Repetitive Transcranial Magnetic Stimulation for Refractory Auditory Hallucinations in Schizophrenia

Center for Addiction and Mental Health (CAMH)

Status: Completed

Conditions: Refractory Schizophrenia

Treatments: Device: repetitive Transcranial Magnetic Stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT01386918

127/2003

Details and patient eligibility

About

Studies using repetitive transcranial magnetic stimulation (rTMS) as a treatment for refractory auditory hallucinations (AH) in schizophrenia have shown promise. The majority of studies have examined the effect of low frequency left-sided stimulation (LFL) (i.e., 1 Hz) to the temporal parietal cortex (TPC). Priming stimulation (6 Hz) prior to LFL stimulation (hereby simply referred to as priming) has been shown to enhance the neurophysiological effects of LFL rTMS alone and, as such, may lead to greater attenuation of AH. Therefore, this study evaluated the efficacy of priming rTMS and LFL rTMS, compared to sham, applied to the TPC in patients with schizophrenia experiencing refractory auditory hallucinations (AH).

Enrollment: 144 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• voluntary and capable to consent based on the subject's ability to provide a spontaneous narrative description of the key elements of the study
• have a diagnosis of Schizophrenia or Schizoaffective Disorder as confirmed by the Structured Clinical Interview for the DSM-IV (SCID-IV)
• between the ages of 18 and 65
• meet criteria for AH of at least moderate severity based on the Positive and Negative Symptom Scale (PANSS)
• willing to keep the dose of antipsychotic stable for the duration of the study
• meet criteria for medication resistance, defined as daily AH despite 2 adequate 6-week trials of at least 2 antipsychotic medications and including 1 atypical antipsychotic medication. An adequate trial is defined as a daily dose of 1000 chlorpromazine equivalents for typical antipsychotics medications and the following dosages for atypical antipsychotic medications: risperidone 6 mg, olanzapine 15 mg, quetiapine 500 mg, clozapine 300 mg.

Exclusion criteria

• DSM-IV history of alcohol and/or substance abuse in past month, or alcohol and/or substance dependence in the last 6 months
• presence of concomitant major, unstable medical or neurologic illness, or a history of seizures
• are pregnant
• have received rTMS for any reason in the past
• have had a dose change of usual psychotropic medications in the 4 weeks preceding study entry.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

144 participants in 3 patient groups

Low frequency left (LFL) sided rTMS

Experimental group

Description:

LFL rTMS was administered at an intensity of 115% resting motor threshold at 1HZ for 20 minutes. The treatment targeted the left temporoparietal cortex (TPC).

Treatment:

Device: repetitive Transcranial Magnetic Stimulation

Priming stimulation

Experimental group

Description:

Priming stimulation was administered as follows: 10 minutes of 6 Hz at 90% resting motor threshold (RMT) administered to the left temporoparietal cortex followed by 10 minutes of 1 Hz stimulation at 115% RMT.

Treatment:

Device: repetitive Transcranial Magnetic Stimulation

Sham Control

Sham Comparator group

Description:

Sham stimulation was applied with identical parameters to those for the LFL condition but with the coil angled at 90 degrees off the scalp in a single wing tilt position.

Treatment:

Device: repetitive Transcranial Magnetic Stimulation