Concurrent decoding of distinct neurophysiological fingerprints of tremor and bradykinesia in Parkinson’s disease

Abstract

Parkinson’s disease (PD) is characterized by distinct motor phenomena that are expressed asynchronously. Understanding the neurophysiological correlates of these motor states could facilitate monitoring of disease progression and allow improved assessments of therapeutic efficacy, as well as enable optimal closed-loop neuromodulation. We examined neural activity in the basal ganglia and cortex of 31 subjects with PD during a quantitative motor task to decode tremor and bradykinesia – two cardinal motor signs of PD – and relatively asymptomatic periods of behavior. Support vector regression analysis of microelectrode and electrocorticography recordings revealed that tremor and bradykinesia had nearly opposite neural signatures, while effective motor control displayed unique, differentiating features. The neurophysiological signatures of these motor states depended on the signal type and location. Cortical decoding generally outperformed subcortical decoding. Within the subthalamic nucleus (STN), tremor and bradykinesia were better decoded from distinct subregions. These results demonstrate how to leverage neurophysiology to more precisely treat PD.

Invasive neurophysiology and whole brain connectomics for neural decoding in patients with brain implants

“…In the future, our platform may provide the foundation for network specific and brain-state dependent closed-loop neurostimulation approaches that dissociate symptoms 46 , side-effects 1 and volitional behavior 4 , 43 to offer the best therapy for the individual situation our patients are facing. To give a practical example, symptom specific brain networks have recently been discovered for STN-DBS in PD that differentially underlie improvement in tremor, bradykinesia, rigidity and gait disturbance 47 .…”