we're
talking about what sounds likemore of a peripheral nervous
system, which is kind of thebane of a lot of people.
A lot of even neurologists aremore focused on the central
nervous system, right, which iskind of the bane of a lot of
people, right, a lot of evenneurologists are more focused on
the central nervous system.
So let's go back to our patienthere.
So we've got a patient, somefatigable weakness on the exam.
It does seem to be moreproximal than distal.

(13:50):
A bit of weakness with neckflexion.
They have a breath count of 25at this point in time.
On sensation exam there are noabnormalities, pinprick,
vibration etc.
Reflexes also normal, nofasciculations, no atrophy.
Where does that guide yourthoughts in terms of ruling
things more?
in up, or I should say up ordown, in your differential

(14:12):
diagnosis.

Derrick Cheng (14:13):
Perfect.
So so far we've kind of framedthis patient as a progressive
rapid-onset neuromuscularweakness.
And one of the things that Ilike to do after I've finished
seeing my patient, I'm goingupstairs, I'm writing my note, I
just think through all of thedifferent parts of the neuraxis.
Could this be a brain problem?
You know, probably not.
A lot of people will say youknow, some bulbar symptoms can

(14:35):
be related to a brainstem, butthat might be a red herring.
Here.
Some bulbar symptoms can berelated to a brainstem, but that
might be a red herring.
Here, you know, we'd probablyexpect some other features, some
other localizing, somelateralizing deficits, something
on one side or the other.
And similarly, a spinal cordproblem might look similar.
You might have some spasticity,some hyperreflexia, something
that looks more like what wecall myelopathic picture.

(14:56):
Then, going on to some of ourmore peripheral nervous system,
like you mentioned, it's alittle bit harder to parse out
for some of us and it candefinitely be tricky to figure
out what's what.
So, thinking through thedifferent parts of the
peripheral nervous system, couldit be a motor neuron process?
Could this be something likeALS?
You know, maybe we often hearabout the combination of bulbar

(15:19):
symptoms and weakness.
We can certainly keep this onour differential, but you might
expect to see some more mixturesof some upper motor neuron
features, where we might seethings like spasticity or
hyperreflexia, and lower motorneuron features, things like
muscle atrophy, fasciculations.
Could this be a nerve problem?
Anytime we hear about rapidlyprogressive weakness, we always

(15:43):
want to include Guillain-Barresyndrome or AIDP or all of those
cousins of nerve problems, evenwith these bulbar symptoms that
you might not classically hearabout with ascending symptoms.
But, importantly, not all ofthese patients have this classic
story of a preceding infectionfollowed by ascending numbness
and ascending weakness.

(16:04):
One key takeaway that I'velearned is that many of these
nerve problems involve bothsensory and motor function.
You know there are somevariants of Yom Beret that are
motor only, but these patientswill often almost always have
hyporeflexia or areflexia.
Sometimes that might not showup early on in the disease

(16:24):
process.
So it's something I think about, definitely want to rule out.
And then, more importantly,could this be a neuromuscular
junction problem?
You mentioned myasthenia earlieron today and that's something
that I'm worried about hearingthis case, because we're hearing
about things like fatigability.
They're getting weaker as youexamine them.
They're getting weaker as theday goes on, as well as bulbar

(16:45):
symptoms, motor-only symptoms.
It doesn't really sound likesome of the other neuromuscular
junction processes that you hearabout.
Don't commonly see things likebotulism or Lambert-Eaton, and
that would probably be more of atopic for another day, but
something to always think aboutwhen you hear these patients
with new progressive weakness.

(17:06):
And then, finally, could thisbe a muscle problem?
Could this be a myopathy or amyositis?
There are some things that kindof line up with that.
In this presentation We'veheard about things like some
difficulty standing up from achair, some motor-only symptoms.
So it's something that I'mthinking about, but isn't
necessarily the highest on mydifferential.

Michael Kentris (17:28):
Excellent summation and I think that's an
excellent example of how aneurologist thinks about these
things, in terms of what toprioritize, what's most likely,
what are the can't-miss kinds ofthings.
So, speaking of things that wecan't miss when we're triaging
this patient in the acute stages, what are the first things that

(17:49):
you're thinking of, like yourtop three?
And then what are the firstthings you're going to be doing
to make sure this patientdoesn't have any rapid decline
or make sure that they'restabilized to the best of your
ability?

