Intraputamenal Cerebral Dopamine Neurotrophic Factor in Parkinson's Disease: A Randomized, Double-Blind, Multicenter Phase 1 Trial.

BACKGROUND: Cerebral dopamine neurotrophic factor (CDNF) is an unconventional neurotrophic factor that protects dopamine neurons and improves motor function in animal models of Parkinson's disease (PD). OBJECTIVE: The primary objectives of this study were to assess the safety and tolerability of both CDNF and the drug delivery system (DDS) in patients with PD of moderate severity. METHODS: We assessed the safety and tolerability of monthly intraputamenal CDNF infusions in patients with PD using an investigational DDS, a bone-anchored transcutaneous port connected to four catheters. This phase 1 trial was divided into a placebo-controlled, double-blind, 6-month main study followed by an active-treatment 6-month extension. Eligible patients, aged 35 to 75 years, had moderate idiopathic PD for 5 to 15 years and Hoehn and Yahr score ≤ 3 (off state). Seventeen patients were randomized to placebo (n = 6), 0.4 mg CDNF (n = 6), or 1.2 mg CDNF (n = 5). The primary endpoints were safety and tolerability of CDNF and DDS and catheter implantation accuracy. Secondary endpoints were measures of PD symptoms, including Unified Parkinson's Disease Rating Scale, and DDS patency and port stability. Exploratory endpoints included motor symptom assessment (PKG, Global Kinetics Pty Ltd, Melbourne, Australia) and positron emission tomography using dopamine transporter radioligand [18 F]FE-PE2I. RESULTS: Drug-related adverse events were mild to moderate with no difference between placebo and treatment groups. No severe adverse events were associated with the drug, and device delivery accuracy met specification. The severe adverse events recorded were associated with the infusion procedure and did not reoccur after procedural modification. There were no significant changes between placebo and CDNF treatment groups in secondary endpoints between baseline and the end of the main and extension studies. CONCLUSIONS: Intraputamenally administered CDNF was safe and well tolerated, and possible signs of biological response to the drug were observed in individual patients. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A Review of Techniques for Biodelivery of Nerve Growth Factor (NGF) to the Brain in Relation to Alzheimer's Disease.

Age-dependent progressive neurodegeneration and associated cognitive dysfunction represent a serious concern worldwide. Currently, dementia accounts for the fifth highest cause of death, among which Alzheimer's disease (AD) represents more than 60% of the cases. AD is associated with progressive cognitive dysfunction which affects daily life of the affected individual and associated family. The cognitive dysfunctions are at least partially due to the degeneration of a specific set of neurons (cholinergic neurons) whose cell bodies are situated in the basal forebrain region (basal forebrain cholinergic neurons, BFCNs) but innervate wide areas of the brain. It has been explicitly shown that the delivery of the neurotrophic protein nerve growth factor (NGF) can rescue BFCNs and restore cognitive dysfunction, making NGF interesting as a potential therapeutic substance for AD. Unfortunately, NGF cannot pass through the blood-brain barrier (BBB) and thus peripheral administration of NGF protein is not viable therapeutically. NGF must be delivered in a way which will allow its brain penetration and availability to the BFCNs to modulate BFCN activity and viability. Over the past few decades, various methodologies have been developed to deliver NGF to the brain tissue. In this chapter, NGF delivery methods are discussed in the context of AD.

Acute effect of spinal cord stimulation on autonomic nervous system function in patients with heart failure.

AIMS: To test the hypothesis that spinal cord stimulation (SCS) acutely improves heart rate variability (HRV) and baroreceptor sensitivity (BRS) in patients with heart failure (HF). METHODS: SCS (15 minutes) was delivered in four different settings: 90% of maximal tolerated stimulation amplitude (MTA) targeting the T1-T4 spinal cord segments (SCS90T1-4), 60% of MTA (SCS60T1-4), 90% of MTA with cranial (SCS90CR) and caudal (SCS90CA) electrode configuration. HRV and BRS were recorded continuously and stimulation was compared to device off. RESULTS: Fifteen HF patients were included. SCS90T1-4 did not change the standard deviation of intervals between normal beats (SDNN, p = 0.90), BRS (p = 0.55) or other HRV parameters. In patients with baseline SDNN <50 ms, SCS90T1-4 significantly increased SDNN (p = 0.004). CONCLUSIONS: Acute SCS at 60-90% of MTA targeting upper thoracic spinal cord segments does not improve autonomic balance or baroreceptor sensitivity in unselected patients with heart failure but may improve HRV in patients with low SDNN.

