Title : Optimizing deep brain stimulation parameters in intractable epilepsy: An EEG-based innovative approach
Abstract:
Deep brain stimulation (DBS) of anterior thalamic nucleus (ATN) is establishing as an effective adjunctive therapy for patients with intractable epilepsy (IE) not suitable for epilepsy brain surgery and/or vagal nerve stimulation. The success of ATN-DBS is dependent upon accurate placement of the DBS electrodes and judicious selection of DBS parameters (DBSPs) and patients; however, the success has been observed to be limited to one form of intractable seizures (IS), namely complex partial seizures with other forms of IS failing to respond satisfactorily. Furthermore, the conventional mode of selection of DBSPs is by trial and error and the desired adjustments in the DBSPs are governed by the clinical response (i.e. improvement in the seizure profile) over the course of multiple sessions and hospital visits, thus, warranting a strong need for optimization of the DBSPs with objective assessment of its influence on the electrophysiology of the brain. We present an EEG-guided innovative and superior approach to the selection of effective DBSPs and advocate replacement of the conventional mode of selection with a mode targeted to induce EEG-desynchronization. The objective of this innovative strategy is based upon strong documentation of the potent antiepileptic influence exerted by EEG-desynchronization with possibly possession of an additional anti-kindling effect that can suppress or even arrest the ongoing process of epileptogenesis in the patients with intractable epilepsy in addition to exercising control over the IS. Fortunately, the EEG changes induced by the adjustments of the DBSPs are immediately visualized in the ongoing simultaneous EEG recording. It is further claimed that the innovative EEG-guided approach can successfully optimize the DBSPs resulting in minimum sessions of DBSP adjustments reducing the frequency of hospital visits, minimum side effects and minimum consumption of the device battery thus prolonging its life. Preliminary results of the clinical application of the novel approach in the selection of the DBSPs in a small case series have been very promising and encouraging despite which it is strongly recommended that well designed large sized studies are required for its validation and successful clinical outcome. EEG guidance is already in vogue in the conventional mode of selection of the DBSPs, albeit for the verification of the placement of the DBS electrodes.