Derrick Cheng (18:01):
Absolutely so.
With these patients who arehaving rapidly progressive or
rapid onset weakness.
In this case, we've talkedabout how we might be worried
that this patient might havemyasthenia, specifically if
they're having a myastheniaflare or they're having a
myasthenia crisis, one of thefirst things that I'll always do
, especially as someone who'sgoing to eventually become an

(18:23):
ICU physician, is to think aboutwhere this patient is going to
go in the hospital.
Is this someone that I can sendto the floor with Q2, q4
neurochecks, or is this someonethat I need to be keeping a
really close eye on?
Moving to the ICU, maybethinking about intubating them?
When I think through theseproblems, there are a couple of

(18:44):
things that I like to do in theemergency department to really
help me triage.
First of all, doing things likeour classic ABCs, our airway
breathing circulation.
Thinking about whether or notthey have a lot of secretions,
whether they're controllingtheir secretions, what their
bulbar function is looking like.
We've already talked a littlebit about some exam maneuvers
that can help us push in onedirection or another.
Thinking about what they looklike in terms of their breathing

(19:06):
, whether they have stridor orusing accessory muscles to
breathe, and there are sometests, specifically pulmonary
function tests in the ED andsome labs that can help us
triage this as well.
One of the things that we oftenlook for as neurologists is a
NIF or a MIF, which is kind ofour maximum inspiratory force,

(19:26):
as well as our vital capacity,our functional vital capacity.
What we're looking for isessentially the strength that a
patient has when they're takinga deep breath in.
What we normally want to seefor our MIFs is a value of
negative 40, something like thatat least.
Though when our patients starthaving MIFs of negative 30, or

(19:50):
especially when our MIFs starthaving MIFs of negative 20, we
want to start thinking aboutwhether or not they're going to
need additional respiratorysupport, be intubated or be
moved to an ICU.
Similarly, their vital capacity.
We would want to have at least20 mils per kg, which would
equate to about a liter and ahalf, a liter to a liter and a
half, and once patients start tobe under that, that's a point

(20:16):
at which I become concerned.
So, looking through, I makesure the emergency department
checks in the FVC as well as theVBG Once their oxygen
saturations start to drop.
It's starting to be way toolate that some of these patients
can have hypercapnia.
So a couple of high-yield exammaneuvers and high-yield tests
that I'd want to make sure Ithink through before I really
start triaging this patient.

Michael Kentris (20:37):
Those are all great points and I think a lot
of these fundamental principlesare able to be cross-applied to
other forms of neuromuscularrespiratory failure as well
Someone like with motor neurondisease, like ALS or other kinds
of neuromuscular myositis-typeprocesses.
Certainly, these are the thingsthat we always think about.

(20:58):
And to your earlier point, whenwe were talking about visually
assessing the patient, we talkedabout accessory muscle usage,
and one thing that I've alwaysbeen taught and have seen as
well is that a lot of times, theproblem and why we see these
changes on blood gases so lateis because it's the muscles, not
the lungs, right, so themuscles fail before the gases

(21:22):
change significantly, dependingagain on the person and the
rapidity of their decline.
So it is one of those thingswhere you definitely have to
keep that on your radar and it'slike those respiratory vitals
and that single breath counttest are absolutely essential
for identifying these patientsand if they do need an airway,
being able to do that in acontrolled fashion makes

(21:44):
everyone's lives so much morestraightforward as opposed to
having to try and do thatemergently.
So I think those are allexcellent points.
So in this case we have someone,a relatively young woman, who
has new onset weakness, no priorhistory of any autoimmune or
neurologic disorders.
So a kind of a new diagnosis, arelatively progressive weakness

(22:10):
that we suspect is aneuromuscular junction disorder,
very possibly myasthenia gravis.
So when we're thinking aboutbecause most of the time we will
see, maybe people have some,some bulbar symptoms, usually,
you know, ocular, someintermittent diplopia, things
like that may be going on forweeks to months, but it's, it's.
It is somewhat unusual forpeople to present with kind of

(22:33):
acute onset respiratory failure.
So what are some things thatperhaps she has been?
Let's, let's hype, you know's,play a hypothetical scenario
here, let's say that she maybe,after everything's stabilized
you find out.
Yeah, maybe I have been havingsome intermittent I thought it
was just blurred vision for afew months.
What could have happened thatmay have tipped her over the
edge into this more acutetransition in terms of her

(22:55):
weakness?

