Thursday, April 19, 2007

Shrinking BRAINS at risk!

Biologically Resilient Adults in Neurologic Studies (BRAINS, of course) is a 65+ year-old group of "highly educated and motivated subjects who represent the healthy extreme on the normal aging spectrum." This philanthropic group has not only agreed to undergo regular testing of cognitive and physical functioning but also will hand over their brains at death for further analysis.

All 136 of them underwent baseline MRI scans of their brains in 1999. After 5 years, 23 had developed mild cognitive impairment (MCI), demonstrating loss of some memory and cognitive functioning. Individuals with MCI are known to progress to Alzheimer's disease at an increased rate compared to those without impairment. Nine BRAINS subjects developed Alzheimer's disease in this same time frame.

When the investigators compared MRI morphometry--brain size measurements obtained from the original scans--those subjects who developed MCI or AD had measurable and significant volume loss in their temporal lobes and the left anglular gyrus. This shrinkage was visible years before any demonstrated loss of brain function.

Damage to the left angular gyrus (which sits above and behind your ear) causes a condition called anomia or severe word-finding difficulty. (Oh dear, that sounds familiar). Stimulation of the angular gyrus can cause out-of-body experiences; one subject described the feeling of being on the ceiling.

While I have wished, at times, to be on the ceiling, I am more likely to struggle with a sluggish gyrus and grope for words than I am to travel upwards due to its overstimulation.

No comments: