Closed-loop brain stimulation is increasingly used in level 4 epilepsy centers without an understanding of how the device behaves on a daily basis. This lack of insight is a barrier to improving closed-loop therapy and ultimately understanding why some patients never achieve seizure reduction. We aimed to quantify the accuracy of closed-loop seizure detection and stimulation on the RNS device through extrapolating information derived from manually reviewed ECoG recordings and comprehensive device logging information. RNS System event logging data were obtained, reviewed, and analyzed using a custom-built software package. A weighted-means methodology was developed to adjust for bias and incompleteness in event logs and evaluated using Bland-Altman plots and Wilcoxon signed-rank tests to compare adjusted and non-weighted (standard method) results. Twelve patients implanted for a mean of 21.5 (interquartile range 13.5-31) months were reviewed. The mean seizure frequency reduction post-RNS implantation was 40.1% (interquartile range 0-96.2%). Three primary levels of event logging granularity were identified (ECoG recordings: 3.0% complete (interquartile range 0.3-1.8%); Event Lists: 72.9% complete (interquartile range 44.7-99.8%); Activity Logs: 100% complete; completeness measured with respect to Activity Logs). Bland-Altman interpretation confirmed non-equivalence with unpredictable differences in both magnitude and direction. Wilcoxon signed rank tests demonstrated significant (p < 10-6) differences in accuracy, sensitivity, and specificity at >5% absolute mean difference for extrapolated versus standard results. Device behavior logged by the RNS System should be used in conjunction with careful review of stored ECoG data to extrapolate metrics for detector performance and stimulation.

Objective

To understand the safety, putaminal coverage, and enzyme expression of adeno-associated viral vector serotype-2 encoding the complementary DNA for the enzyme, aromatic L-amino acid decarboxylase (VY-AADC01), delivered using novel intraoperative monitoring to optimize delivery.

Methods

Fifteen subjects (three cohorts of 5) with moderately advanced Parkinson's disease and medically refractory motor fluctuations received VY-AADC01 bilaterally coadministered with gadoteridol to the putamen using intraoperative magnetic resonance imaging (MRI) guidance to visualize the anatomic spread of the infusate and calculate coverage. Cohort 1 received 8.3 × 10¹¹ vg/ml and ≤450 μl per putamen (total dose, ≤7.5 × 10¹¹ vg); cohort 2 received the same concentration (8.3 × 10¹¹ vg/ml) and ≤900 μl per putamen (total dose, ≤1.5 × 10¹² vg); and cohort 3 received 2.6 × 10¹² vg/ml and ≤900 μl per putamen (total dose, ≤4.7 × 10¹² vg). (18)F-fluoro-L-dihydroxyphenylalanine positron emission tomography (PET) at baseline and 6 months postprocedure assessed enzyme activity; standard assessments measured clinical outcomes.

Results

MRI-guided administration of ascending VY-AADC01 doses resulted in putaminal coverage of 21% (cohort 1), 34% (cohort 2), and 42% (cohort 3). Cohorts 1, 2, and 3 showed corresponding increases in enzyme activity assessed by PET of 13%, 56%, and 79%, and reductions in antiparkinsonian medication of -15%, -33%, and -42%, respectively, at 6 months. At 12 months, there were dose-related improvements in clinical outcomes, including increases in patient-reported ON-time without troublesome dyskinesia (1.6, 3.3, and 1.5 hours, respectively) and quality of life.

Interpretation

Novel intraoperative monitoring of administration facilitated targeted delivery of VY-AADC01 in this phase 1 study, which was well tolerated. Increases in enzyme expression and clinical improvements were dose dependent. ClinicalTrials.gov Identifier: NCT01973543 Ann Neurol 2019;85:704-714.

Background

As Parkinson's disease progresses, levodopa treatment loses efficacy, partly through the loss of the endogenous dopamine-synthesizing enzyme L-amino acid decarboxylase (AADC). In the phase I PD-1101 study, putaminal administration of VY-AADC01, an investigational adeno-associated virus serotype-2 vector for delivery of the AADC gene in patients with advanced Parkinson's disease, was well tolerated, improved motor function, and reduced antiparkinsonian medication requirements.

