Evaluation of the symmetry of biogeneric design suggestions in Cerec/inLab.

This study evaluates the symmetry of initial proposals for anterior tooth restorations delivered by the Cerec software. By using a symmetric preparation model and a special angulation gauge for restoration axes, the study proves that the restoration proposals are symmetric with respect to the median sagittal plane.

Changes in motor cortex excitability associated with temporal repetitive transcranial magnetic stimulation in tinnitus: hints for cross-modal plasticity?

BACKGROUND: Motor cortex excitability was found to be changed after repetitive transcranial magnetic stimulation (rTMS) of the temporal cortex highlighting the occurrence of cross-modal plasticity in non-invasive brain stimulation. Here, we investigated the effects of temporal low-frequency rTMS on motor cortex plasticity in a large sample of tinnitus patients. In 116 patients with chronic tinnitus different parameters of cortical excitability were assessed before and after ten rTMS treatment sessions. Patients received one of three different protocols all including 1 Hz rTMS over the left temporal cortex. Treatment response was defined as improvement by at least five points in the tinnitus questionnaire (TQ). Variables of interest were resting motor threshold (RMT), short-interval intra-cortical inhibition (SICI), intracortical facilitation (ICF), and cortical silent period (CSP). RESULTS: After rTMS treatment RMT was decreased by about 1% of stimulator output near-significantly in the whole group of patients. SICI was associated with significant changes with respect to treatment response. The group of treatment responders showed a decrease of SICI over the course of treatment, the group of non-responders the reverse pattern. CONCLUSIONS: Minor RMT changes during rTMS treatment do not necessarily suggest the need for systematic re-examination of the RMT for safety and efficacy issues. Treatment response to rTMS was shown to be related to changes in SICI that might reflect modulation of GABAergic mechanisms directly or indirectly related to rTMS treatment effects.

Amygdalohippocampal neuroplastic changes following neuroleptic treatment with quetiapine in first-episode schizophrenia.

Schizophrenia is a severe, debilitating, chronic disease that is accompanied by morphologic changes within the brain. However, it is unclear to what extent alterations of grey and white matter in schizophrenia are linked to the disease itself, or whether they are a consequence of neuroleptic treatment. Typical and atypical antipsychotics exert differential effects on brain structure. Moreover, atypical antipsychotics may have distinct profiles with respect to grey matter in schizophrenic patients. Findings on drug-induced grey matter changes are heterogeneous due to variation in stage of illness, duration of treatment and use of multiple antipsychotics. Using voxel-based morphometry applied to high-resolution magnetic resonance images, we show that monotherapy with the atypical agent quetiapine (mean daily dose = 445 mg ± 200 s.d.) may induce structural brain changes in first-episode schizophrenia patients (N = 20) within 21 d of treatment. Specifically, we demonstrate longitudinal macroscopic changes (i.e. grey matter increases) in the left amygdalohippocampal region that were predicted by drug plasma levels but not daily doses. These structural alterations were accompanied by a clinical improvement of schizophrenic symptoms. Comparison with healthy controls (n = 30) showed that grey matter amount in the respective amygdalar region was significantly reduced in unmedicated first-episode schizophrenia patients. These findings suggest that drug-induced neuroplastic changes in schizophrenia can occur quickly and are dependent on pharmacokinetics.

Assessing the impact of sex on high-frequency repetitive transcranial magnetic stimulation´s clinical response in schizophrenia - results from a secondary analysis.

BACKGROUND: The evidence for repetitive transcranial magnetic stimulation (rTMS) to treat negative symptoms in schizophrenia (SCZ) is increasing, although variable response rates remain a challenge. Subject´s sex critically influences rTMS´ treatment outcomes. Females with major depressive disorder are more likely to respond to rTMS, while SCZ data is scarce. METHODS: Using data from the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial we assessed the impact of sex on rTMS´ clinical response rate from screening up to 105 days after intervention among SCZ patients. The impact of resting motor threshold (RMT) on response rates was also assessed. RESULTS: 157 patients received either active or sham rTMS treatment. No significant group differences were observed. Linear mixed model showed no effects on response rates (all p > 0.519). Apart from a significant sex*time interaction for the positive subscale of the positive and negative syndrome scale (PANSS) scores (p = 0.032), no other significant effects of sex on continuous PANSS scores were observed. RMT had no effect on response rate. CONCLUSION: In the largest rTMS trial on the treatment of SCZ negative symptoms we did not observe any significant effect of sex on treatment outcomes. Better assessments of sex-related differences could improve treatment individualisation.