Effects of Spinal Cord Stimulation on Cardiac Sympathetic Nerve Activity in Patients with Heart Failure.

BACKGROUND: Spinal cord stimulation (SCS) reduces sympathetic activity in animal models of heart failure with reduced ejection fraction (HF) but limited data exist of SCS in patients with HF. The aim of the present study was to test the primary hypothesis that SCS reduces cardiac sympathetic nerve activity in HF patients. Secondary hypotheses were that SCS improves left ventricular function and dimension, exercise capacity, and clinical variables relevant to HF. METHODS: HF patients with a SCS device previously participating in the DEFEAT-HF trial were included in this crossover study with 6-week intervention periods (SCS-ON and SCS-OFF). SCS (50 Hz, 210-µs pulse duration, aiming at T2-T4 segments) was delivered for 12 hours daily. Indices of myocardial sympathetic neuronal function (heart-to-mediastinum ratio, HMR) and activity (washout rate, WR) were assessed using 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Echocardiography, exercise testing, and clinical data collection were also performed. RESULTS: We included 13 patients (65.3 ± 8.0 years, nine males) and MIBG scintigraphy data were available in 10. HMR was not different comparing SCS-ON (1.37 ± 0.16) and SCS-OFF (1.41 ± 0.21, P = 0.46). WR was also unchanged comparing SCS-ON (41.5 ± 5.3) and SCS-OFF (39.1 ± 5.8, P = 0.30). Similarly, average New York Heart Association class (2.4 ± 0.5 vs 2.3 ± 0.6, P = 0.34), quality of life score (24 ± 16 vs 24 ± 16, P = 0.94), and left ventricular dimension and function as well as exercise capacity were all unchanged comparing SCS-ON and SCS-OFF. CONCLUSION: In patients with HF, SCS (12 hours daily, targeting the T2-T4 segments of the spinal cord) does not appear to influence cardiac sympathetic neuronal activity or function as assessed by MIBG scintigraphy.

Therapeutic value of spinal cord stimulation in irritable bowel syndrome: a randomized crossover pilot study.

Irritable bowel syndrome (IBS) is characterized by abdominal pain and changed bowel habits. Spinal cord stimulation (SCS) has been used for treatment of chronic pain syndromes. Animal studies have shown SCS to reduce the reaction to colonic balloon distension, known to be increased in IBS patients. To elucidate the potential for SCS as treatment for IBS, a pilot study was performed. Ten IBS patients (age 26-56 yr) were recruited. A SCS system with a four-polar electrode was implanted at the T5-T8 level. After a 2-wk run-in, a randomized, crossover design SCS during 6 wk was compared with no stimulation, with an ensuing stimulation period for 12 wk; total study period 28 wk. Patients recorded pain level, pain attacks, diarrheas, and global quality of life in a diary. At end of the study patients could choose to retain their SCS system or have it removed. Nine patients completed the whole trial. During stimulation periods the median pain scores were significantly reduced from visual analogue scale (VAS) 7 (4-8) to 3 (2.5-7) and to 4 (2-6) during early and late stimulation periods, respectively (P < 0.03-0.04). Pain attacks were numerically reduced. A few patients reported reduced number of diarrheas. After study termination, six patients chose to retain their SCS system. To conclude, SCS is a minimally invasive treatment option for pain in IBS. With SCS the pain level was reduced though with merely a trend for number of attacks and diarrheas. The efficacy of SCS in IBS pain indicates a possible usefulness in other painful bowel disorders.

Changes in CSF cholinergic biomarkers in response to cell therapy with NGF in patients with Alzheimer's disease.

INTRODUCTION: The extensive loss of central cholinergic functions in Alzheimer's disease (AD) brain is linked to impaired nerve growth factor (NGF) signaling. The cardinal cholinergic biomarker is the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), which has recently been found in cerebrospinal fluid (CSF). The purpose of this study was to see if EC-NGF therapy will alter CSF levels of cholinergic biomarkers, ChAT, and acetylcholinesterase. METHOD: Encapsulated cell implants releasing NGF (EC-NGF) were surgically implanted bilaterally in the basal forebrain of six AD patients for 12 months and cholinergic markers in CSF were analyzed. RESULTS: Activities of both enzymes were altered after 12 months. In particular, the activity of soluble ChAT showed high correlation with cognition, CSF tau and amyloid-ß, in vivo cerebral glucose utilization and nicotinic binding sites, and morphometric and volumetric magnetic resonance imaging measures. DISCUSSION: A clear pattern of association is demonstrated showing a proof-of-principle effect on CSF cholinergic markers, suggestive of a beneficial EC-NGF implant therapy.

