Differentiating Postural and Kinetic Tremor Responses to Deep Brain Stimulation in Essential Tremor.

Background: While deep brain stimulation (DBS) targeting the ventral intermediate nucleus (VIM) of thalamus or posterior subthalamic area (PSA) can suppress forms of action tremor in people with Essential Tremor, previous studies have suggested postural tremor may respond more robustly than kinetic tremor to DBS.

Objectives: In this study, we aimed to more precisely quantify the (1) onset/offset dynamics and (2) steady-state effects of VIM/PSA-DBS on postural and kinetic tremor.

Methods: Tremor data from wireless inertial measurement units were collected from 11 participants with ET (20 unilaterally assessed DBS leads).

Parkinsonism disrupts neuronal modulation in the pre-supplementary motor area during movement preparation.

Multiple studies suggest that Parkinson's disease (PD) is associated with changes in neuronal activity throughout the basal ganglia-thalamocortical motor circuit. There are limited electrophysiological data, however, describing how parkinsonism impacts neuronal activity in the pre-supplementary motor area (pre-SMA), an area in medial frontal cortex involved in movement planning and motor control. In this study, single unit activity was recorded in the pre-SMA of two non-human primates during a visually cued reaching task in both the naive and parkinsonian state using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of parkinsonism.

Impairment of Neuronal Activity in the Dorsolateral Prefrontal Cortex Occurs Early in Parkinsonism.

Background: Parkinson's disease (PD) is often characterized by altered rates and patterns of neuronal activity in the sensorimotor regions of the basal ganglia thalamocortical network. Little is known, however, regarding how neuronal activity in the executive control network of the brain changes in the parkinsonian condition.

Objective: Investigate the impact of parkinsonism on neuronal activity in the dorsolateral prefrontal cortex (DLPFC), a key region in executive control, during a go/nogo reaching task.

Reduced subthalamic and subthalamic-cortical coherences associated with the therapeutic carryover effect of coordinated reset deep brain stimulation.

Coordinated reset deep brain stimulation (CR DBS), a promising treatment for Parkinson's disease (PD), is hypothesized to desynchronize neuronal populations. However, little in vivo data probes this hypothesis. In a parkinsonian nonhuman primate, we found that subthalamic CR DBS suppressed subthalamic and cortical-subthalamic coherences in the beta band, correlating with motor improvements.

A Patient-Centered Perspective on Changes in Personal Characteristics After Deep Brain Stimulation.

Importance: Deep brain stimulation (DBS) results in improvements in motor function and quality of life in patients with Parkinson disease (PD), which might impact a patient's perception of valued personal characteristics. Prior studies investigating whether DBS causes unwanted changes to oneself or one's personality have methodological limitations that should be addressed.

Objective: To determine whether DBS is associated with changes in characteristics that patients with PD identify as personally meaningful.