Paired Pulse Electrical Stimulation In Human Intractable Focal Epilepsy

OBJECTIVE: The purpose of this study was the identification of synaptic changes related to epileptogenesis in patients investigated with intracranial recordings during presurgical assessment.<br/><br/>HYPOTHESIS: The following hypotheses were tested:<br/>1. Suppression, depression or facilitation is related to seizure onset area.<br/>2. The removal of the cortex showing suppression, depression or facilitation is associated with better surgery outcome.<br/><br/>METHODS: A total of 79 patients with intractable focal epilepsy in whom intracranial electrodes were implanted for assessment prior to epilepsy surgery were analysed, using paired pulse electrical stimulation. The amplitude of the response elicited from the first pulse (1st response) was compared with the amplitude of the response elicited from the second pulse (2nd response). Depending on if the 2nd response was absent, of reduced, increased or similar amplitude to that of the 1st response four different conditions were emerged: a) suppression, b) depression, c) facilitation, or d) no change.<br/><br/>RESULTS: The following results were noted: a) Suppression showed better relation with SO lobe than depression and facilitation b) In patients with focal onset, suppression was observed in the area surrounding the focus and c) Resection of the suppressed areas was found to be an unreliable marker of surgical outcome.<br/><br/>DISCUSSION: The distribution of suppression in seizure onset lobe and more specifically in the area surrounding the focus can be of particular interest to identify the epileptogenic lobe and to study the pathophysiology of human focal epilepsy.

Name dc:type.qualificationname

Doctor of Philosophy

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

King's College London

Year dc:date.issued

2012

Author dc:creator

• Manidakis, Ioannis

Advisors dc:contributor.advisor

• Richardson, Mark Philip
• Valentin Huete, Antonio
• Alarcon, Gonzalo

Language dc:language

eng

Identifier

oai:kclpure.kcl.ac.uk:studenttheses/0cae49bb-f24e-4036-a465-10a4b034ed51

OAI identifier oai:identifier

oai:kclpure.kcl.ac.uk:studenttheses/0cae49bb-f24e-4036-a465-10a4b034ed51