Authors :
Zarrar Nashman, MS – Drexel University College of Medicine
Vineetha Yadlapalli, BS – Drexel University College of Medicine
Trenton Kite, BS – Allegheny Health Network
Carol Schramke, PhD – AHN
Jason Gandhi, MD – Allegheny Health Network
Presenting Author: Stephen Jaffee, MD – Allegheny General Hospital
Dorian Kusyk, MD, MS – Allegheny General Hospital
Alexander Whiting, MD – Allegheny General Hospital
Rationale:
Despite the use of antiepileptic drugs, patients with drug-resistant epilepsy (DRE) continue to have seizures, with untreated refractory epilepsy often associated with progressive cognitive decline. Responsive neurostimulation (RNS) provides a neuromodulatory option for patients who would otherwise not be good candidates for resection or ablation. Although there is increasingly robust data on seizure reduction in patients who undergo RNS, significant questions remain about neuropsychiatric outcomes and whether RNS can help slow or halt the cognitive effects of refractory epilepsy.
Methods:
We performed a retrospective review of pre- and post-operative neuropsychiatric evaluations in patients with DRE treated at our institution with RNS. All patients in the study had standard work-up followed by SEEG (stereoelectroencephalography).The RNS device was surgically implanted with leads targeting the seizure onset zone. The patients had pre- and post-operative neuropsychiatric evaluations done which tested general abilities (WAIS-IV, WRAT-5, AMNART), attention (Digit span, symbol span), memory (WMS-IV, CVLT, Rey Complex Figure, TOMM, VSVT), language (F, A, S, Animals), visual spatial/construction naming (Boston naming, NAB naming), executive function (WCST, Trials A, Trials B, STROOP), and motor (finger tapping). Post-operative testing was performed at a minimum of 6 months after implantation. Additionally, baseline demographic and related disease characteristics were also collected. Pre- and post-operative neuropsychiatric outcomes were compared and statistically analyzed.
Results:
A total of 11 patients with DRE underwent the requisite amount of testing. Post-operative neuropsychiatric testing was performed at a mean follow-up time of 14.4 months with a standard deviation of 8.2. No statistically significant difference was observed for tasks of memory, attention, language, visual spatial/construction naming, and executive function. A subtle but statistically significant decrease in VCI score was noted (p=0.028).
Conclusions:
RNS device implantation seems to be correlated with stability in testing for memory, attention, language, visual spatial/construction naming, and executive function. Since clinically significant general verbal and cognitive decline in patients undergoing no intervention has been well documented in the literature, it would further add to the argument for RNS implantation if it showed the ability to halt the slow, progressive cognitive decline which can be so detrimental to patients living with refractory epilepsy. Interestingly there was a slight statistical decrease in raw VCI (Verbal Comprehension Index) score when a paired t test was done. Larger studies with long term analysis are needed.Funding: Allegheny Health Network