A Primer on the Treatment of Schizophrenia Through Repetitive Transcranial Magnetic Stimulation

Daphne Voineskos; Zafiris J Daskalakis

Disclosures

Expert Rev Neurother. 2013;13(10):1079-1082. 

In This Article

Auditory Hallucinations

Auditory hallucinations, as a primary symptom of schizophrenia,[11] can be a main target of antipsychotic treatment. However, up to 40% of patients have only a partial response to medications.[12] As such, there has been extensive exploration of the neurocognitive basis of auditory hallucinations. Neuroanatomical and imaging studies in these 'treatment-resistant' patients have demonstrated hyperactivity in the left temporo-parietal cortex.[13,14] By exploiting its inhibitory role, when applied at low frequencies, an rTMS protocol delivered at 1 Hz to the posterior superior temporal gyrus (STG).[15] Hoffman et al. were able to demonstrate a reduction in auditory hallucinations after application to this speech processing cortex. Moreover, a subsequent study by the same group demonstrated sustained improvement 15 weeks after treatment in many of the subjects.[16]

Other groups targeted different anatomical areas likely to be involved in the genesis of auditory hallucinations. Unfortunately, results of treatment studies have not been robust.[17] It should be noted that the majority of rTMS treatment studies have centered on subjects with medication-resistant auditory hallucinations. Very little is known about the treatment effect rTMS would have for antipsychotic-responsive subjects.

Lastly, a recent meta-analysis by Slotema et al. examined 7 rTMS randomized controlled trials (RCTs) with a total of 189 schizophrenia subjects who were experiencing pervasive auditory hallucinations.[7] One hundred and five subjects received active rTMS treatment and there was a moderate effect size of 0.54, with only an 8.6% occurrence of side effects. While this was a somewhat smaller effect size than a previous meta-analysis,[18] the clear recommendation remains for rTMS as treatment of auditory hallucinations in schizophrenia: specifically in treatment-resistant patients.

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