Katharine Hepburn had it. So did playwright Eugene O'Neill and Sen. Robert Byrd. Essential tremor is a condition that causes involuntary shaking.
While it usually develops in middle age, it can start much earlier. Shari Finsilver was aware of her hands shaking as a child.
"When I was about 11 years old, I noticed in art class that I was never able to draw a straight line," she says. "I really didn't know why. I just thought it was odd. I just thought it was me."
By age 13, the shaking in her hands was getting worse, but she kept it a secret. She did everything she could to hide it from her family, her teachers and her friends.
By the time she was 19, Finsilver could no longer mask it. She remembers sitting at a large family holiday dinner with her mother across the table. She lifted a spoon to her mouth and her hand was shaking badly.
"Suddenly the spoon went flying across the table," she says. "I can still remember the look on my mother's face. It was complete horror."
Terrified that her teenage daughter had Parkinson's disease, she contacted a neurologist, who diagnosed Shari Finsilver with essential tremor. It is the most common of all movement disorders, affecting about 10 million people in this country.
"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, " says Peter Lewitt, a movement disorder specialist at Henry Ford hospital in Detroit.
The shaking can interfere with just about everything getting dressed, eating and drinking, using the telephone. In fact, a small percentage of patients have such bad tremors that they're completely housebound, unable to manage the details of daily living.
"Essential tremor is a condition that has been known about for hundreds of years," Lewitt says.
The word "essential" refers to the fact that we essentially don't know what causes the tremor. Researchers do know there's a genetic component. President John Adams had it; so did his son, John Quincy Adams. About half the people with essential tremor have a family member affected, but not always the same way.
"One sibling could have a hand tremor and the other sibling might have a voice and head tremor," says Lewitt.
It's often confused or even misdiagnosed as Parkinson's disease. But with essential tremor the shaking usually occurs when the person is doing an activity, like writing or lifting a spoon. People with Parkinson's shake when their hands are at rest.
The other major difference is essential tremor does not typically worsen or progress to complete disability, like Parkinson's disease.
There is no cure, but there are some things you can do to reduce the symptoms. Medications like beta blockers or anti-seizure drugs work for some. Alcohol, too: Just a glass of wine may ease the tremor for some, but the relief is usually short-lived, lasting just a half-hour or so, and tolerance builds up.
Finsilver found no relief for her tremors with medicine or alcohol. So 15 years ago, in her late 40s, she decided to try something extreme that has been shown to help deep brain stimulation.
She had electrodes planted in her thalamus, the spot in the brain involved in the tremors. A small electric jolt disrupts the tremor. All through her surgery, Finsilver was wide awake.
"And when they hit the spot in the thalamus with the electrode, the tremor completely subsided," she says. "It was a moment not to be believed. I mean, I cried. It's just so unbelievable."
Initially, the implanted electrodes controlled Finsilver's tremors almost completely, but over the years, her tremors have started to return. Still, she says, they are much less severe. She no longer tries to hide them, and they no longer control her life.