Focused ultrasound thalamotomy, a treatment using ultrasound waves to destroy the area of the brain causing essential tremor, may be effective for up to 3 years, according to a study published recently in Neurology, the medical journal of the American Academy of Neurology.
“For people who have disabling essential tremor that is not responding to medication, this treatment should be considered as a safe and effective option,” says study author Casey H. Halpern, MD, of Stanford University in Stanford, Calif.

The study involved 76 people with an average age of 71 who had essential tremor for an average of 17 years. In the initial study, 56 people received the treatment and 20 people had a sham therapy. After 3 months, participants were told whether they received the treatment or the sham, and those who received the sham were allowed to have the treatment. All participants were then followed for 2 years. The current study followed the participants for an additional year after the treatment.

Hand tremors, level of disability and quality of life were measured at the start of the study, after 6 months, 1 year, 2 years and 3 years.

After 3 years, on average, the participants improved in hand tremors by 50%, disability by 56%, and quality of life by 42%, a media release from the American Academy of Neurology explains.

No new side effects occurred during the third year after treatment. None of the side effects worsened, and two were resolved. All side effects in the study were mild or moderate. They included numbness and tingling, imbalance, and unsteadiness.

Compared to the scores 6 months after treatment, hand tremors and disability increased slightly after 3 years. On a scale of zero to 32, hand tremor scores initially were an average of 20. At 6 months average scores were nine and by 3 years were 10. For disability, on a scale of zero to 32, scores were initially an average of 16. At 6 months, scores were an average of four and at 3 years an average of six.

The current most frequent treatment for people with severe essential tremor responding insufficiently to medication is deep brain stimulation. Halpern states that while the study did not compare the two treatments, the focused ultrasound thalamotomy offers several advantages to deep brain stimulation.

“This is a less invasive treatment that does not involve incisions or inserting probes or electrodes into the brain. It is performed in one session; there is no need for follow-up visits. And the benefit is immediate,” the release continues.

At the same time, this treatment, in contrast to deep brain stimulation, does produce a brain lesion and is not adjustable or reversible.

Halpern notes that because the people in the study and the researchers all knew that everyone was receiving the treatment, more research is needed with some people receiving a sham treatment to confirm these results.

A limitation of the study was that 23 people, or 31%, did not complete the entire 3 years. The researchers determined that those who later dropped out of the study were not responding as well to the treatment after 3 months as those who completed the study.

[Source(s): American Academy of Neurology, EurekAlert]