The presence of a caregiver is associated with patient outcomes in patients with Parkinson's disease and atypical parkinsonisms.

INTRODUCTION: Approximately 88% of men and 79% of women with Parkinson's disease (PD) identify an informal caregiver. Although caregivers can play a key role in supporting patients, little is known about how and whether PD patients with and without caregivers differ in terms of physical, cognitive, and mood outcomes. This study explored whether caregiver presence was associated with variations in patient presentation and outcomes in a palliative PD and atypical PD population. METHODS: Secondary data on individuals with PD and their caregivers came from baseline data of a 3-site randomized controlled trial of outpatient palliative care for PD in the US and Canada. Measures included: MDS UPDRS III, Montreal Cognitive Assessment, quality of life (QOL) measures, depression, prolonged grief, spirituality (FACIT SP-12) and Palliative Performance Scale. RESULTS: Of 210 participants, 175 (83%) had a caregiver. Patients with caregivers had greater motor difficulty, lower cognitive scores, and greater palliative needs as measured by the Palliative Performance Scale. Despite poorer cognitive and motor function, those with caregivers had higher QOL as measured by the Quality of Life in Alzheimer Disease and less spiritual distress. There were no group differences on anxiety, depression, or grief. Caregiver presence moderated the association between lower MoCA score and worse motor symptoms. CONCLUSION: Findings of the present study highlight the influence of caregiver engagement on PD patient outcomes. These findings have implications for clinical practice and suggest that presence of a caregiver may be an important modifying variable on patient outcomes to examine in future research.

Chronic multisite brain recordings from a totally implantable bidirectional neural interface: experience in 5 patients with Parkinson's disease.

OBJECTIVE Dysfunction of distributed neural networks underlies many brain disorders. The development of neuromodulation therapies depends on a better understanding of these networks. Invasive human brain recordings have a favorable temporal and spatial resolution for the analysis of network phenomena but have generally been limited to acute intraoperative recording or short-term recording through temporarily externalized leads. Here, the authors describe their initial experience with an investigational, first-generation, totally implantable, bidirectional neural interface that allows both continuous therapeutic stimulation and recording of field potentials at multiple sites in a neural network. METHODS Under a physician-sponsored US Food and Drug Administration investigational device exemption, 5 patients with Parkinson's disease were implanted with the Activa PC+S system (Medtronic Inc.). The device was attached to a quadripolar lead placed in the subdural space over motor cortex, for electrocorticography potential recordings, and to a quadripolar lead in the subthalamic nucleus (STN), for both therapeutic stimulation and recording of local field potentials. Recordings from the brain of each patient were performed at multiple time points over a 1-year period. RESULTS There were no serious surgical complications or interruptions in deep brain stimulation therapy. Signals in both the cortex and the STN were relatively stable over time, despite a gradual increase in electrode impedance. Canonical movement-related changes in specific frequency bands in the motor cortex were identified in most but not all recordings. CONCLUSIONS The acquisition of chronic multisite field potentials in humans is feasible. The device performance characteristics described here may inform the design of the next generation of totally implantable neural interfaces. This research tool provides a platform for translating discoveries in brain network dynamics to improved neurostimulation paradigms. Clinical trial registration no.: NCT01934296 (clinicaltrials.gov).

Acute effects of thalamic deep brain stimulation and thalamotomy on sensorimotor cortex local field potentials in essential tremor.

OBJECTIVE: Essential tremor (ET) is characterized by an action tremor believed to be due to excessive theta-alpha activity in the cerebello-thalamo-cortical system. This study aimed to test the hypothesis that therapeutic thalamic stimulation in patients with ET decreases theta-alpha oscillatory activity in primary motor (M1) and sensory (S1) cortices. METHODS: During surgical treatment of ET in 10 patients, an electrocorticography (ECoG) strip electrode was placed temporarily over the arm region of M1 and S1. Local field potentials (LFP) were recorded at rest, during a tremor-inducing posture, during acute therapeutic thalamic stimulation, and following therapeutic thalamotomy (three patients). Power spectral density (PSD) was calculated using the Fast Fourier Transform. RESULTS: At rest, alpha activity (8-13Hz) in M1 was significantly decreased during high-frequency stimulation, while theta activity (4-8Hz) decreased in S1. Following thalamotomy, theta and beta (13-30Hz) was increased in M1. Induction of postural tremor reduced M1 theta, alpha and beta activity compared to the resting state. CONCLUSIONS: High-frequency thalamic deep brain stimulation (DBS) significantly reduces alpha oscillatory activity in the primary motor cortex of patients with ET, though this change is probably not critical for therapeutic efficacy. SIGNIFICANCE: We demonstrate that ECoG can be effectively used to study the effect of subcortical stimulation on cortical oscillations.