rTMS may help as an alternative treatment for schizophrenics needing to shut out voices, Reports South Florida Psychiatrist, Dr. Gregory Marsella

All improved significantly; and two of the six patients had complete remission of the symptom--"the first time they were symptom free in 10 years", Dr. Hoffman said.

NEW YORK -- Transcranial magnetic stimulation (TMS) shows promise for one of the most persistent of schizophrenia symptoms--hallucinated voices, Dr. Ralph E. Hoffman said at a conference on schizophrenia sponsored by Columbia University.

The modality, which has been used experimentally with some success for depression and movement disorders, effected significantly more improvement in auditory hallucinations than placebo stimulation, and for many patients the gains persisted for months after conclusion of the study, said Dr. Hoffman of Yale University; New Haven.

Hallucinated voices--usually whole phrases, sentences, even conversations--are experienced by 60%-70% of individuals with schizophrenia and 10%-20% of bipolar patients, as well as some individuals without psychotic illness. They are highly recognizable--the same voices occur day after day--and their content is typically emotionally charged, often vulgarly sexual or violent.

"It is extremely disruptive, sometimes disabling experience," Dr. Hoffman said at the conference, cosponsored by the New York State Psychiatric Institute.

The course is variable: The symptom may war and wane, or persist. But once voices appear, the patient will remain vulnerable. In 25% of affected patients, voices fail to respond to medication.

"They seem one of the most resistant symptoms of schizophrenia often the last holdout symptom," he said.

There is evidence that such hallucinations originate in the part of the brain that processes perceived speech. The voices have distinct perceptual character--they sound like a particular person, while the normal "inner monologue" sounds like ourselves--and hearers report they "feel like" they are coming from outside, like words spoken aloud.

In one-third to one-half of cases, the hallucinations can be triggered by innocuous sounds, like running water, which are transformed into words and phrases. Patients often misperceive spoken speech as well, Dr. Hoffman said.

Imaging studies have shown that the temporal brain region involved in speech perception (Wericke's area) is activated when patients hear voices, he said.

Dr. Hoffman described several small studies to investigate the use of repeated transcranial magnetic stimulation (rTMS), a modality that manipulates electromagnetic fields to induce small electrical currents in the brain, to alleviate hallucinated voices.

In a controlled trial, patients who experienced frequent voices (five or more times daily) despite medication were randomized to receive 9 days of 1-Hz rTMS directed to the left temporoparietal cortex or placebo stimulation. drug regimens were unchanged during the trial.

Among the first 24 patients, there was a "robust" response in the treated group: 65% had at least a 50% improvement in voices, primarily in reduction of frequency; and some improvement in negative symptoms as well. By comparison, 20% of the controls had appreciable improvements, he said.

The benefits were sustained for periods of weeks to over a year: Half continued to have clinically significant improvements for 12 weeks, Dr. Hoffman said at the meeting.

Adverse events of TMS were minimal, limited to headaches and lightheadedness. None of the patients experienced a worsening of symptoms.

Initial results for the first 49 patients treated with TMS were comparable, he said.

The patients who have not responded toTMS have been, for the most part, those who hear voices continuously throughout the day.

The overall level of improvement for those patients has been 10%, compared with 60% for the others, Dr. Hoffman said.

A refinement of the TMS technique has had "very positive" preliminary results for a small series of such patients. Here, computerized analysis of MRI data was used to identify multiple areas of the brain that are activated during voices to guide the application of individually tailored rTMS.

These additional targets included regions involved in speech production, such as Broca's area in the prefrontal cortex.

Six patients who experienced nearly continuous hallucinated voices received 2-4 weeks of MRI-guided rTMS.

All improved significantly; and two of the six patients had complete remission of the symptom--"the first time they were symptom free in 10 years", Dr. Hoffman said.