Transcranial direct current stimulation in Parkinson's disease dementia: A randomised double-blind crossover trial

The Effect of Adding Transcranial Direct Current Stimulation to Hyperbaric Oxygen Therapy in Patients With Delayed Encephalopathy After Carbon Monoxide Poisoning: A Randomised Controlled Trial

Objective: To investigate the effect of transcranial direct current stimulation (tDCS) combined with hyperbaric oxygen therapy (HBOT) in patients with delayed encephalopathy after carbon monoxide poisoning (DEACMP).

Design: A parallel-group, open-label randomised controlled study.

Setting: Hyperbaric Oxygen Therapy Room of the Second Hospital of Hebei Medical University.

Subjects: A total of 40 patients were recruited for the current study. Patients were randomly divided into a treatment group and a control group (20 cases/group).

Interventions: Control group: conventional, individualised rehabilitation therapy. Treatment group: conventional, individualised rehabilitation therapy and tDCS.

Main Measures: cognitive function of patients, the Barthel Index (BI).

Results: After treatment, significantly higher MMSE and BI scores, as well as a greater reduction in P300 latency and an increase in P300 amplitude, were observed in the treatment group compared to the control group (MMSE: 13 ± 7 vs. 9 ± 5; P300 latency: 342 ± 29 vs. 363 ± 17 ms; P300 amplitude: 7.0 ± 3.3 vs. 5.1 ± 2.7 μV; all P < 0.05). In both groups, however, MMSE and BI scores, in addition to P300 amplitude, were significantly improved; in contrast, there was a decrease in P300 latency in both groups after treatment compared to before treatment (all P < 0.05).

Conclusion: Combined with HBOT, tDCS can help improve cognitive function and ADL in patients with DEACMP. This combination therapy might be a helpful method to enhance the recovery of patients with DEACMP.

Pharmacological management of dementia with Lewy bodies with a focus on zonisamide for treating parkinsonism

INTRODUCTION

Dementia with Lewy bodies (DLB) has no approved symptomatic or disease-modifying treatments in the US and Europe, despite being the second most common cause of neurodegenerative dementia.

AREAS COVERED

Herein, the authors briefly review the DLB drug development pipeline, providing a summary of the current pharmacological intervention studies. They then focus on the anticonvulsant zonisamide, a benzisoxazole derivative with a sulfonamide group and look at its value for treating parkinsonism in DLB.

EXPERT OPINION

Several new compounds are being tested in DLB, the most innovative being those aimed at decreasing brain accumulation of α-synuclein. Unfortunately, new drug testing is challenging in terms of consistent diagnostic criteria and lack of reliable biomarkers. Few randomized controlled trials (RCTs) are well-designed, with enough power to detect significant drug effects. Levodopa monotherapy can treat the parkinsonism in DLB, but it can cause agitation or visual hallucination worsening. Two Phase II/III RCTs of DLB patients recently reported a statistically significant improvement in motor function in those receiving zonisamide as an adjunctive treatment to levodopa. New biomarker strategies and validated outcome measures for DLB or prodromal DLB may enhance clinical trial design for the development of specific disease-modifying treatments.

Non-invasive brain stimulation for Parkinson's disease: Clinical evidence, latest concepts and future goals: A systematic review

Parkinson's disease (PD) is becoming a major public-health issue in an aging population. Available approaches to treat advanced PD still have limitations; new therapies are needed. The non-invasive brain stimulation (NIBS) may offer a complementary approach to treat advanced PD by personalized stimulation. Although NIBS is not as effective as the gold-standard levodopa, recent randomized controlled trials show promising outcomes in the treatment of PD symptoms. Nevertheless, only a few NIBS-stimulation paradigms have shown to improve PD's symptoms. Current clinical recommendations based on the level of evidence are reported in Table 1 through Table 3. Furthermore, novel technological advances hold promise and may soon enable the non-invasive stimulation of deeper brain structures for longer periods.

Tolerability and Blinding of Transcranial Direct Current Stimulation in People with Parkinson's Disease: A Critical Review

Transcranial direct current stimulation (tDCS) is accompanied by transient sensations (e.g., tingling, itching, burning), which may affect treatment outcomes or break the blinding of the study protocol. Assessing tolerability and blinding is integral to providing ample evidence of a "real effect" from the applied stimulation and dispelling the possibility of placebo effects. People with Parkinson's disease (PwPD) endure many motor and non-motor symptoms that might be amenable to tDCS. However, because the disease also affects sensation capabilities, these subjects might report tolerability and blinding differently than other cohorts. Therefore, the purpose of this review was to aggregate the tolerability and blinding reports of tDCS studies in PwPD and recommend a standard tolerability and blinding reporting practice. A literature search of the PubMed and Scopus databases from 1 January 2020 to 1 April 2020 was performed to identify publications that applied tDCS to PwPD. Seventy studies were potentially reviewable, but only 36 (nine with quantitative tolerability reports, 20 with qualitative tolerability reports, and seven that only reported blinding) provided sufficient information to be included in the review. Quantitative information on tDCS tolerability and blinding maintenance in PwPD is scarce, and future reviews and metanalyses should carefully consider the possibility of placebo effects in their included studies.

