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Is MR-Guided Focused Ultrasound treatment for Essential Tremor safe?

A question we are commonly asked by patients interested in treatment for their Essential Tremor, is whether MR-Guided focused ultrasound treatment is a safe procedure?

Safety is always relative, but if you think about MR-Guided focused ultrasound as a type of surgery (which it is) it is remarkably safe. The reason for this is that unlike other forms of neurosurgery, MR-Guided Focused Ultrasound does not require the surgeon to make any cuts or incisions in the skin, or pass any instruments through the brain (as would be necessary for deep brain stimulation or radio frequency ablation). Using focused ultrasound, our neurosurgeons can access deep portions of the brain in an incision-less fashion.

This is not to say that the procedure is free from any side effects. The procedure is performed to create a lesion in the brain, and there can be side effects from this. However, although focused ultrasound is relatively new, treatment sites across the Globe have worked together for many years to find out exactly where to target to optimise the beneficial effects and obtain the best clinical outcome, whilst minimising the adverse effects of treatment.

Where do side effects come from?

The bad, or the adverse effects of any neurosurgery procedure depends on what you’re treating, and where you’re targeting within the brain. The most common indication for focused ultrasound is tremor, so we typically see side effects that are associated with parts of the brain that lie close to the area of the brain that drives tremor. If nearby parts of the brain are affected by a permanent lesion, any side effects will be permanent. However, this is very rare due to the extensive research and clinical experience that our neurosurgeons have in accurate and effective targeting. Most commonly, side effects are caused by swelling around the area of the treatment. Since this swelling will eventually go, these side effects are transient, by which we mean they come, but will eventually go.

What are the most common side effects when focused ultrasound is used to treat essential tremor?

The most common side effects from focused ultrasound treatment for essential tremor tend to be those of imbalance, problems with articulation (where speech isn’t as clear as it should be) or problems with tingling. Much rarer side effects might include a weakness of the hand or the leg. With the experience and clinical data collected over many years of using targeting and lesioning within the brain to treat essential tremor, the risk of side effects and postoperative disability has come down considerably. In fact, the risk of serious and permanent side effects is now understood to be around 1 in 100.

So is focused ultrasound safe?

Yes relatively, but only when used by experienced neurosurgeons. Good patient selection is key, and exclusion criteria for treatment may mean that patients with existing severe problems with balance, should probably think of other therapies for their tremor. However, even if patient’s have mild problems with balance, this can be adequately managed, with proper precautions taken so that this doesn’t necessarily rule out the possibility for treatment.

Where can I find further information about focused ultrasound treatment?

MR-guided focused ultrasound treatment for essential tremor is now available in Queen Square for private patients. If you are interested in treatment and would like to find out more, please contact our treatment coordinators at:

Additional information is also available at

Zrinzo Ludvic

Professor Ludvic Zrinzo
Consultant Neurosurgeon
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