Impaired cholinergic integrity of the colon and pancreas in dementia with Lewy bodies

Dementia with Lewy bodies is characterized by a high burden of autonomic dysfunction and Lewy pathology in peripheral organs and components of the sympathetic and parasympathetic nervous system. Parasympathetic terminals may be quantified with 18F-fluoroetoxybenzovesamicol, a PET tracer that binds to the vesicular acetylcholine transporter in cholinergic presynaptic terminals. Parasympathetic imaging may be useful for diagnostics, improving our understanding of autonomic dysfunction and for clarifying the spatiotemporal relationship of neuronal degeneration in prodromal disease. Therefore, we aimed to investigate the cholinergic parasympathetic integrity in peripheral organs and central autonomic regions of subjects with dementia with Lewy bodies and its association with subjective and objective measures of autonomic dysfunction. We hypothesized that organs with known parasympathetic innervation, especially the pancreas and colon, would have impaired cholinergic integrity. To achieve these aims, we conducted a cross-sectional comparison study including 23 newly diagnosed non-diabetic subjects with dementia with Lewy bodies (74 ± 6 years, 83% male) and 21 elderly control subjects (74 ± 6 years, 67% male). We obtained whole-body images to quantify PET uptake in peripheral organs and brain images to quantify PET uptake in regions of the brainstem and hypothalamus. Autonomic dysfunction was assessed with questionnaires and measurements of orthostatic blood pressure. Subjects with dementia with Lewy bodies displayed reduced cholinergic tracer uptake in the pancreas (32% reduction, P = 0.0003) and colon (19% reduction, P = 0.0048), but not in organs with little or no parasympathetic innervation. Tracer uptake in a region of the medulla oblongata overlapping the dorsal motor nucleus of the vagus correlated with autonomic symptoms (rs = -0.54, P = 0.0077) and changes in orthostatic blood pressure (rs = 0.76, P < 0.0001). Tracer uptake in the pedunculopontine region correlated with autonomic symptoms (rs = -0.52, P = 0.0104) and a measure of non-motor symptoms (rs = -0.47, P = 0.0230). In conclusion, our findings provide the first imaging-based evidence of impaired cholinergic integrity of the pancreas and colon in dementia with Lewy bodies. The observed changes may reflect parasympathetic denervation, implying that this process is initiated well before the point of diagnosis. The findings also support that cholinergic denervation in the brainstem contributes to dysautonomia.

A study of the reliability and validity of the Six-Spot Step Test Cognitive in ambulatory persons with Parkinson's disease

INTRODUCTION

Although dual-task walking deficits challenge ambulatory function in persons with Parkinson's disease (PwPD), ambulation measures that incorporate cognitive dual-task loads seem scarce. In its construct and instruction, the Six-Spot Step Test Cognitive (SSSTcog) ensures an equal focus on cognitive and motor tasks. The present study investigated the construct validity and test-retest reliability of the SSSTcog in PwPD.

METHODS

Seventy-eight PwPD were recruited from outpatient clinics. The SSSTcog was completed twice within the same day and again three to seven days later. In addition, the cognitive Timed "Up and Go" test (TUGcog) and the Mini-BESTest were also conducted on the last day. Reliability and validity were estimated using Bland-Altman statistics, the minimal difference (MD), Intraclass Correlation Coefficient (ICC), and Spearman's rank correlation coefficient (ρ).

RESULTS

The SSSTcog was found reliable (ICC: 0.84-0.89; MD: 23.7%-30.2%) and showed moderate construct validity to the TUGcog (ρ = 0.62, p < 0.001). Weak correlations to the Mini-BESTest (ρ = -0.33, p < 0.003) indicated low construct validity. Significantly (p < 0.001) higher dual-task costs were seen when performing the SSSTcog (77.6%) compared to the TUGcog (24.3%).

CONCLUSIONS

In PwPD, the SSSTcog showed promising construct validity, acceptable to excellent reliability, making it a valid measure of functional mobility, including cognitive dual-tasking. Higher dual-task cost for the SSSTcog indicated actual cognitive-motor interference while performing the test.

Spinal cord stimulation therapy for patients with Parkinson's disease and gait problems (STEP-PD): study protocol for an exploratory, double-blind, randomised, placebo-controlled feasibility trial

Introduction

Gait difficulties are common in Parkinson's disease (PD) and cause significant disability. These symptoms are often resistant to treatment. Spinal cord stimulation (SCS) has been found to improve gait, including freezing of gait, in a small number of patients with PD. The mechanism of action is unclear, and some patients are non-responders. With this double-blind, placebo-controlled efficacy and feasibility clinical and imaging study, we aim to shed light on the mechanism of action of SCS and collect data to inform development of a scientifically sound clinical trial protocol. We also aim to identify clinical and imaging biomarkers at baseline that could be predictive of a favourable or a negative outcome of SCS and improve patient selection.

