Transcript Case Study 7

Case Study 7
Craig Horbinski, M.D, Ph.D.
History
63-year-old male with generalized progressive weakness especially in his
lower extremities with difficulty ambulating. The patient states that he was ill
for approximately three weeks prior to this admission, with 20 pound weight
loss and anorexia during the past two to three weeks. He denies any pain. He
has no neuropathy or paresthesias that he admits to. He denies similar
symptoms in the past. He states that the weakness seems to be symmetrical.
He has no known history of recent infection and he states that his upper
extremity weakness is not nearly as severe as lower extremity weakness. He
states that he had one episode of night sweats prior to his admission. During
his present hospitalization, he has had intermittent temperature elevations as
high as 38.9. No medications on a regular basis except for intermittent inhaler
for COPD.
Question 1
What are the main test results you want to make sure was
done before proceeding (this goes for any neuromuscular
pathology case)?
Answer
Electromyograph (EMG) and nerve conduction
studies. Creatine kinase might also be helpful, particularly
if the clinical impression is of a predominantly muscle
(rather than nerve) etiology.
Question 2
EMG and nerve conduction studies revealed a significant
polyneuropathy. A nerve biopsy was requested.
What is the #1 most popular nerve for biopsy? Are there
any long-term deficits as a result of biopsy?
Answer
The sural nerve in the leg because it is easily
accessed. The only permanent deficit is numbness in the
posterior leg and lateral foot.
Question 3
Describe what you see.
Click here to view slide.
Answer
There are 5 fascicles within the sural nerve cross
section. There is no vasculitis or substantial perivascular
inflammation.
Question 4
What do you see in this toluidine blue plastic
section? (Don’t feel bad if you aren’t sure, this is tough.)
Click here to view slide.
Answer
Patchy loss of myelinated axons, occasional myelin
ovoids (acutely degenerating axons), and possible
vesicular demyelination of some of the axons.
Question 5
What additional histologic preparation might help us
confirm whether there is true demyelination?
Answer
Teased nerve fibers
Question 6
What is the predominant finding in this teased nerve fiber
preparation?
Click here to view slide.
Answer
Demyelination and remyelination. Note the abrupt and
multifocal loss of strongly osmiophilic myelin on many of
the teased axons (demyelination) and weak osmiophilic
thin myelination on many axons (remyelination).
Question 7
Given the patient’s history and the nerve biopsy results,
what is the most likely diagnosis (i.e. what’s the first
demyelinating disorder that comes to mind)?
Answer
Guillain-Barré