The procedure can give patients their lives back, say experts, restoring mobility and helping them manage simple activities such as drinking a cup of tea. However, only a handful of people with the nervous system problem, known as essential tremor, have been offered the treatment as it is available at only two hospitals in England.
A one-time treatment that zaps the brain with high-powered ultrasound waves can ease debilitating tremors that affect more than a million Britons.
Essential tremor is a neurological disorder that causes involuntary shaking of parts of the body, especially the hands, legs and jaw. It is the most common tremor condition in the UK, affecting five times as many people as Parkinson’s, which also causes tremors and most commonly appears after middle age.
A one-time treatment that zaps the brain with high-powered ultrasound waves can ease debilitating tremors that affect more than a million Britons
Although experts do not know the exact cause of essential tremor, it is thought to be triggered by abnormal electrical signals in the brain which transmit tremors through the nervous system to the muscles
Although experts do not know the exact cause of essential tremor, it is thought to be triggered by abnormal electrical signals in the brain which transmit tremors through the nervous system to the muscles.
Professor Wladyslaw Gedroyc, consultant radiologist at Imperial College Healthcare NHS Trust who offers the ultrasound treatment, says: ‘Essential tremor can cause extreme difficulties. People with it say they feel embarrassed that they shake uncontrollably, so avoid going out, too.’
Mild cases are often left untreated but some patients are offered propranolol, a blood pressure medicine that also suppresses tremors.
However, as patients deteriorate, more powerful drugs are needed. These include primidone, an anti-seizure drug which reduces shaking but can trigger side effects such as extreme drowsiness. About a quarter of patients do not respond to any medication.
Until now, the only option available to these patients has been deep-brain stimulation. This invasive treatment, which costs about £50,000 per patient, involves implanting a tiny electrode into a part of the brain called the thalamus which helps control the body’s movement. This is attached by wires under the skin to a small electrical generator implanted in the chest. The current delivered to the thalamus disrupts the nerve signals that cause tremors.
Studies show that deep-brain stimulation is effective in up to 90 per cent of cases. However, over time, scar tissue builds up around the electrode, decreasing its effectiveness.
The new treatment, known as MRI-guided focused ultrasound, is performed under local anaesthetic and costs about £26,000 – half the price of deep-brain stimulation. Patients lie inside an MRI scanner to locate the thalamus, which then has beams of ultrasound fired at it – energy waves like the ones used for pregnancy scans but 40,000 times more powerful. The rays generate heat, deadening the area responsible for the tremors.
This provides ‘a significant, immediate response, with few side effects’, says Prof Gedroyc. ‘We can improve the severity of tremors by 80 to 90 per cent.’
At the moment, the main challenge faced by patients is accessing the treatment. MRI-guided focused ultrasound is currently offered only by Imperial College Healthcare NHS Trust in London, and The Walton Centre NHS Foundation Trust in Liverpool. As a result, to date just 69 patients have had the treatment and 184 are on a waiting list.
One patient to benefit is Keith Pearson, 73, a musician from Cambridge. The married father-of-two had suffered from essential tremor in his right hand for 30 years. It got steadily worse until he could no longer play his banjo. He says: ‘My hand had a mind of its own. Then I noticed I was having difficulty writing.’
Mr Pearson underwent the treatment in November. He says: ‘They would pop me out of the MRI scanner every once in a while and ask me to draw a spiral. Extraordinarily, on the fifth time of asking, the spiral came out perfectly – I was as surprised as anybody. Then I picked up a cup of tea with one hand and didn’t spill it – the first time I’d managed that in 15 years.’
The tremors have been suppressed so successfully that Mr Pearson is now able to play the banjo again – something he feared would never happen.