For the first time, scientists have identified an area of the brain involved in hearing voices — a symptom experienced by many patients with schizophrenia — and found that by targeting this region of the brain with magnetic pulses, the condition is improved in some patients.
The findings were recently presented at the the European College of Neuropsychopharmacology (ECNP) conference in Paris.
“This is the first controlled trial to precisely determine an anatomically defined brain area where high frequency magnetic pulses can improve the hearing of voices,” said lead researcher Professor Sonia Dollfus at the University of Caen (CHU) in France.
Schizophrenia is a debilitating long-term mental health problem. Patients experience a range of symptoms, including delusions, muddled thoughts, and hallucinations. One of the most common and disturbing symptoms is the hearing of voices, also known as Auditory Verbal Hallucination (AVH), experienced by about 70 percent of people with schizophrenia.
These voices may be “heard” as internal or external, friendly, or threatening; they may be continuously present or present only occasionally, and so on.
Transcranial magnetic stimulation (TMS), which uses a series of magnetic pulses to the brain, has been suggested as a possible way of treating the hearing of voices in schizophrenia. The method has been shown to be effective in several psychiatric conditions. Until now, however, there is a lack of controlled trials to show that TMS works effectively with people with AVH.
For the study, the French research team worked with 26 patients who received active TMS treatment and 33 control participants who received sham (placebo) treatment. The researchers interviewed the patients using a standard protocol, the Auditory Hallucinations Rating Scale, which revealed most of the characteristic features of the voices which they were hearing.
The TMS treatment involved a series of 20 Hz high-frequency magnetic pulses over two sessions a day for two days. Using magnetic resonance imaging (MRI), the pulses targeted a specific brain area in the temporal lobe, associated with language (the exact area is the crossing of the projection of the ascending branch of the left lateral sulcus and the left superior temporal sulcus).
After two weeks, the patients were re-evaluated. The researchers found that 34.6 percent of the patients being treated by TMS showed a significant response, whereas only 9.1 percent of patients in the sham group responded (‘significant response’ was defined as a more than 30 percent decrease in the Total Auditory Hallucinations Rating Scale score).
“Auditory Verbal Hallucinations, or ‘hearing voices’ can be a disturbing symptom of schizophrenia, both for patients and for those close to sufferers,” said Dollfus.
”This is the first controlled trial to show an improvement in these patients by targeting a specific area of the brain and using high frequency TMS. This means two things; firstly it seems that we now can say with some certainty that we have found a specific anatomical area of the brain associated with auditory verbal hallucinations in schizophrenia.”
“Secondly, we have shown that treatment with high frequency TMS makes a difference to at least some sufferers, although there is a long way to go before we will know if TMS is the best route to treat these patients in the long-term.”