Neuroimmune Modulation Through Vagus Nerve Stimulation Reduces Inflammatory Activity in Crohn's Disease Patients: A Prospective Open-label Study.

BACKGROUND AND AIMS: Crohn's disease [CD] is a debilitating, inflammatory condition affecting the gastrointestinal tract. There is no cure and sustained clinical and endoscopic remission is achieved by fewer than half of patients with current therapies. The immunoregulatory function of the vagus nerve, the 'inflammatory reflex', has been established in patients with rheumatoid arthritis and biologic-naive CD. The aim of this study was to explore the safety and efficacy of vagus nerve stimulation in patients with treatment-refractory CD, in a 16-week, open-label, multicentre, clinical trial. METHODS: A vagus nerve stimulator was implanted in 17 biologic drug-refractory patients with moderately to severely active CD. One patient exited the study pre-treatment, and 16 patients were treated with vagus nerve stimulation [4/16 receiving concomitant biologics] during 16 weeks of induction and 24 months of maintenance treatment. Endpoints included clinical improvement, patient-reported outcomes, objective measures of inflammation [endoscopic/molecular], and safety. RESULTS: There was a statistically significant and clinically meaningful decrease in CD Activity Index at Week 16 [mean ±â€…SD: -86.2 ±â€…92.8, p = 0.003], a significant decrease in faecal calprotectin [-2923 ±â€…4104, p = 0.015], a decrease in mucosal inflammation in 11/15 patients with paired endoscopies [-2.1 ±â€…1.7, p = 0.23], and a decrease in serum tumour necrosis factor and interferon-γ [46-52%]. Two quality-of-life indices improved in 7/11 patients treated without biologics. There was one study-related severe adverse event: a postoperative infection requiring device explantation. CONCLUSIONS: Neuroimmune modulation via vagus nerve stimulation was generally safe and well tolerated, with a clinically meaningful reduction in clinical disease activity associated with endoscopic improvement, reduced levels of faecal calprotectin and serum cytokines, and improved quality of life.

Encapsulated cell biodelivery of nerve growth factor to the Basal forebrain in patients with Alzheimer's disease.

BACKGROUND/AIMS: Degeneration of cholinergic neurons in the basal forebrain correlates with cognitive decline in patients with Alzheimer's disease (AD). Targeted delivery of exogenous nerve growth factor (NGF) has emerged as a potential AD therapy due to its regenerative effects on the basal forebrain cholinergic neurons in AD animal models. Here we report the results of a first-in-man study of encapsulated cell (EC) biodelivery of NGF to the basal forebrain of AD patients with the primary objective to explore safety and tolerability. METHODS: This was an open-label, 12-month study in 6 AD patients. Patients were implanted stereotactically with EC-NGF biodelivery devices targeting the basal forebrain. Patients were monitored with respect to safety, tolerability, disease progression and implant functionality. RESULTS: All patients were implanted successfully with bilateral single or double implants without complications or signs of toxicity. No adverse events were related to NGF or the device. All patients completed the study, including removal of implants at 12 months. Positive findings in cognition, EEG and nicotinic receptor binding in 2 of 6 patients were detected. CONCLUSIONS: This study demonstrates that surgical implantation and removal of EC-NGF biodelivery to the basal forebrain in AD patients is safe, well tolerated and feasible.

Fast Alpha Activity in EEG of Patients With Alzheimer's Disease Is Paralleled by Changes in Cognition and Cholinergic Markers During Encapsulated Cell Biodelivery of Nerve Growth Factor.

