What is Multiple Sclerosis?
Multiple sclerosis (MS) is a disease which affects the nerve fibres within the brain and spinal cord. It usually affects females aged 20-40 years.

MS usually causes episodes of neurological problems, such as blurred vision, slurred speech, numbness, or weakness.

The underlying pathological process is known as "demyelination." Relapses are usually treated with medications, such as interferon or corticosteroids.

How common is tremor in MS?
15% of MS patients experience significant tremor, usually involving one or both arms. This tremor frequently causes significant disability.

What problems does MS tremor cause?
MS tremor causes problems including difficulty opening doors, writing, feeding, and taking care of personal hygiene. In many cases the affected arm is completely useless.

In the worst cases, there is so much tremor that the arm flails about violently, making it difficult for carers to administer basic nursing.

How is it treated?
MS tremor is notoriously difficult to treat. There is usually no effective medication available.

Some patients are suitable for surgery, either deep brain stimulation (DBS) or thalamotomy.

What is deep brain stimulation?
Deep brain stimulation is a highly specialised technique in which a fine electrode (wire) is passed with precision into deep structures within the brain, and a small pulse of electric current is used to inactivate these regions.

What is thalamotomy?
Thalamotomy is a surgical technique whereby a tiny portion of the brain (in an area known as the thalamus) is inactivated by heating, in order to reduce tremor.

Which type of surgery is best?
Both DBS and thalamotomy are partially effective in the majority of patients with MS tremor.

It appears that thalamotomy is more effective; however this comparative benefit occurs at the expense of a higher risk of complications.

Because DBS is non-destructive, this is usually the preferred initial option. If this does not work, a thalamotomy can always be considered later.

Who may benefit from surgery?
Patients with disabling MS tremor may be candidates for surgery. It is critical to differentiate tremor (which can be treated with surgery) from 'ataxia' (incoordination). Ataxia is seen commonly in MS patients, and unfortunately is not treatable with surgery.

MS patients who suffer from a predominant tremor, with only a small or no element of ataxia, may benefit from DBS or thalamotomy.

What are the risks of surgery?
The greatest risk in surgery for MS tremor is weakness of the arm, leg or both. This is frequently temporary following surgery, however may be permanent in up to 10% of patients undergoing DBS for MS tremor. There is a 2-3% risk of infection and haemorrhage (bleeding). The risk that the surgery could cause death is extremely small (less than 1 in 100 patients).

What are the benefits of surgery?
The vast majority of well-selected patients improved following surgery. The reduction in tremor severity may be up to 80%. In addition to a reduction in the tremor itself, patients frequently experience a substantial improvement in function.

MS Tremor Surgery at Precision Neurosurgery
Dr Richard Bittar is a neurosurgeon with specific training and expertise in movement disorder surgery. He is experienced in the surgical treatment of MS tremor, using both DBS and thalamotomy techniques. He has published research into this technique, and has lectured internationally on surgery for MS tremor.