Focused ultrasound eased tremor without a single incision

A device called Exablate Neuro focused about a thousand ultrasound beams through the intact skull onto a tiny target deep in the brain, heating it just enough to disable the circuit driving the tremor, without opening the skull at all.

W. Jeff Elias and colleagues at the University of Virginia randomly assigned 76 patients with medication-resistant essential tremor, three to one, to focused ultrasound thalamotomy or a sham procedure. Hand tremor scores improved by about 47 percent in the treated group at three months, against almost no change in the sham group.

The Food and Drug Administration approved the device for essential tremor that same year, and follow-up studies out to several years found the benefit mostly held, though some patients developed lasting numbness or balance problems. The trial tested only one side of the brain at a time, since treating both carried a higher risk of speech and gait complications.

A tremor eased through an intact skull.