Acute bilateral mydriasis associated with anti-GQ1b antibody

Sudden-Onset Bilateral Mydriasis in a Young Girl

A 3-year-old girl presented to the emergency department with 1 day of abnormal gait and bilateral mydriasis. Repeat magnetic resonance imaging demonstrated diffuse enhancement of the lower thoracic and cauda equina nerve roots and enhancement of the left oculomotor nerve.

Acute isolated bilateral mydriasis: case reports and review of the literature

Isolated bilateral internal ophthalmoplegia is a rare and problematic condition affecting activities of daily living. Herein, we describe the cases of 2 patients with postinfectious isolated bilateral internal ophthalmoplegia, i.e., mydriasis without external ophthalmoplegia. One patient demonstrated no other neurological symptom, while the other patient showed mild gait ataxia. Magnetic resonance imaging revealed no abnormal findings in the brain or brainstem. Light-near dissociation of the pupils was not recognized in either patient, and supersensitivity to dilute pilocarpine was observed in 1 of the 2 patients. An increased titer of the anti-GQ1b IgG antibody was noted in 1 patient. A review of the literature revealed five similar cases; the symptomatic characteristics, ratio of positive anti-GQ1b IgG antibody, and effective treatment are discussed.

Pupillary Involvement in Miller Fisher Syndrome

Miller Fisher Syndrome is characterised by the classical triad of ophthalmoplegia, ataxia, and areflexia. Ophthalmoparesis without ataxia, without areflexia, or with neither have been attributed as atypical forms of MFS. We report two patients with MFS who had tonic pupils and raised anti-GQ1b antibody titres. Bilateral dilated pupils (either tonic or fixed) can be a manifestation of MFS and anti-GQ1b immunoglobulin G (IgG) antibodies are useful to confirm the diagnosis in unexplained cases. The site of involvement is thought to be the ciliary ganglion or short ciliary nerves.

An unusual case of Parinaud's syndrome

A 25-year-old man presented with blurred vision, headache and dizziness. On questioning, there was also a history of a preceding diarrhoeal illness. Initial investigations were normal. However, after a week, he represented with a Parinaud's syndrome. In view of the preceding diarrhoea, the transient unsteadiness and the areflexia on examination, anti-GQ1b antibodies were requested. The resulting titre was positive confirming the suspected diagnosis of Miller Fisher syndrome. He responded to intravenous immunoglobulins with full resolution of his symptoms and signs. Although various unusual neuro-ophthalmological signs have been reported localising to the brainstem, to our knowledge, this is the first case report of Parinaud's syndrome being the presenting symptom of Miller Fisher syndrome.