Multifocal repetitive TMS for motor and mood symptoms of Parkinson disease: A randomized trial

Repetitive transcranial magnetic stimulation therapy for motor recovery in Parkinson's disease: A Meta-analysis

INTRODUCTION

Therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on motor recovery of Parkinson's disease (PD) have been reported; however, the protocols of these studies varied greatly. The aim of this meta-analysis was to evaluate the optimal rTMS parameters for motor recovery of PD.

METHODS

Electronic databases were searched for studies investigating the therapeutic effects of rTMS on motor function in patients with PD. The section III of the Unified Parkinson's Disease Rating Scale (UPDRS) was extracted as the primary outcome, and the standardized mean difference (SMD) with 95% confidence interval (CI) was calculated.

RESULTS

Twenty-three studies with a total of 646 participants were included. The pooled estimates of rTMS revealed significant short-term (SMD, 0.37; p < 0.00001) and long-term (SMD, 0.39; p = 0.005) effects on motor function improvement of PD. Subgroup analysis observed that high-frequency rTMS (HF-rTMS) was significant in improving motor function (SMD, 0.48; p < 0.00001), but low-frequency rTMS (LF-rTMS) was not. In particular, when HF-rTMS targeted over the primary motor cortex (M1), in which the bilateral M1 revealed a larger effect size than unilateral M1. Compared to single-session, multi-session of HF-rTMS over the M1 showed significant effect size. In addition, HF-rTMS over the M1 with a total of 18,000-20,000 stimulation pulses yielded more significant effects (SMD, 0.97; p = 0.01) than other dosages.

CONCLUSIONS

In conclusion, multi-session of HF-rTMS over the M1 (especially bilateral M1) with a total of 18,000-20,000 pulses appears to be the optimal parameters for motor improvement of PD.

Repetitive Deep TMS for Parkinson Disease: A 3-Month Double-Blind, Randomized Sham-Controlled Study

PURPOSE

To study the effects of a repetitive deep transcranial magnetic stimulation (rDTMS) in patients with Parkinson disease using the H5 coil for the low-frequency stimulation of the primary motor cortex, followed by the high-frequency rDTMS of the prefrontal cortex.

METHODS

The main outcome measures were the total and motor scores of the Unified Parkinson's Disease Rating Scale (UPDRS). Secondary measures included rating of depression and quantitative motor tasks.

RESULTS

Forty-eight patients were randomized 1:1 into real or sham rDTMS treatment arms. Analyses (n = 42) of both UPDRS scores revealed a significant main effect for time between baseline and day 90 (end of treatment), indicating that there was an improvement of both scores over time in the whole sample. Although effects of treatment and time-by-treatment were insignificant, simple effects analysis of both measures was significant in the rDTMS group and reached a P-value of 0.06 in the sham group. The response rate was higher in patients with longer disease duration and higher motor UPDRS scores. Side effects were more common in the rDTMS group but were transient and tolerable.

CONCLUSIONS

Although rDTMS treatment exhibited some motor improvements, we could not demonstrate an advantage for real treatment over sham. Further research is required to establish stimulation parameters that may induce potentially more beneficial outcomes, probably in patients with longer and more sever disease.

Repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex to alleviate depression and cognitive impairment associated with Parkinson's disease: A review and clinical implications

The rapid methodological development and growing availability of neuromodulation techniques have spurred myriad studies investigating their clinical effectiveness. Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) has in many instances been proven to exert antidepressant-like effects superior to placebo and equivalent to standard psychopharmacological treatment. Due to the similar neuroanatomy and neurophysiology of executive and affective control processes, rTMS to the DLPFC may be able to address multiple issues simultaneously. This review pools available literature on the therapeutic usage of rTMS on non-motor symptoms of Parkinson's disease associated with the DLPFC (i.e. mood disturbance and cognitive impairment). To the best of the author's knowledge, it is one of the few available of its' kind, up to this date. Most studies included in the review found beneficial effects of high frequency prefrontal rTMS on PD-related depression. In regard to the usability of rTMS to alleviate cognitive impairment associated with PD, definitive claims are yet to be established.

Transcranial magnetic stimulation and environmental enrichment enhances cortical excitability and functional outcomes after traumatic brain injury

BACKGROUND

Therapeutic strategies for traumatic brain injury (TBI) in the last three decades have failed to show significant benefit in large scale studies. Given the multitude of pathological mechanisms involved in TBI, strategies focusing on multimodality regimen have gained interest as promising future interventions.

HYPOTHESIS

We hypothesized that combining noninvasive transcranial magnetic stimulation (TMS) with rehabilitative training in an environmental enrichment (EE) can facilitate post-TBI recovery in rats via cortical excitability and reorganization.

METHODS

We subjected rats to controlled cortical impact, and then assigned them to one of four groups: 1. No treatments (TBI), 2. EE after injury (TBI + EE), 3. TMS for one week (TBI + TMS), and 4. TMS for one week combined with EE (TBI + TMS/EE). For TMS, a 10 Hz repetitive TMS protocol was used.

