Single‐fiber electromyography in amyotrophic lateral sclerosis and cervical spondylosis

Cervical spondylosis ( CS ) is a common disease in adults and may coexist with amyotrophic lateral sclerosis ( ALS ). It is important to detect ALS coexisting with CS ( ALS ‐cs) at an early stage, especially when surgical treatment of CS is planned. Methods Single‐fiber electromyography was performed in 26 patients with ALS , 19 with ALS ‐cs, and 22 with CS . Results Mean jitter, percentage of jitter >55 μs, and percentage of impulse blocking were not statistically different between ALS and ALS ‐cs cases, but they were significantly lower in CS . Mean fiber density was not statistically different among the 3 groups. The percentage of pairs with jitter >55 μs exceeding 40% and mean jitter exceeding 55 μs had high sensitivity and specificity in the diagnosis of ALS . Conclusions Single‐fiber electromyography can supply valuable information in helping to differentiate ALS from CS . Muscle Nerve , 2013