[Role of fasciculation potentials in the diagnosis of amyotrophic lateral sclerosis].

OBJECTIVE

To explore the role of fasciculation potentials in the diagnosis of amyotrophic lateral sclerosis (ALS).

METHODS

A total of 60 ALS patients were recruited from August 2009 to August 2010 at our hospital. Standard examinations of electromyography and nerve conduction were performed. And fasciculation potentials were measured in the resting muscles with a band pass of 20 Hz-10 kHz, a sensitivity of 0.05 - 0.5 mV/D and a sweep speed of 5 ms/D. Each muscle was observed for 1 - 5 minutes. The amplitude, duration and phase of fasciculation potentials were recorded.

RESULTS

The occurrence rate of fasciculation potential in sternocleidomastoid was more than that of fibrillation and positive sharp wave in ALS patients (36.7% vs 13.3%, χ² = 8.71, P < 0.05). The amplitude and duration of fasciculation potentials in ALS patients with a duration of over 18 months were higher than that of those with a duration of under 8 months [(1.8 ± 0.9) mV, (1.0 ± 0.6) mV; (15.2 ± 4.1) ms, (11.2 ± 3.0) ms; q = 3.43, 3.51, P < 0.05)]. The patients with definite ALS might increase if fasciculation potentials were considered as spontaneous potential (80% vs 60%; χ² = 5.71, P = 0.02).

CONCLUSION

With different morphologies at different disease stages, fasciculation potentials may be useful in the earlier diagnosis of amyotrophic lateral sclerosis.