Objectives

This substudy aimed to determine whether the timing and magnitude of motor response to intravenous levodopa changed in PD-1101 patients after VY-AADC01 administration.

Methods

Participants received 2-hour threshold (0.6 mg/kg/h) and suprathreshold (1.2 mg/kg/h) levodopa infusions on each of 2 days, both before and approximately 6 months after VY-AADC01. Infusion order was randomized and double blinded. Unified Parkinson's Disease Rating Scale motor scores, finger-tapping speeds, and dyskinesia rating scores were assessed every 30 minutes for 1 hour before and ≥3 hours after start of levodopa infusion.

Results

Of 15 PD-1101 patients, 13 participated in the substudy. Unified Parkinson's Disease Rating Scale motor score area under the curve responses to threshold and suprathreshold levodopa infusions increased by 168% and 67%, respectively, after VY-AADC01; finger-tapping speeds improved by 162% and 113%, and dyskinesia scores increased by 208% and 72%, respectively, after VY-AADC01. Adverse events (mild/moderate severity) were reported in 5 participants during levodopa infusions pre-VY-AADC01 and 2 participants post-VY-AADC01 administration.

Conclusions

VY-AADC01 improved motor responses to intravenous levodopa given under controlled conditions. These data and findings from the parent study support further clinical development of AADC gene therapy for people with Parkinson's disease. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Objective

To understand the safety, putaminal coverage, and enzyme expression of adeno-associated viral vector serotype-2 encoding the complementary DNA for the enzyme, aromatic L-amino acid decarboxylase (VY-AADC01), delivered using novel intraoperative monitoring to optimize delivery.

Methods

Fifteen subjects (three cohorts of 5) with moderately advanced Parkinson's disease and medically refractory motor fluctuations received VY-AADC01 bilaterally coadministered with gadoteridol to the putamen using intraoperative magnetic resonance imaging (MRI) guidance to visualize the anatomic spread of the infusate and calculate coverage. Cohort 1 received 8.3 × 10¹¹ vg/ml and ≤450 μl per putamen (total dose, ≤7.5 × 10¹¹ vg); cohort 2 received the same concentration (8.3 × 10¹¹ vg/ml) and ≤900 μl per putamen (total dose, ≤1.5 × 10¹² vg); and cohort 3 received 2.6 × 10¹² vg/ml and ≤900 μl per putamen (total dose, ≤4.7 × 10¹² vg). (18)F-fluoro-L-dihydroxyphenylalanine positron emission tomography (PET) at baseline and 6 months postprocedure assessed enzyme activity; standard assessments measured clinical outcomes.

Results

MRI-guided administration of ascending VY-AADC01 doses resulted in putaminal coverage of 21% (cohort 1), 34% (cohort 2), and 42% (cohort 3). Cohorts 1, 2, and 3 showed corresponding increases in enzyme activity assessed by PET of 13%, 56%, and 79%, and reductions in antiparkinsonian medication of -15%, -33%, and -42%, respectively, at 6 months. At 12 months, there were dose-related improvements in clinical outcomes, including increases in patient-reported ON-time without troublesome dyskinesia (1.6, 3.3, and 1.5 hours, respectively) and quality of life.

Interpretation

Novel intraoperative monitoring of administration facilitated targeted delivery of VY-AADC01 in this phase 1 study, which was well tolerated. Increases in enzyme expression and clinical improvements were dose dependent. ClinicalTrials.gov Identifier: NCT01973543 Ann Neurol 2019;85:704-714.

Loss of nigrostriatal dopaminergic projection neurons is a key pathology in Parkinson's disease, leading to abnormal function of basal ganglia motor circuits and the accompanying characteristic motor features. A number of intraparenchymally delivered gene therapies designed to modify underlying disease and/or improve clinical symptoms have shown promise in preclinical studies and subsequently were evaluated in clinical trials. Here we review the challenges with surgical delivery of gene therapy vectors that limited therapeutic outcomes in these trials, particularly the lack of real-time monitoring of vector administration. These challenges have recently been addressed during the evolution of novel techniques for vector delivery that include the use of intraoperative MRI. The preclinical development of these techniques are described in relation to recent clinical translation in an adeno-associated virus serotype 2-mediated human aromatic L-amino acid decarboxylase gene therapy development programme. This new paradigm allows visualisation of the accuracy and adequacy of viral vector delivery within target structures, enabling intertrial modifications in surgical approaches, cannula design, vector volumes and dosing. The rapid, data-driven evolution of these procedures is unique and has led to improved vector delivery.

