Vertical one-and-a-half syndrome overlapping with pupillary abnormality

Excerpt

A 64-year-old man with a history of hypertension and stroke presented with acute-onset drowsy, slurred speech, and left-sided hemiplegia. Neuro-ophthalmological examination revealed bilateral upgaze palsy and right downgaze palsy, the right dilated pupil (4.5 mm) with poor reactivity to light compared to the left pupil (2.5 mm) (Fig. 1A), and the weak convergence eye movement and accommodation reflex. In addition, the patient had decreased muscle strength in the left upper and lower extremities (Medical Research Council (MRC) Grade 3), and the left Babinski sign was positive. Brain magnetic resonance imaging (MRI) demonstrated an acute infarct at the right thalamo-mesencephalic junction (Fig. 1B–D) and CT angiography (CTA) of the head and neck vessels suggested the right posterior cerebral artery (PCA) occlusion, the right vertebral artery (VA) hypoplasia and bilateral VA stenosis (Fig. 1E). The diagnosis of thalamo-mesencephalic infarction was made with a presumed etiology of large-artery atherosclerosis. Dual antiplatelet therapy with aspirin and clopidogrel was then started. Three months later, the patient's left limb muscle strength returned to normal, with only slight vertical eye movement disorders.

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