Streamlining deep brain stimulation surgery by reversing the staging order

Direct delivery of an investigational cell therapy in patients with Parkinson's disease: an interim analysis of feasibility and safety of an open-label study using DBS-Plus clinical trial design

Objective

To evaluate the interim feasibility, safety and clinical measures data of direct delivery of regenerating peripheral nerve tissue (PNT) to the substantia nigra (SN) in participants with Parkinson’s disease (PD).

Methods

Eighteen (13 men/5 women) participants were unilaterally implanted with PNT to the SN, contralateral to the most affected side during the same surgery they were receiving deep brain stimulation (DBS) surgery. Autologous PNT was collected from the sural nerve. Participants were followed for safety and clinical outcomes for 2 years (including off-state Unified Parkinson’s Disease Rating Scale (UPDRS) Part III assessments) with study visits every 6 months.

Results

All 18 participants scheduled to receive PNT implantation received targeted delivery to the SN in addition to their DBS. All subjects were discharged the following day except for two: post-op day 2; post-op day 3. The most common study-related adverse events were hypoaesthesia and hyperaesthesias to the lateral aspect of the foot and ankle of the biopsied nerve (6 of 18 participants experienced). Clinical measures did not identify any hastening of PD measures providing evidence of safety and tolerability. Off-state UPDRS Part III mean difference scores were reduced at 12 months compared with baseline (difference=−8.1, 95% CI −2.4 to −13.9 points, p=0.005). No complications involving dyskinesias were observed.

Conclusions

Targeting the SN for direct delivery of PNT was feasible with no serious adverse events related to the study intervention. Interim clinical outcomes show promising results meriting continued examination of this investigational approach.

Trial registration number

NCT02369003.

RNA Sequencing of Human Peripheral Nerve in Response to Injury: Distinctive Analysis of the Nerve Repair Pathways

The development of regenerative therapies for central nervous system diseases can likely benefit from an understanding of the peripheral nervous system repair process, particularly in identifying potential gene pathways involved in human nerve repair. This study employed RNA sequencing (RNA-seq) technology to analyze the whole transcriptome profile of the human peripheral nerve in response to an injury. The distal sural nerve was exposed, completely transected, and a 1 to 2 cm section of nerve fascicles was collected for RNA-seq from six participants with Parkinson’s disease, ranging in age between 53 and 70 yr. Two weeks after the initial injury, another section of the nerve fascicles of the distal and pre-degenerated stump of the nerve was dissected and processed for RNA-seq studies. An initial analysis between the pre-lesion status and the postinjury gene expression revealed 3,641 genes that were significantly differentially expressed. In addition, the results support a clear transdifferentiation process that occurred by the end of the 2-wk postinjury. Gene ontology (GO) and hierarchical clustering were used to identify the major signaling pathways affected by the injury. In contrast to previous nonclinical studies, important changes were observed in molecular pathways related to antiapoptotic signaling, neurotrophic factor processes, cell motility, and immune cell chemotactic signaling. The results of our current study provide new insights regarding the essential interactions of different molecular pathways that drive neuronal repair and axonal regeneration in humans.

Single-Stage Deep Brain Stimulator Placement for Movement Disorders: A Case Series

With more than two decades of experience and thousands of patients treated worldwide, deep brain stimulation (DBS) has established itself as an efficacious and common surgical treatment for movement disorders. However, a substantial majority of patients in the United States still undergo multiple, “staged” surgeries to implant a DBS system. Despite several reports suggesting no significant difference in complications or efficacy between staged and non-staged approaches, the continued use of staging implies surgeons harbor continued reservations about placing all portions of a system during the index procedure. In an effort to eliminate multiple surgeries and simplify patient care, DBS implantations at our institution have been routinely performed in a single surgery over the past four years. Patients who underwent placement of new DBS systems at our institution from January 2016 to June 2019 were identified and their records were reviewed. Revision surgeries were excluded. Total operative time, length of stay and rates of surgical site infections, lead fracture or migration, and other complications were evaluated. This series expands the body of evidence suggesting placement of a complete DBS system during a single procedure appears to be an efficacious and well-tolerated option.

Peripheral nerve grafts implanted into the substantia nigra in patients with Parkinson's disease during deep brain stimulation surgery: 1-year follow-up study of safety, feasibility, and clinical outcome

OBJECTIVECurrently, there is no treatment that slows or halts the progression of Parkinson's disease. Delivery of various neurotrophic factors to restore dopaminergic function has become a focus of study in an effort to fill this unmet need for patients with Parkinson's disease. Schwann cells provide a readily available source of such factors. This study presents a 12-month evaluation of safety and feasibility, as well as the clinical response, of implanting autologous peripheral nerve grafts into the substantia nigra of patients with Parkinson's disease at the time of deep brain stimulation (DBS) surgery.METHODSStandard DBS surgery targeting the subthalamic nucleus was performed in 8 study participants. After DBS lead implantation, a section of the sural nerve containing Schwann cells was harvested and unilaterally grafted to the substantia nigra. Adverse events were continually monitored. Baseline clinical data were obtained during standard preoperative evaluations. Clinical outcome data were obtained with postoperative clinical evaluations, neuropsychological testing, and MRI at 1 year after surgery.RESULTSAll 8 participants were implanted with DBS systems and grafts. Adverse event profiles were comparable to those of standard DBS surgery with the exception of 1 superficial infection at the sural nerve harvest site. Three participants also reported numbness in the distribution of the sural nerve distal to the harvest site. Motor scores on Unified Parkinson's Disease Rating Scale (UPDRS) part III while the participant was off therapy at 12 months improved from baseline (mean ± SD 25.1 ± 15.9 points at 12 months vs 32.5 ± 9.7 points at baseline). An analysis of the lateralized UPDRS scores also showed a greater overall reduction in scores on the side contralateral to the graft.CONCLUSIONSPeripheral nerve graft delivery to the substantia nigra at the time of DBS surgery is feasible and safe based on the results of this initial pilot study. Clinical outcome data from this phase I trial suggests that grafting may have some clinical benefit and certainly warrants further study to determine if this is an efficacious and neurorestorative therapy.Clinical trial registration no.: NCT01833364 (clinicaltrials.gov).

Implantation of autologous peripheral nerve grafts into the substantia nigra of subjects with idiopathic Parkinson's disease treated with bilateral STN DBS: a report of safety and feasibility

OBJECTIVE One avenue of intense efforts to treat Parkinson's disease (PD) involves the delivery of neurotrophic factors to restore dopaminergic cell function. A source of neurotrophic factors that could be used is the Schwann cell from the peripheral nervous system. The authors have begun an open-label safety study to examine the safety and feasibility of implanting an autologous peripheral nerve graft into the substantia nigra of PD patients undergoing deep brain stimulation (DBS) surgery. METHODS Multistage DBS surgery targeting the subthalamic nucleus was performed using standard procedures in 8 study participants. After the DBS leads were implanted, a section of sural nerve containing Schwann cells was excised and unilaterally delivered into the area of the substantia nigra. Adverse events were continuously monitored. RESULTS Eight of 8 participants were implanted with DBS systems and grafts. Adverse event profiles were comparable to those of standard DBS surgery. Postoperative MR images did not reveal edema, hemorrhage, or significant signal changes in the graft target region. Three participants reported a patch of numbness on the outside of the foot below the sural nerve harvest site. CONCLUSIONS Based on the safety outcome of the procedure, targeted peripheral nerve graft delivery to the substantia nigra at the time of DBS surgery is feasible and may provide a means to deliver neurorestorative therapy. Clinical trial registration no.: NCT01833364 ( clinicaltrials.gov ).