Peripheral Neuropathies

Question 1

Guillain-Barre Syndrome (GBS)‏

Answer 1

acute immune-mediated group of polyneuropathies, usually provoked by preceding infectionusually Campylobacter jejuni or respiratory tract infection, others are CMV and EBV
Dysautonia (70%)–tachycardia, urinary retention, HTN alternating w/ hypotension, orthostatic hypotension, bradycardia, ileus, loss of sweating

Question 2

Therapy for GBS

Answer 2

plasmapheresis or IV immune globulin

Question 3

Bell’s Palsy

Answer 3

Fibers for motor output to the facial muscles
CN 7
Herpes simplex most common cause of Bell’s palsy
Other infectious causes—EBV, adenovirus, rubella, mumps, influenza B, herpes zoster

Question 4

Bell’s Palsy–Management

Answer 4

Eye care: poor lid closure- eye drops at day, ointment at night, and patch at night
Early short term glucocorticoid therapy:
Should begin within 3 days of symptoms
Antivirals not added to treatment

Question 5

Myasthenia Gravis

Answer 5

Autoimmune disorder characterized by weakness and fatiguability of skeletal muscle
Autoantibodies against acetylcholine receptors (AChR-Ab)
T-cells bind to acetylcholine receptors and activate B cells

Question 6

MG—Clinical Manifestations

Answer 6

Fluctuating skeletal muscle weakness
Ocular:
Ptosis, can be bilateral or unilateral
EOM often involved leading to diplopia
Bulbar:
Weakness w/ prolonged chewing, jaw weakness at rest
Oropharyngeal muscle weakness–dysarthria and dysphagia (imminent risk of aspiration can produce “myasthenic crisis”)
Facial:
Patient appears expressionless
Neck and limb:
Weight of head overcome extensors resulting in “dropped head syndrome”

Question 7

treatment for MG

Answer 7

Anticholinesterase agents for Sx. Tx,
Pyridostgigmine (Mestinon)

Chronic immunotherapies:
Moderate doses corticosteroids
Immunosuppressive medications

Rapid immunotherapies:
Plasmapheresis
IV immunoglobulin

Surgery—thymectomy for thymoma

Question 8

Polyneuropathy—Symptomatic Rx

Answer 8

Gabapentin (Neurontin): reduces pain, well tolerated
TCAs: such as amitriptyline and desipramine
Pregabalin (Lyrica) : targeted for diabetics but is worth trying for patients regardless of etiology
Duloxetine (Cymbalta) has the advantage of being an antidepressant as well as helping control pain

Question 9

Vitamin B12 (Cobalamin)‏ Deficiency Treatment

Answer 9

IM B12 injections 1000microgms twice weekly for 2 weeks followed by weekly for 2 months and then monthly