What is pallidotomy

Pallidotomy is a surgical procedure that can decrease dyskinesia, reduce tremor, and improve bradykinesia. The ideal candidate is a young person who is healthy with no impairment in thinking and memory. The person should have a good response to PD drugs. This is unlike thalamotomy, where a good response to drugs is not necessary. Remember, tremor may not respond to PD drugs, while bradykinesia does, and dyskinesia results from PD drugs (levodopa). Pallidotomy is similar to thalamotomy except the target region is the globus pallidus. This region of the brain is known to be overactive in animal models of PD. The interruption of the outflow from the globus pallidus inhibits (blocks) the pathway that causes dyskinesias. The interruption of the outflow from the globus pallidus also "releases" a brake that blocks the substantia nigra. The results of pallidotomy on reducing dyskinesia, reducing tremor, and increasing movement are less consistent than the results of DBS on the globus pallidus or the subthala-mic nucleus. Pallidotomy is done on the side of the brain opposite the side of the most dyskinesia or the most severe bradykinesia. Bilateral simultaneous palli-dotomy carries the risk of speech and thinking difficulty. As with any surgery, there are risks, especially with older people. There is a 1% to 3% risk of stroke or hemorrhage with thalamotomy or pallidotomy.

Stimulation surgery or deep brain stimulation (DBS) refers to implanting a probe or electrode, a stimulator into a clearly defined, abnormally discharging brain region—a region generating "static." This is usually, but not always, the same region targeted in ablative or destructive surgery. By generating a blocking or inhibiting counter-current, the effects of the static are lessened or negated. Technically, DBS is a mis-nomer—the abnormal discharging brain region isn't stimulated; rather, it's blocked or inhibited by a reverse or counter-current.

Deep brain stimulation a treatment in which a probe or electrode is implanted and used to stimulate a clearly defined, abnormally discharging brain region to block the abnormal activity.

There is renewed interest in DBS because is it seen as a refinement of thalamotomy and pallidotomy. However, instead of destroying a section of brain tissue, DBS uses a high-frequency electrical charge to stimulate the brain. Where the electrode is placed in the brain determines which symptoms will be alleviated. Two surgeries are required. In one surgery, a micro-electrode is implanted in a specific region to remain there permanently. Wires from the implanted electrode are then passed beneath the skin to a small battery pack placed under the skin near the shoulder. This device is then adjusted to the patient's own needs to regulate the frequency in the electrode. The patient will be able to turn it off and on by means of a magnet. When the device is on, the stimulation will stop the tremor, the dyskinesia, or improve bradykinesia within a few seconds. When it is turned off, the tremor or dyskinesia will return. The major advantage of this surgery is that it has fewer complications than thalam-otomy or pallidotomy, and there is significant improvement of symptoms, sometimes requiring smaller amounts of PD drugs. The regions targeted by DBS are the thalamus, the globus pallidus, and the subthal-amic nucleus. Increasingly, the subthalamic nucleus is becoming the preferred target. The subthalamic nucleus is located below the thalamus, and it acts as "brake" on the substantia nigra. Studies have compared DBS to thalamotomy and pallidotomy, and although sufficient data still need to be collected, these studies have shown promising results in favor of DBS.

Brain Blaster

Brain Blaster

Have you ever been envious of people who seem to have no end of clever ideas, who are able to think quickly in any situation, or who seem to have flawless memories? Could it be that they're just born smarter or quicker than the rest of us? Or are there some secrets that they might know that we don't?

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