Background: Basal forebrain cholinergic neurons are dependent on nerve growth factor (NGF) for growth and survival and these cells are among the first to degenerate in Alzheimer's disease (AD). Targeted delivery of NGF has been suggested as a potential therapy for AD. This hypothesis was tested in a clinical trial with encapsulated cell biodelivery of NGF (NGF-ECB) in AD patients. Three of six patients showed improved biomarkers for cognition by the end of the study. Here, we report on the effects of targeted delivery of NGF on human resting EEG. Materials and methods: NGF-ECB implants were implanted bilaterally in the basal forebrain of six AD patients for 12 months. EEG recordings and quantitative analysis were performed at baseline, 3 and 12 months of NGF delivery, and analyzed for correlation with changes in Mini-mental state examination (MMSE) and levels of the cholinergic marker choline acetyltransferase (ChAT) in cerebrospinal fluid (CSF). Results: We found significant correlations between the topographic variance of EEG spectral power at the three study points (baseline, 3 and 12 months) and changes in MMSE and CSF ChAT. This possible effect of NGF was identified in a narrow window of alpha frequency 10-11.5 Hz, where a stabilization in MMSE score during treatment was related to an increase in EEG alpha power. A similar relation was observed between the alpha power and ChAT. More theta power at 6.5 Hz was on the contrary associated with a decrease in CSF ChAT during the trial period. Conclusion: In this exploratory study, there was a positive correlative pattern between physiological high-frequency alpha activity and stabilization in MMSE and increase in CSF ChAT in AD patients receiving targeted delivery of NGF to the cholinergic basal forebrain.

The cholinergic system in subtypes of Alzheimer's disease: an in vivo longitudinal MRI study.

BACKGROUND: The heterogeneity within Alzheimer's disease (AD) seriously challenges the development of disease-modifying treatments. We investigated volume of the basal forebrain, hippocampus, and precuneus in atrophy subtypes of AD and explored the relevance of subtype stratification in a small clinical trial on encapsulated cell biodelivery (ECB) of nerve growth factor (NGF) to the basal forebrain. METHODS: Structural MRI data was collected for 90 amyloid-positive patients and 69 amyloid-negative healthy controls at baseline, 6-, 12-, and 24-month follow-up. The effect of the NGF treatment was investigated in 10 biopsy-verified AD patients with structural MRI data at baseline and at 6- or 12-month follow-up. Patients were classified as typical, limbic-predominant, hippocampal-sparing, or minimal atrophy AD, using a validated visual assessment method. Volumetric analyses were performed using a region-of-interest approach. RESULTS: All AD subtypes showed reduced basal forebrain volume as compared with the healthy controls. The limbic-predominant subtype showed the fastest basal forebrain atrophy rate, whereas the minimal atrophy subtype did not show any significant volume decline over time. Atrophy rates of the hippocampus and precuneus also differed across subtypes. Our preliminary data from the small NGF cohort suggest that the NGF treatment seemed to slow the rate of atrophy in the precuneus and hippocampus in some hippocampal-sparing AD patients and in one typical AD patient. CONCLUSIONS: The cholinergic system is differentially affected in distinct atrophy subtypes of AD. Larger studies in the future should confirm that this differential involvement of the cholinergic system may contribute to subtype-specific response to cholinergic treatment. Our preliminary findings suggest that future clinical trials should target specific subtypes of AD, or at least report treatment effects stratified by subtype. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01163825. Registered 14 July 2010.

One Hundred Eleven Percutaneous Balloon Compressions for Trigeminal Neuralgia in a Cohort of 66 Patients with Multiple Sclerosis.

BACKGROUND: Trigeminal neuralgia associated with multiple sclerosis (MS-TN) is comparatively rare and larger series of percutaneous balloon compression (PBC) in such cases are few in the literature. OBJECTIVE: To evaluate the results after PBC for MS-TN with regards to therapeutic effect, side effects, and complications. METHODS: One hundred eleven procedures with PBC performed in 66 cases of MS-TN were analyzed. Therapeutic effect was measured as postoperative time to pain recurrence without medication. All complications were compiled and the sensory function was evaluated in a subgroup of cases. RESULTS: The initial pain free rate was 67% and the median time to pain recurrence was 8 mo. Thirty-six patients were treated with PBC only, and among them, the results were worse if treated 3 to 4 times before, compared to first treatment (P = .009-.034). Patients who had several PBCs had worse results already after the first surgery (P < .001). A significant number of patients had impaired sensation to light touch directly after surgery, which was normalized at the late follow-up. Sensimetric testing showed raised thresholds for perception and pain directly after surgery (P = .004-.03), but these were also normalized at the late follow-up. CONCLUSION: PBC is a treatment that can be effective for many patients with MS-TN. Repeated previous surgeries is a risk factor for an unsatisfactory outcome. However, the patients with multiple surgeries had less satisfactory results already at the first procedure, indicating that a therapy resistant disease can be predicted after the first two PBCs. Postoperative sensory deficits were common but not lasting.

