Acalculia: The overlooked struggle stroke survivors face with numbers

An inability to understand what numbers mean can be devastating to a person's ability to live independently.

- Yael Benn

Numbers are all around us. In the morning, we wake up to an alarm that tells us it's time to get out of bed. When deciding what to wear, we often check the temperature outside. We count out the vitamins or prescription pills we need to take while eating our breakfast, we estimate how long it will take to get to the station and then check what platform we need to be on to catch the train to work.

Every single one of these examples involves using and understanding numbers. Being able to carry out such small calculations and estimations makes our life possible.

This is why acalculia, a neurological condition that impairs the ability to process and understand numbers, can have a devastating effect on a person's life.

The condition commonly afflicts people who have had a stroke or suffered a brain injury. It's estimated that it affects between 30 per cent and 60 per cent of stroke survivors.

The brain is a complex organ that controls both our movements and senses. It enables us to receive signals from the environment, process information and execute motor actions.

But a stroke or brain injury interrupts blood supply to the brain. If this stroke or injury happens on the left side of the brain, it can cause problems with language processing and other cognitive functions, such as memory. It can also affect movement on the right side of the body.

If it happens on the right side of the brain, movement on the left side of the body will be affected. There may also be cognitive deficits - typically those involved with processing visual information.