Optimizing Noninvasive Vagus Nerve Stimulation for Systemic Lupus Erythematosus: Protocol for a Multicenter Randomized Controlled Trial.

BACKGROUND: Systemic lupus erythematosus is a chronic, multisystem, inflammatory disease of autoimmune etiology occurring predominantly in women. A major hurdle to the diagnosis, treatment, and therapeutic advancement of this disease is its heterogeneous nature, which presents as a wide range of symptoms such as fatigue, fever, musculoskeletal involvement, neuropsychiatric disorders, and cardiovascular involvement with varying severity. The current therapeutic approach to this disease includes the administration of immunomodulatory drugs that may produce unfavorable secondary effects. OBJECTIVE: This study explores the known relationship between the autonomic nervous system and inflammatory pathways to improve patient outcomes by treating autonomic nervous system dysregulation in patients via noninvasive vagus nerve stimulation. In this study, data including biomarkers, physiological signals, patient outcomes, and patient quality of life are being collected and analyzed. After completion of the clinical trial, a computer model will be developed to identify the biomarkers and physiological signals related to lupus activity in order to understand how they change with different noninvasive vagus nerve stimulation frequency parameters. Finally, we propose building a decision support system with integrated noninvasive wearable technologies for continuous cardiovascular and peripheral physiological sensing for adaptive, patient-specific optimization of the noninvasive vagus nerve stimulation frequency parameters in real time. METHODS: The protocol was designed to evaluate the efficacy and safety of transauricular vagus nerve stimulation in patients with systemic lupus erythematosus. This multicenter, national, randomized, double-blind, parallel-group, placebo-controlled study will recruit a minimum of 18 patients diagnosed with this disease. Evaluation and treatment of patients will be conducted in an outpatient clinic and will include 12 visits. Visit 1 consists of a screening session. Subsequent visits up to visit 6 involve mixing treatment and evaluation sessions. Finally, the remaining visits correspond with early and late posttreatment follow-ups. RESULTS: On November 2022, data collection was initiated. Of the 10 participants scheduled for their initial appointment, 8 met the inclusion criteria, and 6 successfully completed the entire protocol. Patient enrollment and data collection are currently underway and are expected to be completed in December 2023. CONCLUSIONS: The results of this study will advance patient-tailored vagus nerve stimulation therapies, providing an adjunctive treatment solution for systemic lupus erythematosus that will foster adoption of technology and, thus, expand the population with systemic lupus erythematosus who can benefit from improved autonomic dysregulation, translating into reduced costs and better quality of life. TRIAL REGISTRATION: ClinicalTrials.gov NCT05704153; https://clinicaltrials.gov/study/NCT05704153. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48387.

Diabetic Neuropathy Is Independently Associated With Worse Graft Outcomes and Incident Cardiovascular Disease After Pancreas Transplantation: A Retrospective Cohort Study in Type 1 Diabetes.

BACKGROUND: Information about the impact of diabetic neuropathy (DN) on outcomes after pancreas transplantation (PT) is scarce. We assessed the independent relationship between DN markers with both graft survival and incident cardiovascular disease (CVD) after transplantation. METHODS: A cohort study in individuals with type 1 diabetes and end-stage kidney disease who underwent PT between 1999 and 2015 was conducted. DN was assessed with vibration perception thresholds (VPTs) and orthostatic hypotension (pre-PT and 6 mo, 2-3, 5-6, and 8-10 y after transplantation). Pretransplantation and posttransplantation DN markers were related with graft failure/dysfunction and incident CVD during follow-up. RESULTS: We included 187 participants (70% men, age 39.9 ± 7.1 y, diabetes duration 27.1 y), with a median follow-up of 11.3 y. Abnormal VPTs (≥25 V) were observed in 53%. After transplantation, VPTs improved (22.4 ± 8.4 pretransplant versus 16.1 ± 6.1 V at 8-10 y post-PT; P < 0.001); additionally, the prevalence of abnormal VPTs decreased (53% pretransplant versus 24.4% at 8-10 y; P < 0.001). After adjusting for age, sex, diabetes duration, blood pressure, body mass index, and previous CVD, pretransplant VPTs ≥25 V were independently associated with pancreas graft failure/dysfunction (hazard ratio [HR], 2.01 [1.01-4.00]) and incident CVD (HR, 2.57 [1.17-5.64]). Furthermore, persistent abnormal VPTs after 6 mo posttransplantation were associated with the worst outcomes (HR, 2.80 [1.25-6.23] and HR, 3.19 [1.14-8.96], for graft failure/dysfunction and incident CVD, respectively). CONCLUSIONS: In individuals with type 1 diabetes and end-stage kidney disease, PT was associated with an improvement of VPTs. This simple and widely available DN study was independently associated with pancreas graft function and CVD posttransplantation.

