Ultrasonographic assessment of the prevalence of fasciculations in lesions of the peripheral nervous system.

In previous studies, ultrasonography was a very sensitive method in detecting fasciculations. The present study was intended to examine the prevalence of ultrasonographically visible fasciculations in patients with neuromuscular diseases affecting the lower extremities. Ultrasonography of 9 muscles (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis, sartorius, semitendinosus, tibialis anterior, gastrocnemius, and soleus muscles) was performed bilaterally in 70 adult healthy subjects and 172 patients with various neuromuscular diseases. Fasciculations were detected in 109 (63%) of 172 patients. The median value of affected muscles was 10 (range 1-18). Patients with spinal muscular atrophy (37/38, p < 0.001), hereditary motor and sensory neuropathy (24/25, p < 0.001), and lumbosacral radiculopathy with motor deficits (24/29, p < 0.001) exhibited fasciculations more frequently than did healthy volunteers. Radiculopathy with sensory deficits, lesions of either plexus or peripheral nerves, compartment syndrome, and myopathy were not associated with a significantly enhanced prevalence of fasciculations in the patient group compared to the control group. In summary, fasciculations are a frequent ultrasonographic sign in neuromuscular diseases. They are almost regularly found in patients with spinal muscular atrophy and those with hereditary motor and sensory neuropathy. Thus, the absence of fasciculations in ultrasonographic assessment should give cause for reconsidering these diagnoses.