Recurrent idiopathic lateral rectus muscle palsy in adults

Recurrent, unilateral, isolated, idiopathic lateral rectus muscle palsy is an uncommon but well-recognized disorder in children that has not been recognized as well in other age groups. We studied five cases of this uncommon entity that we encountered in adults and adolescents. Ages at onset ranged from 15 to 72 years and there were three to eight episodes per patient. Most of the patients shared the followng features with the previously reported pediatric cases: ipsilateral recurrence, lack of pain, spontaneous recovery within six months, and no clear cause. Unlike the children, females or left-eye involvement was not preponderant in adults.
Paralysis of the lateral rectus muscle, which rotates the eyeball outward, causes horizontal diplopia (double vision). Recurrent, isolated, idiopathic lateral rectus palsy involving one eye is a well known but uncommon disorder in children, the cause of which is unknown. Five cases of recurrent idiopathic lateral rectus muscle palsy occurring in adolescents or adults are reported. These patients were seen between 1966 and 1990 and represent 1.6 percent of all outpatients seen at one practice with lateral rectus muscle palsy. Age of onset of symptoms ranged from 15 to 72; each patient experienced from three to eight episodes of palsy. Common features of most of these patients included recurrence on the same side as the original palsy; no pain; no clear cause; and spontaneous recovery within six months. One patient, a 28-year-old man, had three episodes of palsy, all seemingly related to eating turkey; however a fourth episode occurred without the stimulus of turkey, and the possibility of turkey allergy was thus discounted. When this condition occurs in children there is a preponderance of left eye involvement and it afflicts more girls than boys; this was not found to be true in adults. It is concluded that this is an uncommon condition, and that the palsy does not become permanent despite recurrences and is usually self-limited and benign. (Consumer Summary produced by Reliance Medical Information, Inc.)