The cortical silent period and amyotrophic lateral sclerosis

✍ Scribed by Alister J. Prout; Andrew A. Eisen

• Book ID: 102955357
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 628 KB
• Volume: 17
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/mus.880170213

✦ Synopsis

The cortical silent period (C-SP) was elicited by transcranial magnetic stimulation in 25 normal subjects and 19 patients with amyotrophic lateral sclerosis (ALS). The inhibitory (S-X) period was highly stimulus intensity (SI)-dependent (mean P = 0.89 for both normals and patients with ALS). The range of the C-SP (difference between maximum and minimum S-X intervals) was age-dependent for normals (12 = 0.701, P < 0.001) but not patients with ALS. Means, maximums and ranges for the C-SP were not significantly different between normal and ALS groups and thresholds to cortical stimulation were also comparable.

There was a significant, linear, relation between the maximum C-SP and disease duration of ALS (P = 0.002). The maximum C-SP was shorter early in the disease. It is hypothesized that the reduced inhibition early in the course of ALS might reflect glutamate-induced corticomotoneuronal excitotoxicity.