MedWire News: Results from a small, preliminary Israeli study suggest that deep transcranial magnetic stimulation (TMS) may help reduce chronic auditory hallucinations in patients with schizophrenia.
Up to 70% of patients with schizophrenia experience auditory hallucinations, which are usually treated successfully with antipsychotic medications.
However, around a third of schizophrenia patients continue to experience auditory hallucinations after receiving such treatment, say Oded Rosenberg (University of Tel Aviv) and team.
They explain that previous studies have shown that repetitive TMS over the temporoparietal cortex may help reduce auditory hallucinations in schizophrenia patients, but few have investigated the benefits of deep TMS, which "could be more effective than repetitive TMS due to the larger and deeper spread of field it can produce."
The researchers therefore recruited eight patients (four women) with schizophrenia, aged an average of 28.8 years, who continued to experience auditory hallucinations at least five times a day despite treatment with antipsychotics.
The participants were assigned to undergo either 10 or 20 10-minute sessions of low-frequency deep TMS delivered to the temporoparietal cortex over 10 or 20 days, respectively.
They were evaluated before and after treatment using the Auditory Hallucinations Rating Scale (AHRS), the Scale for the Assessment of Positive Symptoms (SAPS), the Clinical Global Impressions (CGI) scale, and the Scale for Assessment of Negative Symptoms (SANS).
In the five patients who received 10 sessions of deep TMS, average AHRS scores improved by 34.5%, average SAPS scores improved by 23.1%, and there were minor reductions of 11.2% and 9.2% in CGI and SANS scores, respectively. However, these improvements were gradually lost during follow-up and scores returned to baseline levels after 1 month.
Among the three patients who received 20 deep TMS sessions, one was lost to follow-up, but the remaining two experienced an average 27.8% improvement in AHRS scores, a 13.8% improvement in SAPS scores, and a minor reduction of 6.5% in SANS scores.
In contrast to the first five patients, symptom scores among these two patients continued to improve over follow-up, and at 1 month the average reduction in AHRS and SAPS scores reached 42.6% and 17.9%, respectively.
Rosenberg and team conclude: "We have demonstrated the potential of deep TMS treatment over the temporoparietal cortex as an add-on treatment for chronic auditory hallucinations in schizophrenic patients."
They add: "We believe that a future large-scale, double-blind, sham-controlled study, targeting various brain regions, could clarify the effectiveness of deep TMS in the treatment of resistant auditory hallucinations."
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