Pallidal Deep Brain Stimulation in DYT6 Dystonia: Clinical Outcome and Predictive Factors for Motor Improvement.

Pallidal deep brain stimulation is an established treatment in dystonia. Available data on the effect in DYT-THAP1 dystonia (also known as DYT6 dystonia) are scarce and long-term follow-up studies are lacking. In this retrospective, multicenter follow-up case series of medical records of such patients, the clinical outcome of pallidal deep brain stimulation in DYT-THAP1 dystonia, was evaluated. The Burke Fahn Marsden Dystonia Rating Scale served as an outcome measure. Nine females and 5 males were enrolled, with a median follow-up of 4 years and 10 months after implant. All benefited from surgery: dystonia severity was reduced by a median of 58% (IQR 31-62, p = 0.001) at last follow-up, as assessed by the Burke Fahn Marsden movement subscale. In the majority of individuals, there was no improvement of speech or swallowing, and overall, the effect was greater in the trunk and limbs as compared to the cranio-cervical and orolaryngeal regions. No correlation was found between disease duration before surgery, age at surgery, or preoperative disease burden and the outcome of deep brain stimulation. Device- and therapy-related side-effects were few. Accordingly, pallidal deep brain stimulation should be considered in clinically impairing and pharmaco-resistant DYT-THAP1 dystonia. The method is safe and effective, both short- and long-term.

Subthalamic stimulation for essential tremor. Short- and long-term results and critical target area.

BACKGROUND/AIMS/METHODS: In order to explore the usefulness and long-term result of subthalamic nucleus (STN) stimulation for the treatment of essential tremor (ET), we evaluated 3 groups of patients undergoing deep brain stimulation (DBS) for ET. RESULTS: Group 1 consisted of 3 patients who 9 years ago at intra-operative testing had good tremor reduction from STN stimulation. The second group consisted of 10 patients treated with DBS in the ventral intermediate (Vim) nucleus of the thalamus. The third group comprised 9 patients subjected to STN stimulation for ET with 1-3 years of follow-up. The 3 ET patients with STN stimulation in group 1 have continued to have excellent tremor reduction for up to 9 years. The second group, with Vim stimulation, showed less favourable long-term results. All of the recent STN stimulation group experienced good tremor reduction, but some of the patients above 70 years of age reported troublesome side effects. CONCLUSION: Provided that intra-operative test stimulation produces satisfactory tremor control, STN is a good target for long-term treatment of ET. For patients above the age of 70 years, however, the Vim is a preferable target.

Targeted delivery of nerve growth factor to the cholinergic basal forebrain of Alzheimer's disease patients: application of a second-generation encapsulated cell biodelivery device.

BACKGROUND: Targeted delivery of nerve growth factor (NGF) has emerged as a potential therapy for Alzheimer's disease (AD) due to its regenerative effects on basal forebrain cholinergic neurons. This hypothesis has been tested in patients with AD using encapsulated cell biodelivery of NGF (NGF-ECB) in a first-in-human study. We report our results from a third-dose cohort of patients receiving second-generation NGF-ECB implants with improved NGF secretion. METHODS: Four patients with mild to moderate AD were recruited to participate in an open-label, phase Ib dose escalation study with a 6-month duration. Each patient underwent stereotactic implant surgery with four NGF-ECB implants targeted at the cholinergic basal forebrain. The NGF secretion of the second-generation implants was improved by using the Sleeping Beauty transposon gene expression technology and an improved three-dimensional internal scaffolding, resulting in production of about 10 ng NGF/device/day. RESULTS: All patients underwent successful implant procedures without complications, and all patients completed the study, including implant removal after 6 months. Upon removal, 13 of 16 implants released NGF, 8 implants released NGF at the same rate or higher than before the implant procedure, and 3 implants failed to release detectable amounts of NGF. Of 16 adverse events, none was NGF-, or implant-related. Changes from baseline values of cholinergic markers in cerebrospinal fluid (CSF) correlated with cortical nicotinic receptor expression and Mini Mental State Examination score. Levels of neurofilament light chain (NFL) protein increased in CSF after NGF-ECB implant, while glial fibrillary acidic protein (GFAP) remained stable. CONCLUSIONS: The data derived from this patient cohort demonstrate the safety and tolerability of sustained NGF release by a second-generation NGF-ECB implant to the basal forebrain, with uneventful surgical implant and removal of NGF-ECB implants in a new dosing cohort of four patients with AD. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01163825 . Registered on 14 Jul 2010.

