Scientists discover brain abnormality which causes Parkinson's patients to see 'ghosts'

Scientists have discovered a brain abnormality that could explain why people suffering from Parkinson’s believe they can see ghosts. Roughly half of the people suffering from the disease have ‘presence hallucinations’ which causes them to sense a shadowy presence nearby.

A disorder of the central nervous system, Parkinson’s disease is characterized by depression, anxiety and hallucinations. While it is traditionally defined as a movement disorder, some of the patient's developmental symptoms to the extent of dementia. While the spontaneous nature of the hallucinations has made it hard to study, researchers have now found that a frontal-temporal disconnection could be responsible for the same.

The study

For the purpose of the study, researchers observed 56 Parkinson’s sufferers from across the countries of Switzerland and Spain. They used the techniques of brain imaging and robotics to conduct the experiment. Participants were asked to complete a task in front of themselves using their dominant hand while a robot arm traced the same movement on the back of their body a few seconds later. This technique convincingly mimics the hair-raising sense of another person's presence.

Participants also went through the same test while their brains were scanned using magnetic resonance. This allowed the researchers to pinpoint the regions of the brain involved in the 'presence hallucinations'. The researchers found that patients who experienced hallucinations had a loss of connectivity in the frontal-temporal network of the brain.

"We were able to identify a circuit that implies some frontal-temporal disconnection in the brain, explaining this phenomenon of presence hallucinations," Jamie Kulisevsky, co-author of the study said. "This has very important implications for understanding what is happening in the brains of patients and how we can develop treatments to control or avoid patients suffering these hallucinations."

In the aftermath, the team from the Swiss Federal Institute of Technology touted that hallucinations in Parkinson’s patients might be precursors to more severe mental health symptoms but they often remain under-diagnosed, as patients don’t report them fearing embarrassment.

Representative Image/ Credits: contemplative-studies.org