[Non-invasive neurostimulation in the treatment of child and adolescent psychiatry]

Neurostimulation is a potentially interesting treatment option for children and adolescents with psychiatric disorders.<br/> AIM: To review the efficacy of two non-invasive neurostimulation techniques, namely repetitive transcranial magnetic stimulation (rtms) and transcranial direct current stimulation (tdcs), in the treatment of child and adolescent psychiatric disorders.<br/> METHOD: We searched the literature research using PubMed.<br/> RESULTS: There is some evidence that rtms is being used to treat unipolar depression, psychosis, autism spectrum disorder, attention deficit hyperactivity disorder and tic disorder. So far, however, very little research has been done on tdcs.<br/> CONCLUSION: Further research is vitally important in order to ensure the safety and efficacy of rtms and tdcs.

[Brain stimulation: the most direct form of neurostimulation]

BACKGROUND

Brain stimulation is the most direct form of neuromodulation. Direct brain stimulation is an older procedure that has taken various forms, but 'non-invasive brain stimulation' is a more recent development.

AIM

To provide an overview of the current arsenal of non-invasive brain stimulation techniques.

METHOD

We discuss the underlying principles, the pros and cons, and the applicability of non-invasive brain stimulation in experimental research and treatment of neuropsychiatric disorders.

RESULTS

Non-invasive brain stimulation is a direct form of neuromodulation, which is not invasive, harmful or painful. Its effects are in principle temporary, which makes the technique suitable for experimental research. At the same time, temporary effects can have lasting clinical consequences, if they target neuroplasticity to aid rehabilitation or alleviate symptoms.

CONCLUSION

Whereas the value of non-invasive brain stimulation for research purposes is undisputed, its efficacy and value as a treatment for neuropsychiatric disorders are still being debated. Nevertheless, the accumulated evidence about the clinical efficacy of the treatment for certain disorders is sufficiently compelling to start thinking about European regulations and standard medical insurance coverage.

[Non-invasive brain stimulation techniques in psychiatric disorders: influential factors and combination of interventions]

BACKGROUND

The causal influence of cortico-subcortical connectivity by means of brain stimulation seems to be an effective biological treatment in psychiatric patients.

AIM

To review the working mechanisms and moderating factors of two non-invasive brain stimulation techniques (NIBS), namely repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS).

METHOD

We reviewed the current literature on the use of nibs in neuropsychiatric disorders.

RESULTS

First of all, stimulation parameters (location of the stimulation, intensity and duration of the stimulation, number of sessions) are important for the effect of nibs. Secondly, it is important to consider the non-specific neuroplasticity that results from NIBS. Thirdly, recent studies suggest that NIBS should be combined with neurobehavioral interventions, namely cognitive interventions, for the purpose of modulating specific neural processes (i.e. specific neuroplasticity).

CONCLUSION

If we want to improve the NIBS treatment in neuropsychiatric patients, we need to consider the factors that influence the patients' response to treatment with rTMS and tDCS.

Dual Target Repetitive Transcranial Magnetic Stimulation In The Treatment Of Comorbid Obsessive-Compulsive Disorder In Patients With Anorexia Nervosa: Preliminary Results Of Two Case Reports

Introduction

Obsessive-compulsive disorder (OCD) is a frequently reported comorbid disorder (20–30%) in patients with anorexia nervosa (AN). Increasing evidence suggests that repetitive transcranial magnetic stimulation (r-TMS) may be effective in the treatment of refractory OCD and to a lesser extent in AN. Hereby, different target areas: supplemental motor area (SMA) and orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex in AN. We report two patients with enduring AN and comorbid treatment resistant OCD treated with r-TMS.

Methods

Both female patients (34 and 26 years respectively) were hospitalized at the Eating Disorder Unit at the Ghent University Hospital. Treatment responses were evaluated with Yale Brown Obsessive Compulsive Scale (Y-BOCS) and weight gain. Inhibitory continuous thetaburst stimulation (cTBS) of the SMA followed by cTBS of the OFC was conducted during 20 sessions, 5 sessions a week, during 4 weeks. Stimulation intensity was respectively 100% and 80% of the motor treshold.

Results

After cTBS treatment Y-BOCS score of both patients decreased (31 to 24 and 31 to 23 respectively). Only one patient showed a 10% increase of weight. The treatment was well tolerated. No significant side effects were reported.

Conclusion

Treatment resistant comorbid OCD in patients with AN may be succesfully treated with cTBS.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Reduced intra-individual reaction time variability during a Go-NoGo task in detoxified alcohol-dependent patients after one right-sided dorsolateral prefrontal HF-rTMS session

AIMS

As alcohol dependency is characterized by severe executive function deficits, we examined the influence of high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) applied to the right dorsolateral prefrontal cortex (DLPFC) on executive functioning in recently detoxified alcohol-dependent patients.

