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Academic Journal
AUDITORY HALLUCINATION SCHIZOPHRENIA
| Title: |
Effects of bilateral repetitive transcranial magnetic stimulation on treatment resistant auditory-verbal hallucinations in schizophrenia: A randomized controlled trial.
| | Date: | August 13, 2009 | | Author(s): |
Vercammen A, Knegtering H, Bruggeman R, Westenbroek HM, Jenner JA, Slooff CJ, Wunderink L, Aleman A.
| | Source: | Schizophr Res. | | Abstract: |
BACKGROUND: Neuroimaging findings implicate bilateral superior temporal regions in the genesis of auditory-verbal hallucinations (AVH). This study aimed to investigate whether 1Hz repetitive transcranial magnetic stimulation (rTMS) of the bilateral temporo-parietal region would lead to increased effectiveness in the management of AVH, compared to left rTMS or placebo. METHODS: 38 patients with schizophrenia (DSM-IV) and medication-resistant AVH were randomly assigned to 1Hz rTMS treatment of the left temporo-parietal region, bilateral temporo-parietal regions, or placebo. Stimulation was conducted over 6days, twice daily for 20min, at 90% of the motor threshold. Effect measures included the Auditory Hallucination Rating Scale (AHRS), Positive and Negative Affect Scale (PANAS), and a score for hallucination severity obtained from the Positive and Negative Syndrome Scale (PANSS). RESULTS: All groups showed some improvement on the total AHRS. Hallucination frequency was significantly reduced in the left rTMS group only. The bilateral rTMS group demonstrated the most remarkable reduction in self-reported affective responsiveness to AVH. A modest, but significant decrease on the PANSS hallucination item was observed in the combined rTMS treatment group, whereas no change occurred in the placebo group. The left rTMS group showed a significant reduction on the general psychopathology subscale. CONCLUSION: Compared to bilateral or sham stimulation, rTMS of the left temporo-parietal region appears most effective in reducing auditory hallucinations, and additionally may have an effect on general psychopathology. Placebo effects should however not be ruled out, since sham stimulation also led to improvement on a number of AVH parameters.
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| | Title: |
Effect of augmentatory repetitive transcranial magnetic stimulation on auditory hallucinations in schizophrenia: randomized controlled study
| | Date: | 2009 | | Author(s): | Dhruv Bagati, Shamshul Haque Nizamie, Ravi Prakash | | Source: | Australian and New Zealand Journal of Psychiatry 2009; 43:386_392 | | Keywords: |
auditory hallucinations, low frequency, schizophrenia, temporoparietal cortex.
| | Abstract: |
Objective: Auditory hallucinations are a characteristic symptom of schizophrenia and are usually resistant to treatment. The present study was conducted to further support the findings that repetitive transcranial magnetic stimulation (rTMS) reduces auditory hallucinations, and to evaluate the effect of low-frequency rTMS on auditory hallucinations in schizophrenia.
Methods: Forty schizophrenia patients were included in the study. Patients were randomized to control or experimental group. Low-frequency rTMS (1 Hz, 90% motor threshold) was applied to the left temporoparietal cortex of patients in the experimental group for 10 days following the standard guidelines as an addition to antipsychotic treatment. The control group received only antipsychotics. The changes in the psychopathology scores for the auditory hallucinations were recorded using auditory hallucination recording scale. The rater was blind to the intervention procedure.
Results: A significant improvement was found in auditory hallucinations in the experimental group as compared to the control group.
Conclusion: Left temporoparietal rTMS warrants further study as an intervention for auditory hallucinations. Data suggest that this intervention selectively alters neurobiological factors determining frequency of these hallucinations.
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| | Title: |
Meta-analysis of the effects of repetitive transcranial magnetic stimulation
(rTMS) on negative and positive symptoms in schizophrenia
| | Date: | 2009 | | Author(s): | Catarina Freitas, Felipe Fregni, Alvaro Pascual-Leone | | Source: | Schizophrenia Research 108 (2009) 11–24 | | Keywords: |
Schizophrenia, rTMS, Meta-analysis, Negative symptoms, Positive symptoms, Auditory hallucinations
| | Abstract: |
Background: A growing body of evidence suggests that repetitive transcranial magnetic
stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed.
Methods:We performed meta-analyses of all prospective studies of the therapeutic application of rTMS in refractory schizophrenia assessing the effects of high-frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) to treat negative symptoms, and low-frequency rTMS to the left temporo-parietal cortex (TPC) to treat auditory hallucinations (AH) and overall positive symptoms. Results: When analyzing controlled (active arms) and uncontrolled studies together, the effectsizes showed significant and moderate effects of rTMS on negative and positive symptoms (based on PANSS-N or SANS, and PANSS-P or SAPS, respectively). However, the analysis for the sham-controlled studies revealed a small non-significant effect size for negative (0.27, p=0.417)and for positive symptoms (0.17, p=0.129). When specifically analyzing AH (based on AHRS, HCS or SAH), the effect size for the sham-controlled studies was large and significant (1.04; p=0.002). Conclusions: These meta-analyses support the need for further controlled, larger trials to assess the clinical efficacy of rTMS on negative and positive symptoms of schizophrenia, while suggesting the need for exploration for alternative stimulation protocols.
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