Stroke in the artery of percheron territory: the two edges of one diagnosis.

Occlusion of artery of Percheron is a rare condition caused by a peculiar anatomic variation in cerebral blood supply, leading to a bilateral thalamic infarction. Strokes in artery of Percheron account for 0.1% to 2% of all cerebral infarctions. Thalamic area is supplied by the arteries arising directly from the P1 segment of the posterior cerebral artery. However, in 1/3 of cases the supply is provided by a single trunk referred to as artery of Percheron (AOP). Early diagnosis of stroke in AOP can be very challenging due to an ambiguous clinical presentation and the absence of neurovisualization findings. This article presents two clinical cases of stroke in artery of Percheron observed at Lviv Emergency Hospital. Different clinical progression of a cerebrovascular accident contrasted with a similar neurovisualization pattern was a distinctive feature in these patients. Taking into consideration the rarity of this condition and a characteristic clinical presentation, these clinical cases were retrospectively analyzed and compared. A stroke in AOP should be suspected in all patients with symptoms of interrupted blood supply in the vertebrobasilar territory. The diagnosis primarily depends on clinical features; patients with paramedian bilateral thalamic lesions may develop sudden problems with consciousness, vertical gaze palsy and memory disorders. Early diagnosis of this condition allows for more effective therapeutic interventions and improves patient prognosis.

Invasive intracranial arterial pressure monitoring during endovascular cerebral aneurysms embolization for cerebral perfusion evaluation.

The purpose of the study was to define a method of estimation of cerebral blood flow by a determination of parameters of the hemodynamics during neuroendovascular procedures. Materials and Methods. Extracranial and intracranial mean arterial pressure (MAP) was invasively monitored with the help of a transducing system during an endovascular coiling procedure in 19 patients. The measurements were performed at the tip of the guiding catheter and microcatheter placed into internal carotid artery (ICA) C1 segments and of the microcatheter placed into C4 ICA segments, at different stages of the aneurysm repair. Results. As measured, the diameter of the ICA in the C1 and C4 segments did not differ substantially. MAP in the ICA was determined to be 91.2 ± 9.6 mmHg in the skull cavity, and 102.4 ± 6.3 mmHg outside of the skull cavity, with an average difference of 9.2 ± 3.0 mmHg. Conclusion. The difference in MAP, as measured in the ICA outside and inside the skull cavity, was ascribed to the influence of intracranial pressure. Further investigation is required to check the accuracy of invasive intra-arterial pressure recording for an objective and direct measurement of the cerebral perfusion in reference to the intracranial pressure level.