Essential tremors are the most common movement disorder, affecting an estimated 10 million people a year. The disorder is believed to be genetic and usually causes involuntary shaking of the arms and hands.
Sometimes it can be treated with drugs, but that is a stopgap measure.
The most serious cases are being treated at HCA Florida Orange Park.
In just a few hours, patients leave the hospital without the tremors. This happens with no incision, no general anesthetic and with little pain.
Neurosurgeon Dr. Michael Horowitz uses an MRI-guided focused ultrasound device, the only one in the region, to find the receptor cells in the brain that cause the tremors and remove the muscle and nerve connection that causes the involuntary movement.
He has treated patients throughout the Southeast.
“So it’d be sort of like if we know that some poison is being transported from Connecticut to Vermont, and it has to travel through Grand Central Station, if we destroy Grand Central Station, the substance can never get up to Vermont and have its effect,” he explained.
Essential tremors can be debilitating, Horowitz said.
Someone with the disorder rarely has any tremors while at rest. But if a patient tries to raise a spoon to eat, the tremors begin and become worse the closer the spoon comes to the mouth.
“They can’t get anywhere near their mouth. That is why it is termed an intention tremor, meaning it develops when you have the intention to do something and you do it,” he said.
Essential tremors are different from Parkinson’s disease, where tremors also occur at rest. The treatment can be used to ease Parkinson’s tremors as well.
For someone undergoing the procedure, being prepped may be the worst part. The patient’s head has to be shaved so that the MRI helmet can fit tightly against the scalp.
“We’ve had a few patients say they won’t have it done because they have to have their head shaved,” he said.
“But the feeling is that it’s a good psychological test to determine how much the tremor is affecting their activities of daily living.”
Neurosurgeons use the MRI-guided focused ultrasound device to find a spot in the brain about three millimeters in size. The device scans the thalamus portion of the brain until it finds the receptor cells.
The patient is not sedated because the neurosurgeon needs to see whether the tremor stops when the correct receptor is found.
Being certain that the correct receptor is severed is critical because the thalamus comprises many receptors. This is where all of the senses except for smell first send information to the brain.
A shot of energy severs the connection. Horowitz said the patient may feel pain similar to a slight headache, but it only lasts a few seconds.
If the patient has tremors in both arms, the second arm will be treated nine months later.
If the procedure doesn’t stop the tremor completely, it eliminates more than 90% of the uncontrolled shaking, Horowitz said.
“I’d say that the majority of people that we’ve treated so far have no tremor at the end.”