Repetitive transcranial magnetic stimulation is as effective as fluoxetine in the treatment of depression in patients with Parkinson's disease

Efficacy and safety of newer-generation antidepressants medications in Parkinson's disease with depression - A meta-analysis of randomized controllde trials

BACKGROUND

Depression is common as non-motor symptom in Parkinson's disease (PD). Evidence of antidepressants for PD with depression remain unclear. This meta-analysis examines the efficacy and tolerability of newer-generation antidepressants for PD with depression.

METHODS

Six international electronic databases (Cochrane, PubMed, Embase, Web of Science, CINAHL, and PsycINFO) and four Chinese electronic databases (CBM, CNKI, WanFang Data, and VIP) were systematically searched up to October 31, 2023. The primary outcomes were efficacy (change in depressive symptoms) and tolerability (all-cause discontinuations). Secondary outcomes contained improvement in motor symptoms, change score of anxiety rating scales, improvement in cognitive function, and adverse events. This study was registered with PROSPERO, number CRD42020198364.

RESULT

A total of 11 trials with 713 participants were included. Newer-generation antidepressants significantly improved depressive symptoms (standardized mean differences (SMD) = -1.12 [-1.72; -0.52]), anxiety scores (SMD = -0.60 [-1.04; -0.17]). However, there was insufficient evidence in improving motor function in PD (SMD = -1.19 [-2.74; 0.36]) and the cognitive function (SMD = 0.57 [-0.33; 1.47]). Newer-generation antidepressants were associated with increased diminished sexual desire (RR = 2.34 [1.13; 4.86]) and insomnia (RR = 0.42 [0.22; 0.82]), but similar risk of all-cause discontinuations when compared with the control group (RR = 1.25 [0.85; 1.85]).

CONCLUSION

Newer-generation antidepressants appear to be beneficial and safe in treating depression in PD.

Theta Burst Stimulation Protocols for Schizophrenia: A Systematic Review and Network Meta-Analysis

Importance

To date, several theta burst stimulation (TBS) protocols, such as intermittent TBS (iTBS), have been proposed; however, previous systematic reviews have revealed inconsistent efficacy findings in individual TBS studies for schizophrenia.

Objective

To examine which TBS protocols are associated with the most favorable and acceptable outcomes in adults with schizophrenia.

Data Sources

The Cochrane Library, PubMed, and Embase databases were searched for studies published before May 22, 2024.

Study Selection

The inclusion criteria were as follows: (1) published and unpublished randomized clinical trials (RCTs) of any TBS treatment and (2) RCTs including individuals with schizophrenia spectrum disorders, other psychotic disorders, or both.

Data Extraction and Synthesis

This study followed the Cochrane standards for data extraction and data quality assessment and used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline for reporting. The risk of bias of individual studies was assessed using the second version of the Cochrane risk of bias tool, and the Confidence in Network Meta-Analysis application was used to rate the certainty of evidence for meta-analysis results. At least 2 authors double-checked the literature search, data transfer accuracy, and calculations.

Main Outcomes and Measures

The primary outcome of this study was improvement in scores related to negative symptoms. Our frequentist network meta-analysis used a random-effects model. The standardized mean difference (SMD) or odds ratio for continuous or dichotomous variables, respectively, was calculated with 95% CIs.

Results

A total of 30 RCTs of 9 TBS protocols, with 1424 participants, were included. Only iTBS over the left dorsolateral prefrontal cortex (L-DLPFC) was associated with reduced negative symptom scores (SMD, -0.89; 95% CI, -1.24 to -0.55), overall symptom scores (SMD, -0.81; 95% CI, -1.15 to -0.48), Positive and Negative Syndrome Scale general subscale scores (SMD, -0.57; 95% CI, -0.89 to -0.25), depressive symptom scores (SMD, -0.70; 95% CI, -1.04 to -0.37), and anxiety symptom scores (SMD, -0.58; 95% CI, -0.92 to -0.24) and improved overall cognitive impairment scores (SMD, -0.52; 95% CI, -0.89 to -0.15) compared with a sham. However, positive symptom score changes, all-cause discontinuation rate, discontinuation rate due to adverse events, headache incidence, and dizziness incidence did not significantly differ between any TBS protocols and sham.

Conclusions and Relevance

In this network meta-analysis, iTBS over the L-DLPFC was associated with improved scores for negative, depressive, anxiety, and cognitive symptoms in individuals with schizophrenia and was well tolerated by the participants. Other forms of TBS were not associated with benefit. Further research is needed to assess the potential role of TBS in the treatment of schizophrenia.

Clinical neurophysiology in the treatment of movement disorders: IFCN handbook chapter

In this review, different aspects of the use of clinical neurophysiology techniques for the treatment of movement disorders are addressed. First of all, these techniques can be used to guide neuromodulation techniques or to perform therapeutic neuromodulation as such. Neuromodulation includes invasive techniques based on the surgical implantation of electrodes and a pulse generator, such as deep brain stimulation (DBS) or spinal cord stimulation (SCS) on the one hand, and non-invasive techniques aimed at modulating or even lesioning neural structures by transcranial application. Movement disorders are one of the main areas of indication for the various neuromodulation techniques. This review focuses on the following techniques: DBS, repetitive transcranial magnetic stimulation (rTMS), low-intensity transcranial electrical stimulation, including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), and focused ultrasound (FUS), including high-intensity magnetic resonance-guided FUS (MRgFUS), and pulsed mode low-intensity transcranial FUS stimulation (TUS). The main clinical conditions in which neuromodulation has proven its efficacy are Parkinson's disease, dystonia, and essential tremor, mainly using DBS or MRgFUS. There is also some evidence for Tourette syndrome (DBS), Huntington's disease (DBS), cerebellar ataxia (tDCS), and axial signs (SCS) and depression (rTMS) in PD. The development of non-invasive transcranial neuromodulation techniques is limited by the short-term clinical impact of these techniques, especially rTMS, in the context of very chronic diseases. However, at-home use (tDCS) or current advances in the design of closed-loop stimulation (tACS) may open new perspectives for the application of these techniques in patients, favored by their easier use and lower rate of adverse effects compared to invasive or lesioning methods. Finally, this review summarizes the evidence for keeping the use of electromyography to optimize the identification of muscles to be treated with botulinum toxin injection, which is indicated and widely performed for the treatment of various movement disorders.

