Deep brain stimulation (DBS) in the ventral intermediate nucleus of thalamus (Vim) is known to exert a therapeutic effect on postural and kinetic tremor in patients with essential tremor. For DBS leads implanted near the caudal border of Vim, however, there is an increased likelihood that one will also induce paresthesia side-effects by stimulating neurons within the sensory pathway of the ventral caudal (Vc) nucleus of thalamus. The aim of this computational study was to 1) investigate the neuronal pathways modulated by therapeutic, sub-therapeutic, and paresthesia-inducing DBS settings in three patients with essential tremor, and 2) determine how much better of an outcome could have been achieved had these patients been implanted with a DBS lead containing directionally-segmented electrodes (dDBS). Multi-compartment neuron models of the thalamocortical, cerebellothalamic, and medial lemniscal pathways were first simulated in the context of patient-specific anatomies, lead placements, and programming parameters from three ET patients who had been implanted with Medtronic 3389 DBS leads. The models showed that in these patients, complete suppression of tremor was associated most closely with activating an average of 62% of the cerebellothalamic afferent input into Vim (n=10), while persistent paresthesias were associated with activating 35% of the medial lemniscal tract input into Vc thalamus (n=12). The dDBS lead design demonstrated superior targeting of the cerebello-thalamo-cortical pathway, especially in cases of misaligned DBS leads. Given the close proximity of Vim to Vc thalamus, the models suggest that dDBS will enable clinicians to more effectively sculpt current through and around thalamus in order to achieve a more consistent therapeutic effect without inducing side effects.

Background: The COVID-19 pandemic restricted usual healthcare management for movement-disorders patients, with a consequent upsurge in telemedicine to bridge the gap. Objective: To assess global telemedicine usage in the context of the pandemic. Methods: The Movement Disorder Society (MDS) Telemedicine Study Group surveyed telemedicine experts from 40 countries across all continents in March-April 2020. Four domains of telemedicine were assessed: legal regulations, reimbursement, clinical use, and barriers; comparing emerging responses to the pandemic versus the baseline scenario. Results: All forms of telemedicine for movement disorders increased globally, irrespective of country income categorization, as an immediate response to the pandemic. This was aided by widespread availability of technology and updated government regulations. However, privacy concerns, lack of reimbursement, limited access, and lack of telemedicine training were barriers highlighted worldwide. Conclusions: Questions remain about the longevity and extent of changes in regulations and reimbursement regarding telemedicine in the aftermath of the pandemic.

Subthalamic nucleus (STN) or globus pallidus interna (GPi) deep brain stimulation (DBS) is considered a robust therapeutic tool in the treatment of Parkinson's disease (PD) patients, although it has been reported to potentially cause cognitive decline in some cases. We here provide an in-depth and critical review of the current literature regarding cognition after DBS in PD, summarizing the available data on the impact of STN and GPi DBS as monotherapies and also comparative data across these two therapies on 7 cognitive domains. We provide evidence that, in appropriately screened PD patients, worsening of one or more cognitive functions is rare and subtle after DBS, without negative impact on quality of life, and that there is very little data supporting that STN DBS has a worse cognitive outcome than GPi DBS.

Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.

More than 250 respondents around the world engage in telemedicine for movement disorders; most perceived benefit for patients, despite challenges and reimbursement for clinicians. Formal instruction on telemedicine is highly desired. Although the survey response was low and possibly biased to over represent those with telemedicine experience, the study provides baseline data for future comparison and to improve telemedicine delivery.