Methods and analysis

A total of 14 patients will be assessed with clinical rating scales and gait evaluations at baseline, and at 6 and 12 months after SCS implantation. They will also receive serial ¹⁸F-deoxyglucose and ¹⁸FEOBV PET scans to assess the effects of SCS on cortical/subcortical activity and brain cholinergic function. The first two patients will be included in an open pilot study while the rest will be randomised to receive active treatment or placebo (no stimulation) for 6 months. From this point, the entire cohort will enter an open label active treatment phase for a subsequent 6 months.

Ethics and dissemination

This study was reviewed and approved by the Committee on Health Research Ethics, Central Denmark RM. It is funded by the Danish Council for Independent Research. Independent of outcome, the results will be published in peer-reviewed journals and presented at national and international conferences.

Trial registration number

NCT05110053; ClinicalTrials.gov Identifier.

STN-DBS affects language processing differentially in Parkinson's disease: Multiple-case MEG study

OBJECTIVES

In this study, we investigated the effects of bilateral and unilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) in PD patients on neural responses associated with two aspects of spoken language processing: semantics of action-related verbs and morphosyntactic processing.

MATERIALS AND METHODS

Using a passive unattended paradigm to present spoken linguistic stimuli, we recorded magnetoencephalographic (MEG) responses in three PD patients in four DBS conditions: left unilateral STN-DBS, right unilateral STN-DBS, bilateral STN-DBS, and no STN-DBS. To ensure that any observed effects of DBS on the neuromagnetic responses could be attributed to the linguistic context per se and were not merely induced by the electrical stimulation, we assessed the effects of STN-DBS on linguistic contrasts within each stimulation condition. Hence, we contrasted the processing of action vs. abstract verbs as well as the processing of correct vs. incorrect morphosyntactic inflections within each DBS condition.

RESULTS

The results revealed that, compared to the DBS-off state, both bilateral and right unilateral stimulation of the STN yielded significant dissociations in the processing of action and abstract verbs, with greater neuromagnetic responses for action verbs compared to abstract verbs. For morphosyntax processing, only left unilateral stimulation yielded significant dissociations (relative to the DBS-off state), with greater neuromagnetic responses to the incorrect inflections compared to the correct inflections.

CONCLUSION

The results reflect differential effects of unilateral and bilateral STN-DBS on neuromagnetic responses associated with the processing of spoken language. They suggest that different specific aspects of linguistic information processing in PD are affected differently by STN-DBS.

Prednisolone versus placebo addition in the treatment of patients with recent-onset psychotic disorder: a trial design

BACKGROUND

The symptom severity of a substantial group of schizophrenia patients (30-40%) does not improve through pharmacotherapy with antipsychotic medication, indicating a clear need for new treatment options to improve schizophrenia outcome. Meta-analyses, genetic studies, randomized controlled trials, and post-mortem studies suggest that immune dysregulation plays a role in the pathophysiology of schizophrenia. Some anti-inflammatory drugs have shown beneficial effects on the symptom severity of schizophrenia patients. Corticosteroids are effective in various chronic inflammatory and autoimmune disorders. Prednisolone, a potent glucocorticosteroid, has minor mineral-corticosteroid potencies and can adequately pass the blood-brain barrier and its side effects and safety profile are well known. Therefore, the effect of prednisolone can be studied as a proof of concept for immune modulation as a treatment for schizophrenia.

METHODS/DESIGN

In total, 90 subjects aged 18-70 years and diagnosed with schizophrenia, schizoaffective disorder, or schizophreniform disorder (Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) 295.x) or psychosis not otherwise specified (NOS; 298.9) will be included. The time interval between the onset of psychosis and study entry should not exceed 7 years. Patients will be randomized 1:1 to either prednisolone or placebo daily for a period of 6 weeks in addition to a stable dose of antipsychotic medication. Study medication will be initiated at 40 mg for 3 days, after which it will be tapered down within 6 weeks after initiation, following inflammatory bowel diseases treatment guidelines. Primary outcome is change in symptom severity, expressed as change in total score on the Positive and Negative Symptom Scale (PANSS) from baseline to end of treatment. Cognitive functioning (measured through the Brief Assessment of Cognition in Schizophrenia (BACS)) and change in Global Assessment Functioning (GAF) and depressive symptoms as measured with the Calgary Depression Scale for Schizophrenia (CDS) will be assessed, in addition to various immunological biomarkers. Secondary outcomes are a 4- and 6-month follow-up assessment of PANSS, BACS, and GAF scores and immunological biomarkers. Additionally, a subgroup of patients will be included in the magnetic resonance imaging (MRI) part of the study where MR spectroscopy and structural, functional, and diffusion MRI will be conducted.

DISCUSSION

It is expected that prednisolone addition to current antipsychotic medication use will reduce symptom severity and will improve cognition when compared to placebo.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02949232 and NCT03340909. Registered 31 October 2016 and 14 November 2017. EudraCT-number 2014-000520-14 and 2017-000163-32.

Surviving 10 years with deep brain stimulation for Parkinson's disease--a follow-up of 79 patients

BACKGROUND AND PURPOSE

Deep brain stimulation (DBS) for severe Parkinson's disease (PD) outperforms the best medical treatment in controlling motor symptoms and improving quality of life. Nevertheless disease progression cannot be controlled, and the development of dementia over time is nearly inevitable, often resulting in nursing home placement. Ten-year survival, development of hallucinations, dementia and nursing home placement were examined and adverse events were assessed.

