BACKGROUND: Essential tremor is a progressive neurological disorder where the arms, hands head and neck shake during voluntary movements such as eating and writing. Some patients may have unsteadiness and problems with gait and balance that are above and beyond the signs of normal aging. Other diseases or conditions don't cause essential tremor, although it's sometimes confused with Parkinson's disease. It can happen at any age, but it's most common in older adults. According to the National Institutes of Health, essential tremor may affect as many as 14 percent of people over the age of 65. Essential tremor is ten to twenty times more prevalent than Parkinson's disease and is the most common of the movement disorders, affecting more than 10 million Americans.

ESSENTIAL TREMOR VS. PARKINSON'S DISEASE: Many people associate tremors with Parkinson's disease, but the two conditions are very different.

· Essential tremor typically occurs when hands are in use. Tremors from Parkinson's are most prominent when a person's hands are at their side or resting in their lap.

· Essential tremor doesn't cause other health problems. Parkinson's is associated with a stooped posture, slow movement and shuffling gait.

· Essential tremor can involve your hands, head and voice. Tremors from Parkinson's typically affect your hands, but not the head and voice.

DEEP BRAIN STIMULATION: For almost 50 percent of people with essential tremor, medication doesn't work or it carries debilitating side effects. That's when many consider surgery. During deep brain stimulation surgery, the patient is awake. A neurosurgeon implants an electrode into the thalamus portion of the brain. That electrode is connected to an implanted neurostimulator placed near the collarbone. During the surgery, patients are asked to perform tasks that have been difficult or impossible prior to surgery, like holding a mug and touching the point of their finger to something. As surgeons adjust the setting, they often see immediate improvement and the shaking stops. The signal emitted from the stimulator interrupts the signal in the brain that tells the body to move uncontrollably. Patients routinely go back to the doctor to have their stimulators fine-tuned. Patients also take home a remote control that can switch the device on or off. When it's in the off mode, tremors come back immediately.