Immediate placebo effect in Parkinson's disease--is the subjective relief accompanied by objective improvement?

Characteristics of Surface Electromyograph Activity of Cervical Extensors and Flexors in Nonspecific Neck Pain Patients: A Cross-Sectional Study

Background and Objectives: We identified typical surface electromyogram (sEMG) activities of the cervical extensors and flexors during motions in the three anatomical planes in healthy adults. The aim of this study was to explore characteristics of sEMG activities of these cervical muscles in nonspecific neck pain (NSNP) patients based on healthy adults. Materials and Methods: Participants were 24 NSNP patients (NSNP group, mean ± SD of age, 47.5 ± 15.5) and 24 healthy adults (control group, 20.5 ± 1.4). For each participant, sEMG of the cervical extensors and flexors was recorded during neck flexion, extension, bilateral lateral flexion, bilateral rotation, and at the neutral position in Phase I (the neck from the neutral position to the maximum range of motion), Phase II (at the maximum range of motion), and Phase III (from the maximum range of motion to the neutral position), yielding a total of 42 phases. A percentage of maximum voluntary contraction to normalize muscle activity in each phase was calculated to obtain the ratio of muscle activities in the extensors and flexors in each of 36 phases of the motions to the neutral position and ratio of the flexors to extensors in activity for 21 phases. Results: In 28 of 36 phases of the motions, the ratios of muscle activities in the extensors and flexors to the neutral position in the NSNP group were significantly larger than the control group (p < 0.05). In 6 of 21 phases, the ratios of the flexors to extensors in activity in the NSNP group were significantly larger than in the control group (p < 0.05). Conclusions: In NSNP patients, the activity of the cervical extensors and flexors associated with neck motion increased with an imbalance in activity between these muscles compared to their activity in healthy adults. The results of this study will be useful in understanding the pathogenesis of NSNP and in constructing an objective evaluation of the treatment efficacy on NSNP patients.

How Should Transcranial Direct Current Stimulation be Used in Populations With Severe Alcohol Use Disorder? A Clinically Oriented Systematic Review

Background and rationale. Severe alcohol use disorder (SAUD) is a major public health concern, given its massive individual, interpersonal, and societal consequences. The available prevention and treatment programs have proven limited effectiveness, as relapse rates are still high in this clinical population. Developing effective interventions reducing the appearance and persistence of SAUD thus constitutes an experimental and clinical priority. Among the new therapeutic approaches, there is a growing interest for noninvasive neuromodulation techniques, and particularly for transcranial direct current stimulation (tDCS) as an adjunctive treatment in neuropsychiatric disorders, including SAUD. Methods. We propose a systematic review, based on preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, evaluating the available evidence on the effectiveness of tDCS to improve clinical interventions in SAUD. Results. We provide an integrative overview of studies applying tDCS in clinical populations with SAUD, together with a standardized methodological quality assessment. We show that the currently available data remain inconsistent. Some data suggested that tDCS can (1) reduce craving, relapse or alcohol-cue reactivity and (2) improve cognitive control and inhibition. However, other studies did not observe any beneficial effect of tDCS in SAUD. Conclusions. Capitalizing on the identified strengths and shortcomings of available results, we present evidence-based clinical guidelines to integrate tDCS in current clinical settings and to combine it with neurocognitive training.

Wearable Sensors Measure Ankle Joint Changes of Patients with Parkinson's Disease before and after Acute Levodopa Challenge

Background

Previous studies found levodopa could improve the activity of the ankle joints of patients with Parkinson's disease (PD). But ankle joint movement is composed of four motion ranges. The specific changes of four motion ranges in PD remain unknown.

Objective

The purpose of this study was to decompose the complex ankle joint movement, measure ankle joint changes before and after the acute levodopa challenge test (ALCT), and investigate the effects of these parameters on gait performance.

Methods

29 PD patients and 30 healthy control subjects (HC) completed the Instrumented Stand and Walk (ISAW) test and gait parameters were collected by the JiBuEn gait analysis system. The percentage of improvement of gait data and the UPDRS III in the on-drug condition (ON) were determined with respect to the off-drug condition (OFF).

