title: Memory modulation by weak synchronous deep brain stimulation: a pilot study.
abstract: Zero-lag phase synchronization of EEG activity has been reported to be a central mechanism accompanying long-term memory formation. In this pilot study, we examined the effects of synchronous low-amplitude stimulation of the rhinal cortex and the hippocampus in eleven temporal lobe epilepsy patients. The impact of in-phase stimulation (zero lag) on long-term memory encoding of words was contrasted with anti-phase (180° phase lag) and sham stimulation. We hypothesized more correctly remembered words for the in-phase compared to the sham condition and fewer correctly remembered words for the anti-phase vs. the sham condition. Indeed, we observed a trend for a linear condition effect for correctly remembered words, which is in accordance to our prediction (in-phase > sham > anti-phase). This finding suggests that even weak synchronous deep brain stimulation of rhinal cortex and hippocampus may modulate memory performance, while clear evidence for an enhancement of memory by this kind of deep brain simulation is still lacking.
authors.affiliation: Department of Epileptology, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany. juergen.fell@ukb.uni-bonn.de
authors.forename: Juergen
authors.initials: J
authors.lastname: Fell
authors.forename: Bernhard P
authors.initials: BP
authors.lastname: Staresina
authors.forename: Anne T A
authors.initials: AT
authors.lastname: Do Lam
authors.forename: Guido
authors.initials: G
authors.lastname: Widman
authors.forename: Christoph
authors.initials: C
authors.lastname: Helmstaedter
authors.forename: Christian E
authors.initials: CE
authors.lastname: Elger
authors.forename: Nikolai
authors.initials: N
authors.lastname: Axmacher
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D046690:Deep Brain Stimulation / Q000379:methods*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000150:complications* / Q000628:therapy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000628:therapy*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010865:Pilot Projects; D014706:Verbal Learning