scholarly journals Adaptive Estimation of the Neural Activation Extent in Computational Volume Conductor Models of Deep Brain Stimulation

2018 ◽  
Vol 65 (8) ◽  
pp. 1828-1839 ◽  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Adaptive Estimation ◽  
Volume Conductor ◽  
Neural Activation ◽  
Deep Brain

scholarly journals Neural origin of evoked potentials during thalamic deep brain stimulation

2013 ◽  
Vol 110 (4) ◽  
pp. 826-843 ◽  
Author(s):  
Alexander R. Kent ◽  
Warren M. Grill
Keyword(s):  
Deep Brain Stimulation ◽  
Feedback Control ◽  
Brain Stimulation ◽  
Closed Loop ◽  
Control Signal ◽  
Neural Activation ◽  
Secondary Phases ◽  
Signal Energy ◽  
Stimulation Parameters ◽  
Deep Brain

Closed-loop deep brain stimulation (DBS) systems could provide automatic adjustment of stimulation parameters and improve outcomes in the treatment of Parkinson's disease and essential tremor. The evoked compound action potential (ECAP), generated by activated neurons near the DBS electrode, may provide a suitable feedback control signal for closed-loop DBS. The objectives of this work were to characterize the ECAP across stimulation parameters and determine the neural elements contributing to the signal. We recorded ECAPs during thalamic DBS in anesthetized cats and conducted computer simulations to calculate the ECAP of a population of thalamic neurons. The experimental and computational ECAPs were similar in shape and had characteristics that were correlated across stimulation parameters ( R2 = 0.80–0.95, P < 0.002). The ECAP signal energy increased with larger DBS amplitudes ( P < 0.0001) and pulse widths ( P < 0.002), and the signal energy of secondary ECAP phases was larger at 10-Hz than at 100-Hz DBS ( P < 0.002). The computational model indicated that these changes resulted from a greater extent of neural activation and an increased synchronization of postsynaptic thalamocortical activity, respectively. Administration of tetrodotoxin, lidocaine, or isoflurane abolished or reduced the magnitude of the experimental and computational ECAPs, glutamate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and d(−)-2-amino-5-phosphonopentanoic acid (APV) reduced secondary ECAP phases by decreasing postsynaptic excitation, and the GABAA receptor agonist muscimol increased the latency of the secondary phases by augmenting postsynaptic hyperpolarization. This study demonstrates that the ECAP provides information about the type and extent of neural activation generated during DBS, and the ECAP may serve as a feedback control signal for closed-loop DBS.

scholarly journals Defining the impact of deep brain stimulation contact size and shape on neural selectivity

2020 ◽  
Author(s):  
Daria Nesterovich Anderson ◽  
Alan D. Dorval ◽  
John D. Rolston ◽  
Stefan M. Pulst ◽  
Collin J Anderson
Keyword(s):  
Deep Brain Stimulation ◽  
Charge Density ◽  
Brain Stimulation ◽  
Grey Matter ◽  
Neural Activation ◽  
Micro Scale ◽  
Size And Shape ◽  
Neural Selectivity ◽  
Contact Size ◽  
Deep Brain

AbstractBackgroundUnderstanding neural selectivity is essential for optimizing medical applications of deep brain stimulation (DBS). We previously showed that modulation of the DBS waveform can induce changes in orientation-based selectivity, and that lengthening of DBS pulses or directional segmentation can reduce preferential selectivity for large axons. In this work, we sought to answer a simple, but important question: how do the size and shape of the contact influence neural selectivity?MethodsWe created multicompartment neuron models for several axon diameters and used finite element modeling with standard-sized cylindrical leads to determine the effects on changing contact size and shape on axon activation profiles and volumes of tissue activated. Contacts ranged in size from 0.04 to 16 mm2, compared with a standard size of 6 mm2.ResultsWe found that changes in contact size induce substantial changes in orientation-based selectivity in the context of a cylindrical lead, and rectangular shaping of the contact can alter this selectivity. Smaller contact sizes were more effective in constraining neural activation to small, nearby axons representative of grey matter. However, micro-scale contacts enable only limited spread of neural activation before exceeding standard charge density limitations; further, energetic efficiency is optimized by somewhat larger contacts.InterpretationsSmall-scale contacts are optimal for constraining stimulation in nearby grey matter and avoiding orientation-selective activation. However, given charge density limitations and energy inefficiency of micro-scale contacts, our results suggest that contacts about half the size of those on segmented clinical leads may optimize efficiency and charge density limitation avoidance.

Sign in / Sign up

Export Citation Format

Share Document