Transcranial Magnetic Stimulation for Auditory Verbal Hallucinations in Schizophrenia with Comorbid Hyperthyroidism: A Case Report

Abstract

Background: Auditory verbal hallucinations (AVH) are among the most frequent and distressing positive symptoms of schizophrenia and may persist despite adequate pharmacological treatment. Antipsychotic dose escalation is often required; however, certain medical comorbidities, such as hyperthyroidism, can increase vulnerability to extrapyramidal symptoms (EPS), thereby limiting optimal pharmacotherapy. Low-frequency repetitive transcranial magnetic stimulation (rTMS) represents a potential non-pharmacological adjunctive treatment in such clinical situations. Case: We report a 32-year-old woman diagnosed with schizophrenia according to DSM-5-TR criteria with comorbid hyperthyroidism under medical treatment. The patient experienced persistent AVH and developed EPS, including hypersalivation and generalized weakness, following antipsychotic dose escalation. She underwent adjunctive low-frequency rTMS (1 Hz) targeting the left temporoparietal junction at an intensity of 100% motor threshold, delivering 900 pulses per session over 10 sessions. Discussion: Following rTMS intervention, the patient showed marked clinical improvement, with complete resolution of AVH and a reduction in the Positive and Negative Syndrome Scale (PANSS) total score from 156 to 38. Adverse effects were minimal and limited to mild transient headache. This case supports existing evidence that low-frequency rTMS targeting the left temporoparietal junction may effectively reduce AVH by modulating abnormal cortical excitability. Conclusion: Low-frequency rTMS may serve as an effective and well-tolerated adjunctive therapy for patients with schizophrenia who experience limitations in pharmacological management due to comorbid hyperthyroidism.