Detecting fasciculations in cranial nerve innervated muscles with ultrasound in amyotrophic lateral sclerosis.

INTRODUCTION: Cranial muscle fasciculations may be difficult to detect in amyotrophic lateral sclerosis (ALS). Ultrasound (US) detection of fasciculations in these muscles may have clinical utility. METHODS: Patients with suspected ALS were prospectively enrolled. Nerve conduction studies, needle electromyography (EMG), and US examination of cranial muscles were performed. Controls were examined by US only. Fasciculations were counted and scored for each muscle after 10 or 30 seconds. RESULTS: There were 84 patients with ALS. Fasciculations were most frequently found in the genioglossus muscle. Overall, detection rates by US and EMG were similar, but US was more likely to detect frequent fasciculations. Fasciculations were rare in controls, seen in 7 of 1,090 (0.6%) muscles. No control had > 5 fasciculations in any muscle. DISCUSSION: Fasciculations were frequently detected in cranial muscles of patients with ALS. US was found to be a sensitive method, and was not impaired by factors such as anxiety and the inability of the patient to relax. Muscle Nerve 56: 1072-1076, 2017.