Charles Bonnet hallucination syndrome

Charles Bonnet (CBS) hallucination syndrome - known by the name of Swiss natural scientist Charles Bonnet - often occurs in people whose eyesight is severely impaired (when the brain region dominates vision begin to create their own images) and lack of stimuli in the area of ​​the brain that dominates the sight.

Dr Dominic Ffytche of the Royal Institute of Psychiatry at London University and CBS expert reported more than 200,000 cases of the disease in the UK. However, people with CBS are often reluctant to reveal their strange hallucinations, so the actual number is probably much higher.

Lillian Boyd has been blind for more than 20 years and suddenly sees dim images moving. Boyd was surprised to see two large Labrador-like dogs appear in her home in the county of Durham in England. She even saw some beautiful girls and strange men.

Charles Bonnet, the first scientist to describe the syndrome named after him

At the age of 86, Lillian Boyd was afraid that if she told her case to the doctor, it would be attributed to her insanity due to advanced age! But, Lillian Boyd actually had CBS due to eye disease rather than mental problems. The illusion has no sound and cannot feel them but is seen. Boyd said the uninvited guests often "stay all day" in her home.

Dr. Ffytche was a pioneer in the campaign launched by the Royal Eye Association, calling on doctors to warn people with early macular degeneration (AMD) due to the advanced age of CBS. Statistics reveal that in the UK, about 60% of patients lose sight of CBS. Normally, nerve cells in the retina constantly send pulses of energy to the area of ​​the brain that dominates the sight. If the retina is damaged, the impulse will weaken and the area of ​​the brain that governs the eye will automatically create its own images that lead to the appearance of hallucinations. Illusion occurs depending on which area of ​​the brain is most active.

The current problem is that scientists have not explained why young people with macular degeneration are less likely to have CBS than older people. In addition, CBS may also develop after the optic nerve on the sides of the eye is damaged by methanol poisoning.

Often, hallucinations appear only for a few seconds or a few hours but can last as long as the case of Lillian Boyd. There are even some cases of hallucinations for 3 consecutive years. According to Ffytche, even people with normal vision sometimes fall into CBS if they have a blindfold for a long time.

A study conducted by Ffytche and his colleagues found that about 20% of the patients felt excited when they saw strange images, while about half said they had no sympathy. Any contact, and another 30% expressed discomfort.

In 2003, a TV show producer named Sandra Jones, 54, saw faces appearing on a book or computer screen. 2 to 4 times a day, especially when the mind is stressed or sleepless. Finally, she only knew CBS when searching the Internet. In 2009, Sandra Jones' diagnosis doctors suffered from Sorsby ophthalmic dystrophy - a rare hereditary eye disease that led to AMD.

Ms. Lillian Boyd

The hallucinogen syndrome first described by Charles Bonnet in 1769, that was the case with his 89-year-old grandfather - who almost blinded both eyes due to cataract (dry bead) but still looked see men, women, birds, chariots, houses, floor mats.

The Lord Dacre of Glanton also had CBS and saw horses and bicycles and lots of scenes gliding through his eyes like a person sitting in a fast-moving train. Human faces or objects that are seen are often blurry, flickering and unclear. One feature of hallucinations is that patients often see smaller or normal objects or humans.

According to statistics, CBS usually occurs in people over 65 with a rate of 10% to 40%. Currently, no treatment has been proven effective for CBS. But, there is a report that antidepressants and anxiety may work for CBS patients.

Charles Bonnet hallucination syndrome is described in many books - such as "Ghosts in the brain" by Vilayanur S. Ramachandran, Oliver Sacks' "Hallucinations" or Vikram Chandra's "Divine Games" . There is even an Indian film about CBS "Jawan of Vellimala" aired in 2012.

Dr. Ffytche is trying to find ways to help CBS patients get rid of unpleasant hallucinations. He said: "Illusion tends to appear in people with insomnia, so the best way is to try to keep your mind alert and get enough sleep."

Ffytche also recommends practicing finger tips with rubik or dice blocks. In addition, patients may also exercise eye movement, stand up and sit down, hold their breaths, etc. Sedation is often indicated for severe cases but it is easy to experience unpleasant side effects such as vomiting, shivering. or diarrhea.