Bilateral Trigeminal Myokymia in Chronic Inflammatory Demyelinating Polyneuropathy Associated With Systemic Lupus Erythematosus–Sjögren Overlap Syndrome

Myokymia is an involuntary spontaneous quivering or twitching of muscles. It is most often temporary and benign but is well-known to occur in demyelinating polyneuropathies. This video shows myokymia of the masseter and temporalis muscles in a 24-year-old woman with chronic inflammatory demyelinating polyneuropathy (CIDP) associated with systemic lupus erythematosus (SLE)–Sjögren overlap syndrome. It is unusual because, to our knowledge, bilateral myokymia of trigeminal nerve-innervated muscles has not been described. The latter part of the video shows myokymic discharges in the patient’s left masseter muscle on electromyography. Click the Related Article link for full case details.