People with Parkinson’s disease are getting brain implants that can automatically detect and reduce harmful nerve cell activity, to test if the technique could reduce movement difficulties.

The device is a step up from a conventional brain implant because it is designed to reduce the side effects of this invasive treatment.

Parkinson’s disease causes worsening tremors and difficulties with movement, especially when initiating actions. Medication can help, but as symptoms progress, some people have a more drastic treatment, …