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Objective: Previous studies showed that deep brain stimulation (DBS) relieves pain symptoms in Parkinson disease (PD) patients when programmed for motor-symptom relief. One factor involved in pain processing is sensory perception of stimuli. With the advent of directional leads, we explore whether directional DBS affects quantitative sensory testing (QST) metrics acutely. Methods: PD patients with subthalamic (STN) DBS and directional leads were tested in 5 settings (DBS-OFF, DBS-ON with omnidirectional stimulation, and DBS-ON) for each of three directional segments of contact used for clinical programming. The Unified Parkinson's Disease Rating Scale (UPDRS-III) assessed patient's motor skills at time of study visit at clinical contact and at contact which produced optimal sensory threshold (defined by the greatest tolerance to mechanical stimuli). Correlation analyses were performed between stimulation parameters [amplitude, frequency, pulse width (PW), total electrical energy delivered (TEED)] and outcome metrics. Results: Sensory thresholds were obtained in nine patients. Directional stimulation did not significantly alter patient perceptions of sensory stimulus [cold pain (p = 0.69), warm pain (p = 0.99), Von frey fibers (p = 0.09), pin-prick (p = 0.88), vibration (p = 0.40), pressure (p = 0.98)]. With correlation analysis, increasing PW at the posterior contact increased pin prick and vibration sensitivity (p < 0.001). Additionally, an increase in TEED caused a decrease in sensitivity to warm detection when using the anterior (p = 0.04), lateral (p = 0.02), and medial contacts (p = 0.03), and also caused a decrease in sensitivity to cold detection when using the medial contact (p = 0.03). UPDRS-III remained stable during testing. Conclusion: Motor benefit can be acutely maintained at directional contacts, whereas directional stimulation can modulate thermal and mechanical sensitivity. Further investigation will determine whether these changes are maintained chronically or can be improved with optimized programming. [ABSTRACT FROM AUTHOR]

Background: At least 14% of Parkinson disease (PD) patients develop impulse control disorders (ICDs). The pathophysiology behind these behaviors and the impact of deep brain stimulation in a real-life setting remain unclear. Objectives: We prospectively examined the impact of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on ICDs in PD patients, as well as the relationship between impaired sensorimotor gaiting and impulsivity. Methods: Patients undergoing bilateral STN-DBS were assessed for ICDs preoperatively and 1-year postoperatively using a validated questionnaire (QUIP-RS). A subset of patients completed the Balloon Analogue Risk Task (BART) and auditory prepulse inhibition (PPI) testing. Results: Analysis revealed 12 patients had an improvement in score assessing ICDs ('good responders'; p = 0.006) while 4 had a worse or stable score ('poor responders'; p > 0.05). Good responders further exemplified a significant decrease in hypersexual behavior (p = 0.005) and binge eating (p = 0.01). Impaired PPI responses also significantly correlated with impulsivity in BART (r = -0.72, p = 0.044). Discussion: Following bilateral STN-DBS, 75% of our cohort had a reduction in ICDs, thus suggesting deep brain stimulation effectively manages ICDs in PD. The role of impaired PPI in predisposition to ICDs in PD warrants further investigation. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Up to 60% of Parkinson's disease (PD) patients suffer from low back pain (LBP) during the course of their disease. How LBP affects daily functional status and how to manage this aspect of PD has not been adequately explored. Methods: We examined 16 patients undergoing bilateral subthalamic nucleus deep brain stimulation (STN DBS) who met the inclusion criteria for moderate disability from LBP, as classified by the Oswestry Low Back Pain Disability Index (OLBPD). Results: Thirteen of 16 patients had attempted additional treatments for LBP, including medical management, massage, chiropractic, epidural steroid injections and/or surgery, with minimal relief. Following DBS, there was a significant improvement in the OLBPD at both the 6-month and 1-year time points (p < 0.02, p < 0.005, respectively). A mean improvement of 31.7% on the OLBPD score was noted. The Visual Analogue Scale (VAS) similarly decreased significantly at 1 year (p = 0.015). There was no correlation between the OLBPD score and other measures, including the Unified Parkinson's Disease Rating Scale (UPDRS), age and other nonmotor symptoms. Conclusion: Given the prevalent yet undertreated disability associated with LBP in PD, these results are novel in that they show that STN DBS has a significant positive effect on disability associated with LBP. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Introduction There is limited evidence regarding the precise location and connections of thermoregulatory centers in humans. We present two patients managed with subthalamic nucleus (STN) Deep Brain Stimulation (DBS) for motor fluctuations in PD that developed reproducible hyperhidrosis with high frequency DBS. Objective To describe the clinical features and analyze the location of the electrodes leading to autonomic activation in both patients. Methods We retrospectively assessed the anatomical localization, electrode programming settings and effects of unilateral STN DBS leading to hyperhidrosis. Results Unilateral stimulation of anterior and medially located contacts within the STN and zona incerta (Zi) caused bilateral, consistent, reproducible, and reversible sweating in our patients. Adequate control of motor symptoms without autonomic side effects was accomplished with alternative programming settings. Conclusion Stimulation of the medial Zi and medial and anterior STN causes hyperhidrosis in a pattern similar to that described in primates and rats. We speculate that central autonomic fibers originating in the lateral hypothalamic area project laterally to the ventral/medial Zi and then to brainstem nuclei following an medial and posterior trajectory in relationship to STN. [ABSTRACT FROM AUTHOR]