Man ‘feels’ colour in rare condition developed after stroke

A man being treated at St. Michael’s Hospital is believed to be only the second person in the world known to have developed synesthesia — a rare neurological condition — after suffering a stroke.

Nine months after having a stroke, the anonymous patient began to experience symptoms of synesthesia, in which a patient experiences multiple senses simultaneously.

Synesthetes may see words or numbers as colours, hear sounds in response to scents or feel something in response to sight.

“The brain has this immense power to kind of rewire itself,” Dr. Corinne Fischer, director of the memory disorders clinic at St. Mikes, told 680News.

“You not only see colour but you hear colour, you taste colour,” in this condition.

Food is also associated with colours. For example, raspberries “tasted” like blue to the patient and blue “tasted” like raspberries. The patient also reported that words written in a certain shade of blue evoked a strong feeling of disgust.

Neurologist Dr. Tom Schweizer of St. Mike’s says it appears that when the man’s brain tried to repair itself following the stroke, it got “cross-wired.”

Schweizer and a team of neurology colleagues decided to look for physical proof of George’s synesthesia. They imaged his brain using functional MRI while playing the James Bond theme “and it lit up all over the place,” he said.

They also put six healthy volunteers of the same age and education through the same test — and as expected, only their brains’ auditory cortex was activated by the music.

It is the first reported case of acquired synesthesia manifesting itself in multiple senses.

“It’s typically a genetic condition. In other words, you’re born with it. It’s hereditary in most instances,” said Fischer.

Most synesthetes are born with the condition, according to St. Mike’s. Those born with the condition include singer-songwriter Billy Joel, author Vladimir Nabakov and composer Franz Liszt.

The only previously reported case of acquired synesthesia was a 35-year-old American woman who felt tingling on her body in response to sound after suffering a stroke, the hospital says.

The patient is also unique in that he can stop the sensations at will.

“He has the ability to turn this off. Most synesthetes can’t do that. They sort of experience the synesthesia involuntarily.”

Fischer says the patient is OK with the condition.

“It’s been a wonderful thing because he can now taste colour. He has sensory experiences that he did not have before.”

The Toronto patient’s case is described in the journal Neurology.