[Limb myokymia with involuntary finger movement caused by peripheral neuropathy due to systemic lupus erythematosus (SLE)--a case report].

A 24-year-old woman with SLE since the age of 12 developed sensory-motor peripheral neuropathy in 1990. Her sensory neuropathy was symmetrical in all limbs and distally dominant. Electrophysiological study showed marked reduction of motor and sensory conduction velocities. Sural nerve biopsy revealed vasculitis and axonopathy. Symptoms of neuropathy and nerve conduction velocities were improved by high dose steroid treatment. After one year she had a fever of unknown origin, and then presented limb myokymia with involuntary finger movement which was fine, irregular, and continuous. Needle EMG revealed myokymic discharge at dorsal interosseous and flexor pollicis brevis muscles. Because myokymia was increased by hyperventilation and suppressed by local anesthesia at the wrist, her myokymia was thought to originate in the peripheral nerve. This is the first case report of limb myokymia with finger involuntary movement caused by peripheral neuropathy due to SLE.