Derrick Cheng (23:00):
in terms of her weakness.
Totally.
Every time someone comes inwith a history of myasthenia and
they're doing worse, we alwaysgo looking for what triggered it
, what might've caused some ofthese things.
You know there are a lot of.
There's a long list ofoffending agents.
You know there's in this case,maybe recent antibiotics, but a
long list of other medications,including antibiotics, beta
blockers, that can allprecipitate myasthenia, flares

(23:23):
or worsening of myasthenia.
When I think about some ofthese patients in the acute
setting, I am also trying to bevery cognizant about what we're
giving them and how we couldpotentially make this worse.
So things like steroids,especially in the acute phase,
or neoperitostigmine, andcausing secretions, and things
like steroids, especially in theacute phase, or
neoprotostigmine, and causingsecretions and things like that,
or if they're going to the, orif they're getting intubated,

(23:45):
things like neuromuscularblocking agents all of these
things can make thispresentation look much scarier,
Absolutely so we mentionedearlier this patient.

Michael Kentris (23:57):
they got some initial labs.

Derrick Cheng (24:09):
What are the other kinds of studies that we
really want to be checking intoin the kind of next steps?
Presented the tempo and yourconstellation of different
symptoms, could this be a nerveor a neuromuscular junction or
muscle issue?
And while we think thatneuromuscular junction is
probably the highest on ourdifferential, I'd probably send
off some basic labs.
Look for other causes ofweakness in addition to some of

(24:31):
our neuromuscular values.
Neuromuscular labs that wouldinclude our acetylcholinase
receptor antibodies, bindingantibodies, blocking antibodies,
modulating antibodies, as wellas our anti-musk.
Those are some of our classicmyasthenia labs, especially if
this is a patient who's neverbeen diagnosed with myasthenia

(24:53):
before, at least formerly.
Other things that I'd belooking for include a CK that
can help us figure out whetheror not there's myopathy or
myositis going on, even thoughthat's a little lower on our
differential.
And there's always labs that wecan send off for acute onset
neuropathies, things like heavymetals, esr and CRP.
Often these patients willundergo CSF testing as well, and

(25:16):
in any patient with a newdiagnosis of myasthenia, one
thing I'm always curious aboutis whether or not they've had a
CT of their chest in the past,looking for something like a
thymoma, because that wouldreally change our management.

Michael Kentris (25:31):
Excellent points.
That's always the problem.
I work at a smaller hospital,so when I suspect myasthenia
gravis and I order acetylcholinereceptor antibodies of the
various stripes, in 7 to 14 daysI'll have those results.
So it very much is one of thosethings where you can certainly

(25:51):
have a suspicion, but thediagnostic lag can certainly be
challenging in a real-worldscenario.
So you're very often, if thereisn't a pre-existing diagnosis,
then you kind of have to followyour clinical acumen and decide
do I start this person on anacute treatment or not, as the

(26:13):
case may be, and that'scertainly challenging because
none of our treatments areentirely without risk, although
I would say that risk versusbenefit for most people
certainly weighs in favor oftreatment.
Tell us a little bit about well, actually, before we go on.
You mentioned the muskantibodies.
I thought that was obviouslythat's very important this
patient in particular.

(26:33):
Could you just talk a littlebit about musk versus the more
generic acetylcholine receptorantibodies?

Derrick Cheng (26:39):
So musk is an antibody called the
muscle-specific kinase and it'san antibody that we can see in
some of these patients who arepresenting like myasthenia.

Michael Kentris (26:50):
So musk specifically, they do have a
much higher preponderance ofbulbar symptoms as opposed to
the more traditionalacetylcholine receptor
antibodies.
So in someone who has veryprominent bulbar onset at the
beginning, you do keep that inthe back of your mind,
especially if they have earlydysphagia and ventilation issues

(27:11):
.
Musk is certainly high on thelist, although very often we
check you can still get theatypical presentation of the
regular acetylcholine receptorantibodies as well.
But if those are negative youdefinitely want to get that musk
in there and they keep findingnew antibodies every year or two
.
So there are some other onesfloating around out there that I

(27:31):
haven't had too much occasionmyself clinically to play around
with, but they do exist.
But that being said, let's sayclinically this looks like
myasthenia.
You threw an ice pack on thateye with the ptosis.
That ptosis popped right backup.
You know, after holding itthere for two to five minutes
you're like nothing else isgoing to be except neuromuscular

(27:52):
junction.
How do we proceed in terms ofstabilizing this patient,
getting them back on their feetboth literally and figuratively,
and kind of starting the courseof treatment down the road?

