In search of a normal diagnosis

 

MEDICAL MATTERS:Glad to hear there’s no treatment required

MOST OF the time, we go to see a doctor hoping to be told that a symptom we have is actually a variation of normal. Sometimes, with say bleeding from the back passage or blood in phlegm, the possibility of something serious crosses our mind. But, human nature being what it is, reassurance is what we are really after.

Then there are symptoms that are embarrassing or so bizarre we are afraid to even mention them. I was reminded of this by a “patient journey” article in a recent issue of the British Medical Journal. The woman concerned was in middle age before she felt able to admit she experienced numbers as colours. “I think I was about 15 when I mentioned to a friend that my numbers were colours, and she said I was weird. So I didn’t tell anyone again for nearly 25 years. For most of that time I thought maybe I really was weird and a bit mad. You see, it’s not only numbers that have crossed over. Whole words are either strong or weak shades, and I have the unnerving experience of my feelings presenting through bursts and swirls of colour.”

To the untrained observer, the woman could be describing visual hallucinations. Psychosis and schizophrenia may even be considered as potential diagnoses. Luckily, the psychiatrist who assessed her recognised her condition and was able to tell her she was completely normal.

The anonymous writer experiences synaesthesia. She is not mad or weird. Synaesthesia is a harmless neurological phenomenon; it is estimated that at least 1 per cent of normal people experience the world this way. In synaesthesia, stimulation of one sense triggers unusual perceptual experiences. For example, music may be not only heard but also seen, tasted or felt as a touch. Synaesthesia is a fusion of different sensory perceptions and comes in many varieties, and a person can have several different types. Experiencing letters and numbers with colours or textures is an especially prevalent form. While the experience can be pleasant, one man with the phenomenon hates driving because road signs flood his mouth with flavours like pistachio ice cream and earwax.

Aristotle formulated the idea that each of the five senses – smell, taste, touch, hearing and sight – had its own proper and distinct sphere of activity. And while synaesthesia was first described in the journal Nature 126 years ago, its study was hindered for almost a century by the absence of tests to verify the phenomenon. Now the authenticity of synaesthesia has been confirmed by functional magnetic resonance imaging of the brain. It seems to reflect crosstalk between normally separated brain areas, so that activity in one area triggers activity in another. Whether this crosstalk results from increased physical connectivity between areas or a slight imbalance of inhibition and excitation is unclear. The results of one study suggest that parts of the brain normally used to process colour derived from vision are used instead to process colour derived from speech.

While not recommended, you could experience temporary synaesthesia by taking hallucinogenic drugs such as LSD, magic mushrooms or mescaline.

According to the UK Synaesthesia Association (uksynaesthesia.com), most synaesthetes could not imagine life without their experiences and are either positively disposed towards it (“I feel so sorry for people who don’t have this”), or neutral (“it is like being asked whether you enjoy having a left arm – it is just there, and I neither like it nor dislike it”).

Research carried out by the association has shown that many synaesthetes have better memory for things in which their synaesthetic colours are involved. They also have more finely tuned colour perception.

But back to bizarre symptoms. The BMJpatient says: “So often emphasis is given to treatment, but for me the value has been in the diagnosis. It was an ‘Aha!’ moment that has enabled me to progress on a personal journey of learning about how my perceptions work.”

A diagnostic outcome that says, “you’re normal, no treatment required”, may well be worth a visit to your doctor.


mhouston@irishtimes.com