00:00
Let’s look at this more through a case. This is a 54-year-old woman who presents with
weakness. A 54-year-old female presents for new evaluation of weakness. And weakness is
an important and common chief complaint for many peripheral nervous system conditions
and for problems developing in the muscle. This person has been a long-time patient and has
a history of thyroid disease treated with levothyroxine, as well as hyperlipidemia managed
with atorvastatin. And for the past 2 months, the patient has had noticed progressive
weakness. This is most prominent in the legs where the patient now has difficulty arising out
of a chair in the morning after breakfast or has had to use arms when helping to walk
upstairs at times. We’re seeing proximal weakness, difficulty getting up out of a chair or
walking upstairs. More recently, the patient has noticed difficulty with arm strength as well.
00:54
There are no sensory complaints and the patient denies swallowing difficulty and has no
signs of ptosis, diplopia, dysarthria or dysphasia. On exam, the patient has proximal weakness
in the legs, and normal deep tendon reflexes. So where do we localize this problem? Here,
the distribution is strikingly proximal. On both history and examination we’re getting symptoms
and signs that suggest a proximal disorder. The patient has difficulty arising out of a chair,
difficulty walking upstairs and those are really important historical details that suggest that
this is a problem with the proximal, the muscles, and the legs. Our exam confirms that. How
about sensation? The sensory exam is normal. We’re not getting reports of numbness, and
tingling, and paresthesias, and we see no problems with sensory findings on exam. What
about reflexes? Well, the reflex exam is normal. We don’t see areflexia like we would see
with the peripheral nervous system disorder. We see normal reflexes as we would see with
muscle and neuromuscular junction conditions. And there’s an important wild card present in
the case as well. And this is a pertinent negative. The patient doesn’t have swallowing
dysfunction. There’s not ptosis or diplopia or dysarthria. No dysphagia. Those bulbar symptoms
point us in the direction of a neuromuscular junction condition. An absence of those suggests
that this may be somewhere else. Maybe this is coming from the muscle. There are some other
important clinical features that we may need to dig in to as we understand the etiology of
this presentation. This is a 54-year-old woman. She has thyroid disease and hyperlipidemia
on a statin or cholesterol lowering medicine. She has progressive weakness and those clinical
features we’re going to dive into as we hone more in onto the etiology of this presentation.
02:45
So, where do we localize this problem? Is this something in the muscle, the neuromuscular
junction or the peripheral nerve? Let us take a minute to think a little bit more about the
muscle and we’ll come back to this question in case.