Stimulation to visual cortex could reduce hallucinations in blind
Using a non-invasive stimulation on the brain may be effective in reducing the frequency of visual hallucinations in blind patients, a new study has found.
A technique called ‘transcranial direct current stimulation’ (tDCS) has been trialled on patients by researchers at Newcastle University and Kings College London, as part of the 18-month study funded by national sight loss charity the Macular Society.
The technique involves passing a weak electric current between electrodes placed on a person’s scalp and has been found to change activity levels in certain areas of the brain.
Previous research suggests that loss of information from the eyes results in increased spontaneous activity in the visual cortex, which contributes to the occurrence of visual hallucinations in Charles Bonnet Syndrome (CBS). The study aimed to use tDCS to reduce this activity and return it to normal levels.
Results from the study, which has been published in Ophthalmology, have shown that the stimulation may reduce the frequency of visual hallucinations in people with CBS, particularly individuals who have increased spontaneous activity levels in the visual parts of their brain.
Dr John-Paul Taylor, from Newcastle University’s Faculty of Medical Sciences, leads the NIHR Newcastle Biomedical Research Centre’s theme in dementia, mental health and neurodegeneration. He said:
“CBS, where people experience visual hallucinations is a common experience for people who develop eye disease and visual loss.
“We don’t unfortunately have any good treatments for CBS and drugs which are typically used are often associated with significant side effects.
“We are excited by our initial findings that using a form of non-invasive brain stimulation, which was well tolerated and can be delivered in a person’s own home, may reduce the frequency of visual hallucinations for people with CBS.
“Our next steps are to conduct a larger, multicentre trial to prove whether this treatment is truly effective and can be used clinically.”