Results

We observed a reduction in the heel strike angle (HS), 3-plantarflexion (3-PF) angle, and 4-dorsiflexion (4-DF) angle of ankle joints. We did not find significant difference in the toe-off angle (TO), 1-plantarflexion (1-PF) angle, and 2-dorsiflexion (2-DF) angle among three groups. Stride length improvement rate was significantly correlated with HS (r _s = 0.616, P < 0.001) and 3-PF (r _s = 0.639, P < 0.001) improvement rates. The improvement in the sum of rigidity items (UPDRS motor subsection item 22) was also correlated with HS (r _s = 0.389, P=0.037) and 3-PF (r _s = 0.373, P=0.046) improvement rates.

Conclusions

Exogenous levodopa supplementation can significantly reduce the rigidity of patients with PD, improve their 3-PF and 4-DF of ankle joint kinematic parameters, and ultimately enhance their gait.

Neurobiology of placebo effect in Parkinson's disease: What we have learned and where we are going

The placebo effect is a phenomenon produced when an inert substance administered like a regular treatment improves the clinical outcome. Parkinson's disease (PD) is one of the main clinical disorders for which the placebo response rates are high. The first evidence of the neurobiological mechanisms underlying the placebo effect in PD stems from 2001, when de la Fuente-Fernandez and colleagues demonstrated that a placebo injection led to the release of dopamine in the striatal nuclei of PD measured with positron emission tomography technology. Since then, several studies have been conducted to investigate the neurobiological underpinnings of placebo responses. This article presents a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Of an initial yield of 143 papers, 19 were included. The lessons learned from these studies are threefold: (i) motor improvement is dependent on the activation of the entire nigrostriatal pathway induced by dopamine release in the dorsal striatum; (ii) the magnitude of placebo-induced effects is modulated by an expectancy of improvement, which is in turn related to the release of dopamine within the ventral striatum; (iii) the functioning of the neural pathways underlying the placebo response can be tuned by prior exposure and learning strategies. In conclusion, although the neural network underlying the placebo effect in PD has been largely confirmed and accepted, what remains to be established is how, when, and where the expectation of reward (mediated by the ventral striatum) interacts with the primary motor system (mediated by the dorsal striatum) to induce clinical improvement in motor symptoms. © 2018 International Parkinson and Movement Disorder Society.

Distinct behavioral response of primary motor cortex stimulation in itch and pain after burn injury

It is still unclear whether chronic neuropathic pain and itch share similar neural mechanisms. They are two of the most commonly reported challenges following a burn injury and can be some of the most difficult to treat. Transcranial direct current stimulation (tDCS) has previously been studied as a method to modulate pain related neural circuits. Therefore, we aimed to test the effects of tDCS on post-burn neuropathic pain and itch as to understand whether this would induce a simultaneous modulation of these two sensory manifestations. We conducted a pilot randomized controlled clinical trial comprised of two phases of active or sham M1 tDCS (Phase I: 10 sessions followed by a follow-up period of 8 weeks; Phase II: additional 5 sessions followed by a follow-up period of 8 weeks, and a final visit 12 months from baseline). Pain levels were assessed with the Brief Pain Inventory (BPI) and levels of itch severity were assessed with the Visual Analogue Scale (VAS). Measurements were collected at baseline, after the stimulation periods, at 2, 4 and 8-week follow up both for Phase I and II, and at the final visit. Sixteen patients were assigned to the active group and 15 to the sham group. Ten sessions of active tDCS did not reduce the level of pain or itch. We identified that itch levels were reduced at 2-week follow-up after the sham tDCS session, while no placebo effect was found for the active group. No difference between active and sham groups was observed for pain. We did not find any treatment effects during Phase II. Based on these findings, it seems that an important placebo effect occurred during sham tDCS for itch, while active M1 tDCS seems to disrupt sensory compensatory mechanisms. We hypothesize that pain and itch are complementary but distinct mechanisms of adaptation after peripheral sensory injury following a burn injury and need to be treated differently.

Evaluation of D1/D5 Partial Agonist PF-06412562 in Parkinson's Disease following Oral Administration

BACKGROUND

PF-06412562 is a moderately potent, highly selective oral D1/D5 dopamine receptor partial agonist.

OBJECTIVE

To study the efficacy and safety of a single, oral, split dose of PF-06412562 in patients with Parkinson's disease.

