[The relationship between bioelectrical activity and cerebral blood flow]

It is widely accepted that neuronal activation leads to a fast localized increase in cerebral blood flow. In the analyzed studies researchers demonstrated findings, aimed to better understanding of neurovascular coupling. Practical consequences are of great importance.

Analysis of data from literature on relationship between clinical events, bioelectrical activation and changes of cerebral blood flow during epileptic attacks, syncope and migraine.

The systematic review of papers publishing results of experimental and clinical studies considering electroencephalography and functional examinations as well.

The most common clinical indication for vascular tests was the presurgical evaluation to localize epileptogenic lesion area in patients with refractory epilepsy. Results of hemodynamic examinations were in agreement with videoEEG. The methods used to establish spatial and temporal changes of cerebral blood flow resulted from focal neuronal activation were: MRI, xenon/CT, PET (positron emission tomography) and SPECT (single photon emission computed tomography). The functional method used in patients with migraine and epilepsy was transcranial cerebrovascular ultrasound (TCD), useful also for monitoring of cerebral blood flow during provoked at the tilt table neurocardiogenic syncope. The method allowing demonstration of ictal and interictal hemo-dynamic changes during bioelectrical discharges as well as during different epileptic attacks was near infrared spectrometry (NIRS), a non-invasive technique of monitoring of tissue oxygenation.

The vascular examinations performed with parallel registration of cerebral bioelectrical activity contribute to understanding of pathomechanism of attacks. They also have a practical significance, especially to localize an epileptogenic lesion and the diagnosis of migraine with aura.