Selective Serotonin Reuptake Inhibitors for the Treatment of Depression in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Although selective serotonin reuptake inhibitors (SSRIs) are usually considered safe to use in patients with Parkinson's disease (PD), there are mixed data about their effectiveness, and only a few investigations have led to a total improvement of depressive symptoms in patients with PD.

OBJECTIVES

We aimed to conduct a comprehensive systematic review and meta-analysis of all studies that investigated the effectiveness of SSRIs in treating depression in the context of PD.

METHODS

From its commencement to June 2024, the databases of MEDLINE via PubMed, Scopus, Embase, and Google Scholar were electronically searched for the relevant papers. All full-text journal articles assessing the effectiveness of SSRIs in treating depression in patients with PD were included. The tool developed by the Cochrane Collaboration was utilized to evaluate the bias risk. Data were analyzed utilizing a pair-wise comparison meta-analysis using the standardized mean difference.

RESULTS

A total of 19 articles and 22 separate interventions were included. We found that SSRI treatment attenuated depression in patients with PD (1.242 standardized mean difference, 95% confidence interval 0.956, 1.529, p < 0.001). The general heterogeneity of the studies was medium (ϰ2 = 72.818, T2 = 0.317, df = 21, I2 = 71.15%, p < 0.001). The funnel plot was reasonably symmetrical. However, three studies were trimmed to the left of the mean. Begg's test (p = 0.080), Egger's test (p = 0.121), and funnel plot showed no significant risk of publication bias. The meta-regression showed that the treatment effect increased as a function of paroxetine treatment duration (slope p = 0.001) but decreased as a function of sertraline treatment duration (slope p = 0.019).

CONCLUSIONS

There are few controlled antidepressant trials on the PD population, even though patients with PD frequently experience depression and use antidepressants. Clinical studies that are larger and better structured are needed in the future to determine if antidepressants are useful for treating patients with PD with depression.

Non-Pharmacological Interventions for Depression and Anxiety in Parkinson's Disease

Non-pharmacological interventions, including cognitive-behavioral therapy (CBT), non-invasive brain stimulation (NIBS), electroconvulsive therapy (ECT), light therapy (LT), and physical rehabilitation/exercise, have shown promise as effective approaches to treat symptoms of depression and anxiety in individuals with Parkinson's disease (PD). In this narrative literature overview, we discuss the state-of-the-art regarding these treatment options and address future perspectives for clinical practice and research. Non-pharmacological interventions hold promise to treat depression and anxiety in PD. There is meta-analytic evidence for the efficacy of CBT, NIBS, ECT, LT, and exercise on improving depressive symptoms. For the treatment of anxiety symptoms, CBT shows large effects but scientific evidence of other non-pharmacological interventions is limited. Importantly, these treatments are safe interventions with no or mild side-effects. More research is needed to tailor treatment to the individuals' needs and combined interventions may provide synergistic effects.We conclude that non-pharmacological interventions should be considered as alternative or augmentative treatments to pharmacological and neurosurgical approaches for the treatment of depression and anxiety in individuals with PD.

Neuronavigated repetitive transcranial magnetic stimulation improves depression, anxiety and motor symptoms in Parkinson's disease

Background

Repetitive transcranial magnetic stimulation (rTMS) is a potential treatment option for Parkinson's disease patients with depression (DPD), but conflicting results in previous studies have questioned its efficacy.

Method

To investigate the safety and efficacy of neuronavigated high-frequency rTMS at the left DLPFC in DPD patients, we conducted a randomized, double-blind, sham-controlled study (NCT04707378). Sixty patients were randomly assigned to either a sham or active stimulation group and received rTMS for ten consecutive days. The primary outcome was HAMD, while secondary outcomes included HAMA, MMSE, MoCA and MDS-UPDRS-III. Assessments were performed at baseline, immediately after treatment, 2 weeks, and 4 weeks post-treatment.

Results

The GEE analysis showed that the active stimulation group had significant improvements in depression, anxiety, and motor symptoms at various time points. Specifically, there were significant time-by-group interaction effects in depression immediately after treatment (β, -4.34 [95% CI, -6.90 to -1.74; P = 0.001]), at 2 weeks post-treatment (β, -3.66 [95% CI, -6.43 to -0.90; P = 0.010]), and at 4 weeks post-treatment (β, -4.94 [95% CI, -7.60 to -2.29; P < 0.001]). Similarly, there were significant time-by-group interaction effects in anxiety at 4 weeks post-treatment (β, -2.65 [95% CI, -4.96 to -0.34; P = 0.024]) and in motor symptoms immediately after treatment (β, -5.72 [95% CI, -9.10 to -2.34; P = 0.001] and at 4 weeks post-treatment (β, -5.43 [95% CI, -10.24 to -0.61; P = 0.027]).

Conclusion

The study suggested that neuronavigated high-frequency rTMS at left DLPFC is effective for depression, anxiety, and motor symptoms in PD patients.

Using causal methods to map symptoms to brain circuits in neurodevelopment disorders: moving from identifying correlates to developing treatments

A wide variety of model systems and experimental techniques can provide insight into the structure and function of the human brain in typical development and in neurodevelopmental disorders. Unfortunately, this work, whether based on manipulation of animal models or observational and correlational methods in humans, has a high attrition rate in translating scientific discovery into practicable treatments and therapies for neurodevelopmental disorders.With new computational and neuromodulatory approaches to interrogating brain networks, opportunities exist for "bedside-to bedside-translation" with a potentially shorter path to therapeutic options. Specifically, methods like lesion network mapping can identify brain networks involved in the generation of complex symptomatology, both from acute onset lesion-related symptoms and from focal developmental anomalies. Traditional neuroimaging can examine the generalizability of these findings to idiopathic populations, while non-invasive neuromodulation techniques such as transcranial magnetic stimulation provide the ability to do targeted activation or inhibition of these specific brain regions and networks. In parallel, real-time functional MRI neurofeedback also allow for endogenous neuromodulation of specific targets that may be out of reach for transcranial exogenous methods.Discovery of novel neuroanatomical circuits for transdiagnostic symptoms and neuroimaging-based endophenotypes may now be feasible for neurodevelopmental disorders using data from cohorts with focal brain anomalies. These novel circuits, after validation in large-scale highly characterized research cohorts and tested prospectively using noninvasive neuromodulation and neurofeedback techniques, may represent a new pathway for symptom-based targeted therapy.

