Experience with Transcranial Electrical Stimulation in the Assessment of the Microvascular Bed by Contrast-Free Magnetic Resonance Perfusion Imaging in Patients with Chronic Cerebral Ischemia

Abstract

Objective: to define the role of transcranial electrical stimulation in the assessment of the microvascular bed by contrast-free magnetic resonance (MR) perfusion imaging in patients with chronic cerebral ischemia. Material and methods. Examinations were made in 37 people aged 65-70 years who were diagnosed with chronic cerebral ischemia. The patients were divided into two groups: with and without cognitive impairment (CI). The investigation algorithm involved brain magnetic resonance imaging (MRI) (Toshiba Vantage Titan, 1.5 T), transcranial electrical stimulation (TES) using a TETOS computer hardware diagnostics (Research and Production Firm “BIOSS”) and repeated brain MRI in the arterial spin labelling (ASL) perfusion mode. ASL perfusion data were used to assess cerebral blood flow in the regions of interest before and after TES. Results. Contrast-free MR perfusion imaging revealed relative hyperperfusion within the cortex of the frontal and parietal lobes concurrent with hypoperfusion of the subcortical nuclei and cerebral white matter in patients with CI, which suggests that enhanced cortical blood flow is ineffective and shunting blood flow forms. TES caused a statistically significant change in cerebral perfusion in the non-CI group of patients with chronic cerebral ischemia. After TES by ASL perfusion imaging, the patients without CI showed a diffuse increase in cerebral blood flow (p = 0.002), whereas the group of apparently healthy volunteers exhibited this increase in blood flow. Conclusion. Cerebral perfusion indices before and after TES in patients of all the examined groups define its role as a complementary tool to assess the compensatory capabilities of the microvascular bed by contrast-free MR perfusion imaging in chronic cerebral ischemia.