Reducing excess brain activity improves memory in aMCI

June, 2012

A small study supports the view that excess activity in the hippocampus seen in aMCI is not compensatory but a sign of dysfunction, and shows that an epileptic drug reduces activity and improves memory.

Interpreting brain activity is a very tricky business. Even the most basic difference can be interpreted in two ways — i.e., what does it mean if a region is more active in one group of people compared to another? A new study not only indicates a new therapeutic approach to amnestic mild cognitive impairment, but also demonstrates the folly of assuming that greater activity is good.

Higher activity in the dentate gyrus/CA3 region of the hippocampus is often seen in disorders associated with an increased Alzheimer's risk, such as aMCI. It’s been thought, reasonably enough, that this might reflect compensatory activity, as the brain recruits extra resources in the face of memory loss. But rodent studies have suggested an alternative interpretation: that the increased activity might itself be part of the problem.

Following on from animal studies, this new study has investigated the effects of a drug that reduces hippocampal hyperactivity. The drug, levetiracetam, is used to treat epilepsy. The 17 patients with aMCI (average age 73) were given a placebo in the first two-week treatment phase and a low dose of the epilepsy drug during the second treatment phase, while 17 controls (average age 69) were given a placebo in both treatment phases. The treatments were separated by four weeks, and brain scans were given at the end of each phase. Participants carried out a cognitive task designed to assess memory errors attributable to a dysfunction in the dentate gyrus/CA3 region (note that these neighboring areas are not clearly demarcated from each other, and so are best analyzed as one).

As predicted, those with aMCI showed greater activity in this region, and treatment with the drug significantly reduced that activity. The drug treatment also significantly improved their performance on the three-choice recognition task, with a significant decrease in memory errors. It did not have a significant effect on general cognition or memory (as measured by delayed recall on the Verbal Paired Associates subtest of the Wechsler Memory Scale, the Benton Visual Retention Test, and the Buschke Selective Reminding Test).

These findings make it clear that the excess activity in the hippocampus is not compensatory, and also point to the therapeutic value of targeting this hyperactivity for those with aMCI. It also raises the possibility that other conditions might benefit from this approach. For example, those who carry the Alzheimer’s gene, APOE4, also show increased hippocampal activity.


Related News

Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.

Unplanned hospitalizations accelerate cognitive decline in older adults

Data from the Rush Memory and Aging Project has found that emergency and urgent hospitalizations are associated with an increased rate of cognitive decline in older adults.

A Finnish study involving 338 older adults (average age 66) has found that greater muscle strength is associated with better cognitive function.

Data from over 11,500 participants in the Atherosclerosis Risk in Communities (ARIC) cohort has found evidence that orthostatic hypotension in middle age may increase the risk of cognitive impairment and dementia 20 years later.

A review of 39 studies investigating the effect of exercise on cognition in older adults (50+) confirms that physical exercise does indeed improve cognitive function in the over 50s, regardless of their cognitive status.

A Canadian study involving 40 older adults (59-81), none of whom were aware of any major memory problems, has found that those scoring below 26 on the Montreal Cognitive Assessment (MoCA) dementia screening test also showed shrinking of the anterolateral

A study involving 35 adults with

In Australia, it has beens estimated that 9% of people aged over 65, and 30% of those aged over 85 have dementia. However, these estimates are largely based on older data from other countries, or small local samples.

In the past few months, several studies have come out showing the value of three different tests of people's sense of smell for improving the accuracy of

A study comparing the language abilities of 22 healthy young individuals, 24 healthy older individuals and 22 people with


Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health news