Neuromodulation of cognition in Parkinson's disease

Neuromodulation is a widely used treatment for motor symptoms of Parkinson's disease (PD). It can be a highly effective treatment as a result of knowledge of circuit dysfunction associated with motor symptoms in PD. However, the mechanisms underlying cognitive symptoms of PD are less well-known, and the effects of neuromodulation on these symptoms are less consistent. Nonetheless, neuromodulation provides a unique opportunity to modulate motor and cognitive circuits while minimizing off-target side effects. We review the modalities of neuromodulation used in PD and the potential implications for cognitive symptoms. There have been some encouraging findings with both invasive and noninvasive modalities of neuromodulation, and there are promising advances being made in the field of therapeutic neuromodulation. Substantial work is needed to determine which modulation targets are most effective for the different types of cognitive deficits of PD.

Parkinson and depression: review and outlook

Depression in Parkinson's Disorder (DPD) has been estimated to appear in up to 40% of people with PD and negatively impacts quality of life, motor and cognitive deficits and functional disability. Knowledge of the pathophysiology of DPD is unclear, DPD may be related to dysfunction in subcortical nuclei and the prefrontal cortex, striatal-thalamic-prefrontal and basotemporal limbic circuits, brainstem monoamine, and indolamine (i.e. dopamine, serotonin, and norepinephrine) systems. DPD is characterized by sadness, loss of interest, increased exhaustibility, feelings of helplessness, reduced drive, dysphoria, irritability, and pessimism about future. The diagnosis is complicated by overlap with PD symptoms, Detection of depression in PD should be made by psychometric depression scales. DPD is underrecognized and undertreated in clinical practice. Treatment mainly includes antidepressive medications and behavioral interventions as psychotherapy. Dopamine agonists showed some antidepressant effects, there are no sufficient numbers of RCTs. Important randomized clinical trials (RCTs) are summarized. SSRIs and SNRIs have a satisfying efficacy in DPD. TCAs are also good for improving depression. Side effects of different antidepressants (e.g. TCAs, SSRIs, SNRIs, bupropion, MAOIs) and potential interactions should be considered. In existing guidelines so far no statements, algorithms and recommendations are given for diagnosis and treatment of DPD. Methodologically adequate designed RCTs and comparative studies (NIS) which offer evidence-based results are urgently needed having the impact of DPD in mind.

Noninvasive neuromodulation in Parkinson's disease: Neuroplasticity implication and therapeutic perspectives

Noninvasive brain stimulation techniques can be used to study in vivo the changes of cortical activity and plasticity in subjects with Parkinson's disease (PD). Also, an increasing number of studies have suggested a potential therapeutic effect of these techniques. High-frequency repetitive transcranial magnetic stimulation (rTMS) and anodal transcranial direct current stimulation (tDCS) represent the most used stimulation paradigms to treat motor and nonmotor symptoms of PD. Both techniques can enhance cortical activity, compensating for its reduction related to subcortical dysfunction in PD. However, the use of suboptimal stimulation parameters can lead to therapeutic failure. Clinical studies are warranted to clarify in PD the additional effects of these stimulation techniques on pharmacologic and neurorehabilitation treatments.

Therapeutic application of rTMS in neurodegenerative and movement disorders: A review

Transcranial magnetic stimulation (TMS) is a non-invasive form of brain stimulation that makes use of the magnetic field generated when an electric current passes through a magnetic coil placed over the scalp. It can be applied as a single stimulus at a time, in pairs of stimuli, or repetitively in trains of stimuli (repetitive TMS, rTMS). RTMS can induce changes in brain activity, whose after-effects reflect the processes of long-term potentiation and long-term depression, as certain protocols, namely those using low frequencies (≤1 Hz) seem to suppress cortical excitability, while those using high frequencies (>1 Hz) seem to enhance it. It is a technique with very few and mostly mild side-effects, whose effects can persist for long time periods, and as such, it has been studied as a potential treatment option in a multitude of neurodegenerative diseases, including those affecting movement. Although rTMS has received approval as a treatment strategy of only a few aspects in movement disorders in the latest guidelines, its further use seems to also be promising in their context. In this review, we gathered the available literature on the therapeutic application of rTMS in movement disorders, namely Parkinson's disease, Amyotrophic Lateral Sclerosis, Huntington's disease, Dystonia, Tic disorders and Essential Tremor.

Repetitive transcranial magnetic stimulation (rTMS) fails to improve cognition in patients with parkinson's disease: a Meta-analysis of randomized controlled trials

BACKGROUND

Cognitive decline is one of the greatest concerns for patients with Parkinson's disease (PD) and their care partners. Repetitive transcranial magnetic stimulation (rTMS) is a nonpharmacological treatment option used to improve cognitive function in PD, but its efficacy is unclear. We performed a meta-analysis to determine whether rTMS improves cognition in PD patients.

METHODS

Eligibility criteria (PICOS) were as follows: (1) 'P': The patients participating were diagnosed with idiopathic PD; (2) 'I': Intervention using rTMS; (3) 'C': Sham stimulation as control; (4) 'O': The outcome of the study included cognitive evaluations; (5) 'S': The study adopted randomized controlled design. The standardized mean difference (SMD) of change of score was applied to measure efficacy, and we used Version 2 of the Cochrane tool to assess risk of bias.

RESULTS

Twelve studies met the inclusion criteria. Compared with sham-controlled group, the pooled result showed a non-significant short-term effect of rTMS on global cognition (SMD: -0.15, 95% CI: -0.59 to 0.29, I² = 36.7%), executive function (SMD: 0.03, 95% CI: -0.21 to 0.26, I² = 0.0%), and attention and working memory (SMD: 0.05, 95% CI: -0.25 to 0.35, I² = 0.0%). Long-term outcomes were either shown to be statistically nonsignificant.

CONCLUSIONS

Based on a limited number of studies, rTMS fails to improve cognition in PD. We call for additional high-quality randomized controlled trials with adequate sample sizes to determine the efficacy of rTMS.

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.

Motor recovery and antidepressant effects of repetitive transcranial magnetic stimulation on Parkinson disease: A PRISMA-compliant meta-analysis

BACKGROUND

Clinical symptoms of Parkinson disease (PD) included both motor and nonmotor symptoms. Previous studies indicated inconsistent results for the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on motor and depression in PD. The study aimed to assess the therapeutic effect of rTMS with different mode on motor and depression in PD using a meta-analysis.

