Clinical, electrophysiologic, and pathologic evidence for sensory abnormalities in ALS

Area of Science:

• Neurology
• Neuroscience
• Pathology

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease.
• Sensory nerve involvement in ALS is not fully understood, with varied reports.

Purpose of the Study:

• To investigate the prevalence and nature of sensory nerve involvement in ALS patients.
• To correlate clinical sensory symptoms with electrophysiologic and pathologic findings.

Main Methods:

• Retrospective review of 103 ALS patients from the Emory University motor neuron disease registry (1997-2004).
• Analysis of electrodiagnostic studies and sural nerve biopsies.
• Comparison with 12 control biopsies for blinded pathologic evaluation.

Main Results:

• Sensory symptoms or signs were reported in 32% of ALS patients.
• Abnormal sural sensory nerve action potential amplitudes were found in 27% of patients.
• Pathologic abnormalities were present in 91% of biopsies, predominantly affecting large-caliber myelinated fibers.

Conclusions:

• Approximately one-third of ALS patients experience sensory symptoms.
• Electrophysiologic and pathologic findings indicate axonal loss primarily affecting large myelinated fibers.
• Sural nerve biopsy reveals significant sensory nerve pathology in most ALS patients.