METHODS

In this randomized, single blind, sham (placebo)-controlled, crossover study, we included 50 detoxified alcohol-dependent patients. We examined the effect of a single right DLPFC HF-rTMS session on commission errors, mean reaction times (RTs) and intra-individual reaction time variability (IIRTV) during a Go-NoGo task (50% Go/50% NoGo condition) in 29 alcohol-dependent patients. Patients completed this cognitive task immediately before and immediately after the stimulation session. In order to avoid carry-over effects between stimulation sessions, a 1-week inter-session interval was respected. Because rTMS treatment has been shown to affect subjective craving, all patients were also assessed with the Obsessive Compulsive Drinking Scale (OCDS).

RESULTS

After both stimulation conditions, we observed a significant decrease of commission errors, without differences between active and sham HF-rTMS stimulation. No significant difference was observed between active and sham stimulation on mean RT. However, only active stimulation resulted in a significant decrease in IIRTV. No effects of stimulation were found for the craving measurements.

CONCLUSION

Our findings suggest that in recently detoxified alcohol-dependent patients, one right-sided HF-rTMS session stabilizes cognitive performance during executive control tasks, implying that active stimulation reduces patients' proneness to attentional lapses.

Parsing the components of the psychomotor syndrome in schizophrenia

OBJECTIVE

Catatonia, extrapyramidal signs, psychomotor slowing, and (motoric) neurological soft signs are well-known psychomotor symptoms in schizophrenia. This study aims at investigating the interrelations between these symptoms. In addition, associations between psychomotor symptoms, clinical symptoms, and cognitive functioning will be studied.

METHOD

An extensive test battery containing psychomotor (Bush Francis Catatonia Rating Scale; St Hans Rating Scale; Salpêtrière Retardation Rating Scale; Neurological Evaluation Scale) and clinical (Positive and Negative Syndrome Scale; Calgary Depression Scale) rating scales as well as instrumental psychomotor tests (Line Copying Task; Finger Tapping Task) and cognitive tasks (Symbol Digit Substitution Test; Stroop Colour Word Test; Continuous Performance Test; Letter Number Sequencing) was administered to a sample of 124 patients with schizophrenia or schizoaffective disorder.

RESULTS

Correlational analyses showed that two clusters emerge from our data: first, a psychomotor poverty cluster referring to the interrelations between catatonia, parkinsonism, psychomotor slowing, and negative symptoms; second, a cluster containing motoric neurological soft signs, which were found to be correlated with cognitive functioning.

CONCLUSION

Psychomotor abnormalities are highly prevalent phenomena in schizophrenia that have to be considered as a heterogeneous construct. However, longitudinal and neurobiological research is needed to further explore the precise nature of the interrelations found in this study.

Impact of one HF-rTMS session on fine motor function in right-handed healthy female subjects: a comparison of stimulation over the left versus the right dorsolateral prefrontal cortex

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool to investigate neural conduction in motor processes. Most rTMS research has been conducted by targeting the primary motor cortex. Several studies have also found increased psychomotor speed after rTMS of the dorsolateral prefrontal cortex (DLPFC). However, these studies were mainly performed in psychiatric patients, only targeting the left DLPFC, and often without sham control. Moreover, psychomotor speed is mostly measured based on tasks that also require higher executive functions.

METHODS

Here, we examined the lateralized effect of one sham-controlled high-frequency rTMS session applied to the left or right DLPFC on fine motor function in 36 healthy right-handed females, using the Fitts' paradigm.

RESULTS

We found a significant improvement in psychomotor speed only after actively stimulating the right DLPFC.

CONCLUSION

Our results support the assumption of a right prefrontal neural network implicated in visuomotor behavior and performance processes, and that the improvement in psychomotor speed is not a secondary effect of decreased mood.

No influence of one right-sided prefrontal HF-rTMS session on alcohol craving in recently detoxified alcohol-dependent patients: results of a naturalistic study

BACKGROUND

Prior research in substance dependence has suggested potential anti-craving effects of repetitive transcranial magnetic stimulation (rTMS) when applied to the dorsolateral prefrontal cortex (DLPFC). However, no single sham-controlled session studies applied to the right DLPFC have been carried-out in recently detoxified alcohol-dependent patients. Furthermore, no studies examined the effect of a single HF-rTMS session on craving in these patients' natural habitat.

METHODS

To further investigate the effect of high-frequency (HF)-rTMS of the right DLPFC on alcohol craving, we performed a prospective, single-blind, sham-controlled study involving 36 hospitalized patients with alcohol dependence syndrome. After successful detoxification, patients were allocated receiving one active or one sham HF-rTMS session. The obsessive-compulsive drinking scale (OCDS) was administered to evaluate the extent of craving just before and after the HF-rTMS session (on Friday), on Saturday and Sunday during the weekend at home, and on Monday when the patient returned to the hospital.

