Why did a brain implant that worked for six years in a woman with ALS stop working? · Grey Matter

Because the disease reached the cortex under it.

Why did a brain implant that worked for six years in a woman with ALS stop working?

Because the disease reached the cortex under it. Electrode strips placed on the surface of her sensorimotor cortex in 2015 let her signal her carers with attempted hand movements, and by 2020 it had become her only way to call them, even at night. After about six years the signals shrank and her use of it fell, until it ended in 2023; scans taken eight years apart showed her brain tissue wasting, while the hardware had no fault. A device that reads the cortex lasts only as long as the cortex it reads.