METHODS

Following overnight levodopa (L-dopa, Sinemet®) washout, subjects received a single dose of levodopa in open-label period 1. Periods 2 and 3 had a double-blinded, sponsor-open, randomized, 2-way cross-over, placebo-controlled design, during which subjects were randomized to PF-06412562 30 mg (+ 20 mg 4 h later) or placebo. Maximum percent improvement from baseline in finger-tapping speed (measure of bradykinesia) measured using KinesiaTM technology (as the primary end point) and change from baseline in the Movement Disorder Society's Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS-III) motor section scores (the preferred exploratory end point) were evaluated.

RESULTS

Nineteen subjects received levodopa; 13 met the period 2/3 entry criteria and received PF-06412562, 30 + 20 mg, or placebo. The prespecified primary efficacy criterion for significant improvement in finger-tapping was not met due to inconsistencies in the task leading to large between-period fluctuations of within-patient baseline values. Change from baseline in MDS-UPDRS-III score with PF-06412562 resulted in a placebo-adjusted point estimate of -10.59 with a one-sided 90% upper CI of PF-06412562 versus placebo model-based contrast of (-inf, -7.44) at 1.5-2.5 h after the dose (p < 0.0001). All adverse events were mild-to-moderate.

CONCLUSIONS

We report the first evidence of potential anti-parkinsonian efficacy of the oral selective D1/D5 partial agonist PF-06412562 without the significant acute changes in cardiovascular parameters reported with previous D1 agonists.

Effect of Subthalamic Deep Brain Stimulation on Upper Limb Dexterity in Patients with Parkinson Disease

OBJECTIVE

The efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on dexterity remains controversial despite its recognition as an effective strategy for Parkinson disease. The present study investigated the efficacy of STN-DBS for ameliorating bradykinesia and dexterity compared with dopaminergic medications.

METHODS

Part III of the Unified Parkinson's Disease Rating Scale was used for the evaluation of bradykinesia, whereas the Purdue Pegboard Test and the Box and Block test were selected for dexterity.

RESULTS

Our findings indicate that bradykinesia is significantly improved with both DBS and dopaminergic medication, whereas dexterity is improved only with DBS. Dopaminergic medication did not show a satisfactory efficacy on dexterity, and there was little synergistic effect of dopaminergic medication and STN-DBS for improving dexterity associated with Parkinson disease.

CONCLUSIONS

Our results suggest that DBS is potentially more effective than dopaminergic medications for improving dexterity. The disparities in efficacy for bradykinesia and dexterity between DBS and dopaminergic medication hint at the potential mechanisms of STN-DBS. We speculate that DBS follows at least 2 different mechanisms for improving parkinsonian symptoms: 1) the dopaminergic system, primarily for the improvement of bradykinesia and 2) the nondopaminergic system, for the improvement of dexterity. This hypothesis requires further verification and investigation.

Effects of Transcranial Direct Current Stimulation, Transcranial Pulsed Current Stimulation, and Their Combination on Brain Oscillations in Patients with Chronic Visceral Pain: A Pilot Crossover Randomized Controlled Study

OBJECTIVE

Chronic visceral pain (CVP) syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different neuromodulation techniques in patients with CVP on cortical activity, through electreocephalography (EEG) and on pain perception, through clinical tests.

DESIGN

A pilot crossover randomized controlled study.

SETTINGS

Out-patient.

SUBJECTS

Adults with CVP (>3 months).

METHODS

Participants received four interventions in a randomized order: (1) transcranial pulsed current stimulation (tPCS) and active transcranial direct current stimulation (tDCS) combined, (2) tPCS alone, (3) tDCS alone, and (4) sham condition. Resting state quantitative electroencephalography (qEEG) and pain assessments were performed before and after each intervention. Results were compared with a cohort of 47 healthy controls.

RESULTS

We enrolled six patients with CVP for a total of 21 visits completed. Compared with healthy participants, patients with CVP showed altered cortical activity characterized by increased power in theta, alpha and beta bands, and a significant reduction in the alpha/beta ratio. Regarding tES, the combination of tDCS with tPCS had no effect on power in any of the bandwidths, nor brain regions. Comparing tPCS with tDCS alone, we found that tPCS induced higher increase in power within the theta and alpha bandwidths.

CONCLUSION

This study confirms that patients with CVP present abnormal EEG-indexed cortical activity compared with healthy controls. Moreover, we showed that combining two types of neurostimulation techniques had no effect, whereas the two interventions, when applied individually, have different neural signatures.