RESULTS

One single blind sham-controlled HF-rTMS session applied to the right DLPFC did not result in changes in craving (neither immediately after the stimulation session, nor in patients' natural environment during the weekend).

CONCLUSIONS

One HF-rTMS stimulation session applied to the right DLPFC had no significant effects on alcohol craving in alcohol dependent patients. One such session could have been too short to alter alcohol craving in a sample of alcohol dependent patients.

The Effect of One Left-Sided Preferontal HF-rTMS Session on Emotional Brain Processes

Introduction

Although repetitive Transcranial Magnetic Stimulation (rTMS) is frequently used to examine emotional changes in healthy volunteers, it remains largely unknown how rTMS is able to influence emotion.

Objectives, aims & methods

In this sham-controlled single-blind crossover study using fMRI, we examined in 20 right-handed healthy female volunteers whether a single high frequency (HF)-rTMS session applied to the left dorsolateral prefrontal cortex (DLPFC) could influence emotional processing while focussing on blocks of positively and negatively valenced baby faces. The task instruction was to focus on one's own emotional status elicited by the visual stimuli.

Results

A single HF-rTMS session selectively influenced the processing of positively and negatively valenced baby faces. When positive information was being processed, one active left-sided HF-rTMS session resulted in enhanced neuronal activity in the left superior frontal cortex (Brodmann area 10) and right inferior parietal cortex (Brodmann area 39). When negative information was processed, one active stimulation session attenuated neuronal activity in the right insula, while sham stimulation did not.

Discussion

These observations suggest that after one active HF-rTMS session, psychophysiological reactions while processing withdrawal-related stimuli decrease. The increased neuronal activity while processing of positively valenced baby faces might reflect enhanced task-related processing caused by the neuronal activation of the left DLPFC, which could indicate that females are more able to empathize with the depicted happy baby faces. Our results add further evidence as to why HF-rTMS applied to the left DLPFC might improve mood in depressive populations.

The effect of right-sided prefrontal HF-rTMS on alcohol craving: Preliminary results

Introduction

Repetitive transcranial magnetic stimulation (rTMS) affects neuronal circuits and neurotransmitter systems in the brain. Recent data suggest that this application could diminish ‘craving’ in patients with alcohol dependence.

Objectives and aims

Given these preliminary data, we examined whether one high frequency (HF)- rTMS session over the right dorsolateral prefrontal cortex (DLPFC) would reduce alcohol craving in alcohol dependent patients in their natural habitat.

Methods

After detoxification during hospitalization, 22 current alcohol dependent inpatients were included (8 female, 14 male; age = 49.95 ± 8.82y).

We used a sham-controlled between-subjects design where after randomization patients received under MRI guidance one right-sided DLPFC active HF-rTMS session or sham. In each high-frequency (20 Hz) stimulation session, patients received 1560 pulses at 110 % MT. The obsessive-compulsive drinking scale (OCDS) was collected at baseline, just before and just after the stimulation session on Friday after detoxification and on the three consecutive days following stimulation in patient's natural habitat.

Results

Although the OCDS total score significantly decreased after the detoxification period, one sham-controlled stimulation session did not affect immediate craving measurements. Furthermore, no significant group differences were observed on OCDS total scores when patients were in their natural habitat.

Conclusions

Although the right DLPFC was targeted under MRI guidance, our preliminary results indicate that one sham-controlled HF-rTMS session does not affect craving in recently detoxified alcohol dependent patients. Besides the limited number of patients it could be possible that only one stimulation session could be insufficient to have a subjective effect on craving.

The influence of treatment-resistance on the serotonin 2A receptor in unipolar melancholic depression

Introduction

Major depression is one of the most common mental diseases, and quite a number of patients are resistant to several psychopharmacological interventions, even when applying current treatment guidelines. To date, it remains unclear as to how the serotonergic system is implicated in treatment-resistance found in melancholically depressed patients.

Objectives & aims

In this study, we examined the involvement of post-synaptic 5-HT2A receptors in the pathophysiology of treatment resistance in major depression with 123I-5-I-R91150 SPECT, focusing on the frontal cortex and hippocampus.

Method

15 unipolar antidepressant naïve (ADN) patients and 15 treatment-resistant depressed (TRD) patients, all of the melancholic subtype, matched for age and gender were studied. All subjects were antidepressant free when they underwent a static 123I-5-I-R91150 SPECT scan.

Results

Compared to ADN patients, TRD patients displayed significantly less 5-HT2A receptor binding index (BI) in the dorsal regions of the prefrontal cortex and in the anterior cingulate cortex. No hippocampal 5-HT2A receptor BI differences were observed.