Diagnosing Premotor Multiple System Atrophy: Natural History and Autonomic Testing in an Autopsy-Confirmed Cohort.

BACKGROUND AND OBJECTIVES: Nonmotor features precede motor symptoms in many patients with multiple system atrophy (MSA). However, little is known about differences between the natural history, progression, and prognostic factors for survival in patients with MSA with nonmotor vs motor presentations. We aimed to compare initial symptoms, disease progression, and clinical features at final evaluation and investigate differences in survival and natural history between patients with MSA with motor and nonmotor presentations. METHODS: Medical records of autopsy-confirmed MSA cases at Queen Square Brain Bank who underwent both clinical examination and cardiovascular autonomic testing were identified. Clinical features, age at onset, sex, time from onset to diagnosis, disease duration, autonomic function tests, and plasma noradrenaline levels were evaluated. RESULTS: Forty-seven patients with autopsy-confirmed MSA (age 60 ± 8 years; 28 men) were identified. Time from symptom onset to first autonomic evaluation was 4 ± 2 years, and the disease duration was 7.7 ± 2.2 years. Fifteen (32%) patients presented with nonmotor features including genitourinary dysfunction, orthostatic hypotension, or REM sleep behavior disorder before developing motor involvement (median delay 1-6 years). A third (5/15) were initially diagnosed with pure autonomic failure (PAF) before evolving into MSA. All these patients had normal supine plasma noradrenaline levels (332.0 ± 120.3 pg/mL) with no rise on head-up tilt (0.1 ± 0.3 pg/mL). Patients with MSA with early cardiovascular autonomic dysfunction (within 3 years of symptom onset) had shorter survival compared with those with later onset of cardiovascular autonomic impairment (6.8 years [5.6-7.9] vs 8.5 years [7.9-9.2]; p = 0.026). Patients with early urinary catheterization had shorter survival than those requiring catheterization later (6.2 years [4.6-7.8] vs 8.5 years [7.6-9.4]; p = 0.02). The survival of patients with MSA presenting with motor and nonmotor symptoms did not differ (p > 0.05). DISCUSSION: Almost one-third of patients with MSA presented with nonmotor features, which could predate motor symptoms by up to 6 years. Cardiovascular autonomic failure and early urinary catheterization were predictors of poorer outcomes. A normal supine plasma noradrenaline level in patients presenting with PAF phenotype is a possible autonomic biomarker indicating later conversion to MSA.

Acute lumbar polyradiculoneuropathy as early sign of methotrexate intrathecal neurotoxicity: Case report and literature review.

Acute paraplegia after treatment with intrathecal methotrexate requires a complete spinal cord neuroimaging as well as electrodiagnostic examination. The absence of lumbosacral F waves motor responses without demyelinating findings may indicate early direct root toxicity. Early electromyography (EMG) screening could be a valuable tool for detecting peripheral neurotoxicity.

Motor preparation in picture naming tasks.

In certain circumstances, words can be uttered as an involuntary action. We hypothesize that, once pronunciation of a word is fully prepared it can be triggered as a reflex with no need for cortical processing. We used modified protocols of picture naming tasks, with different levels of cognitive demands, to measure reaction time to word pronunciation (RTWP). In test trials, picture presentation was accompanied by a startling auditory stimulus (SAS). When one and the same picture was repeatedly shown, SAS shortened RTWP by about 30% (StartReact effect), which did not occur when random pictures were shown. If subjects were led to learn which picture was to appear after repeated presentation of three pictures in sequence, they exhibited again the StartReact effect. We conclude that word pronunciation may be fully prepared for execution in absence of cognitive demands. However, the StartReact effect is inhibited during cognitive tasks.

The endocannabinoid system in cardiovascular function: novel insights and clinical implications.

