Trigeminal myokymia in a young girl.
Myokymia results from complex bursts of repetitive discharges of a motor unit typically attributable to a demyelinating condition. We report a 12-year-old girl with unilateral trigeminal myokymia who presented with involuntary jaw movements. Electromyography demonstrated unilateral rhythmic myokymic discharges in the left masseter and temporalis muscles at a rate of 3.5 Hz. Abnormal jaw movements spontaneously resolved over 8 months without treatment or residual deficits. The pathophysiology of myokymic discharges is discussed.
D000293:Adolescent; D004576:Electromyography; D005260:Female; D006801:Humans; D007568:Jaw / Q000503:physiopathology*; D008406:Masseter Muscle / Q000503:physiopathology*; D020385:Myokymia / Q000175:diagnosis / Q000503:physiopathology*; D014276:Trigeminal Nerve / Q000473:pathology