An overview of H-reflex studies in amyotrophic lateral sclerosis.

H-reflex methods were used to investigate motor neuron excitability and the basic physiology of segmental spinal reflexes. While many studies have been performed using these electrophysiological techniques, in both normal subjects and patients with different neurological diseases, few studies have focused on patients affected by amyotrophic lateral sclerosis (ALS). This article reviews the various electrophysiological techniques which use H-reflex to study the physiology of segmental spinal reflexes in motor neuron diseases. Their possible applications for elucidating pathophysiological mechanisms in ALS and for monitoring the disease during clinical trials are discussed.