Brain Research: New Alzheimer's Theory, and those "Brain Exercises"

Research on the brain and how it works has yielded some interesting findings related to cognitive function, namely how it may decline and whether popular techniques can really stave off this decline.

Scientists at the biotech company Genentech have offered a new theory of how Alzheimer's disease kills brain cells, a finding that could yield new ideas for developing effective treatments. The researchers "believe a chemical mechanism that naturally prunes away unwanted brain cells during early brain development somehow gets hijacked in Alzheimer's disease." A chemical called amyloid precursor protein (APP), which is a key part of the plaques found in the brain in Alzheimer's patients, is thought to be the "driving force" behind the process.

In another dementia-related finding, the author of a study on "brain exercises" that have been pitched to older adults says that these programs are not effective at warding off cognitive decline, at least not in healthy adults.

The programs, which range from Web sites to PC-based games, have seen sales skyrocket as older adults try to find ways to prevent Alzheimer's and other forms of dementia. Reuters Health quoted Dr. Peter J. Snyder of Lifespan Affiliated Hospitals in Providence, Rhode Island as saying, "These marketed products don't confer any additional benefit over and above being socially and intellectually active in one's normal daily life."

The study found that some types of "brain training" may be of use to patients who already have memory problems, but they haven't clearly shown a benefit to patients who don't have cognitive impairment.

Chiari Malformation: Links for More Medical Information

Here are a number of links from trusted medical sources where you can find more information on Chiari malformations:

U.S. National Institutes of Health Chiari Malformation Information Page


Description of Chiari malformations, from Chiari Instititue at North Shore-LIJ Health System (Long Island, NY)

The World Arnold Chiari Malformation Association - "Information, support, and education for patients, caregivers, and health professionals"

Introduction to Chiari malformation, from the Institute for Neurology and Neurosurgery, New York

Chiari Malformation: Definition, Causes, Symptoms, and More

A Chiari malformation (CM) is a structural defect in the cerebellum, the round portion of the brain at the base of the back of the skull. The cerebellum controls balance, among other things, and normally rests in an indented space above an opening to the spinal canal.

In a Chiari malformation, part of the cerebellum is located below this opening. A CM may occur when the bony space is smaller than normal, which causes the cerebellum and brainstem to be pushed down through the opening and into the upper spinal canal.

This puts pressure on the cerebellum and brainstem, which may affect a person's functions that are controlled by these areas of the brain.

A Chiari malformation may be caused by a structural defect in the brain and spinal cord arising during the development of the fetus. This can result from a genetic mutation or a lack of nutrition in the mother's diet.

Symptoms of a Chiari malformation depend on the type of CM a person has. Some people with a Chiari malformation may have neck pain, balance problems, muscle weakness, numbness or other unusual feelings in the arms or legs, or dizziness. Other symptoms can include vision problems, difficulty swallowing, ringing or buzzing in the ears, hearing loss, vomiting, insomnia, depression, or headache.

People who have a Chiari malformation often have another related condition, such as hydrocephalus (an excessive buildup of cerebrospinal fluid in the brain); spina bifida (the incomplete development of the spinal cord and/or its protective covering); and spinal curvature.

Treatment for Chiari malformations is limited: if a person has functional disturbances or progressive damage to the central nervous system, surgery must be performed to correct the disturbances or prevent the damage from worsening.

For more information, see this fact sheet from the U.S. National Institutes of Health, and...
this article for links to medical sources for more information.