Repetitive transcranial magnetic stimulation for the treatment of chronic tinnitus after traumatic brain injury: a case study.

Tinnitus is a frequent symptom of traumatic brain injury, which is difficult to treat. Repetitive transcranial magnetic stimulation has shown beneficial effects in some forms of tinnitus. However, traumatic brain injury in the past has been considered as a relative contraindication for repetitive transcranial magnetic stimulation because of the increased risk of seizures. Here we present the case of a 53-year-old male patient suffering from severe tinnitus after traumatic brain injury with comorbid depression and alcohol abuse, who received 5 treatment series of repetitive transcranial magnetic stimulation (1 Hz stimulation protocol over left primary auditory cortex, 10 sessions of 2000 stimuli each, stimulation intensity 110% resting motor threshold). Repetitive transcranial magnetic stimulation was tolerated without any side effects and tinnitus complaints (measured by a validated tinnitus questionnaire and numeric rating scales) were improved in a replicable way throughout 5 courses of transcranial magnetic stimulation up to now.

Reduction of tinnitus severity by the centrally acting muscle relaxant cyclobenzaprine: an open-label pilot study.

Tinnitus, the phantom perception of sounds, is a highly prevalent disorder. Although a wide variety of drugs have been investigated off label for the treatment of tinnitus, there is no approved pharmacotherapy. We report an open-label exploratory pilot study to assess the effect of muscle relaxants acting on the central nervous system on tinnitus patients. Cyclobenzaprine at high (30 mg) and low doses (10 mg), orphenadrine (100 mg), tizanidine (24 mg) and eperisone (50 mg) were administered to a maximum of 20 patients per group over a 12-week period. High-dose cyclobenzaprine resulted in a significant reduction in the Tinnitus Handicap Inventory (THI) score between baseline and week 12 in the intention-to-treat sample. On the other hand, other treatments were not effective. These results were confirmed in an explorative analysis where baseline corrected THI and Clinical Global Impression scores at week 12 were compared between groups. The present open trial presents a new promising pharmacotherapy for tinnitus that should be validated in placebo-controlled double-blind trials.

Transcranial magnetic stimulation for the treatment of depression: feasibility and results under naturalistic conditions: a retrospective analysis.

An increasing number of controlled studies strongly support an antidepressant effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex. However, these data come from highly selected study populations. Whether rTMS is a feasible therapeutic tool for the treatment of depression under naturalistic condition has not yet been addressed. Here, we report results from 232 depressive patients [aged 20-76 years, baseline Hamilton Depression Rating Score (HDRS-21) 24.0 ± 7.3] treated with rTMS add-on to continued psychopharmacological treatment in a naturalistic clinical setting. Two thousand stimuli of 20-Hz rTMS were applied daily over the left dorsolateral prefrontal cortex with an intensity of 110% of motor threshold. Treatment duration was individually planned and varied between 10 and 20 sessions. In average, patients received 13 ± 6.1 rTMS sessions. In 90% of the cases, treatment was terminated regularly. No severe side effects were observed. Only four patients stopped rTMS treatment because of side effects. Ratings with the HDRS-21 before and after treatment were available in 130 patients. The average improvement of the HDRS-21 in this subsample was 9.0 ± 9.2 points. Fifty-three patients had an improvement of 50% or more. These results document that rTMS is feasible, safe and well tolerated under naturalistic conditions.

Effects of high-frequency prefrontal rTMS on heart frequency rates and blood pressure in schizophrenia.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a safe non-invasive neuromodulation technique used for the treatment of various neuropsychiatric disorders. The effect of rTMS applied to the cortex on autonomic functions has not been studied in detail in patient cohorts, yet patients who receive rTMS may have disease-associated impairments in the autonomic system and may receive medication that may pronounce autonomic dysfunctions. METHODS: Using data from the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial we evaluated the effect of rTMS applied to the left dorsolateral prefrontal cortex (DLPFC) on autonomic nervous system-related parameters such as blood pressure (BP) and heart rate (HR) in both reclining and standing postures from screening up to 105 days after intervention among patients with schizophrenia. RESULTS: 157 patients received either active (n = 76) or sham (n = 81) rTMS treatment. Apart from gender no significant group differences were observed. During intervention, Linear Mixed Model (LMM) analyses showed no significant time × group interactions nor time effects for any of the variables (all p > 0.055). During the whole trial beside a significant time × group interaction for diastolic BP (p = 0.017) in the standing posture, no significant time × group interactions for other variables (all p > 0.140) were found. CONCLUSION: These secondary analyses of the largest available rTMS trial on the treatment of negative symptoms in schizophrenia did not show a significant effect of active rTMS compared to sham rTMS on heart rate or blood pressure, neither during the intervention period nor during the follow-up period.

