Stimulating visual cortex may reduce Charles Bonnet Syndrome hallucinations

Researchers from Newcastle University and King’s College London have explored the potential of non-invasive brain stimulation for reducing the frequency of Charles Bonnet Syndrome (CBS) hallucinations.

The research, which was funded by the Macular Society and published in Ophthalmology, involved 16 patients diagnosed with CBS who received four days of active and placebo treatment.

The intervention, known as transcranial direct current stimulation, involved passing a weak electric current between electrodes placed on a person’s scalp.

The scientists concluded that the technique may reduce the frequency of hallucinations in people with CBS – particularly in those who have increased activity in the visual parts of the brain.

They highlighted that there were no significant side effects of the treatment, with the results of the study warranting further larger-scale trials to investigate its efficacy.

Dr John-Paul Taylor, of Newcastle University, shared that CBS 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,” he said.

“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,” he added.

Dr Dominic Ffytche, of King's College London, highlighted that the intervention is not a cure.

“CBS did not stop completely for anyone – but by reducing how often hallucinations occur, the hope is we can shift CBS from a highly distressing and unpleasant experience to something that no longer troubles you,” he said.