Essential Tremor (ET)

Essential Tremor is the most common cause of tremor.  It often runs in families, and is most apparent in the elderly.  

Typically the tremor is mild, but as it progresses over decades the tremor can become disabling.  If the tremor has reached this point, and medications do not help, then DBS surgery is an option for you.

The tremor of ET is described as postural (or intentional).  This means that the tremor is worse when you use your hand, and if the hand is at rest the tremor usually goes away.  Disabling tremor impairs your ability to perform regular daily activities such as feeding yourself, writing legibly, drinking from a glass, and doing fine motor tasks such as buttoning a shirt or tying shoes.  Most patients have tremor in their hands.  Some patients develop tremor in their head and voice, which can make it difficult to understand their conversations.  Unlike Parkinson's disease, ET patient only have tremor.  They do not have walking difficulties, falls, slowness, or cognitive decline.

There are a few medications that help the symptoms of ET.  They work best when the tremor is mild.  Alcohol often is the most therapeutic, although not recommended on a routine basis.  When the tremor becomes severe these medications are often insufficient to prevent disability.  

DBS surgery is highly effect at controlling tremor.  Most patient experience at least 80% reduction in the severity of the tremor.  More importantly, this reduction in tremor usually eliminates the disability of ET.  Even through patients have a slight residual tremor they are able to feed themselves, and write.  The social stigma of their tremor is gone.  

DBS is most effective at treating tremor in the hand.  It helps the voice and head tremor, but to a lesser degree.  Usually we treat only one side of the body first.  If there is a good effect then the other side is treated several months later.  It takes bilateral DBS surgery to treat head and voice tremor effectively.

The ventrointermedius nucleus of the thalamus (Vim) is the region of the brain where the DBS electrode is implanted.  This is a small portion of the brain, about the size of a large pearl. It is adjacent to the sensory region of the thalamus, and next to the fibers (wires) carrying​ motor control of the face, tongue, and arm.  The DBS electrode has 4 contacts, or electrodes that can be selected for stimulation.  This allows for refinement of the stimulation to find just the right spot to control your tremor, reducing side effects of tingling and slurred speech (dysarthria).