Brain changes in Alzheimer's disease patients with implanted encapsulated cells releasing nerve growth factor.

New therapies with disease-modifying effects are urgently needed for treating Alzheimer's disease (AD). Nerve growth factor (NGF) protein has demonstrated regenerative and neuroprotective effects on basal forebrain cholinergic neurons in animal studies. In addition, AD patients treated with NGF have previously shown improved cognition, EEG activity, nicotinic binding, and glucose metabolism. However, no study to date has analyzed brain atrophy in patients treated with NGF producing cells. In this study we present MRI results of the first clinical trial in patients with AD using encapsulated NGF biodelivery to the basal forebrain. Six AD patients received the treatment during twelve months. Patients were grouped as responders and non-responders according to their twelve-months change in MMSE. Normative values were created from 131 AD patients from ADNI, selecting 36 age- and MMSE-matched patients for interpreting the longitudinal changes in MMSE and brain atrophy. Results at baseline indicated that responders showed better clinical status and less pathological levels of cerebrospinal fluid (CSF) Aß1-42. However, they showed more brain atrophy, and neuronal degeneration as evidenced by higher CSF levels of T-tau and neurofilaments. At follow-up, responders showed less brain shrinkage and better progression in the clinical variables and CSF biomarkers. Noteworthy, two responders showed less brain shrinkage than the normative ADNI group. These results together with previous evidence supports the idea that encapsulated biodelivery of NGF might have the potential to become a new treatment strategy for AD with both symptomatic and disease-modifying effects.

Safety and tolerability of intracerebroventricular PDGF-BB in Parkinson's disease patients.

BACKGROUND. Recombinant human PDGF-BB (rhPDGF-BB) reduces Parkinsonian symptoms and increases dopamine transporter (DAT) binding in several animal models of Parkinson's disease (PD). Effects of rhPDGF-BB are the result of proliferation of ventricular wall progenitor cells and reversed by blocking mitosis. Based on these restorative effects, we assessed the safety and tolerability of intracerebroventricular (i.c.v.) rhPDGF-BB administration in individuals with PD. METHODS. We conducted a double-blind, randomized, placebo-controlled phase I/IIa study at two clinical centers in Sweden. Twelve patients with moderate PD received rhPDGF-BB via an implanted drug infusion pump and an investigational i.c.v. catheter. Patients were assigned to a dose cohort (0.2, 1.5, or 5 µg rhPDGF-BB per day) and then randomized to active treatment or placebo (3:1) for a 12-day treatment period. The primary objective was to assess safety and tolerability of i.c.v.-delivered rhPDGF-BB. Secondary outcome assessments included several clinical rating scales and changes in DAT binding. The follow-up period was 85 days. RESULTS. All patients completed the study. There were no unresolved adverse events. Serious adverse events occurred in three patients; however, these were unrelated to rhPDGF-BB administration. Secondary outcome parameters did not show dose-dependent changes in clinical rating scales, but there was a positive effect on DAT binding in the right putamen. CONCLUSION. At all doses tested, i.c.v. administration of rhPDGF-BB was well tolerated. Results support further clinical development of rhPDGF-BB for patients with PD. TRIAL REGISTRATION. Clinical Trials.gov NCT00866502. FUNDING. Newron Sweden AB (former NeuroNova AB) and Swedish Governmental Agency for Innovation Systems (VINNOVA).

Intrathecal baclofen as adjuvant therapy to enhance the effect of spinal cord stimulation in neuropathic pain: a pilot study.

Only about 60-70% of well selected patients with neuropathic pain syndromes of peripheral origin enjoy sufficient pain relief with spinal cord stimulation (SCS). Since recent animal experiments have demonstrated that the GABA-B receptor is pivotal in the effect of SCS on certain neuropathic symptoms, the use of baclofen as an adjunct to stimulation emerged as an option in patients not responding satisfactorily to SCS. Forty-eight patients with neuropathic pain of peripheral origin responding poorly to SCS were enrolled in a study with intrathecal baclofen; in a few cases adenosine was also tried. Twenty patients reported significant pain reduction at bolus trials and were offered implantation of a drug pump. Seven patients subsequently had pumps implanted together with SCS and four had pumps alone. Three patients had only peroral baclofen therapy as an adjunct to SCS. The 14 patients continuing with baclofen therapy as an adjunct to SCS, or alone, were followed for an average of 35 months after pump implant. The group with SCS+pump n=5; 2 explanted) reported an average decrease of pain ratings from VAS 82 to 33. The group with i.t. baclofen only had a pain decrease from VAS 63 to 33, while the three patients with peroral baclofen+SCS had less benefit from drug therapy. Adjunctive drug therapy for patients with unsatisfactory pain relief by SCS may offer a possibility to enhance pain alleviation.

