Watershed ischemic stroke - clinical and imaging peculiarities

Abstract

Introduction: Watershed Stroke (WS) is a subtype of ischemic stroke, produced at the borderzones of main brain arteries’ vascularisation, and has proved to have specific features. Purpose and objectives: Specific clinical aspects’ analisis of WS as a classic ischemic stroke subtype. Determination of specific imaging pattern in patients with WS. Early neurological manifestations’ study in patients with WS. WS risk factors analysis. Study of classic brain CT use in WS diagnosis. Materials and Methods: 60 patients with ischemic stroke (IS), with male-female ratio= 1:0,86, divided in 2 groups: main group-30 patients wuth WS, and control group-30 patients with classic IS. Comparative imaging, clinical, and paraclinical features, together with statistic analysis were provided. Results: Inclusion criteria were the presence of 1 or 2 IS in past with a maximum of 3 years from the onset, the age ranking from 18 to 81, and CT-confirmed IS. Exclusion criteria were concomitant decompensated vascular pathologies, hemorrhagic stroke, and a period of more than 3 years from the first stroke. More frequently IS occurred in the middle cerebral artery territory, and more often it was primary, and bilateral or combined (involving 2 border zones at a time). The neurological deficit was found to be directly proportional with the proximity of the affected cerebral artery. Differences between neurological manifestations were found. In patients with WS they were characterizing generalized brain ischemic suffering (headache- 25,8%, dizziness- 27,3%, vision diminuation-6,6%, phosphenes-19,5%, tinnitus20,8%). A higher rate of internal carotid artery (ICA) stenosis was found in patients from the main group (46,6% versus 40%), with an evident prevalence for patients with moderate stenosis (41,66% for 51-70% of ICA stenosis versus other degrees of stenosis). The types and morphology of atherosclerotic plaque (AP) also showed differences between those 2 groups: a higher frequency of „hard” (ateromatous) plaques was identified in patients with WS in comparison with those from control group (46,66% versus 43,33%), together with higher rate of calcificates and emboligen potential were found in WS patients. Cerebral lacunarism was found much more frequently in patients with WS, especially in those with ICA stenosis. Conclusions: Neurological score in patients with WS is directly proportional with the proximity of the cerebral artery that was affected; Primary WS episodes have smaller neurological deficit score; ICA stenosis is a WS risk factor; AP has specific morphology in patients that underwent WS; Cerebral lacunarism development is directly dependent on the stenosis degree, being more frequently associated with WS; Neurological manifestations in patient with WS are specific for cerebral hypoperfusion state; Brain CT allows cortical WS diagnosis, but has some limitations in subcortical WS identification; The relationship between cerebral metabolism’s modifications adapted to brain hypoperfusion, are still a domain of further research.