METHODS

Articles published before July 2019 were searched based on the following databases (PubMed, Web of Science, Medline, Embase, and Google Scholar). The therapeutic effects were assessed by computing the standard mean difference (SMD) and a 95% confidence interval (CI).

RESULTS

The present study indicated that rTMS showed significant therapeutic effects on motor in PD (SMD 2.05, 95% CI 1.57-2.53, I = 93.0%, P < .001). Both high-frequency (HF)-rTMS and low-frequency rTMS showed therapeutic effects on motor; stimulation over primary motor cortex (M1), supplementary motor area, dorsal lateral prefrontal cortex (DLPFC) or M1+DLPFC showed therapeutic effects; stimulation during "on" and "off" states showed therapeutic effects; the study showed long-term effect of rTMS on motor in PD. In addition, the study indicated that rTMS showed significant therapeutic effects on depression in PD (SMD 0.80, 95% CI 0.31-1.29, I = 89.1%, P < .001). Stimulation over left DLPFC showed significant therapeutic effects on depression in PD; only HF-rTMS showed therapeutic effects; ages, disease durations, numbers of pulses, and session durations displayed influence on the therapeutic effects of rTMS on depression in PD; the therapeutic effects on depression was long term. However, no significant difference in therapeutic effects on depression were showed between rTMS and oral Fluoxetine (SMD 0.74, 95% CI -0.83 to 2.31, I = 92.5%, P < .001).

CONCLUSION

The rTMS showed significant therapeutic effects on motor in PD. HF-rTMS showed a significant positive antidepressive effect in PD only over DLPFC.

Neuropsychiatric aspects of Parkinson disease psychopharmacology: Insights from circuit dynamics

Parkinson disease (PD) is a neurodegenerative disorder with a complex pathophysiology characterized by the progressive loss of dopaminergic neurons within the substantia nigra. Persons with PD experience several motoric and neuropsychiatric symptoms. Neuropsychiatric features of PD include depression, anxiety, psychosis, impulse control disorders, and apathy. In this chapter, we will utilize the National Institutes of Mental Health Research Domain Criteria (RDoC) to frame and integrate observations from two prevailing disease constructions: neurotransmitter anomalies and circuit physiology. When there is available evidence, we posit how unified translational observations may have clinical relevance and postulate importance outside of PD. Finally, we review the limited evidence available for pharmacologic management of these symptoms.

Non-pharmacological treatment for Parkinson disease patients with depression: a meta-analysis of repetitive transcranial magnetic stimulation and cognitive-behavioral treatment

Background: Nowadays, antidepressants still are the mainstay of treatment for depression in Parkinson's disease (PD) but some recent studies report that medication might aggravate motor symptoms in PD patients. This meta-analysis aims to assess the effect of non-pharmacological treatments for depression in patients with PD.Materials and Methods: Only randomized controlled trials (RCTs) were included. The participants were PD patients with comorbid depression (dPD). The interventions had the equivalent effect of non-pharmacological treatments alone compared with control(s). Scores of depression scale were selected as the primary outcome, while scores of Unified Parkinson's Disease Rating Scale part III and the incidence of side effects were the secondary outcome. The statistics were pooled and presented as weighted mean differences (WMDs), standardized mean differences (SMDs), or risk ratios (RRs) with their 95% confidence intervals (CIs).Results: Fifteen articles were eventually included; twelve studies reported on repetitive transcranial magnetic stimulation (rTMS) and three used cognitive behavioral therapy (CBT). Other interventions failed to have qualified studies. Our data indicated that both rTMS and CBT could significantly improve depression scores in a short term (SMD = -0.621, 95% CI [-0.964, -0.278]; SMD = -1.148, 95% CI [-1.498, -0.798], respectively). In addition, rTMS could alleviate motor symptom (WMD = -2.617, 95% CI [-4.183, -1.051]) and was relatively safe (RR = 1.054, 95% CI [0.698, 1.592]).Conclusion: Our data suggest that rTMS can safely alleviate depression and motor symptoms in dPD at least for a short period. Moreover, compared with clinical monitoring, CBT can improve depressive symptoms.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

High-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex of patients with Parkinson's disease and treatment-resistant depression: a pilot study

An increasing amount of evidence is showing the therapeutic effects of rTMS on PD-related non-motor functions neuroanatomically linked to the DLPFC. This presents an ongoing need to apply an optimal combination of stimulation parameters to clinically heterogeneous patient populations, including those with neuropsychiatric problems and other comorbidities along with the neurodegenerative process. In this prospective pilot study, six patients with PD and treatment-resistant depression were thoroughly assessed and carefully monitored before, during, and after each stimulation procedure. The results can provide the basis for developing an extended rTMS protocol that is both effective and safe.

The use of transcranial magnetic stimulation as a treatment for movement disorders: A critical review

BACKGROUND

Transcranial magnetic stimulation is a safe and painless non-invasive brain stimulation technique that has been largely used in the past 30 years to explore cortical function in healthy participants and, inter alia, the pathophysiology of movement disorders. During the years, its use has evolved from primarily research purposes to treatment of a large variety of neurological and psychiatric diseases. In this article, we illustrate the basic principles on which the therapeutic use of transcranial magnetic stimulation is based and review the clinical trials that have been performed in patients with movement disorders.

METHODS

A search of the PubMed database for research and review articles was performed on therapeutic applications of transcranial magnetic stimulation in movement disorders. The search included the following conditions: Parkinson's disease, dystonia, Tourette syndrome and other chronic tic disorders, Huntington's disease and choreas, and essential tremor. The results of the studies and possible mechanistic explanations for the relatively minor effects of transcranial magnetic stimulation are discussed. Possible ways to improve the methodology and achieve greater therapeutic efficacy are discussed.

CONCLUSION

Despite the promising and robust rationales for the use of transcranial magnetic stimulations as a treatment tool in movement disorders, the results taken as a whole are not as successful as were initially expected. There is encouraging evidence that transcranial magnetic stimulation may improve motor symptoms and depression in Parkinson's disease, but the efficacy in other movement disorders is unclear. Possible improvements in methodology are on the horizon but have yet to be implemented in large clinical studies. © 2019 International Parkinson and Movement Disorder Society © 2019 International Parkinson and Movement Disorder Society.

