Acquired abducens nerve palsy can be due to many causes.' The palsy could be associated with: tumors of the brain,2-6 tumors of the nasopharynx,7 head trauma,8 and inflammatory and vascular lesions.9-10 Transient sixth nerve paralysis of undetermined origin is of rather frequent occurrence in middle-aged elderly individuals.11
It is also a known phenomenon in children after febrile illnesses.12"13 We have recently had the opportunity to follow a patient from childhood to adulthood, showing three recurrent episodes of isolated benign sixth nerve palsy in the same eye at different ages.
This case is, to the best of our knowledge, the first of its kind to be presented.
A 25-year-old woman, six months pregnant, was seen in the Jerusalem Shaare Zedek Eye Clinic suffering from left convergent squint and diplopia, which started suddenly one day before admission. Two weeks earlier she had experienced a febrile illness with fever up to 39.5°C. Prior to this she reported two similar incidents. The first occurred at the age of three years. Left abducens palsy appeared a week after the onset of high fever and lasted for about eight weeks. During that time the right eye was occluded to prevent amblyopia. Full motor and sensory functions were restored completely.
The second attack, having the same clinical picture as the first, occurred when the patient was 1 3 years old. She regained full motor ocular function within 1 2 weeks. Other than this there was no abnormal medical history known to the patient or her family.
Examination of the eyes on the third admission revealed visual acuity of 6/6 in both eyes with mild myopic correction. Left paralytic convergent squint of 50 prism diopters was observed. Intraocular pressure and anterior and posterior segments of the eyes were normal. No visual field defects were found. The physical examination was normal. Neurological findings were confined to the left eye only. EEG, Echo, and CAT scan of the brain showed no pathology. The ECG as well as x-rays of the chest, skull, and optic foramen were normal. Blood chemistry, serology, immunology, and urinalysis were all normal. Endocrine screening was within normal limits. The only treatment given was the occlusion of the left eye to prevent diplopia. The patient was seen every two weeks and showed gradual improvement. Fourteen weeks later the left abducens function was fully recovered. The patient gave birth to a healthy, fullterm baby.
Children can manifest benign abducens nerve palsy, especially after mild febrile episodes or upper respiratory tract infections. The exact cause of this condition is unknown. Some authors suggest viral etiology.9'12'13
A case of sixth nerve palsy that appeared during the incubation period of varicella was published by Nemet et al.14 Knox et al12 presented a series of 1 1 children with benign sixth nerve palsy after febrile condition that showed complete recovery within ten weeks. The illness usually appears two to three weeks prior to the onset of palsy, and in the majority of cases there is no residual disability in eye movements. Scharf and Zonis15 published a case of a 5-year-old both with a benign abducens palsy that appeared in full health and recovered in 3-1/2 months without any treatment. The palsy as an isolated neurological phenomenon was described by Birndorf et alIA following prolonged general anesthesia. In diabetic patients transient paralysis of the sixth nerve is most probably due to ischemic neuropathies from occlusive disease in nutrient vessels." Lillie17 has reported on such occurrences in nondiabetic patients and attributed them to unknown inflammatory or vascular lesions.
The patient presented in our case report probably had a febrile viral illness with sixth nerve palsy that attained full recovery. It is, however, an exceptional case. The palsy recurred three times in the same eye, once in childhood, once during puberty, and lastly in adulthood during pregnancy. We would like to emphasize the fact, that recurrence of this benign entity of sixth nerve palsy can appear in the same patient at different times, with no grave implications.
A case presenting with three episodes of recurrent benign abducens palsy is reported. The patient experienced her first episode at age of 3 years, her second when she was 1 3 years old, and the last at the age of 25 during pregnancy. Full recovery was attained within approximately three months after each episode.
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