Trochlear nerve palsy

A right-handed 53-year-old woman was admitted to hospital for management of acute gastritis. Two days after admission she developed acute diplopia on looking downwards or to the left. She has a history of hypertension and hyperlipidaemia and took ramipril 5 mg and atorvastatin 40 mg daily. Examination showed a right superior oblique palsy (figure 1A–C) and was otherwise normal. Bielschowsky’s head tilt test was positive: head tilt towards the side of the affected superior oblique muscle increased image separation, with improvement of the diplopia on head tilt down to the left. MR scan of brain showed restricted diffusion in the region …