Stimulating the brains of schizophrenics with magnetic fields could help improve their memory, according to a study from the University of Toronto.
The researchers used a technique called repetitive transcranial magnetic stimultion (rTMS), which appears to allow the brain to ‘rewire’ itself and change the way certain neural structures operate.
Memory is one of several brain functions that is affected by schizophrenia, and is associated with some of the other impairments experienced by sufferers, such as difficulty with speaking and attention. There has been some work on using computer games to ‘exercise’ the affected parts of the brain, but rTMS represents a more direct method of affecting the nerve structures inside the brain.
First developed in the UK in the 1980s, transcranial magnetic stimulation uses a moving magnetic field applied to the patient’s head to induce nerve impulses. Dending on which part of the brain the magnetic field is applied to, it’s been found to induce effects such as involuntary movement and the hallucination of flashes of light. In medicine, its early uses involve testing the activity of brain circuits to diagnose problems affecting motor functions, such as stroke, multiple sclerosis and motor neurone diseases.
More recently, psychologists have started to investigate its effect on the parts of the brain involved in cognition. In 2008, the FDA approved rTMS for non-drug responsive depression, and researchers have found that using the technique repeatedly seems to have a long-term effect on the brain.
‘TMS can have lasting effects on brain circuit function becaise this approach not only changes the activity of the circuit being stimulated, but it also may change th epalsticity of the circuit; that is, the capacity of the circuit to remodel itself functionally and structurally to support cognitive function,’ explained John Krystal, editor of the journal Biological Psychiatry, which has published the Toronto researchers’ paper.
The team, led by Mera Barr and Zafurus Daskalakis, selected schizophrenia patients who were receiving drug treatments, and gave them a memory test before and after four weeks of treatment. The trial was double-blind, with a control group receiving a treatment which looked and felt real, reproducing the scalp-tickling sensation of TMS but delivering no magnetic field; neither the patients or the clinicians delivering the treatment knew which patients were receiving the magnetic effects.
After four weeks, the team found that the real treatment group’s memories had improved to the level of healthy subjects; the team hope that additional research will support these findings.‘Working memory is an important predictor of functional outcome,’ the researcher say in their paper. ‘Developing novel treatments aimed at improving these deficits may ultimately translate into meaningful changes in lives of patients suffering from this debilitating disorder.’