RATIONALE: Cardiovascular disease is now recognized as the number one cause of death in the world, and the size of the population at risk continues to increase rapidly. The dysregulation of the endocannabinoid (eCB) system plays a central role in a wide variety of conditions including cardiovascular disorders. Cannabinoid receptors, their endogenous ligands, as well as enzymes conferring their synthesis and degradation, exhibit overlapping distributions in the cardiovascular system. Furthermore, the pharmacological manipulation of the eCB system has effects on blood pressure, cardiac contractility, and endothelial vasomotor control. Growing evidence from animal studies supports the significance of the eCB system in cardiovascular disorders. OBJECTIVE: To summarize the literature surrounding the eCB system in cardiovascular function and disease and the new compounds that may potentially extend the range of available interventions. RESULTS: Drugs targeting CB1R, CB2R, TRPV1 and PPARs are proven effective in animal models mimicking cardiovascular disorders such as hypertension, atherosclerosis and myocardial infarction. Despite the setback of two clinical trials that exhibited unexpected harmful side-effects, preclinical studies are accelerating the development of more selective drugs with promising results devoid of adverse effects. CONCLUSION: Over the last years, increasing evidence from basic and clinical research supports the role of the eCB system in cardiovascular function. Whereas new discoveries are paving the way for the identification of novel drugs and therapeutic targets, the close cooperation of researchers, clinicians and pharmaceutical companies is needed to achieve successful outcomes.

Enteric nervous system α-synuclein immunoreactivity in idiopathic REM sleep behavior disorder.

OBJECTIVE: To investigate the expression of α-synuclein in colonic biopsies of patients with idiopathic REM sleep behavior disorder (iRBD) and address if α-synuclein immunostaining of tissue obtained via colonic biopsies holds promise as a diagnostic biomarker for prodromal Parkinson disease (PD). METHODS: Patients with iRBD, patients with PD, and healthy controls were prospectively recruited to undergo colonic biopsies for comparison of α-synuclein immunoreactivity patterns between the groups by using 2 different antibodies. RESULTS: There was no difference in colonic mucosal and submucosal immunostaining between groups using the 15G7 α-synuclein antibody, which was found in almost all participants enrolled in this study. By contrast, immunostaining for serine 129-phosphorylated α-synuclein (pSyn) in submucosal nerve fibers or ganglia was found in none of 14 controls but was observed in 4 of 17 participants with iRBD and 1 out of 19 patients with PD. CONCLUSIONS: The present findings of pSyn immunostaining of colonic biopsies in a substantial proportion of iRBD participants raise the possibility that this tissue marker may be a suitable candidate to study further as a prodromal PD marker in at-risk cohorts.

Alpha-synuclein immunoreactivity patterns in the enteric nervous system.

We aimed to compare immunoreactivity patterns of four different anti-α-syn antibodies in surgical specimens of the gastrointestinal tract of Parkinson disease and control cases. Surgical specimens from stomach, small and large bowel of 6 PD cases and 12 controls were studied. Primary antibodies: anti-α-syn clone KM51, anti-phosphorylated α-syn Ser129, anti-α-syn clone 15G7 and anti-nitrated α-syn505. We found different immunoreactivity patterns: (a) coarse, Lewy-body-like aggregates labelled by the 4 antibodies and detected in 4/6 PD cases and in 1/12 controls; (b) distinct punctate cytoplasmic staining of ganglion cells labelled by anti-phosphorylated-α-syn and detected in 3/6 PD cases and 3/12 controls; (c) fine diffuse, synaptic-type staining of neural structures labelled by anti-α-syn-15G7 and anti-nitrated-α-syn505 and detected in all subjects. We conclude that different specific and non-specific immunoreactivity patterns are detected in surgical specimens of gastrointestinal tract when using different anti-α-syn antibodies, as they recognize different epitopes and states of alpha-synuclein protein. Coarse aggregates in neural structures seem to be the most promising marker for the diagnosis of Lewy-body parkinsonism when evaluating abnormal α-syn in the gastrointestinal tract.

Cutaneous autonomic denervation in Parkinson's disease.

Numerous studies have detailed involvement of the peripheral autonomic nervous system (PANS) in Parkinson's disease (PD). We assessed autonomic innervation of dermal annexes through quantitative fluorescence measurement from skin obtained via punch biopsies at distal leg region in PD and control subjects. We defined a ratio between the area corresponding to protein gen product (PGP) immunoreactivity and the area corresponding to blood vessel or sweat gland as a quantitative measure of autonomic innervation. Presence of alpha-synuclein (AS) deposits in dermis and hypodermis was also assessed by immunohistochemistry. Skin biopsies form six PD patients and six healthy controls were studied. Autonomic innervation scores were lower in PD than in controls in both blood vessels and sweat glands. No AS or phosphorylated AS (pAS) immunoreactivity was detected in dermis or hypodermis in any of the studied subjects. The results of this investigation suggest that autonomic innervation of dermal annexes in living patients with PD is reduced compared to controls. AS or pAS deposits were not found in dermis or hypodermis suggesting that distal leg skin study is not useful for in vivo detection of AS in PD.

Multiple organ involvement by alpha-synuclein pathology in Lewy body disorders.

