title: Blood, brain and binocular vision.
abstract: A man aged 51 years presented with sudden onset, horizontal, binocular, double vision and right facial weakness. Ocular motility examination demonstrated a right horizontal gaze palsy pattern in keeping with a one-and-a-half syndrome. Since this was associated with a concomitant, ipsilateral, lower motor neuron (LMN) facial (VIIth) cranial nerve palsy, he had acquired an eight-and-a-half syndrome. Diffusion-weighted MRI confirmed a small infarcted area in the pons of the brainstem which correlated with anatomical location of the horizontal gaze centre and VIIth cranial nerve fasciculus. As a result of this presentation, further investigations uncovered a hitherto undiagnosed blood dyscrasia-namely polycythaemia vera. Regular venesection was started which resulted in complete resolution of his ocular motility dysfunction and an improvement of his LMN facial nerve palsy.
authors.affiliation: Ophthalmology Department, St James Hospital, Leeds, UK.
authors.forename: Egle
authors.initials: E
authors.lastname: Rostron
authors.affiliation: Ophthalmology Department, St James Hospital, Leeds, UK.
authors.forename: Mary Polly
authors.initials: MP
authors.lastname: Dickerson
authors.affiliation: Ophthalmology Department, York Teaching Hospital, York, UK.
authors.forename: Gregory
authors.initials: G
authors.lastname: Heath
mesh_terms: D020526:Brain Stem Infarctions / Q000000981:diagnostic imaging / Q000209:etiology*; D038524:Diffusion Magnetic Resonance Imaging; D004172:Diplopia / Q000209:etiology*; D005158:Facial Paralysis / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology*; D011087:Polycythemia Vera / Q000150:complications* / Q000175:diagnosis; D011149:Pons / Q000000981:diagnostic imaging*