Dados do Trabalho

Título

Artery of Percheron territory infarct: an unusual cause of excessive daytime sleepiness.

RESUMO

Case Presentation: A 23yo female comes to the emergency department complaining of excessive daytime sleepiness (EDS) starting in the last three days. Before, the patient went to bed around 11 pm, slept at 1:30 am, and woke up at 8:00 am. Currently, the patient sleeps around 18 to 20 hours per day. The patient refers one episode of visual hallucination three days ago. After that, permanent mild dizziness and sleep attacks. Her Epworth sleepiness scale was 14/21. The neurology exam was normal, except by subjectively drowsy but aroused easily to voice. The general labs, cerebrospinal fluid, serum tests, rheumatological and hypercoagulability panels were normal. Axial FLAIR and T2-weighted MRI show symmetrical hyperintense lesions on the paramedial thalamus with abnormal restriction of water diffusion on DWI and a low ADC. The findings above confirmed the diagnosis of an acute infarction of the artery of Percheron (AOP). Discussion: EDS is a common complaint in neurologic practice and has a wide spectrum of differential diagnoses. We describe an unusual cause of EDS caused by stroke in the bilateral thalamus. Thalamus is a large egg-shaped mass of grey matter situated at the core of the diencephalon and lies between the midbrain and forebrain, acting as a central hub. The medial thalamus is involved in memory and is essential for regulating arousal because it represents the superior extension of the midbrain reticular activating system. Bilateral lesions of the medial thalamus can cause hypersomnia and decrease consciousness. Paramedian arteries usually supply the medial thalamus. AOP is a rare anatomical variation presented in 4-12% of the population when a single arterial trunk originating from the posterior cerebral artery irrigates the paramedian regions of the thalamus and, sometimes, the rostral midbrain. Bilateral paramedian thalamic infarcts account for approximately 0.1% to 2% of all ischemic strokes and 27% of thalamic infarcts. People with AOP infarct have vertical gaze paresis (65%), neuropsychiatric symptoms, coma (42%), and memory impairment (58%). The EDS was the initial complaint in our patient and improved gradually after two months. Final comments: Clinicians must be aware of AOP’s infarction as a differential diagnosis of EDS, especially in the presence of sudden EDS onset or neuropsychological and ophthalmological signs.