RESULTS

At 7 days, TBI + TMS and TBI + TMS/EE groups had significantly increased primary somatosensory cortex local field potential (LFP) compared to TBI and TBI + EE groups (P < 0.05). Also, TBI + TMS/EE group had significantly improved performance on beam walk test compared to TBI group (P < 0.005). At 6 weeks, there was significantly higher response in TBI + TMS/EE group compared to TBI + TMS for somatosensory cortex LFP (P < 0.05), bicep motor evoked potentials (MEP) (P < 0.05), challenge ladder test performance (P < 0.01), and fMRI responses to tactile forepaw stimulation.

CONCLUSIONS

We demonstrate here for the first time the mechanism by which combined therapy using TMS and EE after TBI leads to functional improvement, possibly via cortical excitability and reorganization.

Assessment and Management of Neuropsychiatric Symptoms in Parkinson's Disease

Neuropsychiatric symptoms are highly prevalent in Parkinson's disease and associated with decreased quality of life and adverse health outcomes. In this review, the assessment and management of common neuropsychiatric symptoms are discussed: depression, anxiety, psychosis, cognitive impairment, dementia and apathy. Validated assessment scales are now available for the majority of symptoms. Balancing dopaminergic therapy plays an important role in their management as increasing doses of dopaminergic agents might address depression and anxiety related to 'off' phases, non-motor fluctuations and apathy, while dose reduction might alleviate psychotic symptoms. More targeted treatment is possible through medications utilising different pathways. Although efficacy profiles of individual agents require further exploration, antidepressants as a drug class have shown utility in depression and anxiety in Parkinson's disease. Psychological therapies, especially cognitive behavioural approaches, are effective. Pimavanserin allows the treatment of psychosis in Parkinson's disease without directly affecting the dopaminergic and cholinergic system. The cholinergic system is currently the only target in Parkinson's disease dementia, and antagonists of this system, as are many psychotropic drugs, need to be used with caution. Management of apathy largely relies on non-pharmacological strategies adapted from dementia care, with antidepressants being ineffective and the role of stimulant therapy needing further evaluation.

Treating refractory depression in Parkinson's disease: a meta-analysis of transcranial magnetic stimulation

Background

Parkinson’s disease (PD) is often accompanied by clinically identified depression. Providing effective pharmacotherapies that concomitantly treat both motor and psychological symptoms can pose a challenge to physicians. For this reason, alternatives to standard anti-depressant treatments, such as repetitive transcranial magnetic stimulation (rTMS), have been evaluated within the Parkinson’s population.

Methods

A literature search was conducted on the PubMed database for all studies that evaluated rTMS as a treatment in patients with both depression and PD. A meta-analysis was performed on all studies that reported mean pre- and post-rTMS depression inventory scores. Widely used depression inventories included both self-report and clinician-administered measures. Effect size for individual study groups and across all studies was calculated.

Results

Six of 7 studies meeting inclusion criteria reported significantly improved depression scores, large effect sizes, and significant p-values. Total weighted average effect size was calculated at 1.32 across all study groups that applied rTMS.

Conclusions

Across all but one study, rTMS appears to effectively reduce depression scores among self-reported and clinician administered inventories. The total weight average effect size showed that, when considering study sample sizes and degree of findings, this form of neurostimulation can relieve PD patients of their depressive symptoms. Further, rTMS is a promising alternative to traditional anti-depressant therapies when treating refractory depression in patients with PD.

Effectiveness of high-frequency repetitive transcranial magnetic stimulation in patients with depression and Parkinson's disease: a meta-analysis of randomized, controlled clinical trials

AIM

This meta-analysis aimed to assess the effect of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) for the treatment of depression in patients with Parkinson's disease (PD).

METHODS

The design was a meta-analysis of randomized controlled trials (RCTs). The participants were patients with PD who suffered from depression. The interventions were HF-rTMS alone or in combination with other treatments compared with sham-rTMS, placebo, and anti-depressant treatments. The primary outcome measure was changes in depressive symptoms, defined as the mean change in the total depression score. The secondary outcome was changes in motor symptoms, defined by Unified Parkinson's Disease Rating Scale part III scores, and the acceptability, defined as the risk of all-cause discontinuation. These were expressed as mean differences (MDs), standardized mean differences (SMDs), or risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified nine suitable trials, with data from 332 participants. For the patients with depression in PD, HF-rTMS was not better than sham-rTMS (SMD =-0.33, 95% CI -0.83 to 0.17) or selective serotonin re-uptake inhibitors (SSRIs) (SMD =0.07, 95% CI -0.52 to 0.18) for the treatment of depressive symptoms. However, the motor benefits after treatment with HF-rTMS might be better than sham-rTMS (MD =-2.80, 95% CI -5.45 to -0.15) and SSRIs (MD =-2.70, 95% CI -4.51 to -0.90).

CONCLUSION

This meta-analysis provides some evidence that in patients with PD with depression, HF-rTMS may lead to improvement in motor function but not in depression compared with sham-rTMS or SSRIs.

