Implants in the brains of people with neurological
disorders could help in developing treatments for people with
Parkinson's disease, obsessive compulsive disorder and
depression.
A team from Medtronic of Minneapolis, Minnesota, has reported
on its design for a neurostimulator at the Engineering in Medicine
and Biology Society meeting in Minneapolis. The device uses
electrodes to deliver deep stimulation to specific parts of the
brain.
Neurostimulators are already approved to treat conditions such
as Parkinson's disease, essential tremor, and dystonia, as well as
obsessive compulsive disorder. But existing devices deliver
stimulation on a set schedule, not in response to abnormal brain
activity. The Medtronic researchers think a device that reacts to
brain signals could be more effective, plus the battery would last
longer, an important consideration for implantable devices.
Tim Denison, a Medtronic engineer working on the device, says
that the neurostimulator will initially be useful for studying
brain signals as patients go about their day. Eventually, the data
collected will show whether the sensors would be useful for
detecting and preventing attacks.
Human trials are years away, but elsewhere, NeuroPace a start-up
firm in Mountain View, California, is finishing clinical trials
using its RNS smart implant device in 240 people with epilepsy, the
results of which will be available in December, says Martha
Morrell, chief medical officer at NeuroPace. An earlier feasibility
study on 65 patients provided preliminary evidence that the devices
did reduce seizures.
The NeuroPace device is implanted within the skull where it
monitors electrical activity via electrodes implanted deep in the
brain. If it spots the "signature" of a seizure, it will deliver
brief and mild electrical stimulation to suppress it. Mark George,
a neurologist at the Medical University of South Carolina in
Charleston, says heart pacemakers developed in a similar way, as
researchers learned to make them detect and react to signals from
the heart. "I think it's absolutely inevitable that we'll develop a
smarter, more intelligent way to figure out how and when to
stimulate," George says.