Fluctuating drowsiness following cardiac catheterisation: artery of Percheron ischaemic stroke causing bilateral thalamic infarcts

Abstract

An 81-year-old man underwent cardiac catheterisation to investigate breathlessness and left ventricular impairment of unknown cause. He had unobstructed coronary arteries. Immediately following the procedure, he became suddenly unresponsive with vertical gaze palsy, anisocoria and bilateral upgoing plantar responses. He made a rapid recovery to his premorbid state 25 min later with no residual focal neurological signs. He then had multiple unresponsive episodes, interspaced with complete resolution of symptoms and neurological signs. MRI of the brain identified bilateral medial thalamic infarcts and midbrain infarcts, consistent with an artery of Percheron territory infarction. By the time the diagnosis was reached, the thrombolysis window had elapsed. The unresponsive episodes diminished with time and the patient was discharged to inpatient rehabilitation. At 6-month review after the episode, the patient has a degree of progressive cognitive impairment.

Figure 1

(A and B) Coronal and axial T2-weighted MRI demonstrating ill-defined hyperintensity involving the bilateral thalami (solid arrows) which contiguously involves the brainstem (dotted arrow). (C and D) Axial diffusion-weighted imaging (DWI) showing diffusion restriction in the distribution of artery of Percheron that is, the medial thalami (solid arrows) and the midbrain (dotted arrow).

Figure 2

Pictorial illustration of artery of Percheron.