Implantation of laminotomy electrodes for spinal cord stimulation in spinal anesthesia with intraoperative dorsal column activation.

OBJECTIVE: To optimize the technique of implanting laminotomy plate electrodes for spinal cord stimulation and to minimize the discomfort of the patients during surgery. This operation is often performed while the patient is under local anesthesia, which is very stressful for the patient, or under general anesthesia, which precludes the use of test stimulation. An alternative approach is to perform the implantation with a spinal anesthetic and to examine whether stimulation-induced paresthesiae can still be evoked to guide the positioning of the electrode. METHODS: Spinal anesthesia was induced by bupivacaine (12.5-20 mg), which produced complete motor block and anesthesia up to a midthoracic level. After a single-level laminotomy (thoracic vertebrae 9-11) a four-pole plate electrode was inserted into the epidural space. Stimulation was applied with commonly used parameters, and the electrode was positioned so that the paresthesiae covered the painful region. RESULTS: In 19 patients (20 procedures) with different forms of neuropathic pain, implantation of laminotomy plate electrodes could be performed under spinal anesthesia without problems. In all patients, it was possible to evoke paresthesiae, the distribution of which could be reproduced postoperatively. The paresthesia thresholds during surgery were only moderately higher than those recorded after implantation (mean, 3.1 versus 2.1 V, respectively). During an interview after the intervention, no patient reported that he or she had experienced surgery as painful or uncomfortable. CONCLUSION: Implantation of laminotomy electrodes can be performed conveniently with spinal anesthesia because it minimizes discomfort for the patient and enables the use of intraoperative test stimulation to guide the positioning of the electrode. In spite of the total motor block and anesthesia, paresthesiae representing the activation of the dorsal columns can be evoked and are well perceived, and the thresholds are not abnormally high. This observation supports the notion that the subarachnoidal anesthetic agent acts predominantly on the spinal rootlets rather than on the spinal afferent pathways.

Targeted delivery of nerve growth factor via encapsulated cell biodelivery in Alzheimer disease: a technology platform for restorative neurosurgery.

OBJECT: The authors describe the first clinical trial with encapsulated cell biodelivery (ECB) implants that deliver nerve growth factor (NGF) to the cholinergic basal forebrain with the intention of halting the degeneration of cholinergic neurons and the associated cognitive decline in patients with Alzheimer disease (AD). The NsG0202 implant (NsGene A/S) consists of an NGF-producing, genetically engineered human cell line encapsulated behind a semipermeable hollow fiber membrane that allows the influx of nutrients and the efflux of NGF. The centimeter-long capsule is attached to an inert polymer tether that is used to guide the capsule to the target via stereotactic techniques and is anchored to the skull at the bur hole. METHODS: Six patients with mild to moderate AD were included in this Phase Ib open-label safety study and were divided into 2 dose cohorts. The first cohort of 3 patients received single implants targeting the basal nucleus of Meynert (Ch4 region) bilaterally (2 implants per patient), and after a safety evaluation, a second cohort of 3 patients received bilateral implants (a total of 4 implants per patient) targeting both the Ch4 region and the vertical limb of the diagonal band of Broca (Ch2 region). Stereotactic implantation of the devices was successfully accomplished in all patients. Despite extensive brain atrophy, all targets could be reached without traversing sulci, the insula, or lateral ventricles. RESULTS: Postoperative CT scans allowed visualization of the barium-impregnated tethers, and fusion of the scans with stereotactic MR images scan was used to verify the intended positions of the implants. Follow-up MRI at 3 and 12 months postimplantation showed no evidence of inflammation or device displacement. At 12 months, implants were successfully retrieved, and low but persistent NGF secretion was detected in half of the patients. CONCLUSIONS: With refinement, the ECB technology is positioned to become an important therapeutic platform in restorative neurosurgery and, in combination with other therapeutic factors, may be relevant for the treatment of a variety of neurological disorders. Clinical trial registration no.: NCT01163825.