A systematic approach to evaluating neurologic symptoms includes localizing the problem anatomically and distinguishing peripheral from central etiology. Peripheral nerve disorders may affect sensory, motor, and autonomic functions (Table 146-1).
Table 146-1 Differentiating Central from Peripheral Nervous System Disorders |Favorite Table|Download (.pdf)
Table 146-1 Differentiating Central from Peripheral Nervous System Disorders
Weakness confined to 1 limb
Weakness with pain associated
Posture- or movement-dependent pain
Weakness after prolonged period in 1 position
Brisk reflexes (hyperreflexia)
Asymmetric weakness of ipsilateral upper and lower extremity
|Symmetric proximal weakness|
|Sensory||Asymmetric sensory loss in ipsilateral upper and lower extremity|
Reproduction of symptoms with movement (compressive neuropathy)
All sensory modalities involved
|Coordination||Discoordination without weakness||Loss of proprioception|
Botulism is caused by Clostridium botulinum toxin and occurs in 3 forms: foodborne, wound, and infantile. Foodborne botulism typically comes from improperly preserved canned foods. In infantile botulism, organisms arise from ingested spores, often in honey, and produce a systemically absorbed toxin. Clinical features appear 6 to 48 hours after ingestion and may be preceded by nausea, vomiting, and diarrhea. Wound botulism should be considered in patients with a wound or a history of intravenous drug use. Early complaints involve the eye or bulbar musculature and progress to descending weakness and respiratory insufficiency. Absent light reflex is a diagnostic clue, and mentation is normal. Infants may present with constipation, poor feeding, lethargy, and weak cry. Treatment includes respiratory support, trivalent botulinum antitoxin 10 mL IV, and admission.
Guillain-Barré syndrome (GBS) affects all ages and usually follows a viral or febrile illness, Campylobacter jejuni infection, or vaccination. Although numerous variants exist, the typical presentation includes ascending symmetric weakness or paralysis and loss of deep tendon reflexes. Respiratory failure and lethal autonomic fluctuations may occur. Cerebrospinal fluid (CSF) analysis typically shows high protein and a normal cell count (Table 146-2). Initial treatment includes respiratory support, admission to a monitored setting, and neurologic consultation.
Table 146-2 Diagnostic Criteria for Classic Guillain-Barré Syndrome |Favorite Table|Download (.pdf)
Table 146-2 Diagnostic Criteria for Classic Guillain-Barré Syndrome
Progressive weakness of more than 1 limb
Progression over days to weeks
Recovery beginning 2 to 4 weeks after cessation of progression
Relative symmetry of symptoms
Mild sensory signs and symptoms
Cranial nerve involvement (Bell's palsy, dysphagia, dysarthria, ophthalmoplegia)
Autonomic dysfunction (tachycardia, bradycardia, dysrhythmias, wide variations in blood pressure, postural hypotension, urinary retention, constipation, facial flushing, anhydrosis, hypersalivation)
Absence of fever at onset
Cytoalbuminologic dissociation of cerebrospinal fluid (high protein and low white cell count)
Typical findings on electromyogram and nerve conduction studies
Carpal tunnel syndrome, resulting from compression of the median nerve at the wrist, classically causes pain, paresthesias, and ...