Identifying placebo responders and predictors of response in osteoarthritis: a protocol for individual patient data meta-analysis

BACKGROUND

The management of osteoarthritis (OA) is unsatisfactory, as most treatments are not clinically effective over placebo and most drugs have considerable side effects. On average, 75 % of the analgesic effect from OA treatments in clinical trials can be attributed to a placebo response, and this response varies greatly from patient to patient. This individual patient data (IPD) meta-analysis aims to identify placebo responders and the potential determinants of the placebo response in OA.

METHODS

This study is undertaken in conjunction with the OA Trial Bank, an ongoing international consortium aiming to collect IPD from randomised controlled trials (RCTs) for all treatments of OA. RCTs for each treatment of OA have been systematically searched for, and authors of the relevant trials have been contacted to request the IPD. We will use the IPD of placebo-controlled RCTs held by the OA Trial Bank for this project. The IPD in placebo groups will be used to investigate the placebo response according to the minimum clinically important difference (MCID) threshold (e.g. 20 % pain reduction). Responders to placebo will be compared with non-responders to identify predictors of response. The quality of the trials will be assessed and potential determinants will be examined using multilevel logistic regression analyses.

DISCUSSION

This study explores the varying magnitude of the placebo response and the proportion of participants that experience a clinically important placebo effect in OA RCTs. Potential determinants of the placebo response will also be investigated. These determinants may be useful for future studies as it may allow participants to be stratified into groups based on their likely response to placebo. The results of this study may also be useful for pharmaceutical companies, who could improve the design of their studies in order to separate the specific treatment from the non-specific contextual (i.e. placebo) effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016033212.

Pharmacological treatment in Parkinson's disease: Effects on gait

Gait impairments are a hallmark of Parkinson's disease (PD), both as early symptom and an important cause of disability later in the disease course. Although levodopa has been shown to improve gait speed and step length, the effect of dopamine replacement therapy on other aspects of gait is less well understood. In fact, falls are not reduced and some aspects of postural instability during gait are unresponsive to dopaminergic treatment. Moreover, many medications other than dopaminergic agents, can benefit or impair gait in people with PD. We review the effects of pharmacological interventions used in PD on gait, discriminating, whenever possible, among effects on four components of everyday mobility: straight walking, gait initiation, turning, gait adaptability. Additionally, we summarize the effects on freezing of gait. There is substantial evidence for improvement of spatial characteristics of simple, straight-ahead gait with levodopa and levodopa-enhancing drugs. Recent work suggests that drugs aiming to enhance the acetylcholine system might improve gait stability measures. There is a lack of well-designed studies to evaluate effects on more complex, but highly relevant walking abilities such as turning and making flexible adjustments to gait. Finally, paucity in the literature exists on detrimental effects of drugs used in PD that are known to worsen gait and postural stability in the elderly population.

Long-Term Treatment with High-Dose Thiamine in Parkinson Disease: An Open-Label Pilot Study

OBJECTIVES

To investigate the potential clinical, restorative, and neuroprotective effects of long-term treatment with thiamine in Parkinson disease (PD).

DESIGN

Observational open-label pilot study.

SETTING

Outpatient neurologic rehabilitation clinic.

PATIENTS AND METHODS

Starting in June 2012, we have recruited 50 patients with PD (33 men and 17 women; mean age, 70.4 ± 12.9 years; mean disease duration, 7.3 ± 6.7 years). All the patients were assessed at baseline with the Unified Parkinson's Disease Rating Scale (UPDRS) and the Fatigue Severity Scale (FSS) and began treatment with 100 mg of thiamine administered intramuscularly twice a week, without any change to personal therapy. All the patients were re-evaluated after 1 month and then every 3 months during treatment.

RESULTS

Thiamine treatment led to significant improvement of motor and nonmotor symptoms: mean UPDRS scores (parts I-IV) improved from 38.55 ± 15.24 to 18.16 ± 15.08 (p = 2.4 × 10(-14), t test for paired data) within 3 months and remained stable over time; motor UPDRS part III score improved from 22.01 ± 8.57 to 9.92 ± 8.66 (p = 3.1 × 10(-22)). Some patients with a milder phenotype had complete clinical recovery. FSS scores, in six patients who had fatigue, improved from 53.00 ± 8.17 to 23.60 ± 7.77 (p < 0.0001, t test for paired data). Follow-up duration ranged from 95 to 831 days (mean, 291.6 ± 207.2 days).

