Cramp fasciculation syndrome

Cramp fasciculation syndrome (CFS) is a rare peripheral nerve hyperexcitability disorder. It is more severe than the related (and common) disorder known as benign fasciculation syndrome; it causes fasciculations, cramps, pain, fatigue, and muscle stiffness similar to those seen in neuromyotonia (another related condition). Patients with CFS, like those with neuromyotonia, may also experience paresthesias. Most cases of cramp fasciculation syndrome are idiopathic.