An atypical stroke manifestation: Sleep disturbance in unilateral thalamic lesion

Thalamic strokes may present with a wide variety of symptoms depending on their location, volume and lateralization. Hypersomnia is a less frequent manifestation, that has been associated with unilateral paramedian thalamic ischemic lesions. We report a case of a patient who presented to the emergency department (ED) with sudden onset of hypersomnolence. Initial head computed tomography (CT) showed no signs of acute ischemia. Follow-up head CT 24 h after thrombolysis exposed a hypodense lesion on the left ventromedial thalamic and mesencephalic regions, with corresponding T2/FLAIR hyperintensity and diffusion restriction on brain magnetic resonance imaging, confirming a recent ischemic stroke. Clinicians should be aware of the association between acute hypersomnia and strategic unilateral thalamic infarcts, particularly when the initial CT scan has no signs of acute ischemia.