Slashdot Mirror
FDA OKs Brain Pacemaker for Depression
Duke Machesne writes "On Friday, the FDA approved a new therapy for the severely depressed who have run out of treatment options: a pacemaker-like implant that sends tiny electric shocks to the brain. The Food and Drug Administration's clearance opens Cyberonics Inc.'s vagus nerve stimulator, or VNS, as a potential treatment for an estimated 4 million Americans with hard-to-treat depression - despite controversy over whether it's really been proven to work."
I don't know about parkinson's, but the same device is used to treat severe epilepsy.
The medieval Latin word vagus means literally "wandering" (the words "vagrant", "vagabond", and "vague" come from the same root).
This nerve supplies motor and sensory parasympathetic fibres to pretty much everything from the neck down to the first third of the transverse colon. In this capacity, it is involved in, amongst other things, such varied tasks as heart rate, gastrointestinal peristalsis, sweating and speech (via the recurrent laryngeal nerve).
The vagus also controls a few skeletal muscles, namely:
* levator veli palatini muscle
* salpingopharyngeus muscle
* stylopharyngeus muscle
* palatoglossus muscle
* palatopharyngeus muscle
* superior, middle and inferior pharyngeal constrictors
* muscles of the larynx (speech).
This means that the vagus nerve is responsible for quite a few muscle movements in the mouth and also is vitally important for speech and in keeping the larynx open for breathing.
It also receives some sensation from the outer ear and part of the meninges.
The vagus nerve and the heart
Parasympathetic innervation of the heart is mediated by the vagus nerve. The right vagus innervates the SA node. Parasympathetic hyperstimulation predisposes those affected to bradyarrhythmias. The left vagus when hyperstimulated predisposes the heart to AV blocks.
isn't this the same treatment for severe cases of Parkinson's?
No, the device you're thinking of is the thalamic stimulator. It's implanted in the brain, with the patient conscious, and I read somewhere that the results are dramatic, so much so that surgeon looks at the patient's hand, probes on the thalamus with the electrode to find the right spot, and when he finds it, the shaking instantly stops. I hear when the implant is in place and working, the only reminder of Parkinson's disease left is slowness of movements, but no more tremors.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
How about some more factual information? NPR has done several stories on this kind of treatment, and how it is (and isn't) used. This is not "rats push the button to feel good". This treatment involves a very precise electrical impulse delivered to the malfunctioning area of the brain; it is to electro-shock therapy what a bonsai knife is to a lawnmower, so the side effects, while not well-characterized, are likely to be orders of magnitude less intrusive.
It's used in cases where the depression is not treatable with current drugs. These are people who are so seriously neurochemically depressed that suicide seems attractive for the relief it would offer. The best we could give them before was a hug and a doctor mumbling that they were "interesting," until eventually they gave up and killed themselves. Now we can offer them this, which has at least one major advantage over suicide.
A better reference:
Ah, the Wire.
After seeing the flood of speculation and information based misunderstanding so endemic to a /. discussion, I thought I'd add a personal comment.
My brother is 45 years old, and has had severe epilepsy since he was 3 years old. He is also learning disabled and orthopedically handicapped. Epilepsy, as you may or may not know, is the brain's equivalent of a 'lightning storm'. The cause varies, and the most common treatment is a combination of drugs and surgery to reduce either the beginning of the epileptic seizure or slow the propagation of the wave of activity across the cereberal cortex.
In many patients, drug therapy has to be regularly fine-tuned or completely changed. Think of it as regular security patches, because the brain figures ways to hack around the chemical defenses. In some patients, the brain is so good at hacking through the barriers that drug therapy loses effectiveness. This happened to my brother.
An FDA approved treatment for patients in this condition is the use of a Vagal Nerve Stimulator (VNS). He has a controller/power source implanted in his shoulder, a wire threaded up inside his neck, and the eletrode implanted next to the Vagal Nerve. This nerve is down in the brain stem / 'hindbrain'. Every 5 minutes the controller sends a signal(started at 250mv, it's up to 500mv) for 30 seconds into this electrode. If we want to, we can command a pulse our of sequence by passing a strong magnet over the controller.
The results have not been Science Fiction Movie class miraculous, but they have been visible. For the first few days he would physically react to the pulses (facial tick/jerk, shoulder hunch, etc..). After three months, he no longer reacts as visibly.
But, his grand mal seizure activity has dropped. His petit mal seizure activity has dropped as well. He's improving ! He is more alert, vocal, communicative, and is cracking jokes once again.
I don't know how it will work on depression, but I can tell you from personal observation that it seems to work for epilepsy !