Study summary

Treating the second side with Gamma Knife was safe and effective

Second-side Gamma Knife trial · 33 people, phase 2, single-arm · Published October 2026, Brain

What was tested

Gamma Knife radiosurgery to the second side of the thalamus (VIM) in people with severe essential tremor already treated on one side.

What they found

• 29 of 33 responded, with tremor improving 74.4% on average in the treated arm.
• Only one side effect (balance and speech) was seen over a year.
• Quality of life improved.

What it means

Bilateral treatment without open surgery may be possible for carefully selected people.