Cerebral blood flow and sources of abnormal EEG activity (VARETA) in neurocysticercosis
A Fernández-Bouzas1, T Harmony, T Fernández
1ENEP Iztacala, Universidad Nacional Autónoma de México (UNAM), Avenida Los Reyes s/n, Los Reyes, Iztacala, Estado de México, Tlanepantla, Mexico. fabouzas@servidor.unam.mx
Objectives:
To compare two different functional procedures in the assessment of brain ischemia in patients with neurocysticercosis (NCC): (1) electroencephalography (EEG) evaluated by brain maps and EEG current sources in the frequency domain using variable resolution electromagnetic tomography and (2) blood flow analyzed by computerized tomography assessed with stable Xe (Xe-CT).
Methods:
Eleven patients with NCC at different evolution stages were studied. CT and Xe-CT scans, as well as quantitative electroencephalography with source calculation in the frequency domain, were obtained. All patients showed cysts and in 6 of them there were also vascular complications: two of them presented calcifications of the middle cerebral artery, two other subjects showed calcifications of the vessels in the circle of Willis and the remaining two had brain infarctions.
Results:
In the cyst areas important hypoperfused zones were observed, as intense as those observed in infarcted areas. Damage to the blood-brain barrier was originated by parasites in colloidal phase (final cysticerci stage) producing large areas of edema and hypoperfusion. Abnormal delta EEG activity was observed in very large lesions, probably generated by partial cortical deafferentation; and abnormal theta activity was mainly related to the presence of edema.
Conclusions:
Sources of abnormal EEG activity were very similar in topography to the hypoperfused areas.
