0071643192.pdf

PATHOPHYSIOLOGY

■ Antibodies →inadequate release of acetylcholine at neuromuscular junc-
tions→symptoms.

SYMPTOMS/EXAM

■ Proximal (primarily leg) muscle weakness that improves with repeated
stimulation
■ Autonomic symptoms (dry mouth, impotence)

DIAGNOSIS

■ Clinical presentation
■ Electrodiagnostic testing

TREATMENT

■ Treat underlying malignancy, when present.
■ Immunosuppressive agents
■ Plasmapheresis and IVIG, if severe

Botulism

Botulism is a toxin-mediated disorder of the neuromuscular junction.

PATHOPHYSIOLOGY

■ Toxin produced by Clostridium botulinum→presynaptic inhibition of
acetylcholine release at the neuromuscular junction.
■ Infants may ingest spores (honey is a common agent)→bacteria ger-
minate in GI tract and produces toxin.

SYMPTOMS/EXAM

■ Onset 6–48 hours after ingestion of toxin or Clostridium botulinumspores
■ Classic presentation = descending flaccid paralysis.
■ Diplopia, dysarthria, and dysphagiaoccur early.
■ Progresses to generalized weakness; ventilatory failure may occur
■ May last for months
■ In children, may present as constipation, feeding difficulty, and
hypotonia.
■ Other anticholinergic symptoms may be present (dry skin, dilated pupils,
increased temperature).
■ Infantile botulism →lethargy, weakness/floppiness, poor feeding.

DIAGNOSIS

■ Clinical suspicion
■ Electrodiagnostic testing
■ Botulinum toxin testing of serum and stool

TREATMENT

■ Supportive care
■ Horse serum antitoxin

Tick Paralysis

Tick paralysis is a toxin-mediated disorder of the neuromuscular junction.

NEUROLOGY

Botulism:

Descending flaccid paralysis

with diplopia, dysarthria, and

dysphagia occurring early;

treat with horse serum

antitoxin

Lambert-Eaton myasthenic

syndrome:

Proximal muscle weakness

that improves with repeated

stimulation;

treat with immunosuppressive

agents or

plasmapheresis/IVIG, if

severe