Antidepressant Effects of Repetitive Transcranial Magnetic Stimulation Over Prefrontal Cortex of Parkinson's Disease Patients With Depression: A Meta-Analysis

Objective: The purpose of this meta-analysis was to investigate the antidepressant effects of repetitive transcranial magnetic stimulation (rTMS) over the prefrontal cortex (PFC) of patients with Parkinson's disease (PD) and to determine the optimal rTMS parameters, such as the intensity, frequency and the delivered pattern of rTMS stimulation. Methods: EMBASE, PubMed, Web of Science, MEDLINE, and Cochrane data bases were researched for papers published before March 12, 2018. Studies investigating the anti-depression effects of rTMS over PFC in patients with PD were considered. The main outcomes of pre- and post-rTMS treatment as well as score changes were all extracted. The mean effect size was estimated by calculating the standardized mean difference (SMD) with 95% confidence interval (CI) by using fixed or random effect models as appropriate. Results: Nine studies containing 137 PD patients with depression were included. The pooled results showed significant pre-post anti-depressive effects of rTMS over PFC in PD patients with depression (SMD = -0.80, P < 0.00001). The subgroup analyses of stimulation intensity, frequencies, and models also revealed significant effects (Intensities: 90% RMT: SMD = -1.16, P = 0.0006; >100% RMT: SMD = -0.82, P < 0.0001. Frequencies: < 1.0 Hz: SMD = -0.83, P = 0.03; 5.0 Hz: SMD = -1.10, P < 0.0001; ≥10.0 Hz: SMD = -0.55, P = 0.02. Models: Continuous: SMD = -0.79, P < 0.0001; Discontinuous: SMD = -0.84, P = 0.02). But the results of the studies with place-controlled designs were not significant (Overall: SMD = -0.27, P = 0.54. Intensities: 90% RMT: SMD = 0.27, P = 0.68; 100% RMT: SMD = -0.32, P = 0.33. Frequencies: 5.0 Hz: SMD = -0.87, P = 0.10; ≥10.0 Hz: SMD = 0.27, P = 0.66. Models: Continuous: SMD = -0.28, P = 0.68; Discontinuous: SMD = -0.32, P = 0.33). The greater effect sizes of rTMS with 90% RMT, 5.0 Hz in discontinuous days can be observed rather than the other parameters in both kinds of analyses across study design. Conclusions: rTMS may have a significant positive pre-post anti-depressive effect over PFC on patients with depression, especially by using 5.0 Hz frequency with 90% RMT intensity in discontinuous days, which may produce better effects than other parameters. The real effect, though, was not different from that of the placebo. Future studies with larger sample sizes and high-quality studies are needed to further corroborate our results and to identify the optimal rTMS protocols.

Neurostimulation in dry eye disease-past, present, and future

Neuromodulation is a novel approach that utilizes electrical signals, pharmaceutical agents, or other forms of energy to modulate abnormal neural function through neurostimulation. Neurostimulation is a novel technique that uses electrical currents to stimulate the nervous system. During the recent few decades, neuromodulation has gained significant attention, in particular for the treatment of chronic neurological diseases, due to its success in treating patients unresponsive to conventional pharmacological therapies. Dry eye disease (DED) is a chronic, multifactorial disease that affects millions of people worldwide. Recent data have demonstrated that neurosensory abnormalities contribute to the pathogenesis of DED. Current mainstays of dry eye therapy include lubrication, tear retention, and anti-inflammatory therapies, among others. The recent development of intranasal neurostimulation therapy for DED utilizes the nasolacrimal reflex as an alternative pathway, not only to increase tear production via increased lacrimation, but also to target other tear film components, such as mucin and meibum secretion, promoting tear film homeostasis. This review aims to describe the different types of neuromodulation devices available and their application for non-ocular diseases, as well as to review recent advances and literature on ocular neurostimulation.

On-Chip Studies of Magnetic Stimulation Effect on Single Neural Cell Viability and Proliferation on Glass and Nanoporous Surfaces

Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation technique, an FDA-approved treatment method for various neurological disorders such as depressive disorder, Parkinson's disease, post-traumatic stress disorder, and migraine. However, information concerning the molecular/cellular-level mechanisms of neurons under magnetic simulation (MS), particularly at the single neural cell level, is still lacking, resulting in very little knowledge of the effects of MS on neural cells. In this paper, the effects of MS on the behaviors of neural cell N27 at the single-cell level on coverslip glass substrate and anodic aluminum oxide (AAO) nanoporous substrate are reported for the first time. First, it has been found that the MS has a negligible cytotoxic effect on N27 cells. Second, MS decreases nuclear localization of paxillin, a focal adhesion protein that is known to enter the nucleus and modulate transcription. Third, the effect of MS on N27 cells can be clearly observed over 24 h, the duration of one cell cycle, after MS is applied to the cells. The size of cells under MS was found to be statistically smaller than that of cells without MS after one cell cycle. Furthermore, directly monitoring cell division process in the microholders on a chip revealed that the cells under MS generated statistically more daughter cells in one average cell cycle time than those without MS. All these results indicate that MS can affect the behavior of N27 cells, promoting their proliferation and regeneration.

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.

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.

Less Might Be More: Conduction Failure as a Factor Possibly Limiting the Efficacy of Higher Frequencies in rTMS Protocols

Introduction: rTMS has been proven effective in the treatment of neuropsychiatric conditions, with class A (definite efficacy) evidence for treatment of depression and pain (Lefaucheur et al., 2014). The efficacy in stimulation protocols is, however, quite heterogeneous. Saturation of neuronal firing by HFrTMS without allowing time for recovery may lead to neuronal response failures (NRFs) that compromise the efficacy of stimulation with higher frequencies.

Objectives: To examine the efficacy of different rTMS temporal stimulation patterns focusing on a possible upper stimulation limit related to response failures. Protocol patterns were derived from published clinical studies on therapeutic rTMS for depression and pain. They were compared with conduction failures in cell cultures.

Methodology: From 57 papers using protocols rated class A for depression and pain (Lefaucheur et al., 2014) we extracted Inter-train interval (ITI), average frequency, total duration and total number of pulses and plotted them against the percent improvement on the outcome scale. Specifically, we compared 10 Hz trains with ITIs of 8 s (protocol A) and 26 s (protocol B) in vitro on cultured cortical neurons.

