Beyond implantation effect? Long-term seizure reduction and freedom following intracranial monitoring without additional surgical interventions.

Beyond implantation effect? Long-term seizure reduction and freedom following intracranial monitoring without additional surgical interventions.
Epilepsy Behav. 2020 Jun 29;111:107231
Authors: Percy J, Zaveri H, Duckrow RB, Gerrard J, Farooque P, Hirsch LJ, Spencer DD, Sivaraju A
Abstract
The term 'implantation effect' is used to describe an immediate and transient improvement in seizure frequency following an intracranial study for seizure onset localization. We conducted a retrospective analysis of 190 consecutive patients undergoing intracranial electroencephalogram (EEG) monitoring, of whom 41 had no subsequent resection/ablation/stimulation; 33 had adequate data and follow-up time available for analysis. Analysis of seizure frequency following an intracranial study showed 36% (12/33) responder rate (>50% seizure reduction) at one year, decreasing and stabilizing at 20% from year 4 onwards. In addition, we describe three patients (9%) who had long term seizure freedom of more than five years following electrode implantation alone, two of whom had thalamic depth electrodes. Electrode implantation perhaps leads to a neuromodulatory effect sufficient enough to disrupt epileptogenic networks. Rarely, this may be significant enough to even result in long term seizure freedom, as seen in our three patients.
PMID: 32615416 [PubMed - as supplied by publisher]

Source: Epilepsy and Behaviour - June 28, 2020 Category: Neurology Authors: Percy J, Zaveri H, Duckrow RB, Gerrard J, Farooque P, Hirsch LJ, Spencer DD, Sivaraju A Tags: Epilepsy Behav Source Type: research