Non-invasive Transcranial Electrical Stimulation in Movement Disorders

Dysfunction within large-scale brain networks as the basis for movement disorders is an accepted hypothesis. The treatment options for restoring network function are limited. Non-invasive brain stimulation techniques such as repetitive transcranial magnetic stimulation are now being studied to modify the network. Transcranial electrical stimulation (tES) is also a portable, cost-effective, and non-invasive way of network modulation. Transcranial direct current stimulation and transcranial alternating current stimulation have been studied in Parkinson’s disease, dystonia, tremor, and ataxia. Transcranial pulsed current stimulation and transcranial random noise stimulation are not yet studied enough. The literature in the use of these techniques is intriguing, yet many unanswered questions remain. In this review, we highlight the studies using these four potential tES techniques and their electrophysiological basis and consider the therapeutic implication in the field of movement disorders. The objectives are to consolidate the current literature, demonstrate that these methods are feasible, and encourage the application of such techniques in the near future.

New evidence on the management of Lewy body dementia

Dementia with Lewy bodies and Parkinson's disease dementia, jointly known as Lewy body dementia, are common neurodegenerative conditions. Patients with Lewy body dementia present with a wide range of cognitive, neuropsychiatric, sleep, motor, and autonomic symptoms. Presentation varies between patients and can vary over time within an individual. Treatments can address one symptom but worsen another, which makes disease management difficult. Symptoms are often managed in isolation and by different specialists, which makes high-quality care difficult to accomplish. Clinical trials and meta-analyses now provide an evidence base for the treatment of cognitive, neuropsychiatric, and motor symptoms in patients with Lewy body dementia. Furthermore, consensus opinion from experts supports the application of treatments for related conditions, such as Parkinson's disease, for the management of common symptoms (eg, autonomic dysfunction) in patients with Lewy body dementia. However, evidence gaps remain and future clinical trials need to focus on the treatment of symptoms specific to patients with Lewy body dementia.

Consecutive sessions of transcranial direct current stimulation do not remediate visual hallucinations in Lewy body dementia: a randomised controlled trial

BACKGROUND

Complex visual hallucinations are common in Lewy body dementia (LBD) and can cause significant patient and caregiver distress. Current treatments are primarily pharmacological in nature and have limited efficacy and associated side effects. The objective of this study was to assess the effects of consecutive sessions of transcranial direct current stimulation (tDCS) on visual hallucination frequency and severity in LBD, at short-term and long-term follow-up stages.

METHODS

The study was a randomised, double-blind, placebo-controlled trial involving 40 participants with LBD (Mage = 75.52 years, SDage = 8.69 years) which was conducted at a single site between November 2013 and December 2017. Participants received two consecutive 20-min sessions of active (0.048 mA/cm2) or placebo tDCS, separated by a 30-min break, over 5 consecutive days. The anodal electrode was applied to the right parietal cortex (P4) and the cathodal electrode was applied to the occipital cortex (Oz). The primary outcome measure was the Neuropsychiatric Inventory (NPI) hallucinations subscale, as completed by a caregiver/informant at baseline and day 5 (short-term) follow-up, and month 1 and month 3 (long-term) follow-up. Secondary outcome measures included visual cortical excitability, as measured using transcranial magnetic stimulation, computerised attentional and visuoperceptual tasks, and measures of global cognition and cognitive fluctuations.

RESULTS

Complete study data were obtained from 36 participants. There was an overall improvement in visual hallucinations (NPI) for both groups at day 5 relative to baseline, with a medium-to-large effect size; however, compared to placebo, active tDCS did not result in any improvements in visual hallucinations (NPI) at day 5 relative to baseline, or at month 1 or month 3 follow-up time points. Additionally, comparisons of secondary outcome measures showed that active tDCS did not result in any improvements on any measure (visual cortical excitability, attentional and visuoperceptual tasks or cognitive measures) at any time point.

CONCLUSIONS

Repeated consecutive sessions of parietal anodal tDCS, and occipital cathodal tDCS, do not improve visual hallucinations or visuoperceptual function, or alter visual cortical excitability in LBD.

TRIAL REGISTRATION

ISRCTN, ISRCTN40214749 . Registered on 25 October 2013.