Results: In the in vitro experiments, protocol A with 8-s ITIs resulted in more frequent response failures, while practically no response failures occurred with protocol B (26-s intervals). The HFrTMS protocol analysis exhibited no significant effect of ITIs on protocol efficiency.

Discussion: In the neuronal culture, longer ITIs appeared to allow the neuronal response to recover. In the available human dataset on both depression and chronic pain, data concerning shorter ITIs is does not allow a significant conclusion.

Significance: NRF may interfere with the efficacy of rTMS stimulation protocols when the average stimulation frequency is too high, proposing ITIs as a variable in rTMS protocol efficacy. Clinical trials are necessary to examine effect of shorter ITIs on the clinical outcome in a controlled setting.

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.

A specific pattern of gray matter atrophy in Alzheimer's disease with depression

Considering the high incidence of depressive symptoms in Alzheimer's disease (AD), we conducted a large-sample study to investigate the pattern of gray matter (GM) abnormalities that differentiates depressive from non-depressive AD patients. We included 201 AD patients who underwent MRI assessment and categorized them into depressive and non-depressive subgroups based on the Geriatric Depression Scale (GDS; cut-off score: ≤9). We performed whole-brain voxel-based morphometry analysis in 173 patients after MRI quality control and used between-group comparisons and regression analysis models to analyze the volumetric data controlling for nuisance variables. Depressive AD patients had extensive GM volume loss mainly in the paracentral region, specifically in post- and pre-central gyrus, supplementary motor areas and thalamus compared to non-depressive patients. Similar findings were obtained for the group of 173 patients using regression analysis and GDS score as predictor variable. We provided the first clear demonstration of a unique pattern of GM atrophy that characterizes AD patients with depression which is consistent with regions implicated in the phenomenon of psychomotor retardation that characterizes depression.

Cognitive Training and Noninvasive Brain Stimulation for Cognition in Parkinson's Disease: A Meta-analysis

BACKGROUND

Many people with Parkinson's disease (PD) experience cognitive decline. It is not known whether cognitive training or noninvasive brain stimulation are effective at alleviating cognitive deficits in PD.

OBJECTIVE

To examine cognitive training and non-invasive brain stimulation interventions for cognition in PD.

METHODS

An extensive search was conducted of published and unpublished studies in online databases. Studies were selected if they were controlled trials examining standard (not individualized) or tailored (individualized) cognitive training, repetitive transcranial magnetic stimulation (rTMS), or transcranial direct current stimulation (tDCS) in PD, with outcomes measured by standardized neuropsychological tests.

RESULTS

Fourteen controlled trials met inclusion criteria. For executive function, the pooled effect size (Hedges' g) for cognitive training (standard and tailored combined) was small ( g = 0.42) but statistically significant (95% CI 0.15-0.68). The pooled effect for standard cognitive training (alone) was medium ( g = 0.51) and significant (95% CI 0.16-0.85). For attention/working memory, small pooled effect sizes were found when combining standard and tailored cognitive training ( g = 0.23; 95% CI 0.02-0.44) and for standard cognitive training alone ( g = 0.29; 95% CI 0.04-0.53), both significant. For memory, small but significant pooled effect sizes were also found when combining standard and tailored cognitive training and for standard cognitive training alone.

CONCLUSIONS

The results suggest that standard and tailored cognitive training may improve executive function, attention/working memory, and memory in PD. Future studies must adopt randomized controlled trial designs to explore the therapeutic potential of these interventions.

Repetitive Transcranial Magnetic Stimulation (5 and 10 Hz) With Modified Parameters in the Treatment of Resistant Unipolar and Bipolar Depression in a Private Practice Setting

BACKGROUND

A limited number of studies have investigated the safety and efficacy of repetitive transcranial magnetic stimulation (rTMS) in the treatment of resistant depression in an outpatient private practice setting. We hypothesized that rTMS would be safe and effective in the treatment of resistant depression in a nonresearch population.

METHODS

We treated 22 outpatients with unipolar or bipolar depression who were experiencing a moderate to severe treatment-resistant major depressive episode (MDE). Treatment was based on a flexible dose schedule of either 5 Hz or 10 Hz rTMS applied over the left dorsolateral prefrontal cortex with modified parameters. Assessments were performed at baseline, then on a weekly basis. The patients had received at least 2 trials of antidepressant medication of an adequate dose and duration without satisfactory improvement in the index MDE.

RESULTS

There was a significant change in Montgomery-Asberg Depression Rating Scale scores from baseline (29.14±5.85) to the end of week 4 (16.27±11.20); 50.00% (11/22) were responders and 40.9% (9/22) achieved remission. No major side effects were observed aside from mild headache in some patients.

CONCLUSIONS

rTMS applied to the left dorsolateral prefrontal cortex was safe and effective in an important subset of outpatients with a moderate to severe MDE in a naturalistic setting. Outcomes demonstrated response rates similar to research populations. Further larger studies are needed to confirm the safety and effectiveness of rTMS in naturalistic conditions.

Repetitive Transcranial Magnetic Stimulation for Depression Due to Cerebrovascular Disease: A Systematic Review

OBJECTIVE

This study aims to perform a systematic review evaluating the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in improving depression resulting from cerebrovascular disease including vascular depression (VD) and poststroke depression (PSD).

METHODS

A literature search of multiple scientific databases was conducted for English studies published from January 1980 to June 2016. Studies were included if the sample consisted of 50% or more adult humans with VD or PSD and had 3 or more subjects, the intervention applied was rTMS, and depression was assessed pre- and post intervention using a formal outcome measure. Randomized controlled trials (RCTs) were assessed for methodological quality using the Physiotherapy Evidence Database (PEDro) tool. A level of evidence was assigned to each study according to the modified Sackett Scale.

RESULTS

Five studies met the inclusion criteria including 3 RCTs (level 1b; PEDro range: 6-8) and 2 uncontrolled pre-post studies (level 4). There were 186 participants with either PSD (n = 40) or VD (n = 146); the majority of the participants were female (52.7%) and had a mean age ranging from 51.9 to 67.9 years. There were no adverse effects reported by any of the studies. Using clinically accepted criteria for the response rate, all studies reported a benefit from rTMS for the treatment of depression. Three studies also demonstrated a benefit on remission rates as well.

CONCLUSIONS

rTMS was reported to be beneficial in treating depression among individuals with cerebrovascular disease over the short term. However, heterogeneous populations and variability in study design and protocol, as well as a limited number of studies to review, challenge the ability to form conclusions as to the effectiveness of rTMS.

