Brain's actions offer early dementia clues

Published on Monday 6 April 2009 21:42

OVER-ACTIVITY in a region of the brain vital to memory could provide an early warning of Alzheimer's disease decades before the first symptoms appear, new research suggests.

A genetic fault known to be associated with Alzheimer's is also linked to hyperactivity in the hippocampus, scientists have found.

The pattern was spotted in volunteers as young as 20. Researchers believe carriers of the defective gene who also have signs of over-activity in the brain region may have a heightened risk of Alzheimer's later in life, although this is unproved.

They believe that the hippocampus may become overworked and worn out in people who develop Alzheimer's.

The finding could be a first step towards developing a simple method of spotting young people who are likely to develop the disease when older.

Such a test would make it possible to offer early treatment to those at high risk or provide advice that might help them.

Alzheimer's affects about 417,000 people in the UK. Previous research has shown that people who inherit one copy of the ApoE4 gene linked to Alzheimer's have up to four times the normal risk of developing the disease late in life. People who inherit two copies – genes generally come in pairs – have their risk increased tenfold.

However, not everyone with the ApoE4 gene variant will go on to suffer from Alzheimer's.

The new study is the first to show hyperactivity in the hippocampus of healthy young carriers of ApoE4.

Scientists from Oxford University and Imperial College London carried out scans to compare the brain activity of 36 volunteers aged 20 to 35. Half carried at least one copy of the ApoE4 gene, and the others were healthy non-carriers.

The research was reported today in the journal Proceedings of the National Academy of Sciences.