Oculomotor palsy with cyclic spasms: Electromyographic and electron microscopic evidence of chronic peripheral neuronal involvement

Abstract

Two cases of oculomotor palsy with cyclic spasms are reported. Case 1, a 25-year-old woman, was unable to elicit contractions of her right oculomotor muscles at will. Her right pupil was unresponsive to light and to near stimuli. Accommodation could not be elicited by approaching visual objects. During cyclic spasms, the lid rose to the upper limbus of the cornea, the pupil constricted from 5 to 3 mm, and the eye accommodated 7 diopters. The electromyogram of the levator showed polyphasic units of 8 ms duration instead of the normal 2 ms. To eliminate the conspicuous twitching and intermittent ptosis of the lid, the levator was excised and the lid suspended from the brow by a fascia lata sling. Light- and electron microscopy of the levator revealed a pattern of neurogenic muscular atrophy with secondary myopathic changes. The intramuscular nerves showed signs of ongoing remyelination of axons and recent reinnervation of muscle cells. - In Case 2, slow progression of an oculomotor palsy was documented from birth until the age of seven, when signs of cyclic spasms appeared. The authors suggest that chronic rather than acute damage to the oculomotor nerve, exerted for instance by pressure of a vessel, might have caused the syndrome of oculomotor palsy with cyclic spasms in both of these patients.

Key Words:

• oculomotor palsy
• cyclic spasms
• hemifacial spasm
• pupil