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

OBJECTIVE

To assess whether multifocal, high-frequency repetitive transcranial magnetic stimulation (rTMS) of motor and prefrontal cortex benefits motor and mood symptoms in patients with Parkinson disease (PD).

METHODS

Patients with PD and depression were enrolled in this multicenter, double-blind, sham-controlled, parallel-group study of real or realistic (electric) sham rTMS. Patients were randomized to 1 of 4 groups: bilateral M1 ( + sham dorsolateral prefrontal cortex [DLPFC]), DLPFC ( + sham M1), M1 + DLPFC, or double sham. The TMS course consisted of 10 daily sessions of 2,000 stimuli for the left DLPFC and 1,000 stimuli for each M1 (50 × 4-second trains of 40 stimuli at 10 Hz). Patients were evaluated at baseline, at 1 week, and at 1, 3, and 6 months after treatment. Primary endpoints were changes in motor function assessed with the Unified Parkinson's Disease Rating Scale-III and in mood with the Hamilton Depression Rating Scale at 1 month.

RESULTS

Of the 160 patients planned for recruitment, 85 were screened, 61 were randomized, and 50 completed all study visits. Real M1 rTMS resulted in greater improvement in motor function than sham at the primary endpoint (p < 0.05). There was no improvement in mood in the DLPFC group compared to the double-sham group, as well as no benefit to combining M1 and DLPFC stimulation for either motor or mood symptoms.

CONCLUSIONS

In patients with PD with depression, M1 rTMS is an effective treatment of motor symptoms, while mood benefit after 2 weeks of DLPFC rTMS is not better than sham. Targeting both M1 and DLPFC in each rTMS session showed no evidence of synergistic effects.

CLINICALTRIALSGOV IDENTIFIER

NCT01080794.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in patients with PD with depression, M1 rTMS leads to improvement in motor function while DLPFC rTMS does not lead to improvement in depression compared to sham rTMS.

The Network Model of Depression as a Basis for New Therapeutic Strategies for Treating Major Depressive Disorder in Parkinson's Disease

The high prevalence of major depressive disorder in people with Parkinson’s disease (PD), its negative impact on health-related quality of life and the low response rate to conventional pharmacological therapies call to seek innovative treatments. Here, we review the new approaches for treating major depressive disorder in patients with PD within the framework of the network model of depression. According to this model, major depressive disorder reflects maladaptive neuronal plasticity. Non-invasive brain stimulation (NIBS) using high frequency repetitive transcranial magnetic stimulation (rTMS) over the prefrontal cortex has been proposed as a feasible and effective strategy with minimal risk. The neurobiological basis of its therapeutic effect may involve neuroplastic modifications in limbic and cognitive networks. However, the way this networks reorganize might be strongly influenced by the environment. To address this issue, we propose a combined strategy that includes NIBS together with cognitive and behavioral interventions.

A microfabricated coil for implantable applications of magnetic spinal cord stimulation

In this paper, a microfabricated inductive coil comprising of 125-turn coil windings and a MnZn-based magnetic core in a volume of 200 mm(3) is presented for the magnetic neural stimulation in a spinal cord. The coil winding with the parallel-linkage design instead of the typical serial-linkage one is proposed not only to provide better design flexibility to the current mode driving circuit but also to simplify the fabrication process of the 3-D inductive coil, which can further advance the coil miniaturization. Experimental results show the microcoil with a 1.5 A, 1 kHz square-wave current input can induce a voltages of ~220 μV on the conducting wire with an impedance of ~0.2 Ω @ 1 kHz, 1 mm separation.

Parkinson's Disease and Its Management: Part 5: Treatment of Nonmotor Complications

Most patients with Parkinson's disease experience nonmotor complications, broadly classified as either neuropsychiatric presentations or autonomic disorders. Despite the prevalence of these nonmotor features, treatment options for them are limited.

Mechanisms and therapeutic applications of electromagnetic therapy in Parkinson's disease

Electromagnetic therapy is a non-invasive and safe approach for the management of several pathological conditions including neurodegenerative diseases. Parkinson's disease is a neurodegenerative pathology caused by abnormal degeneration of dopaminergic neurons in the ventral tegmental area and substantia nigra pars compacta in the midbrain resulting in damage to the basal ganglia. Electromagnetic therapy has been extensively used in the clinical setting in the form of transcranial magnetic stimulation, repetitive transcranial magnetic stimulation, high-frequency transcranial magnetic stimulation and pulsed electromagnetic field therapy which can also be used in the domestic setting. In this review, we discuss the mechanisms and therapeutic applications of electromagnetic therapy to alleviate motor and non-motor deficits that characterize Parkinson's disease.

Repetitive Transcranial Magnetic Stimulation (rTMS) Therapy in Parkinson Disease: A Meta-Analysis

OBJECTIVE

Several studies have reported repetitive transcranial magnetic stimulation (rTMS) therapy as an effective treatment for the control of motor symptoms in Parkinson disease. The objective of the study is to quantify the overall efficacy of this treatment.

TYPES

Systematic review and meta-analysis.

LITERATURE SURVEY

We reviewed the literature on clinical rTMS trials in Parkinson disease since the technique was introduced in 1980. We used the following databases: MEDLINE, Web of Science, Cochrane, and CINAHL.

METHODOLOGY

PATIENTS AND SETTING

Patients with Parkinson disease who were participating in prospective clinical trials that included an active arm and a control arm and change in motor scores on Unified Parkinson's Disease Rating Scale as the primary outcome. We pooled data from 21 studies that met these criteria. We then analyzed separately the effects of low- and high-frequency rTMS on clinical motor improvements.

SYNTHESIS

The overall pooled mean difference between treatment and control groups in the Unified Parkinson's Disease Rating Scale motor score was significant (4.0 points, 95% confidence interval, 1.5, 6.7; P = .005). rTMS therapy was effective when low-frequency stimulation (≤ 1 Hz) was used with a pooled mean difference of 3.3 points (95% confidence interval 1.6, 5.0; P = .005). There was a trend for significance when high-frequency stimulation (≥ 5 Hz) studies were evaluated with a pooled mean difference of 3.9 points (95% confidence interval, -0.7, 8.5; P = .08). rTMS therapy demonstrated benefits at short-term follow-up (immediately after a treatment protocol) with a pooled mean difference of 3.4 points (95% confidence interval, 0.3, 6.6; P = .03) as well as at long-term follow-up (average follow-up 6 weeks) with mean difference of 4.1 points (95% confidence interval, -0.15, 8.4; P = .05). There were insufficient data to statistically analyze the effects of rTMS when we specifically examined bradykinesia, gait, and levodopa-induced dyskinesia using quantitative methods.