METHOD

Patient files were scrutinized from baseline up to 10 years of treatment or death on all 79 PD patients treated with DBS of the subthalamic nucleus from 1998 to 2003 at Aarhus University Hospital.

RESULTS

Twenty-four patients died during the follow-up period of 10 years. Age above 60 years at surgery increased mortality 2.3-fold (P = 0.04). Of the 55 surviving patients 29 (53%) were demented and 19 (35%) were in nursing homes. Average time from operation to dementia was 5.6 ± 2.9 years. Hallucinations and nursing home placement were associated with increased mortality.

CONCLUSION

Survival of 70% after a mean of 25 years of PD including 10 years with DBS illustrates that this is a selected group of PD patients. The prevalence of dementia steadily increased after surgery as expected from disease progression and can be an early event. Compared with the few similar long-term studies, the present study presents a larger cohort followed at the same DBS center for a longer period of time and none was lost to follow-up, making conclusions more valid. The present findings are of significant prognostic help for the patient, caregiver and physician when treatment with DBS has to be decided.

MRI verified STN stimulation site--gait improvement and clinical outcome

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective in alleviating Parkinson's disease (PD) symptoms (tremor, rigidity and bradykinesia) and may improve gait and postural impairment associated with the disease. However, improvement of gait is not always as predictable as the clinical outcome. This may relate to the type of gait impairment or localization of the active DBS contact.

METHODS

The active contact was visualized on peri-operative magnetic resonance imaging in 22 patients with idiopathic PD, consecutively treated with bilateral STN DBS. Stimulation site was grouped as either in the dorsal/ventral STN or medial/lateral hereof and anterior/posterior STN or medial/lateral hereof. The localization was compared with relative improvement of clinical outcome (UPDRS-III). In 10 patients, quantitative gait analyses were performed, and the improvement in gait performance was compared with stimulation site in the STN.

RESULTS

Of 44 active contacts, 77% were inside the nucleus, 23% were medial hereof. Stimulation of the dorsal half improved UPDRS-III significantly more than ventral STN DBS (P = 0.02). However, there were no differences between anterior and posterior stimulation in the dorsal STN. Step velocity and length improved significantly more with dorsal stimulation compared with ventral stimulation (P = 0.03 and P = 0.02). Balance during gait was also more improved with dorsal stimulation compared with ventral stimulation.

CONCLUSIONS

Deep brain stimulation of the dorsal STN is superior to stimulation of the ventral STN. Possible different effects of stimulation inside the nucleus underline the need for exact knowledge of the active stimulation site position to target the most effective area.

Improved asymmetry of gait in Parkinson's disease with DBS: gait and postural instability in Parkinson's disease treated with bilateral deep brain stimulation in the subthalamic nucleus

Postural instability is a sign of progression of Parkinson's disease (PD) and often resistant to levodopa treatment. To explore the effect of bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on postural stability and gait, full body gait analyses were performed without medication, OFF and ON DBS in eight PD patients and 12 healthy age-matched controls. DBS setting was changed at least 3 hours before gait analysis. To describe asymmetry most and least affected sides (MAS and LAS) were rated with the Unified Parkinson's Disease Rating Scale, motor part and quantitative gait analysis with the Vicon 612 gait analysis system. Stride length and gait velocity but not cadence improved ON DBS. The distances between the heel markers and center of mass (COM) were asymmetric and reduced OFF DBS. STN DBS increased the distances significantly and reduced asymmetry. The improvement in heel to COM distance was larger on the MAS compared with the LAS. OFF DBS knee momentum asymmetry was inversed so that LAS was more impaired than MAS. ON DBS asymmetry improved. PD patients OFF DBS place the heel too close to COM. The most affected body side has the most impaired swing and the result is a smaller knee moment on the opposite and least affected body side and an asymmetric gait pattern with disturbed balance OFF STN DBS. The asymmetry OFF DBS improved ON DBS. We suggest that DBS facilitates symmetric gait and thereby improves balance during gait.

Contributions of imagery ability to stress and relaxation

This study examined the contribution of imagery ability to psychological and physiological responses to stress and relaxation. Individuals (N = 176) participated in two study sessions. In the first session, participants completed the Creative Imagination Scale and were block-randomized to a stress or relaxation condition based on imaging scores. During the second session, stress and mood were assessed before and after participants watched a stressful movie or listened to a relaxation tape. Finger temperature was monitored during the interventions. Changes in temperature and in self-reports of stress and mood indicated that the manipulations were effective. In comparison to low imagers, high imagers reported greater stress after the movie and less stress and negative affect after the relaxation tape. Imagery ability predicted neither levels of negative affect following the stress condition nor changes in positive affect or temperature during the interventions. In the stress condition, expectations of stress partially mediated the relation between imagery ability andpsychological stress. In contrast, expectations of relaxation did not significantly predict responses to the relaxation intervention. These findings suggest that imagery ability is related to greater subjective responses to both stress and relaxation and that, in stressful situations, expectancies may account for some of the effects of imagery ability on perceived stress.