STEVE INSKEEP, HOST:
And let's continue Your Health with a report on a condition called essential tremors. It causes involuntary shaking, usually develops during middle age. The condition has been around for a long time but remains largely a mystery to researchers.
Michelle Trudeau reports.
MICHELLE TRUDEAU, BYLINE: Shari Finsilver was aware of her hands shaking early on.
SHARI FINSILVER: When I was about 11 years old, I noticed in art class that I was never able to draw a straight line. And I really didn't know why. I just thought it was odd. I just thought it was me.
TRUDEAU: By 13, the shaking in her hands was getting worse, but she kept it a secret.
FINSILVER: I did everything I could to hide it from my family, from my friends, from my teachers.
TRUDEAU: But eventually...
FINSILVER: When I was 19...
TRUDEAU: Shari could no longer mask it.
FINSILVER: We were sitting at a large family holiday dinner, and my mother was sitting across from me. And...
TRUDEAU: Shari was lifting a spoon to her mouth; her hand was shaking badly.
FINSILVER: And the spoon went flying across the table. And I still remember the look on my mother's face. It was complete horror.
TRUDEAU: Terrified her teenage daughter had Parkinson's disease. But a neurologist diagnosed Shari not with Parkinson's but with what's called essential tremor.
DR. PETER LEWITT: Essential tremor is a condition that has been known about for hundreds of years.
TRUDEAU: President John Adams had it as did his son, John Quincy Adams, says Peter Lewitt, a movement disorder specialist at Henry Ford Hospital in Detroit. Actress Katharine Hepburn, playwright Eugene O'Neill, Sen. Robert Byrd all had essential tremor. It's the most common of all movement disorders, affecting about 10 million people in this country.
LEWITT: Essential tremor is a condition in which head, voice, hands or even all parts of the body are engaged in a tremor that can be as frequent as four to eight times per second.
TRUDEAU: That can interfere with just about everything.
LEWITT: Getting dressed, buttoning buttons, putting arms in sleeves, having breakfast, dialing numbers.
TRUDEAU: A small percentage of patients have such bad tremors that they're completely housebound, unable to manage the details of daily living.
The word essential, in medical-speak, means essentially, we don't know what causes the tremor. Researchers do know there' s a genetic component. About half the people with essential tremor have a family member affected, but not always the same way.
LEWITT: One sibling could have a hand tremor, and the other sibling might have a voice and head tremor.
TRUDEAU: It's often confused and misdiagnosed, even, with Parkinson's. The major difference is essential tremor occurs typically when a person tries to do an activity like writing, lifting a spoon, tying a shoelace. This is distinctly different from Parkinson's. There, tremors usually occur when the hands are at rest. Another difference - essential tremor does not typically worsen or progress to complete disability, like Parkinson's.
Still, there's no cure. Medications, such as beta-blockers or anti-seizure drugs do work for some. Even alcohol - having a glass of wine - may ease the tremor, but that's short-lived, a half hour or so and tolerance builds up.
Sheri Finsilver found no relief for her tremors with medicines or alcohol. So 15 years ago, in her late 40's, she decided on something extreme that had been shown to help - brain surgery to implant electrodes in the spot of the brain involved in the tremors called the thalamus. A small electrical jolt disrupts the tremor.
FINSILVER: And then when they hit the spot, the correct spot in the thalamus in the brain, with the electrode, the tremor completely subsided and I'm telling you, it's a moment not to be believed. I mean, I cried. It was - it's just unbelievable.
TRUDEAU: Initially, the implanted electrodes controlled Shari's tremors almost completely, but over the years, her tremors started to return. Still, she says, they're much less. Now she no longer tries to hide them, and now they no longer control her life.
For NPR News, I'm Michelle Trudeau.
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