Levodopa does not enhance the effect of low-frequency repetitive transcranial magnetic stimulation in tinnitus treatment.

OBJECTIVE: Low-frequency repetitive transcranial magnetic stimulation (rTMS) has shown promise for the treatment of tinnitus. Experimental data from motor cortex stimulation in healthy subjects indicate that the suppressing effect of low-frequency rTMS can be enhanced by dopaminergic receptor activation. Here we investigated whether administration of the dopamine precursor levodopa before low-frequency rTMS enhances its efficacy in tinnitus treatment. STUDY DESIGN: Sixteen patients with chronic tinnitus received 100 mg of levodopa before each session of low-frequency rTMS. Results were compared with a matched control group of 16 patients who received the same treatment, but without levodopa. Treatment outcome was assessed with a standardized tinnitus questionnaire. RESULTS: Both stimulation protocols resulted in a significant reduction of tinnitus scores after 10 days of stimulation; however, there was no significant difference between the two groups. CONCLUSION: Our data suggest that 100 mg of levodopa does not enhance the effect of rTMS in the treatment of tinnitus.

Efficacy of high-frequency repetitive transcranial magnetic stimulation in schizophrenia patients with treatment-resistant negative symptoms treated with clozapine.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a promising augmentation treatment for schizophrenia, however there are few controlled studies of rTMS augmentation of clozapine. METHODS: Using data from the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial we examined the impact of rTMS on PANSS total, general, positive and negative symptoms among participants on clozapine. rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) for five treatment sessions/week for 3-weeks as augmentation for patients with a predominant negative syndrome of schizophrenia, as rated on PANSS. RESULTS: 26 participants from the RESIS trial were on clozapine, receiving active (N=12) or sham (N=14) rTMS treatment. In our Linear Mixed Model (LMM) analysis, time×group interactions were significant in the PANSS positive subscale (p=0.003) (not being the corresponding behavioral output for DLPFC stimulation), the PANSS general subscale (p<0.001), the PANSS total scale (p=0.015), but not the PANSS negative subscale (p=0.301) (primary endpoint of the RESIS trial), when all PANSS measurements from screening to day 105 were included. Descriptive data suggests that in the active group the improvement was more pronounced compared to the sham rTMS group. CONCLUSIONS: In this largest available clozapine cohort, active rTMS may be more effective than sham rTMS when added to clozapine for positive and total psychotic symptoms. These findings should be interpreted with caution given this is a secondary analysis with a limited number of participants.

High-frequency priming stimulation does not enhance the effect of low-frequency rTMS in the treatment of tinnitus.

Based on its ability to reduce the excitability of the cortex locally, low-frequency repetitive transcranial magnetic stimulation (rTMS) has been investigated for the treatment of hyperexcitability disorders such as auditory hallucinations and tinnitus. Results are promising, but characterized by only moderate improvement and a high inter-individual variability. Experimental data from motor cortex stimulation in healthy subjects indicates that the depressant effect of low-frequency rTMS can be enhanced by high-frequency priming stimulation. Here we will investigate whether high-frequency priming also improves the therapeutic efficacy of low-frequency rTMS in a clinical application. 32 patients with chronic tinnitus were randomly assigned to either a standard protocol of low-frequency rTMS (110% motor threshold, 1 Hz, 2000 stimuli/day) or a stimulation protocol in which priming stimulation with 6 Hz (90% motor threshold, 960 stimuli) preceded low-frequency rTMS (110% motor threshold, 1 Hz, 1040 stimuli/day). Stimulation was applied over the left auditory cortex by using MRI-guided coil positioning. The treatment outcome was assessed with a standardized tinnitus questionnaire. There was no significant difference between the standard protocol and the protocol involving priming stimulation. Both stimulation protocols resulted in significant clinical improvement after 10 days of stimulation, as compared to baseline. Our data does not support an enhancing effect of higher frequency priming on low-frequency rTMS in the treatment of tinnitus.

