MRI-guided ultrasound system gives hope to tremor patients

Cheng Wong

A new magnetic resonance imaging-guided focused ultrasound has been introduced at Tuen Mun Hospital, with two patients seeing immediate relief from a tremor disorder last month.

The MRI-gFUS treatment system, which costs HK$25 million, is a noninvasive procedure and will be offered this year free of charge to 20 patients with essential tremors - a neurological disorder that causes the hands, head, trunk, voice or legs to shake rhythmically.

Hong Kong has reported over 2,300 essential tremor patients.

The MRI-gFUS will be applied to all seven hospital clusters under a "hub-and-spoke" system, meaning Tuen Mun Hospital will be the center to serve all patients with essential tremors.

"We expect to offer more patients the treatment," said Danny Chan Tat-ming, chairman of the Hospital Authority's coordinating committee of neurosurgery. "There is already relevant experience with this service abroad. And as more people become aware of this effective treatment, we can expect an increase in patients.

"In the past, many [with essential tremors] believed they could not be treated, discouraging them from seeking medical consultation."

According to a US National Institutes of Health article, MRI-gFUS is a "minimally invasive method of targeted tissue thermal ablation that may be of use to treat central neuropathic pain, essential tremors, Parkinson tremor and brain tumors. The system has also been used to temporarily disrupt the blood-brain barrier to allow targeted drug delivery to the brain."

Such patients experience movement disorders, which make it difficult to grip objects, write and even use mobile phones. Previously, they could only reduce tremors through medication or high-risk open brain surgeries. The new treatment system utilizes high-intensity ultrasound waves to target the tissue causing the tremors, passing through the patient's skull and converting it to heat energy for ablation.

The procedure takes two to three hours.

Jason Ho Man-kit, associate consultant of neurosurgery at the hospital, said patients will need to stay overnight for observation. If there are no complications, they can return home the following day.

Ho noted that since ultrasound waves need to pass, patients with a required skull density ratio can undergo the procedure. However, those with metal implants or fear of enclosed spaces are not suitable candidates.

A 62-year-old patient surnamed Chan, who received the treatment last month, said: "My left-hand tremors have significantly improved.

"I can now pour water or hold a glass of water much more steadily, even when the glass is full. Before, I would shake so much that a glass four-fifths full would be reduced to three-fifths."

cheng.wong@singtaonewscorp.com