Effect of Directional Deep Brain Stimulation on Sensory Thresholds in Parkinson’s Disease

Abstract

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.

Does Impaired Plantar Cutaneous Vibration Perception Contribute to Axial Motor Symptoms in Parkinson’s Disease? Effects of Medication and Subthalamic Nucleus Deep Brain Stimulation

“…Finally, the lack of statistical power due to small sample sizes might have contributed to different results as well. However, in addition to studies that investigated tactile perception of the foot, there are a number of studies that analyzed tactile perception at other anatomical locations in PD, including the arms, hands, fingers, and the torso [32][33][34][36][37][38]81,90]. Most of these studies found that PD increases tactile perception thresholds, which confirms the results of our study.…”

“…DBS-induced gait improvements might also be associated with enhanced lower limb muscle strength, the normalization of leg muscle contraction patterns, and inter-limb coordination [125,141,167,212,226,252,255,259,[262][263][264]. As hypothesized in this study, the normalization of proprioceptive functionality and enhanced processing and sensory-motor integration of afferent information through DBS may have additionally caused enhanced gait performance [19,[32][33][34]36,74,90,91,265,266].…”

“…While those motor symptoms can be very prominent and cause a significant loss in patient quality of life, PD can also be accompanied by numerous non-motor sensory symptoms [16][17][18][19]. Among those non-motor sensory symptoms, defective functionality of sensory systems such as visual [20][21][22][23], vestibular [8,[24][25][26][27][28], and somatosensory systems [29][30][31][32][33][34][35][36][37][38] has been reported in PD patients. Since those sensory systems provide valuable information for controlling movements, impaired sensory system functionality might therefore contribute to PD patients' motor symptoms.…”

“…According to the literature, anti-parkinsonian medication seems to have generally minor to no effects [48,64,87,89]. On the other hand, STN-DBS generally seems to be more promising for treating tactile cutaneous perception in PD [32][33][34]36,37,81,[90][91][92]. However, existing studies have only focused on investigations of the upper body, including the torso, arms, hands, or fingers.…”

Directional electrodes in deep brain stimulation: Results of a survey by the European Association of Neurosurgical Societies (EANS)

“…None of them found them to be worse. This positive attitude is only partially reflected by the literature with most papers showing theoretical but no clinical benefits ( Rammo et al, 2021 ; Bruno et al, 2021 ; Steffen et al, 2020 ; Shao et al, 2020 ; Rebelo et al, 2018 ; Schnitzler et al, 2022 ; Sabourin et al, 2020 ; Dembek et al, 2017 ; Steigerwald et al, 2016 ) and only very few showing some benefit ( Krüger et al, 2021a ; Hurt et al, 2023 ; Pintér et al, 2023 ). However, most of these studies are on newly implanted patients with short follow-up times, and the discrepancy could well reflect a gap in the literature that may be filled over time.…”