Connectivity Predicts deep brain stimulation outcome in Parkinson disease

OBJECTIVE

The benefit of deep brain stimulation (DBS) for Parkinson disease (PD) may depend on connectivity between the stimulation site and other brain regions, but which regions and whether connectivity can predict outcome in patients remain unknown. Here, we identify the structural and functional connectivity profile of effective DBS to the subthalamic nucleus (STN) and test its ability to predict outcome in an independent cohort.

METHODS

A training dataset of 51 PD patients with STN DBS was combined with publicly available human connectome data (diffusion tractography and resting state functional connectivity) to identify connections reliably associated with clinical improvement (motor score of the Unified Parkinson Disease Rating Scale [UPDRS]). This connectivity profile was then used to predict outcome in an independent cohort of 44 patients from a different center.

RESULTS

In the training dataset, connectivity between the DBS electrode and a distributed network of brain regions correlated with clinical response including structural connectivity to supplementary motor area and functional anticorrelation to primary motor cortex (p < 0.001). This same connectivity profile predicted response in an independent patient cohort (p < 0.01). Structural and functional connectivity were independent predictors of clinical improvement (p < 0.001) and estimated response in individual patients with an average error of 15% UPDRS improvement. Results were similar using connectome data from normal subjects or a connectome age, sex, and disease matched to our DBS patients.

INTERPRETATION

Effective STN DBS for PD is associated with a specific connectivity profile that can predict clinical outcome across independent cohorts. This prediction does not require specialized imaging in PD patients themselves. Ann Neurol 2017;82:67-78.

Repetitive transcranial magnetic stimulation for treatment of lactacystin-induced Parkinsonian rat model

The dysfunction of ubiquitin-proteasome system is an important pathogenesis in the neurodegenerative process of Parkinson's disease. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive and potential method in treating Parkinson's disease. To investigate whether rTMS has neuroprotective effects in parkinsonian rat model induced by ubiquitin-proteasome system impairment, we gave rTMS daily for 4 weeks to proteasome inhibitor, lactacystin-induced parkinsonian rat model. Rotational behavior test demonstrated that rTMS obviously reduced apomorphine-induced turning number in parkinsonian rats. rTMS could significantly alleviate the loss of tyrosine hydroxylase-positive dopaminergic neurons in lactacystin-lesioned substantia nigra and prevent the loss of striatal dopamine levels. Furthermore, rTMS also reduced the levels of apoptotic protein (cleaved caspase-3) and inflammatory factors (cyclooxygenase-2 and tumor necrosis factor alpha) in lesioned substantia nigra. These results suggest that rTMS can protect nigral dopaminergic neurons against the ubiquitin-proteasome system impairment-induced degeneration by anti-apoptotic and anti-inflammatory molecular mechanism.

[Aphasia: a neuronal network disorder]

Language processing requires the coordinated interaction of local and distant neural populations within distributed networks of the temporal, frontal and parietal brain regions. Poststroke aphasia is the consequence of both local as well as remote dysfunction within language-specific and domain-general networks. Language recovery, in turn, rests on reorganization processes within these networks. These comprise the resolution of an acute network failure (i. e. diaschisis), the subacute activation of right hemisphere homologous regions and the gradual reintegration of left hemisphere remote and perilesional areas. The application of unifocal noninvasive brain stimulation over these regions provides a means of modulating neural plasticity in order to enhance the reorganization processes underlying language recovery. The lack of knowledge as to the optimal stimulation site, the appropriate stimulation protocol and the proper timing of interventions might explain the only marginal effects of brain stimulation adjunct to speech and language therapy. In addition, individually different contributions of left and right hemisphere regions to recovery due to heterogeneous lesion sites among patients limit the possibility to identify general principles for brain stimulation. The assumption that aphasia is not only the consequence of the focal effect of a brain lesion but arises from remote dysfunctions within associated functional networks ignites the concept for individualized, potentially multifocal therapeutic network modulation.

Management of Depression in Parkinson's Disease: A Systematic Review

Background

Depression is a frequent psychiatric condition in Parkinson's disease (PD). The treatment of depression has been examined in several randomized controlled trials and meta-analyses, but no clear guidelines are available.

Methods

We carried out a systematic review of pharmacological and non-pharmacological treatments for depression in patients with PD using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched main medical databases up to December 12, 2016, and included randomized controlled trials, patient-control studies, and case series with data on treatment modality, outcome measures, and side effects.

Results

Selective serotonergic reuptake inhibitors and tricyclic antidepressants may have efficacy for the treatment of depression in patients with PD, although the evidence is not strong. The antidepressant efficacy of dopamine agonists is still controversial, and initial results were positive for pramipexole but not for rotigotine. Cognitive-behavioral therapy showed promising results in two recent randomized controlled trials, but further evidence is required. Studies using repetitive transcranial magnetic stimulation produced conflicting results, and the efficacy results for this treatment have been inconsistent. On the other hand, electroconclusive therapy produced strong positive results in patients with severe depression, but no randomized controlled trials are available.

Conclusion

Selective serotonergic reuptake inhibitors and cognitive-behavioral therapy are currently first-line treatments for depression in patients with PD, although the evidence is still weak. The heterogeneity among contributory factors for depression in PD should be considered for the most effective treatment of depression in this condition.