Effects of colour exposure on auditory and somatosensory perception--hints for cross-modal plasticity.

OBJECTIVES: It is well known that colour exposure can influence emotions, behaviour and perception. To get further insight into these complex synesthetic phenomena, the effect of colour stimulation on auditory and somatosensory perception was systematically investigated. METHODS: 14 healthy male volunteers with normal colour vision rated the loudness of auditory stimuli with a standardized scale during exposure to white, red and green light. Furthermore temperature perception was assessed during exposure of the different colours using a thermal sensory analyser. RESULTS: Colour exposure significantly altered auditory and somatosensory perception. Red light enhanced loudness perception and decreased cold pain thresholds, while green light stimulation reduced loudness perception and increased detection and pain thresholds for warm stimuli. CONCLUSIONS: This data give further evidence for cross-modal plasticity in human perception. Colour stimulation influences auditory and somatosensory perception and may therefore have potential as a new treatment strategy of phantom perceptions such as tinnitus or chronic pain.

Efficacy of high-frequency repetitive transcranial magnetic stimulation on PANSS factors in schizophrenia with predominant negative symptoms - Results from an exploratory re-analysis.

Repetitive transcranial magnetic stimulation (rTMS) applied to the left frontal lobe is discussed to be a promising add-on treatment for negative symptoms in schizophrenia. The Positive and Negative Syndrome Scale (PANSS) has been used as outcome parameter in several previous rTMS trials, but studies focusing on PANSS factor analyses are lacking. For this purpose, we used the available PANSS data of the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial to calculate different literature-based PANSS factors and to re-evaluate the impact of rTMS on negative symptoms in this trial. In an exploratory re-analysis of published data from the RESIS study (Wobrock et al. 2015), we tested the impact of rTMS applied to the left dorsolateral prefrontal cortex on two PANSS factors for negative symptoms in psychotic disorders as well as on a PANSS five-factor consensus model intending to show that active rTMS treatment improves PANSS negative symptom subscores. In accordance to the original analysis, all PANSS factors showed an improvement over time in the active and, to a considerable extent, also in the sham rTMS group. However, comparing the data before and directly after the rTMS intervention, the PANSS excitement factor improved in the active rTMS group significantly more than in the sham group, but this finding did not persist if follow-up data were taken into account. These additional analyses extend the previously reported RESIS trial results showing unspecific improvements in the PANSS positive subscale in the active rTMS group. Our PANSS factor-based approach to investigate the impact of prefrontal rTMS on different negative symptom domains confirmed no overall beneficial effect of the active compared to sham rTMS.

Predicting Response to Repetitive Transcranial Magnetic Stimulation in Patients With Schizophrenia Using Structural Magnetic Resonance Imaging: A Multisite Machine Learning Analysis.

Background: The variability of responses to plasticity-inducing repetitive transcranial magnetic stimulation (rTMS) challenges its successful application in psychiatric care. No objective means currently exists to individually predict the patients' response to rTMS. Methods: We used machine learning to develop and validate such tools using the pre-treatment structural Magnetic Resonance Images (sMRI) of 92 patients with schizophrenia enrolled in the multisite RESIS trial (http://clinicaltrials.gov, NCT00783120): patients were randomized to either active (N = 45) or sham (N = 47) 10-Hz rTMS applied to the left dorsolateral prefrontal cortex 5 days per week for 21 days. The prediction target was nonresponse vs response defined by a ≥20% pre-post Positive and Negative Syndrome Scale (PANSS) negative score reduction. Results: Our models predicted this endpoint with a cross-validated balanced accuracy (BAC) of 85% (nonresponse/response: 79%/90%) in patients receiving active rTMS, but only with 51% (48%/55%) in the sham-treated sample. Leave-site-out cross-validation demonstrated cross-site generalizability of the active rTMS predictor despite smaller training samples (BAC: 71%). The predictive pre-treatment pattern involved gray matter density reductions in prefrontal, insular, medio-temporal, and cerebellar cortices, and increments in parietal and thalamic structures. The low BAC of 58% produced by the active rTMS predictor in sham-treated patients, as well as its poor performance in predicting positive symptom courses supported the therapeutic specificity of this brain pattern. Conclusions: Individual responses to active rTMS in patients with predominant negative schizophrenia may be accurately predicted using structural neuromarkers. Further multisite studies are needed to externally validate the proposed treatment stratifier and develop more personalized and biologically informed rTMS interventions.

