Anterior spinal artery syndrome.

Three patients are presented, each showing clinical and electrophysiological findings indicative of the anterior spinal artery syndrome: sudden onset of nonprogressive weakness and spasticity of one or both legs, associated in one patient with pain and in all three patients with selective impairment of temperature sensation, radiological evidence of aortic calcification, normal sensory and motor conduction velocities and normal amplitude of sensory potentials, but diminished amplitude of evoked motor responses. Electromyography showed widespread fibrillation in muscles of the leg in two patients and evidence of marked loss of motor units in all three patients.