Derrick Cheng (28:03):
So first this patient would likely be admitted
to the neurology servicewhether or not that's the ward
service or the ICU kind ofdepending on their respiratory
function and how some of thoselabs and those tests looked
earlier on and then we'd bethinking about treating them.
Usually when these patients arecoming in with new flares'd be
thinking about treating them.
Usually when these patients arecoming in with new flares.
We're thinking about IVIG,which is intravenous

(28:24):
immunoglobulin, versus PLETS,which is plasma exchange.
There are pros and cons to eachone.
There's a lot of debate aboutwhich one is better, which one
works faster.
There's some folks who say thatPLETS works a little bit faster,
can have a little bit of aquick onset, can keep people in
the ICU for less time, but itrequires a large line, can be

(28:45):
harder to arrange, can be morelogistically challenging for a
lot of different reasons.
You'd want to make sure all ofyour prior testing is sent first
, because IVIG is essentially acombination or a solution of
human autoantibodies and cancreate a lot of false positives
and false negatives in yourtesting if you haven't sent off

(29:07):
all of the antibodies that youwant already.
So picking between the two ofthem is a little bit more
institution-specific,logistic-specific,
provider-specific, but we'dusually treat with one of those
two and then start them back ontheir steroid regimen as well as
think about coming down theroad what they would want to be
treated on as an outpatient,whether this is some kind of

(29:28):
disease modifying therapy orwhether we'd want to just
continue them on steroids longterm you make it sound so, so
straightforward and simple inreality.

Michael Kentris (29:36):
right, we both know that it can be messy, with
many blind rabbit trails that wego down, depending on the
stories that we get and thefluctuation in the examination
and how clear-cut the examfindings are.
There's all these gray areas inthe diagnostic workup, a
challenging presentation and onethat, as you said, we encounter

(29:57):
very frequently.
So, just to put a nice bow onall of it for us, what are the
key takeaways, after kind ofgoing through this thought
exercise, that you would hopeour listeners would take with
them?

Derrick Cheng (30:11):
So some of the key takeaways that I'm hoping
our listeners take away includethat first, not all weakness is
neurologic.
A lot of the times, otherpatients can present with other
things that can look weakSimilarly.
The next thing is that time,course and tempo can really help
us both triage our patient aswell as help us with our

(30:31):
differential for these patientswith new onset weakness.
Next, the presence or absenceof certain exam findings things
like sensory changes or reflexescan help put you into different
buckets and differentlocalizations of neurologic
problems.
With weak patients inparticular, breath count and
neck flexion are twoparticularly good exam maneuvers

(30:53):
in the emergency department orwhen you're first seeing them to
help triage these patients andin the ED.
Some key things to rememberinclude looking at your A's, b's
and C's, checking a MIF and anFBC and using that piece of
information to help figure outwhether a patient needs ICU or
additional respiratory support.

Michael Kentris (31:13):
Excellent summary.
A challenging, I think, all ofus going through our training in
medical school and even as ajunior neurology residence.
Peripheral nervous systemissues are always kind of a
little more scary because wedon't necessarily get that till
later in our neurology training.
And I think you summed it uppretty well a nice algorithmic

(31:35):
way to approach these problems,with plenty of whittle room for
variations there.
So thank you very much.
I really appreciate you takingall this work and you know you
guys can't see he put togetherthis huge outline is very
thorough.
I'm very impressed.
So thank you, derek, I reallyappreciate all the work you put
into this.

Derrick Cheng (31:57):
Thanks so much for having me.
I've been wanting to join youon one of these podcasts
long-time listener, long-timefan and really excited to see
how this came together.

Michael Kentris (32:04):
Absolutely, and anything you want to plug.
Where should people find youonline, any projects you're
working on, shoutouts, etc.

Derrick Cheng (32:13):
So I have lots of shoutouts to all of my mentors
here at UCSF.
I have lots of shout outs toall of my mentors here at UCSF.
You can find me on Twitter, Iguess at D-L-C-H-E-N-G-M-D.
I think that's my Twitterhandle and then otherwise no.
Thank you so much for having meon this podcast.
It's been a lot of fun thinkingabout how to approach some of

(32:35):
these challenging cases.

Michael Kentris (32:36):
Well, hopefully this is just the first of many
and I'll definitely give a callout to anyone who's listening.
If you have an interesting caseor approach to certain kinds of
chief complaints and you'reinterested in coming on, just
shoot us an email at contact atthe neurotransmitterscom.
Or you can also direct messageme on Twitter, slash X at

(33:00):
D-R-K-E-N-T-R-I-S, that's DrKentris or to the podcast social
group directly at neurounderscore podcast.
And, of course, you can alwaysfind our stuff, including links
to different episodes at theneurotransmitterscom on the
website.
So, derek, again thank you andwe'll talk again real soon, I
hope.

Derrick Cheng (33:21):
Absolutely.

Michael Kentris (33:23):
All right, take care.

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