Delayed word processing may predict Alzheimer's risk

London, Oct 21: Do you often find yourself struggling to read words? If yes, you may be at greater risk of Alzheimer's as researchers have found that people with mild memory problems who show a delayed brain response to processing the written word may be at an increased risk of Alzheimer's.

"A prominent feature of Alzheimer's is a progressive decline in language, however, the ability to process language in the period between the appearance of initial symptoms of Alzheimer's to its full development has scarcely previously been investigated," said Ali Mazaheri, associate professor at the University of Birmingham.

Using an electroencephalogram (EEG) -- a test that detects electrical activity in a person's brain via electrodes attached to their scalp -- researchers studied the brain activity of a group of patients to establish how quickly they processed words shown to them on a computer screen.

For the study, published in Neuroimage Clinical, researchers included patients who were a mix of healthy elderly people, patients with mild cognitive impairment (MCI) and patients with MCI who had developed Alzheimer's within three years of diagnosis of MCI.

MCI is a condition in which someone has minor problems with mental abilities such as memory beyond what would normally be expected for a healthy person of their age.

It is estimated to be suffered by up to 20 per cent of people aged over 65. It is not a type of dementia, but a person with MCI is more likely to go on to develop dementia.

"Crucially, what we found in our study is that this brain response is aberrant in individuals who will go on in the future to develop Alzheimer's disease, but intact in patients who remained stable," said Katrien Segaert, lecturer at the University of Birmingham.

"Our findings were unexpected as language is usually affected by Alzheimer's disease in much later stages of the onset of the disease.

"It is possible that this breakdown of the brain network associated with language comprehension in MCI patients could be a crucial biomarker used to identify patients likely to develop Alzheimer's disease," Segaert added.