CONCLUSIONS

Administration of parenteral high-dose thiamine was effective in reversing PD motor and nonmotor symptoms. The clinical improvement was stable over time in all the patients. From our clinical evidence, we hypothesize that a dysfunction of thiamine-dependent metabolic processes could cause selective neural damage in the centers typically affected by this disease and might be a fundamental molecular event provoking neurodegeneration. Thiamine could have both restorative and neuroprotective action in PD.

Retrospective Evaluation of Deep Transcranial Magnetic Stimulation as Add-On Treatment for Parkinson's Disease

Objective

To evaluate the safety and assess the different symptom improvements found after a combined low-frequency primary motor cortex and high-frequency prefrontal cortex (PFC) stimulation using the deep TMS (dTMS) H-coil, as an add-on treatment for Parkinson’s disease (PD).

Methods

Forty-five PD patients underwent 14 dTMS sessions; each consisting of 1 Hz stimulation of the primary motor cortex for 15 min, followed by 10 Hz stimulation of the PFC for 15 min. Clinical assessments were performed, BEFORE, at the MIDDLE, and END of therapy as well as at FOLLOW-UP after 30 days, using Movement Disorder Society-Unified Parkinson’s Disease Rating Scale, TINETTI, UP&GO, SCOPA, HDRS₂₁, Beck Depression Inventory, and self-applied daily motor assessment scales.

Results

Treatment was well-tolerated, without serious adverse effects. dTMS-induced significant PD symptom improvements at END and at FOLLOW-UP, in all subscales of the UPDRS, gait speed, depressive symptoms, balance, autonomic symptoms, and a 73% increase in daily ON time.

Conclusion

In the cohort of PD patients treated, dTMS was well-tolerated with only minor adverse effects. The dTMS-induced significant improvements in motor, postural, and motivational symptoms of PD patients and may potentiate concurrent levodopa treatment.

Significance

The present study demonstrates that dTMS may have a much wider spectrum of beneficial effects than previously reported for TMS, including enhancement of levodopa effects, suggesting that future clinical trials with dTMS should include a broader range of symptom measurements.

A systematic review found no consistent difference in effect between more and less intensive placebo interventions

OBJECTIVES

It has been suggested that some placebo interventions might be associated with larger clinical effects than others. In a systematic review, we investigated whether there is evidence from direct comparisons in randomized clinical trials including two or more placebo groups supporting this hypothesis.

STUDY DESIGN AND SETTING

Eligible trials were identified through electronic database searches and citation tracking up to February 2013. Placebo interventions in a trial were categorized into a more intense and a less intense intervention based on complexity, invasiveness, or route of administration and time needed for application.

RESULTS

Twelve studies with 1,059 patients receiving placebo met the eligibility criteria. Studies were highly heterogeneous regarding patients, interventions, outcomes, and risk of bias. Seven studies did not find any significant differences between the more intense and the less intense placebo intervention, four studies found differences for single outcomes, and one study consistently reported significantly larger effects of the more intense placebo. An explorative meta-analysis yielded a standardized mean difference -0.22 (95% confidence interval: -0.46, 0.02; P = 0.07; I(2) = 68%).

CONCLUSION

In the studies included in this review, more intense placebos were not consistently associated with larger effects than less intense placebos.

Theta burst stimulation over the supplementary motor area in Parkinson's disease

To investigate whether a period of continuous theta burst stimulation (cTBS) over the supplementary motor area (SMA) induces cortical plasticity and thus improves bradykinesia in Parkinson's disease (PD) in the medication ON and OFF state. In total, 26 patients with Parkinson's disease were tested with both real and sham stimulation. The group was divided into an OFF-medication (4 females, mean age 65 years, disease duration 6 years) and an ON-medication group (7 females, mean age 61 years, disease duration 7 years) with each containing 13 individuals. Both groups were evaluated in terms of electrophysiological (motor-evoked potentials) and behavioural [Purdue Pegboard test (PPT), UPDRS motor subscore] parameters before (baseline condition) and after a 40-second period of real or sham continuous theta burst stimulation over the SMA ON and OFF dopaminergic drugs. Patients in the OFF group demonstrated an improved UPDRS III score (p < 0.05) and a better performance in the PPT for the less affected side (p < 0.025) compared to baseline after real stimulation. However, electrophysiological parameters did not change in either the ON or the OFF state. cTBS over the SMA has a mild effect on motor symptoms of the upper limb in the OFF state of PD patients. In contrast, stimulation did not change cortico-spinal excitability. A lack of change (i.e. no plasticity) to brain stimulation protocols is a known finding in PD. A clinical improvement in the OFF state, however, contrasts with this and the mechanism of these induced changes is worth further exploration.

