Short pauses in thalamic deep brain stimulation promote tremor and neuronal bursting.
OBJECTIVE
We conducted intraoperative measurements of tremor during DBS containing short pauses (⩽50 ms) to determine if there is a minimum pause duration that preserves tremor suppression.


METHODS
Nine subjects with ET and thalamic DBS participated during IPG replacement surgery. Patterns of DBS included regular 130 Hz stimulation interrupted by 0, 15, 25 or 50 ms pauses. The same patterns were applied to a model of the thalamic network to quantify effects of pauses on activity of model neurons.


RESULTS
All patterns of DBS decreased tremor relative to 'off'. Patterns with pauses generated less tremor reduction than regular high frequency DBS. The model revealed that rhythmic burst-driver inputs to thalamus were masked during DBS, but pauses in stimulation allowed propagation of bursting activity. The mean firing rate of bursting-type model neurons as well as the firing pattern entropy of model neurons were both strongly correlated with tremor power across stimulation conditions.


CONCLUSIONS
The temporal pattern of stimulation influences the efficacy of thalamic DBS. Pauses in stimulation resulted in decreased tremor suppression indicating that masking of pathological bursting is a mechanism of thalamic DBS for tremor.


CONCLUSIONS
Pauses in stimulation decreased the efficacy of open-loop DBS for suppression of tremor.
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Brandon D
BD
Swan
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
David T
DT
Brocker
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Justin D
JD
Hilliard
Department of Neurosurgery, Wake Forest University Baptist Medical Center, Winston-Salem, NC, USA.
Stephen B
SB
Tatter
Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.
Robert E
RE
Gross
Department of Surgery, Duke University Medical Center, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
Dennis A
DA
Turner
Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Surgery, Duke University Medical Center, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA. Electronic address: warren.grill@duke.edu.
Warren M
WM
Grill
D000200:Action Potentials / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D046690:Deep Brain Stimulation / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000502:physiology*; D013788:Thalamus / Q000502:physiology* / Q000601:surgery; D013997:Time Factors; D014202:Tremor / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*
Computational model; Deep brain stimulation; Essential tremor; Movement disorders; Thalamus