Lewy body (LB) diseases are characterized by alpha-synuclein (AS) aggregates in the central nervous system (CNS). Involvement of the peripheral autonomic nervous system (pANS) is increasingly recognized, although less studied. The aim of this study was to systematically analyze the distribution and severity of AS pathology in the CNS and pANS. Detailed postmortem histopathological study of brain and peripheral tissues from 28 brain bank donors (10 with Parkinson's disease [PD], 5 with dementia with LB [DLB], and 13 with non-LB diseases including atypical parkinsonism and non-LB dementia). AS aggregates were found in the pANS of all 15 LB disease cases (PD, DLB) in stellate and sympathetic ganglia (100%), vagus nerve (86.7%), gastrointestinal tract (86.7%), adrenal gland and/or surrounding fat (53.3%), heart (100%), and genitourinary tract (13.3%), as well as in 1 case of incidental Lewy body disease (iLBD). A craniocaudal gradient of AS burden in sympathetic chain and gastrointestinal tract was observed. DLB cases showed higher amounts of CNS AS aggregates than PD cases, but this was not the case in the pANS. No pANS AS aggregates were detected in Alzheimer's disease (AD) cases with or without CNS AS aggregates. All pathologically confirmed LB disease cases including 1 case of iLBD had AS aggregates in the pANS with a craniocaudal gradient of pathology burden in sympathetic chain and gastrointestinal tract. AS was not detected in the pANS of any AD case. These findings may help in the search of peripheral AS aggregates in vivo for the early diagnosis of PD.

Alpha-synuclein aggregates in epicardial fat tissue in living subjects without parkinsonism.

BACKGROUND: In Parkinson's disease (PD), alpha-synuclein (AS) aggregates occur frequently in peripheral autonomic nervous system (pANS). Their presence in asymptomatic subjects suggests incidental Lewy-body disease (iLBD) that is thought to reflect pre-clinical PD. Cardiac involvement has been detected in post-mortem studies in both, PD and also in iLBD. In vivo documentation of cardiac AS pathology is lacking. OBJECTIVE: To prospectively assess the presence of AS aggregates in epicardial fat tissue from living subjects without parkinsonism undergoing elective cardiac surgery. MATERIAL AND METHODS: Epicardial fat tissue obtained during cardiac surgery from 91 subjects was studied by histology and immunohistochemistry. Areas more likely to contain pANS elements were selected. PD-related motor and non-motor symptoms (NMS) were assessed immediately before or after surgery. RESULTS: Small autonomic nerves, ganglia and/or tyrosine-hydroxylase positive fibres were identified in epicardial fat in each of the 91 subjects (62 male/29 female, mean age 67 years). AS aggregates were detected in 7 subjects (7.7%), and were more frequent in those aged above 70 years. In AS-positive subjects constipation and acting dreams were significantly more frequent than in the AS-negative ones. CONCLUSION: AS aggregates occur in epicardial pANS in subjects without parkinsonism, suggesting the diagnosis of iLBD. The presence in some of these subjects of non-motor symptoms such as acting dreams and constipation known to occur in premotor PD supports this interpretation. Adequate follow-up of the subjects in this study will indicate the time, if any, to progression to motor PD.

Phenotypic variability within the inclusion body spectrum of basophilic inclusion body disease and neuronal intermediate filament inclusion disease in frontotemporal lobar degenerations with FUS-positive inclusions.

Basophilic inclusion body disease and neuronal intermediate filament inclusion disease (NIFID) are rare diseases included among frontotemporal lobar degenerations with FUS-positive inclusions (FTLD-FUS). We report clinical and pathologic features of 2 new patients and reevaluate neuropathologic characteristics of 2 previously described cases, including an early-onset case of basophilic inclusion body disease (aged 38 years) with a 5-year disease course and abundant FUS-positive inclusion bodies and 3 NIFID cases. One NIFID case (aged 37 years) presented with early-onset psychiatric disturbances and rapidly progressive cognitive decline. Two NIFID cases had later onset (aged 64 years and 70 years) and complex neurologic deficits. Postmortem neuropathologic studies in late-onset NIFID cases disclosed α-internexin-positive "hyaline conglomerate"-type inclusions that were positive with 1 commercial anti-FUS antibody directed to residues 200 and 250, but these were negative to amino acids 90 and 220 of human FUS. Early-onset NIFID had similar inclusions that were positive with both commercial anti-FUS antibodies. Genetic testing performed on all cases revealed no FUS gene mutations. These findings indicate that phenotypic variability in NIFID, including clinical manifestations and particular neuropathologic findings, may be related to the age at onset and individual differences in the evolution of lesions.