Mood and cognitive effects of transcranial direct current stimulation in post-stroke depression

Depression following stroke (PSD) affects up to 33% of patients and is associated with increased mortality. Antidepressant drugs have several side effects; therefore novel treatments are needed. Transcranial direct current stimulation (tDCS) has induced mood and cognitive gain in several neuropsychiatric conditions but has not been tested for PSD to date. Here, we report a patient with significant mood and cognitive impairment who showed marked amelioration of these symptoms following anodal stimulation (2 mA per 30 minutes per 10 days) over the left dorsolateral prefrontal cortex. We discuss the possible mechanisms of tDCS in improving PSD. This initial preliminary data is useful to encourage further controlled trials on the field.

A randomized, double-blind trial of transcranial electrostimulation in early Parkinson's disease

We studied the effects of noninvasive transcranial electrical stimulation on the motor and psychological symptoms of early Parkinson's disease. Twenty-three subjects were treated with 10 days of placebo versus active treatment and then followed for 14 weeks. Baseline off medication Unified Parkinson's Disease Rating Scale parts I-III was 29.4 ± 10.0. The primary end point, Unified Parkinson's Disease Rating Scale in week 2 following treatment, reduced by 5.3 ± 9.7 for those in active treatment and 7.7 ± 4.8 for those receiving placebo (not significant). Similarly, no significant differences were seen in the Hamilton Anxiety Scale, Geriatric Depression Scale, and Epworth Sleepiness Scale over the duration of the study. The treatment was well tolerated without device-related adverse events. Despite the negative study, nonpharmacological approaches should continue to be pursued in Parkinson's disease, as they are generally well received by patients.

Student Reactions to the Shootings at Virginia Tech and Northern Illinois University: Does Sharing Grief and Support Over the Internet Affect Recovery?

After the shootings at Virginia Tech and Northern Illinois University, many students gravitated to the Internet for support. Despite the fact that the Internet plays a major role in how people live their lives in contemporary society, little is known about how people use the Internet in times of tragedy and whether this use affects well-being. To address these issues, the current study assessed the types of online activities more than 200 Virginia Tech and Northern Illinois University students participated in 2 weeks after the shootings and again 6 weeks later, as well as their depressive and posttraumatic stress disorder (PTSD) symptoms. Results showed that 2 weeks after the shootings, nearly 75% of students were suffering from significant psychological distress. Additionally, students participated in numerous online activities related to the shootings. Importantly, students perceived their Internet activities as being beneficial, although there was no evidence that Internet use affected their well-being.

Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting

The use of neuromodulation as a treatment for major depressive disorder (MDD) has recently attracted renewed interest due to development of other non-pharmacological therapies besides electroconvulsive therapy (ECT) such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). METHOD: We convened a working group of researchers to discuss the updates and key challenges of neuromodulation use for the treatment of MDD. RESULTS: The state-of-art of neuromodulation techniques was reviewed and discussed in four sections: [1] epidemiology and pathophysiology of MDD; [2] a comprehensive overview of the neuromodulation techniques; [3] using neuromodulation techniques in MDD associated with non-psychiatric conditions; [4] the main challenges of neuromodulation research and alternatives to overcome them. DISCUSSION: ECT is the first-line treatment for severe depression. TMS and tDCS are strategies with a relative benign profile of side effects; however, while TMS effects are comparable to antidepressant drugs for treating MDD; further research is needed to establish the role of tDCS. DBS and VNS are invasive strategies with a possible role in treatment-resistant depression. In summary, MDD is a chronic and incapacitating condition with a high prevalence; therefore clinicians should consider all the treatment options including invasive and non-invasive neuromodulation approaches.

