Myokymic discharge is a train of motor unit potentials that occur spontaneously, recur regularly, and sometimes may be associated with clinical myokymia. We report a 39-years-old male with progressive muscle weakness and atrophy of right upper extremity, who revealed focal myokymic discharges in the intrinsic hand muscles where no denervation was evident on EMG study. The cervical CTMM and MRI study showed a large cervical cord tumor at C3-C6 spine level. Postoperative pathological diagnosis of the tumor was anaplastic astrocytoma.
Astrocytoma ; Atrophy ; Denervation ; Diagnosis ; Hand* ; Humans ; Magnetic Resonance Imaging ; Male ; Muscle Weakness ; Muscles* ; Myokymia ; Spine ; Upper Extremity