So let's learn a little bit more about
Lambert-Eaton Myasthenic Syndrome.
What is it?
And how does it work?
Well, first of all,
it's a rare disease.
Some neurologists go their whole
career without seeing this,
but we're always tested on it.
It's one of those conditions
that test questions like,
that board exams
love to test about
and you really need to know
in order to recognize it.
It is an autoimmune disorder, and frequently
it is a paraneoplastic immune disorder
And that means the immune system
is revved up to fight a cancer
like a new lung cancer
perhaps in our patient.
And as a result of revving up the
immune system to fight the cancer
something happens and the
immune system goes awry
and starts to attack a
certain part of the body.
we see the development of
to the presynaptic
voltage-gated calcium channel.
Those important calcium channels that
recognize the action potential in the nerve
that bring calcium in to
the pre-synaptic terminus
and drive the release of acetylcholine
into the neuromuscular junction,
so that muscles can move.
This condition is associated
with certain types of cancer.
And we think of and most commonly we see,
small cell lung cancers and lymphomas.
Other cancers have
but those are the two
things to think about,
and focus on and evaluate
for a patient who may have
Lambert-Eaton myasthenic syndrome.
How the patients present?
Well, proximal weakness is common as we see
with many neuromuscular junction disorders.
It is often proximal and
then spreads distally.
And importantly, this is a neuromuscular
junction disorder and we see bulbar symptoms.
That's that critical
that points towards a problem
in the neuromuscular junction.
So we look for ptosis,
diplopia, dysarthria, dysphagia.
And here we see in the image a
patient with right-sided ptosis.
Something to focus on and look
for on our neurological exam.
There's a paucity of century
findings, we usually don't hear about
numbness or tingling
Areflexia can be
seen or hyporeflexia.
And this is important.
We said with neuromuscular
we typically see normal
to reduced reflexes.
And this is the one
neuromuscular junction condition
that can actually
present with areflexia.
So an important caveat, an exception
to our neuromuscular junction rule.
Patients also often have prominent autonomic
findings and dry mouth is really common,
it was present for the
patient in our case
and is something that we need to
ask for if we're considering this.
We can also see other autonomic
symptoms like constipation.