August 2003
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Reviewed by Lynne Lamberg |
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Who has the more severe sleep disorder: the person who falls asleep while driving, or the one who falls asleep while conversing? It's the latter, this book asserts. While dozing at the wheel obviously poses a greater hazard to both the driver and others, talking engages more of the brain at one time than driving does. A lapse in this situation thus indicates a greater impairment. That's only one of many catchy facts in THE DANA GUIDE TO BRAIN HEALTH. This comprehensive overview for general readers tells what the brain does and how it does it across the lifetime, in health and disease, awake and asleep. Until 50 years ago, scientists thought sleep a time of rest for both body and brain. The discovery of Rapid Eye Movement, or REM sleep, dispelled that notion. Periodic darting of eyes beneath closed lids proved a marker for concurrent brain activity; in REM sleep, we experience our most vivid dreams. The brain is as active then as in waking, sometimes more so. Illness, injury, and stress sometimes disrupt brain functions, sabotaging both sleep and waking activities. People with sleep apnea stop breathing dozens, occasionally, hundreds of times in sleep. Oxygen levels in their blood plummet, sending a danger signal to the brain. Fortunately, the brain is a vigilant night guard that rouses the sleeper, so that breathing restarts. People with sleep apnea seldom remember their multiple brief awakenings. Large muscles of the arms and legs normally shut down in REM sleep, presumably to keep us from acting out our dreams. But motor activity may persist in people with brain damage caused by neurological illness. Those with REM behavior disorder often fight off imagined attackers in their sleep, sometimes falling off the bed, running into bedroom furniture, or hurting bedpartners. In people with the sleep disorder narcolepsy, REM sleep may intrude into wakefulness. Strong emotions sometimes trigger a brief and sudden loss of muscle strength, known as cataplexy, causing a person to collapse and fall down. Research at Stanford University shows that brains of people with narcolepsy lack a small protein present in the brain cells of healthy people. This finding provides a target for possible treatments. The brain governs sleep, eating, and sex as basic drives, activities necessary for our survival. The hypothalamus, a tiny well-protected structure at the center of the brain, serves as the control center for these activities, which show a complex interrelationship. Eating shuts down in most people in sleep, although there are exceptions, people who frequently awaken to eat at night. In REM sleep, men experience penile erections and women clitoral engorgement, suggesting a brain-driven periodic self-test of body systems. Three leading neuroscientists edited THE DANA GUIDE TO BRAIN HEALTH. One of them, David Kupfer, MD, is a pioneer investigator of REM sleep abnormalities in depression. The book includes contributions by more than 100 physicians, other scientists, and science writers. This reviewer wrote an introductory chapter on the brain-body loop that addresses the role of the body clock in regulating the daily sleep/wake cycle. The book has four sections: understanding your brain, your brain through life, the healthy brain, and conditions of the brain and nervous system. The last consists of 400 pages that explore 72 major illnesses, many of which affect sleep in some way. They include depression, chronic pain, dementia, and headaches. The book also includes a glossary, suggested reading, a guide to generic and brand names of medications used to treat diseases of the brain and nervous system, and a list of organizations offering information and support for people with those diseases. It's a fine addition to the home medical library. |
© 2003
WebSciences and Lynne Lamberg |
THE
DANA GUIDE TO BRAIN HEALTH