Conclusions

Our results suggest that when confronted with treatment resistance in melancholic depression the 5-HT2A receptors in the DPFC-ACC axis are significantly more down-regulated when compared to depressed ADN patients. This might to some extent explain the observed continued cognitive problems and might reflect the long-term serotonin depletion with reduced neurogenesis in treatment resistant patients.

Intensive HF-RTMS treatment in affective disorders: Sample cases

Introduction

Repetitive transcranial magnetic stimulation (rTMS) on the left dorsolateral prefrontal cortex (DLPFC) is safe and efficient for treatment-resistant depression (TRD). More intensive rTMS protocols could improve clinical outcome.

Objectives

We report on an intensive high frequency (HF)-rTMS treatment protocol in patients unresponsive to current treatment strategies.

Aims

Monitoring effectiveness and tolerability.

Methods

Patients were diagnosed with TRD, schizoaffective disorder, bipolar type or bipolar type I disorder, mixed episode. All were unresponsive to adequate therapy (rTMS excluded).HF-rTMS was administrated on the left DLPFC under MRI guidance. In each 20 Hz stimulation session, the patient received 40 trains of 1.9 seconds duration at 120% of the motor threshold. The 20 HF-rTMS sessions were spread over 4 days (5 times/day), yielding a total of 31,200 stimuli.

Results

There were neither seizures nor important adverse events. The bipolar patient clinically responded (Hamilton Depression Rating Scale (HAMD) from 20 to 9) following treatment day 1. After completing the protocol a week earlier, the TRD patient's HAMD went from 28 to 5. There was a 5 point decrease in the score of the schizoaffective patient. He improved on the brief psychiatric rating subscales blunted affect and emotional withdrawal. No positive symptoms occurred. None of the patients had significant elevations in YMRS scores or in psychomotor activity.

Conclusion

‘Intensively’ targeting the left DLPFC was tolerated and safe. Our results suggest a strategy of HF-rTMS protocols in non-responders to classical treatment. Larger sham-controlled HF-rTMS studies should substantiate these recent findings.

Reduced left subgenual anterior cingulate cortical activity during withdrawal-related emotions in melancholic depressed female patients

BACKGROUND

Research regarding the neurocircuitry in mood disorders suggests an important role for affective information processing of the subgenual part of the anterior cingulate cortex (Cg25: Brodmann area 25).

OBJECTIVE

In this study, we focused on Cg25 neuronal responses in depressed females using a paradigm in which emotions are elicited without explicit cognitive control, relying on the salient nature of the mood inducing stimuli eliciting approach-related emotions (like happiness) or withdrawal-related emotions (like disgust).

METHODS

Twelve treatment-resistant melancholic depressed women and 12 healthy female control subjects were asked to passively view blocks of emotionally valenced baby faces while undergoing functional magnetic resonance imaging (fMRI).

RESULTS

Compared to the healthy females, the depressed patients displayed significantly higher bilateral Cg25 neuronal activities in both emotional conditions. In melancholically depressed women, we found significantly less left-sided than right-sided Cg25 neuronal activity during the withdrawal-related emotions, while right-sided Cg25 activity was comparable for both emotional responses.

CONCLUSIONS

Our results indicate that in depressed women the left Cg25 modulates intense visceral emotional responses to aversive visual stimuli. This could help explain why the left Cg25 provides a valid target region for antidepressant treatment strategies in unipolar melancholic depression.

Asperger syndrome, violent thoughts and clinically isolated syndrome

A young man, 23 years old, with a clinically isolated syndrome (CIS), presented violent thoughts during a neurological consultation. He was diagnosed with Asperger Syndrome based on a psychiatric and (neuro)psychological examination. Possible risk factors for acting-out and the implications for treatment, if CIS would evolve to MS, are discussed based on a review of the literature.

HF-rTMS treatment decreases psychomotor retardation in medication-resistant melancholic depression

Repetitive Transcranial Magnetic Stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) might be a promising treatment strategy for depression. As one of the key features of melancholic depression is disturbances in psychomotor activity, we wanted to evaluate whether HF-rTMS treatment could influence psychomotor symptoms. Twenty antidepressant-free unipolar melancholic depressed patients, all at least stage III medication-resistant, were studied. All were treated with 10 sessions of High-Frequency (HF)-rTMS applied to the left dorsolateral prefrontal cortex (DLPFC) under MRI guidance. Forty percent of the patients showed a reduction of at least 50% on their initial 17-item Hamilton Depression Rating Score (HDRS) scale and were defined as clinical responders. Regardless of clinical outcome HF-rTMS treatment resulted in significant decreases on the Depressive Retardation Rating Scale (DRRS) scores. Although this was an open study in a relatively small sample, our results suggest that HF-rTMS might act on the 'psychomotor' level and these findings could add some further information as to why this kind of treatment can be beneficial for severely depressed patients of the melancholic subtype.