DBS and SCS Therapy Improve Motor Function in Multiple System Atrophy With Predominant Parkinsonism

Multiple system atrophy (MSA) is a debilitating and fatal neurodegenerative disorder that characterized pathologically by α-synuclein (aSyn) accumulation in oligodendrocytes, the myelinating glial cells of the central nervous system (CNS), and symptomatic therapeutic strategies are still limited.

The parkinsonian type of multiple system atrophy (MSA-P) has parkinsonian symptoms as its prominent manifestation and may have an initial but short-lived response to levodopa (L-dopa). Deep brain stimulation (DBS) at the subthalamic nucleus (STN) or globus pallidus interna(GPi) has been an established treatment for Parkinson's disease(PD) patients with medically intractable fluctuations and has shown long-term efficacy to improve parkinsonian motor symptoms, such as bradykinesia, rigidity and rest tremor. However, DBS therapy is mostly ineffective in MSA patients. For the patients with MSA-P, improvement in motor function is short-lasting and rapidly followed by the early appearance of freezing of gait (FOG) and postural instability that counteracted DBS benefits and often leads to significant disability and loss of quality of life. Dopaminergic therapy or other symptomatic medications only offer limited alleviation of FOG and often lose their effect over time. Spinal cord stimulation (SCS) is a well-established therapy for treating chronic lower back or low limb pain neuropathic pain. Recently, some pilot studies demonstrated the safety and significant therapeutic outcome of SCS for FOG in PD, MSA-P and primary progressive freezing gait（PPFG）patients.

Can combined DBS with SCS be an alternative approach for symptomatic treatment of parkinsonian symptoms and gait-associated problems in patients with MSA-P? The purpose of this clinical study is to understand the combined treatment effectiveness for MSA-P.

It's a a multi-center, prospective, open label clinical study with a 12 months follow-up period. The intended study population is individuals suffering from multiple system atrophy with predominant parkinsonism. Each subject will complete an enrollment/screening/baseline visit, an DBS\&SCS implant and activation visit, and 3 months, and 12months follow-up visits. Data collected at the enrollment visit after the consent process includes: demographics, baseline clinical status, MSA-related medical history, and inclusion/exclusion criteria assessment.Baseline assessment includes: Movement Disorder Society Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) III,New Freezing of Gait Questionnaire (NFOGQ), Gait and Fall Questionnaire (GFQ), PD-related quality of life (PDQ-39) and Berg Balance Scale(BBS). The participants will proceed to implantation after satisfying implant inclusion and exclusion criteria. Medtronic Model 3389 DBS electrodes (Medtronic, U.S.A.) will be implanted in the STN bilaterally using a stereotactic technique, connected to a dual-channel ACTIVA Neurostimulator (Medtronic); Paddle-shaped SCS electrode with 16 contacts (AdaptiveStim® 39, 565; Medtronic, USA) will be implanted into the epidural space at the thoracic levels ranging from T10 to T12. Electrode positions of DBS will be verified by postoperative CT-MRI image fusion and electrode position of SCS will be verified by X-ray. The stimulators will be turned on within 1 month after electrode implantation surgery. The stimulation parameters could vary freely, but medications will be kept constant during the study period. At the end of month 12, participants will enter the long-term follow-up in which medications could vary freely.