Editing Morvan's syndrome (section)

===Neuromyotonia===
Neuromyotonia refers to muscle twitching and cramping at rest that is exacerbated with exercise.  It is caused by sustained or repetitive spontaneous muscle activity of peripheral nerve origin.  Myokymia, or spontaneous rippling and twitching movements of muscles, is a visible component of neuromyotonia.  [[Electromyography]] (EMG) discloses spontaneous, repetitive [[motor unit]] or single fiber discharges firing in irregular rhythmic bursts at high intraburst frequencies.<ref name=paraneoplastic/> Some of the muscles exhibiting twitching include the bilateral [[gastrocnemius muscle|gastrocnemii]], [[quadriceps femoris]], [[biceps brachii]], and right [[masseter]].<ref name=indian/>  [[In vivo]] electrophysiological studies suggest at least some dysfunction of the muscle [[cell membrane]].<ref name=clinical/>  In the examined muscles, no abnormal insertional activity or [[fibrillation]] potentials were noted.  Nerve conduction studies were normal.<ref name=cardiac/>