Over the past decade, stereotactically placed electrodes have become the gold standard for deep brain recording and stimulation for a wide variety of neurological and psychiatric diseases. Current electrodes, however, are limited in their spatial resolution and ability to record from small populations of neurons, let alone individual neurons. Here, we report on an innovative, customizable, monolithically integrated human-grade flexible depth electrode capable of recording from up to 128 channels and able to record at a depth of 10 cm in brain tissue. This thin, stylet-guided depth electrode is capable of recording local field potentials and single unit neuronal activity (action potentials), validated across species. This device represents an advance in manufacturing and design approaches which extends the capabilities of a mainstay technology in clinical neurology.

Background and objectives

To report final, 36-month safety and clinical outcomes from the PD-1101 trial of NBIb-1817 (VY-AADC01) in participants with moderately advanced Parkinson disease (PD) and motor fluctuations.

Methods

PD-1101 was a phase 1b, open-label, dose escalation trial of VY-AADC01, an experimental AAV2 gene therapy encoding the human aromatic l-amino acid decarboxylase (AADC) enzyme. VY-AADC01 was delivered via bilateral, intraoperative MRI-guided putaminal infusions to 3 cohorts (n = 5 participants per cohort): cohort 1, ≤7.5 × 10¹¹ vector genomes (vg); cohort 2, ≤1.5 × 10¹² vg; cohort 3, ≤4.7 × 10¹² vg.

Results

No serious adverse events (SAEs) attributed to VY-AADC01 were reported. All 4 non-vector-related SAEs (atrial fibrillation and pulmonary embolism in 1 participant and 2 events of small bowel obstruction in another participant) resolved. Requirements for PD medications were reduced by 21%-30% in the 2 highest dose cohorts at 36 months. Standard measures of motor function (PD diary, Unified Parkinson's Disease Rating Scale III "off"-medication and "on"-medication scores), global impressions of improvement (Clinical Global Impression of Improvement, Patient Global Impression of Improvement), and quality of life (39-item Parkinson's Disease Questionnaire) were stable or improved compared with baseline at 12, 24, and 36 months following VY-AADC01 administration across cohorts.

Discussions

VY-AADC01 and the surgical administration procedure were well-tolerated and resulted in stable or improved motor function and quality of life across cohorts, as well as reduced PD medication requirements in cohorts 2 and 3 over 3 years.

Trial registration information

NCT01973543.

Classification of evidence

This study provides Class IV evidence that, in patients with moderately advanced PD and motor fluctuations, putaminal infusion of VY-AADC01 is well tolerated and may improve motor function.

