A Review of Biomarkers Use in Parkinson with Deep Brain Stimulation: A Successful Past Promising a Bright Future

Changing views of the pathophysiology of Parkinsonism

“…A related important change of neuronal activities in parkinsonism is a breakdown of the normal separation of the firing of individual neurons in the basal ganglia. The resulting neuronal synchrony has been directly documented in single‐cell recordings with multiple electrodes and is also implied by the finding of increased amplitudes of local field potentials (LFPs; summed electrical potentials at a brain location) in the beta‐band range of frequencies (10–30 Hz) in the basal ganglia and cortex, in recordings from parkinsonian animals, and from PD patients in whom implanted DBS electrodes were used for recording purposes . The increased beta‐band activity is associated with a reduction in gamma‐band oscillatory power .…”

“…The resulting neuronal synchrony has been directly documented in single-cell recordings with multiple electrodes 44,47,48 and is also implied by the finding of increased amplitudes of local field potentials (LFPs; summed electrical potentials at a brain location) in the beta-band range of frequencies in the basal ganglia and cortex, in recordings from parkinsonian animals, [49][50][51][52][53][54][55][56][57] and from PD patients in whom implanted DBS electrodes were used for recording purposes. 44,[58][59][60][61][62][63][64][65] The increased beta-band activity is associated with a reduction in gamma-band oscillatory power. 44,65 In recent studies, it has been emphasized that an increase in the number and duration of beta-bursts in cortex or STN may be even more predictive of parkinsonism than the absolute level of beta-band activity.…”

Biomarker Optimization of Spinal Cord Stimulation Therapies

“…Auto‐adjusting the stimulation pattern delivered suppresses this abnormal activity and restores more normal function (3). In Parkinson's disease, for example, measuring local field potentials from specific nuclei including the globus pallidus internal segment and the subthalamic nucleus and then decomposing the signals into frequencies revealed a peak in the beta frequency (13–30 Hz) that correlated with rigidity (4). This finding alone started a cascade of research over nearly two decades culminating in the development of the closed‐loop device (4).…”

“…In Parkinson's disease, for example, measuring local field potentials from specific nuclei including the globus pallidus internal segment and the subthalamic nucleus and then decomposing the signals into frequencies revealed a peak in the beta frequency (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) Hz) that correlated with rigidity (4). This finding alone started a cascade of research over nearly two decades culminating in the development of the closed-loop device (4). Adaptive stimulation is also a promising approach for neuropsychiatric indications where unpredictable symptom severity over time might even be detrimental (5).…”

Feasibility and performance of a frameless stereotactic system for targeting subcortical nuclei in nonhuman primates

“…In the case of mechanistic research, the need for precision typically extends beyond placement of the DBS lead to also include depth probes implanted across key nodal points of the relevant neural circuit for the purpose of characterizing electrophysiological changes. 9,11,24 Moreover, subcortical targets may go beyond locations within the cerebral hemispheres to include deep cerebellar nuclei, 32 which can be more dif-ABBREVIATIONS DBS = deep brain stimulation; DN = dentate nucleus; EPE = electrode placement error; MC = midcommissural; NHP = nonhuman primate; STN = subthalamic nucleus.…”