Essential Tremor

    Benign, essential tremor is the most common tremor effecting patients. This tremor condition is quite distinct from Parkinson's disease:

    The tremor usually begins in the arms, often one side before the other and gradually worsens and involves the head, neck and voice. Since activity brings out the tremor, it interferes with activities of daily living and sometimes becomes so severe that even simple activities such as eating and drinking become quite difficult.  The tremor rarely involves the legs, so walking is not a problem. The incidence rises with age, usually beginning in middle age.

    The neurological examination (other than tremor) is normal, and no pathological changes have been found on imaging the brain or at autopsy.

   Medical treatment relies on the use of beta-adrenergic-blockers, such as propranalol (Inderol), primidone (Mysoline) and anticonvulsant and sedatives such as glutethimide.

A patient's attempt at drawing an Archimede's spiral before surgery	Post operative drawing showing significant tremor relief

    In severe cases, refractory to medical management, surgical intervention can bring dramatic relief. Treatment involves destruction or stimulation of a portion of the thalamus, a movement-sensation relay station within the depths of the brain.  Traditionally, local destruction of the nucleus ventrointermedialis within the thalamus by means of a radiofrequency (heating) current has been found to be effective. There is nearly a 50 year experience with this form of thalamotomy. Radiofrequency thalamotomy is carried out by a technique called stereotaxy. A stereotactic frame is fixed to the head with local anesthesia  and  the brain is imaged with CT or MRI technique. Using these images as a guide, a thin electrode is passed into the thalamus by the surgeon. By stimulating the electrode and recording nerve cell activity the surgeon can adjust the electrode to the most optimal position. The patient remains awake during the operation allowing the surgeon to judge the effect of stimulation on the patient's tremor. Then the nucleus is destroyed by passing a RF current throughout the electrode. Complications of infection and bleeding/stroke are rare.

    More recently,  destructive lesions have been placed in the thalamus non-invasively by means of the Gamma Knife. Using stereotactic technique, focused gamma rays can be directed to the ventrolateral thalamus to treat tremor. This is also highly effective and avoids the complications of open operation. The full effect takes several weeks to appear after GK radiothalamotomy.

    Most recently, deep brain stimulation ( DBS) has been shown to be quite effective in tremor relief. Similar to RF thalamotomy, a electrode is introduced into the ventolateral thalamus. Instead of creating a permanent (and irreversible) lesion however, the electrode to attached to a internal stimulator ( Medtronic's Activa Tremor Control TherapyŽ). This allows safe treatment to both sides and the treatment effect can be varied by adjusting the stimulus strength.

Radiofrequency and Gamma Knife thalamotomy as well as DBS tremor control therapy are carried out by members of the Neurosurgical Medical Clinic team. Contact us for more information about what treatment best suits your needs.