To determine if chronic motor deficits secondary to traumatic brain injury (TBI) can be improved by implantation of allogeneic modified bone marrow-derived mesenchymal stromal/stem cells (SB623). This 6-month interim analysis of the 1-year double-blind, randomized, surgical sham-controlled, phase 2 STEMTRA trial (NCT02416492) evaluated safety and efficacy of the stereotactic intracranial implantation of SB623 in patients with stable chronic motor deficits secondary to TBI. Patients in this multi-center trial (N = 63) underwent randomization in a 1:1:1:1 ratio to 2.5 × 106, 5.0 × 106, 10 × 106 SB623 cells or control. Safety was assessed in patients who underwent surgery (N = 61), and efficacy in the modified intent-to-treat population of randomized patients who underwent surgery (N = 61; SB623 = 46, control = 15). The primary efficacy endpoint of significant improvement from baseline of Fugl-Meyer Motor Scale score at 6 months for SB623-treated patients was achieved. SB623-treated patients improved by (LS mean [SE]) +8.3 (1.4) vs +2.3 (2.5) for control at 6 months, the LS mean difference was 6.0 (95% CI: 0.3-11.8); p = 0.040. Secondary efficacy endpoints improved from baseline, but were not statistically significant vs control at 6 months. There were no dose-limiting toxicities or deaths, and 100% of SB623-treated patients experienced treatment-emergent adverse events vs 93.3% of control patients (p = 0.25). SB623 cell implantation appeared to be safe and well tolerated, and patients implanted with SB623 experienced significant improvement from baseline motor status at 6 months compared to controls. This study provides Class I evidence that implantation of SB623 was well tolerated and associated with improvement in motor status.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is frequently characterized by chronic motor deficits. Therefore, this clinical trial assessed whether intracranial implantation of allogeneic modified mesenchymal stromal (SB623) cells can improve chronic motor deficits after TBI. METHODS: Post hoc analysis of the double-blind, randomized, prospective, surgical sham-controlled, phase 2, STEMTRA clinical trial (June 2016 and March 2019) with 48 weeks of follow-up was conducted. In this international, multicenter clinical trial, eligible participants had moderate-to-severe TBI, were ≥12 months postinjury, and had chronic motor deficits. Participants were randomized in a 1:1:1:1 ratio to stereotactic surgical intracranial implantation of SB623 cells (2.5 × 106, 5.0 × 106, 10 × 106) or surgical sham-controlled procedure. The prespecified primary efficacy end point was significantly greater change from baseline of the Fugl-Meyer Motor Scale (FMMS) score, a measure of motor status, for the SB623 pooled vs control arm at 24 weeks. RESULTS: A total of 211 participants were screened, 148 were excluded, and 63 underwent randomization, of which 61 (97%; mean age, 34 [SD, 12] years; 43 men [70.5%]) completed the trial. Single participants in the SB623 2.5 × 106 and 5.0 × 106 cell dose groups discontinued before surgery. Safety and efficacy (modified intent-to-treat) were assessed in participants who underwent surgery (N = 61; SB623 = 46, controls = 15). The primary efficacy end point (FMMS) was achieved (least squares mean [SE] SB623: +8.3 [1.4]; 95% CI 5.5-11.2 vs control: +2.3 [2.5]; 95% CI -2.7 to 7.3; p = 0.04), with faster improvement of the FMMS score in SB623-treated groups than in controls at 24 weeks and sustained improvement at 48 weeks. At 48 weeks, improvement of function and activities of daily living (ADL) was greater, but not significantly different in SB623-treated groups vs controls. The incidence of adverse events was equivalent in SB623-treated groups and controls. There were no deaths or withdrawals due to adverse events. DISCUSSION: Intraparenchymal implantation of SB623 cells was safe and significantly improved motor status at 24 weeks in participants with chronic motor deficits after TBI, with continued improvement of function and ADL at 48 weeks. Cell therapy can modify chronic neurologic deficits after TBI. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02416492. Submitted to registry: April 15, 2015. First participant enrolled: July 6, 2016. Available at: classic.clinicaltrials.gov/ct2/show/NCT02416492. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that intracranial implantation of allogeneic stem (SB623) cells in adults with motor deficits from chronic TBI improves motor function at 24 weeks.

Frontal circuits play a critical role in motor, cognitive and affective processing, and their dysfunction may result in a variety of brain disorders. However, exactly which frontal domains mediate which (dys)functions remains largely elusive. We studied 534 deep brain stimulation electrodes implanted to treat four different brain disorders. By analyzing which connections were modulated for optimal therapeutic response across these disorders, we segregated the frontal cortex into circuits that had become dysfunctional in each of them. Dysfunctional circuits were topographically arranged from occipital to frontal, ranging from interconnections with sensorimotor cortices in dystonia, the primary motor cortex in Tourettes syndrome, the supplementary motor area in Parkinsons disease, to ventromedial prefrontal and anterior cingulate cortices in obsessive-compulsive disorder. Our findings highlight the integration of deep brain stimulation with brain connectomics as a powerful tool to explore couplings between brain structure and functional impairments in the human brain.