A pseudo-Argyll Robertson pupil is a neurological sign indicating a normal near reflex but the absence of a light reflex (light-near dissociation), a lack of miosis, and pupil irregularity. It has been reported in patients with diabetes mellitus, multiple sclerosis, Wernicke’s encephalopathy, sarcoidosis, tumours, and haemorrhage.1 Although the appearance of pseudo-Argyll Robertson pupil is very similar to Holmes-Adie pupil, the first is distinguishable from the second by the location of lesions and pharmacological response. The responsible lesion in pseudo-Argyll Robertson pupil is in the central region, whereas that of Holmes-Adie pupil is peripheral. Dilute pilocarpine constricts the pupils of patients with Holmes-Adie pupil, but it is not effective in patients with pseudo-Argyll Robertson pupil. We present a patient with spinocerebellar ataxia type 1 (SCA1) and her asymptomatic younger brother who both exhibited pseudo-Argyll Robertson pupil.

Patient 1 was a 21 year old woman who complained of gait instability in 1996. Thereafter, she noticed difficulties in speech and in the fine movement of her hands. Her mother had had gait disturbance since her 20s and died of pneumonia at the age of 35. The condition of our patient deteriorated gradually, and she was …