1-Hz rTMS in the treatment of tinnitus: A sham-controlled, randomized multicenter trial.

BACKGROUND: Chronic tinnitus is a frequent, difficult to treat disease with high morbidity. OBJECTIVE: This multicenter randomized, sham-controlled trial investigated the efficacy and safety of 1-Hz repetitive transcranial magnetic stimulation (rTMS) applied to the left temporal cortex in patients with chronic tinnitus. METHODS: Tinnitus patients were randomized to receive 10 sessions of either real or sham 1-Hz-rTMS (2000 stimuli, 110% motor threshold) to the left temporal cortex. The primary outcome was the change in the sum score of the tinnitus questionnaire (TQ) of Goebel and Hiller from baseline to end of treatment. RESULTS: A total of 163 patients were enrolled in the study (real rTMS: 75; sham rTMS: 78). At day 12, the baseline mean of 43.1 TQ points in 71 patients assigned to real rTMS changed by -0.5 points; it changed by 0.5 points from a baseline of 42.1 in 75 patients randomized to sham rTMS (adjusted mean difference between groups: -1.0; 95.19% confidence interval: -3.2 to 1.2; p = 0.36). All secondary outcome measures including measures of depression and quality of life showed no significant differences either (p > 0.11). The number of participants with side-effects or adverse events did not differ between groups. CONCLUSION: Real 1-Hz-rTMS over the left temporal cortex was well tolerated but not superior compared with sham rTMS in improving tinnitus severity. These findings are in contrast to results from studies with smaller sample sizes and put the efficacy of this rTMS protocol for treatment of chronic tinnitus into question. TRIAL REGISTRATION: Controlled Trials: http://www.isrctn.com/ISRCTN89848288.

Cognitive Effects of High-Frequency rTMS in Schizophrenia Patients With Predominant Negative Symptoms: Results From a Multicenter Randomized Sham-Controlled Trial.

Cognitive impairments are one of the main contributors to disability and poor long-term outcome in schizophrenia. Proof-of-concept trials indicate that repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) has the potential to improve cognitive functioning. We analyzed the effects of 10-Hz rTMS to the left DLPFC on cognitive deficits in schizophrenia in a large-scale and multicenter, sham-controlled study. A total of 156 schizophrenia patients with predominant negative symptoms were randomly assigned to a 3-week intervention (10-Hz rTMS, 15 sessions, 1000 stimuli per session) with either active or sham rTMS. The Rey Auditory Verbal Learning Test, Trail Making Test A and B, Wisconsin Card Sorting Test, Digit Span Test, and the Regensburg Word Fluency Test were administered before intervention and at day 21, 45, and 105 follow-up. From the test results, a neuropsychological composite score was computed. Both groups showed no differences in any of the outcome variables before and after intervention. Both groups improved markedly over time, but effect sizes indicate a numeric, but nonsignificant superiority of active rTMS in certain cognitive tests. Active 10-Hz rTMS applied to the left DLPFC for 3 weeks was not superior to sham rTMS in the improvement of various cognitive domains in schizophrenia patients with predominant negative symptoms. This is in contrast to previous preliminary proof-of-concept trials, but highlights the need for more multicenter randomized controlled trials in the field of noninvasive brain stimulation.

Efficacy and Safety of Repeated Courses of rTMS Treatment in Patients with Chronic Subjective Tinnitus.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has shown promising effects in the treatment of chronic subjective tinnitus. However, little is known about maintenance treatment in order to achieve long-lasting improvements. OBJECTIVE: This study addresses the questions whether the repeated application of rTMS treatment can contribute to the maintenance or enhancement of treatment effects and if so in which cases repetitive treatment courses are beneficial. METHODS: 55 patients with chronic tinnitus were treated with two rTMS treatment courses with ten treatment sessions each. The mean intertreatment interval was 20.65 ± 18.56 months. Tinnitus severity was assessed before and after each treatment course. RESULTS: Both treatments were well tolerated and caused significant improvement of tinnitus severity. The main predictor for the outcome of the second treatment was the development of tinnitus distress in the phase between both treatment courses: the more patients worsened in this interval, the more they improved during the second treatment course. CONCLUSION: Repeated application of rTMS seems to be useful in tinnitus management and should preferentially be offered to patients who experience a worsening of their tinnitus during the intertreatment interval, irrespective of their response to the first treatment course.