An fMRI study on the interaction and dissociation between expectation of pain relief and acupuncture treatment

It is well established that expectation can significantly modulate pain perception. In this study, we combined an expectancy manipulation model and fMRI to investigate how expectation can modulate acupuncture treatment. Forty-eight subjects completed the study. The analysis on two verum acupuncture groups with different expectancy levels indicates that expectancy can significantly influence acupuncture analgesia for experimental pain. Conditioning positive expectation can amplify acupuncture analgesia as detected by subjective pain sensory rating changes and objective fMRI signal changes in response to calibrated noxious stimuli. Diminished positive expectation appeared to inhibit acupuncture analgesia. This modulation effect is spatially specific, inducing analgesia exclusively in regions of the body where expectation is focused. Thus, expectation should be used as an important covariate in future studies evaluating acupuncture efficacy. In addition, we also observed dissociation between subjective reported analgesia and objective fMRI signal changes to calibrated pain in the analysis across all four groups. We hypothesize that as a peripheral-central modulation, acupuncture needle stimulation may inhibit incoming noxious stimuli; while as a top-down modulation, expectancy (placebo) may work through the emotional circuit.

Mirror, mirror on the wall: placebo effects that exist only in the eye of the beholder

Rationale The extent to which placebo effects can be driven exclusively by subjective impressions of improvement in the absence of any independent corroboration is unclear. Methods Thirty-six self-referred patients were treated with a light therapy device intended to rejuvenate facial skin. At each of eight weekly treatments, participants' facial skin was exposed for 40 seconds to pulses of multispectral LED-generated light in the range of 588 nm wavelength at 0.1 J cm(-2). Outcomes were assessed by participants as well as by the treating doctor and by blinded, expert raters. Results Patients reported robust and statistically significant improvements in seven facial features at the conclusion of the 8-week treatment regimen as well as at 1-month follow-up (for all comparisons, P </= 0.003, median d = 1.14). In sharp contrast, both the treating doctor and blinded, expert raters were unable to detect any improvement whatsoever (for all comparisons, P > 0.05). Moreover, effect sizes were close to zero and in the opposite direction from improvement (median d = -0.06 for doctor ratings; and for observer ratings, there was only a 46% success rate at identifying post-treatment as compared with pre-treatment photographs). Conclusion The robust placebo responses documented in this trial were confined to the subjective impressions of the patients. Neither the treating doctor nor blinded, expert raters could detect any improvement. Thus, patients can perceive improvement in medical interventions in the absence of any independent corroboration that improvement has occurred. This result is used a heuristic to more clearly define the components of the placebo response.

Expectancy and treatment interactions: a dissociation between acupuncture analgesia and expectancy evoked placebo analgesia

Recent advances in placebo research have demonstrated the mind's power to alter physiology. In this study, we combined an expectancy manipulation model with both verum and sham acupuncture treatments to address: 1) how and to what extent treatment and expectancy effects - including both subjective pain intensity levels (pain sensory ratings) and objective physiological activations (fMRI) - interact; and 2) if the underlying mechanism of expectancy remains the same whether placebo treatment is given alone or in conjunction with active treatment. The results indicate that although verum acupuncture+high expectation and sham acupuncture+high expectation induced subjective reports of analgesia of equal magnitude, fMRI analysis showed that verum acupuncture produced greater fMRI signal decrease in pain related brain regions during application of calibrated heat pain stimuli on the right arm. We believe our study provides brain imaging evidence for the existence of different mechanisms underlying acupuncture analgesia and expectancy evoked placebo analgesia. Our results also suggest that the brain network involved in expectancy may vary under different treatment situations (verum and sham acupuncture treatment).

Training Effects Outweigh Effects of Single-Session Conventional rTMS and Theta Burst Stimulation in PD Patients

Background. Focal single-session repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex has been claimed to be capable of improving motor function in Parkinson's disease. Objective. The authors sought to determine which type of rTMS protocol holds the highest potential for future therapeutic application. Methods. Twenty-two patients with Parkinson's disease received 5 different rTMS protocols on 5 consecutive days in a pseudorandomized and counterbalanced order either in the defined OFF condition or with their usual medication. The protocols tested in the present study included 2 conventional rTMS protocols (0.5 and 10 Hz) as well as the recently introduced theta burst stimulation (cTBS, iTBS) and a sham condition. Cortical excitability, motor performance (pointing movement, pronation-supination, Purdue Pegboard Test, walking), and mood were assessed before and after each session. Results . The authors observed motor training from days 1 to 4, particularly in the group on dopaminergic medication. None of the rTMS paradigms excelled placebo stimulation. The only exception was the Purdue Pegboard Test, in which all active stimulation paradigms yielded slightly stronger effects than sham stimulation. Conclusions. Within a single session, no clinically relevant difference in the rTMS protocols could be detected. Training effects outweigh and may have masked rTMS effects, particularly in the group on dopaminergic mediation.

