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DEALING WITH IT

In general, says DeShon, he enjoys his family and his work and lets his wife worry about the medical details. He does, however, keep a sharp eye on his sodium intake. "You learn how to deal with it."

The DeShons lost a baby in 1986 to what doctors believe may have been early-onset periodic paralysis. Since then, they've adopted two children from Korea. (They also have a son and a daughter they had before the baby was lost.) They didn't want to take a chance on another tragedy with a baby of their own, although, since 1986 predates genetic testing, they can't be sure periodic paralysis was the cause of the child's death. They worry about their biological daughter, Rachel, but, says DeShon, if she does develop the disorder, life will certainly be easier for her than it was for him because she'll be surrounded with understanding.

Feigert has found renewed energy and spirit through her exercise program. She started by exercising under the watchful eye of a physical therapist because she "just needed to get over that fear" of having a paralysis attack. Now, she rides her bike to work every day and is "feeling better than ever." She's taken off most of the prednisone-related extra weight and is working on stress reduction. "I can do more if I don't dwell on things, so that's what I'm trying to do now."

STEPS TO MUSCLE CONTRACTION

Muscle contraction results from a complex series of bio-chemical events that take place in a fraction of a second.

1. A chemical transmitter called acetylcholine leaves the nerve terminal.

2. The acetylcholine contacts its receptor in the muscle fiber, which opens a channel that lets sodium ions flow into the muscle fiber. As sodium enters the fiber, the membrane around the fiber "depolarizes," or becomes more positive with respect to its electrical charge.

3. As the membrane depolarizes, sodium channels in the membrane open, allowing more sodium to enter the muscle fiber, further depolarizing the membrane. These probably stay open too long in hyperKPP.

4. Calcium channels open, letting calcium flow into the fiber. These malfunction in hypoKPP.

5. In response to this influx of calcium, an internal calcium channel opens, releasing calcium from inside the fiber. This internal release of calcium allows two muscle proteins, actin and myosin, to interact, which is the final step in muscle contraction.

The whole process must reverse to "reset" the muscle fiber before it can contract again.

GENETIC TESTING FOR PERIODIC PARALYSIS

Genetic diagnosis for hyperKPP and hypoKPP is available through the DNA Diagnostic Lab at Massachusetts General Hospital in Boston, and genetic diagnosis for hypoKPP is available at the University of Utah DNA Diagnostic Lab. Have your doctor call (617) 726-5721 for the lab at Mass General or (801) 581-8334 for the lab at Utah.

Testing is becoming more widely available, so check with the genetic counselor at the nearest university medical center for up-to-date information. Your MDA clinic can make the referral.

TRAVEL AND SAFETY

If you or a family member has periodic paralysis, it's a good idea to travel with the name and phone number of your neurologist and a brief summary of your condition. Many people have discovered that the average emergency room physician has never heard of this disorder, leading to possible complications.

Attacks of periodic paralysis usually don't affect speech. However, because you never know when you might be unable to speak for yourself (for example, after an accident that renders you unconscious), it's a good idea to get a Medic Alert bracelet or necklace. Medic Alert metal tags have critical medical information, such as your disorder's name, engraved on them, and also have a 24-hour phone number that any emergency physician can call for detailed medical information about you. You can join Medic Alert by calling (800) 825-3785 or via the Web site, http://www.medicalert.org/.

• Don't swim alone. Attacks of paralysis in the water can lead to drowning.
• Make sure attacks are under control before driving a car or operating machinery.
• Let a few trustworthy people at your workplace or school know about your condition and what to do if you should become incapacitated.

EDITOR'S NOTE:

Daniel DeShon would like to hear from anyone wishing to talk about periodic paralysis. His phone number is (425) 488-3678. Christine Feigert would specifically like to hear from people with hyperkalemic periodic paralysis. Her number is (503) 335-8596.