At the age of 23, this 48-year-old woman complained of diplopia. Thereafter, she had a history of stepwise bilateral impairment of eye movements. On examination, VA was 20/30 OD, pinhole increased the acuity to 20/20; 20/100 OS, pinhole increased the acuity to 20/40. Visual fields were full. Funduscopy was normal, without pigmentary retinopathy. Pupils were 4 and 4.5 mm in diameter with normal reaction to light. There was no relative afferent pupillary defect (RAPD). Ocular motility is shown in the video.

At the age of 23, our patient had diplopia due to abduction weakness of the right eye. This was preceded by a 2-week history of a sharp needlelike pain behind that eye. Thereafter, she had a history of stepwise bilateral impairment of eye movements. About 8 years prior to this assessment, she noted severe ptosis of the left upper lid. Because of the marked ophthalmoplegia of the right eye and tonic deviation downward of that eye, she had strabismus surgery to elevate the globe. She continued to suffer from intermittent headaches.

Subsequently, she noted bowel incontinence and occasional dizziness, probably related to head movements and her severe eye movement impairment. She also had occasional dull bitemporal headaches and had more difficulty with nocturnal vision. She had no skeletal muscle weakness, hearing loss, seizures, incoordination, diabetes, or other endocrinopathy. She had no diurnal variability of her left eyelid ptosis or dry eyes.

On examination, she was of normal stature. There was a slight chin-up head position and complete left upper lid ptosis. There was no exophthalmos. Visual acuity was 20/30-1 in the OD; pinhole increased acuity to 20/20. Visual acuity in the OS was 20/100; pinhole increased acuity to 20/40. Confrontation visual fields were full. On color vision examination, she identified 11 out of 15 plates with each eye. Funduscopy showed normal appearance of the discs, vessels, and periphery. There was a slight enhancement of the pigmentation in the macula, but no definite sign of pigmentary retinopathy. Ocular motility showed marked restriction of range of movements in every direction of gaze, with lack of horizontal movements and slowed saccades on the minimal residual vertical gaze. Oculocephalic and Bell eye movements were absent. Remainder of the neurologic examination was unremarkable.