Transient anisocoria in a migraineur.

EVALUATING THE “PROBLEM PUPIL” Clinical History.— A 43-year-old woman presented for evaluation of transient anisocoria. Eleven days previously on awakening in the morning, she noted that the right pupil was larger than the left and that she had trouble focusing. About 4 hours later, she saw an optometrist who found the right pupil to be 3 mm in bright light and 6 mm in dim light and the left pupil, 2 mm in bright light and 4 mm in dim light. The pupils were reactive to light. On testing the near response, the right pupil sluggishly constricted and the left was normal. There was no ptosis. Extraocular movements were full. Visual acuity with correction in the right eye was 20/25 and in the left eye, 20/20. Four and one half hours after the first examination, the optometrist repeated the examination and measured the right pupil as 2.5 mm in bright light and 4.5 mm in dim light and the left pupil, 2 mm in bright light and 4 mm in dim light. About 6 hours after she first noted the anisocoria, she developed a mild, nonthrobbing, tense feeling in the right temple without associated symptoms and lasting about 4 hours. Ten hours after her initial observation, she found her pupils to be the same size and she had no further visual complaints. She reported a prior history of occasional migraine without aura lasting about 1 day and migraine aura (an enlarging flashing light in both eyes with a duration of less than 1 hour) without headache about once every 3 months. Neurologic examination was normal. In room light, the pupils were 4 mm, equal and reactive to light, and the palpebral fissures were both 10 mm. Extraocular movements were full. A magnetic resonance imaging (MRI) scan of the brain and magnetic resonance angiography (MRA) of the brain and neck were normal. Questions.— What is the diagnosis? Was neuroimaging indicated?