CONCLUSION

rTMS therapy in patients with Parkinson disease results in mild-to-moderate motor improvements and has the potential to be used as an adjunct therapy for the treatment of Parkinson disease. Future large, sample studies should be designed to isolate the specific clinical features of Parkinson disease that respond well to rTMS therapy.

Repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression in Parkinson disease: a meta-analysis of randomized controlled clinical trials

The objective of this meta-analysis was to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression in patients with Parkinson disease in order to arrive at qualitative and quantitative conclusions about the efficacy of rTMS. We included randomized controlled trials examining the effects of rTMS compared with sham-rTMS or selective serotonin re-uptake inhibitors (SSRIs). The quality of included studies was strictly evaluated. Data analyses were performed using the RevMan5.1 software. Eight studies including 312 patients met all inclusion criteria. The results showed that rTMS could evidently improve the HRSD score compared with sham-rTMS (p < 0.00001). However, we found similar antidepressant efficacy between rTMS and SSRIs groups in terms of HRSD and BDI score (p = 0.65; p = 0.75, respectively). Furthermore, patients who received rTMS could evidently show improvement on the unified Parkinson's disease rating scale (UPDRS), ADL score, and UPDRS motor score compared with sham-rTMS or SSRIs (p < 0.05, p = 0.05, respectively). The subgroup analysis by frequency of rTMS evidenced that the efficacy of low-frequency rTMS was superior to sham-rTMS (p < 0.0001) in terms of the outcome measure according to HAMD scale. Meanwhile, the high-frequency rTMS has the same antidepressant efficacy as SSRIs (p = 0.94). The current meta-analysis provided evidence that rTMS was superior to sham-rTMS and had similar antidepressant efficacy as SSRIs, and may have the additional advantage of some improvement in motor function.

Antidepressive treatments for Parkinson's disease: A systematic review and meta-analysis

CONTEXT

Depression affects 50-70% of patients with Parkinson's disease resulting in significant comorbidity, executive dysfunction, and poorer quality of life. Divergent results from studies of different treatments preclude definite treatment recommendations.

OBJECTIVE

To perform a systematic review and meta-analysis of published randomized controlled trials (RCTS) evaluating the efficacy of pharmacologic and behavioral interventions, and repetitive transcranial magnetic stimulation (rTMS) for depression among patients with idiopathic Parkinson's disease.

DATA SOURCES

Trial registers and the following databases were searched: PubMed, CINAHL, EMBASE, and PsycInfo. Bibliographies of relevant articles were cross-referenced.

STUDY SELECTION AND DATA EXTRACTION

RCTs comparing pharmacologic, behavioral, or rTMS with a placebo/other drugs or methods with no restrictions on participant age, gender, and duration or setting of treatment were included. Eligibility assessment was performed independently. Identified records were sequentially screened according to eligibility criteria. Differences in mean depression score and 95% confidence intervals were calculated.

RESULTS

A total of 893 idiopathic Parkinson's disease patients with clinical depression across 20 RCTs were included. The overall standard mean difference for all pharmacologic interventions was 0.30 (95% CI -0.00, 0.61, p = 0.054). On stratification, there was a distinct difference in effect between antidepressants (SMD of 0.54, 95%CI 0.24, 0.83, p = 0.000) and non-antidepressants (SMD of -0.29, 95% CI -0.86, 0.29, p = 0.328). Behavioral interventions demonstrated significant efficacy with an effect size of 0.87 (95% CI 0.41, 1.33, p = 0.000).

CONCLUSIONS

This meta-analysis demonstrates that pharmacologic treatment with antidepressant medications, specifically the selective serotonin reuptake inhibitors (SSRIs), and behavioral interventions (CBT) significantly improved depression among Parkinson's disease patients.

Monoamine reuptake inhibitors in Parkinson's disease

The motor manifestations of Parkinson's disease (PD) are secondary to a dopamine deficiency in the striatum. However, the degenerative process in PD is not limited to the dopaminergic system and also affects serotonergic and noradrenergic neurons. Because they can increase monoamine levels throughout the brain, monoamine reuptake inhibitors (MAUIs) represent potential therapeutic agents in PD. However, they are seldom used in clinical practice other than as antidepressants and wake-promoting agents. This review article summarises all of the available literature on use of 50 MAUIs in PD. The compounds are divided according to their relative potency for each of the monoamine transporters. Despite wide discrepancy in the methodology of the studies reviewed, the following conclusions can be drawn: (1) selective serotonin transporter (SERT), selective noradrenaline transporter (NET), and dual SERT/NET inhibitors are effective against PD depression; (2) selective dopamine transporter (DAT) and dual DAT/NET inhibitors exert an anti-Parkinsonian effect when administered as monotherapy but do not enhance the anti-Parkinsonian actions of L-3,4-dihydroxyphenylalanine (L-DOPA); (3) dual DAT/SERT inhibitors might enhance the anti-Parkinsonian actions of L-DOPA without worsening dyskinesia; (4) triple DAT/NET/SERT inhibitors might exert an anti-Parkinsonian action as monotherapy and might enhance the anti-Parkinsonian effects of L-DOPA, though at the expense of worsening dyskinesia.

Current Concepts in the Treatment of Multiple System Atrophy

MSA is a progressive neurodegenerative disorder characterized by autonomic failure and a variable combination of poor levodopa-responsive parkinsonism and cerebellar ataxia (CA). Current therapeutic management is based on symptomatic treatment. Almost one third of MSA patients may benefit from l-dopa for the symptomatic treatment of parkinsonism, whereas physiotherapy remains the best therapeutic option for CA. Only midodrine and droxidopa were found to be efficient for neurogenic hypotension in double-blind, controlled studies, whereas other symptoms of autonomic failure may be managed with off-label treatments. To date, no curative treatment is available for MSA. Recent results of neuroprotective and -restorative trials have provided some hope for future advances. Considerations for future clinical trials are also discussed in this review.