Glycocalyx in epilepsy.

Rationale:

Pathophysiology of temporal lobe epilepsy (TLE) has not been elucidated yet. Endothelial dysfunction may play a role. The inner part of the endothelium is lined by glycocalyx. It is the first barrier between vessel lumen and the brain, and is affected in cerebrovascular disease. We hypothesize that in epilepsy patients, the glycocalyx is affected as well.



Objective:
Main objective: to explore cerebral glycocalyx characteristics in epilepsy patients. Other objectives: to correlate sublingual glycocalyx characteristics to directly measured cerebral glycocalyx characteristics; to establish the effect of anaesthetics on glycocalyx characteristics, to correlate glycocalyx characteristics to hippocampal sclerosis, seizure severity, and history of febrile seizures (FS) or traumatic brain injury (TBI).



Study design:
Observational case-control study.



Study population:
Adult TLE-patients suffering from medically refractory seizures who are candidates for resective brain surgery, and adult controls that are undergoing resective brain surgery for oncological indications.



Intervention (if applicable):
Sublingual and cerebral glycocalyx measurements. On admission to the hospital one day prior to surgery the first sublingual glycocalyx measurements will be performed. This sublingual measurement is repeated in the operating theatre after induction of anaesthesia, and immediately prior to resection of the temporal lobe. Cerebral glycocalyx measurements are performed twice: once cortically prior to temporal corticectomy, and once hippocampally prior to hippocampectomy Thus, glycocalyx thickness is measured five times in all patients. Hippocampus glycocalyx will not be measured in the control patients.



Main study parameters/endpoints:
Successful measurement of glycocalyx, expressed in
perfused boundary region (PBR, in ìm) and Dperf (in ìm), in epilepsy patients and controls.

Epilepsy is associated with thinner glycocalyx in cerebral microcirculation, but not with systemic microvascular differences (sublingually).

Interim analysis yearly and/or after 5 included candidates in both arms.

Measurement of sublingual and cerebral (cortical and hippocampal) glycocalyx in temporal lobe epilepsy patients and patients with intracranial tumor. Measurement is performed using a SDF camera.