Noninvasive brain stimulation for Parkinson's disease and dystonia

Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are promising noninvasive cortical stimulation methods for adjunctive treatment of movement disorders. They avoid surgical risks and provide theoretical advantages of specific neural circuit neuromodulation. Neuromodulatory effects depend on extrinsic stimulation factors (cortical target, frequency, intensity, duration, number of sessions), intrinsic patient factors (disease process, individual variability and symptoms, state of medication treatment), and outcome measures. Most studies to date have shown beneficial effects of rTMS or tDCS on clinical symptoms in Parkinson's disease (PD) and support the notion of spatial specificity to the effects on motor and nonmotor symptoms. Stimulation parameters have varied widely, however, and some studies are poorly controlled. Studies of rTMS or tDCS in dystonia have provided abundant data on physiology, but few on clinical effects. Multiple mechanisms likely contribute to the clinical effects of rTMS and tDCS in movement disorders, including normalization of cortical excitability, rebalancing of distributed neural network activity, and induction of dopamine release. It remains unclear how to individually adjust rTMS or tDCS factors for the most beneficial effects on symptoms of PD or dystonia. Nonetheless, the noninvasive nature, minimal side effects, positive effects in preliminary clinical studies, and increasing evidence for rational mechanisms make rTMS and tDCS attractive for ongoing investigation.

rTMS treatment for depression in Parkinson's disease increases BOLD responses in the left prefrontal cortex

The mechanisms underlying the effects of antidepressant treatment in patients with Parkinson's disease (PD) are unclear. The neural changes after successful therapy investigated by neuroimaging methods can give insights into the mechanisms of action related to a specific treatment choice. To study the mechanisms of neural modulation of repetitive transcranial magnetic stimulation (rTMS) and fluoxetine, 21 PD depressed patients were randomized into only two active treatment groups for 4 wk: active rTMS over left dorsolateral prefrontal cortex (DLPFC) (5 Hz rTMS; 120% motor threshold) with placebo pill and sham rTMS with fluoxetine 20 mg/d. Event-related functional magnetic resonance imaging (fMRI) with emotional stimuli was performed before and after treatment - in two sessions (test and re-test) at each time-point. The two groups of treatment had a significant, similar mood improvement. After rTMS treatment, there were brain activity decreases in left fusiform gyrus, cerebellum and right DLPFC and brain activity increases in left DLPFC and anterior cingulate gyrus compared to baseline. In contrast, after fluoxetine treatment, there were brain activity increases in right premotor and right medial prefrontal cortex. There was a significant interaction effect between groups vs. time in the left medial prefrontal cortex, suggesting that the activity in this area changed differently in the two treatment groups. Our findings show that antidepressant effects of rTMS and fluoxetine in PD are associated with changes in different areas of the depression-related neural network.

Technology insight: noninvasive brain stimulation in neurology-perspectives on the therapeutic potential of rTMS and tDCS

In neurology, as in all branches of medicine, symptoms of disease and the resulting burden of illness and disability are not simply the consequence of the injury, inflammation or dysfunction of a given organ; they also reflect the consequences of the nervous system's attempt to adapt to the insult. This plastic response includes compensatory changes that prove adaptive for the individual, as well as changes that contribute to functional disability and are, therefore, maladaptive. In this context, brain stimulation techniques tailored to modulate individual plastic changes associated with neurological diseases might enhance clinical benefits and minimize adverse effects. In this Review, we discuss the use of two noninvasive brain stimulation techniques--repetitive transcranial magnetic stimulation and transcranial direct current stimulation--to modulate activity in the targeted cortex or in a dysfunctional network, to restore an adaptive equilibrium in a disrupted network for best behavioral outcome, and to suppress plastic changes for functional advantage. We review randomized controlled studies, in focal epilepsy, Parkinson's disease, recovery from stroke, and chronic pain, to illustrate these principles, and we present evidence for the clinical effects of these two techniques.