Teaching Case

63-year-old male found at home in coma. The neurology service activated him as a stroke code. CT was performed without relevant findings and angio-CT showed occlusion of the left posterior cerebral artery. Mechanical thrombectomy was successfully performed but a new CT scan was performed after 48 h showing ischemic lesions.

Figure 1. Simple CT without relevant findings
Figure 2. Angio- TC (coronal (a) and axial (b) reconstructions) showing an occlusion of the left cerebral artery
Figure 3. a, Mesencephalic and posterior cerebral artery ischemic lesions. b, Bilateral thalamic ischemic lesions

In a coma patient with an occlusion of the posterior cerebral artery treated early, we must consider the possibility of an anatomical variant as in our case. In view of the appearance of bilateral thalamic ischemic lesions, we must consider the Percheron´s syndrome in which the irrigation of both thalamus originates only from one of the posterior cerebral arteries (1). There are different subtypes but independently of their origins they all irrigate the bilateral thalamic paramedial regions and the rostral midbrain (2,3). Bilateral thalamic infarction usually results in an acute process of psychic and neurological deterioration of the patient. Consciousness, oculomotor and cognitive behavioural disorders are the typical presentation triad (3). In the context of our patient, the poor clinical evolution and the findings of the CT made evident a left Percheron's artery with secondary ischemic lesions that triggered the patient's death.

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