"How neurosurgery works
There are three possible techniques used in neurosurgery, but all of the procedures are carried out on the frontal lobes of your brain, which are behind your forehead. This area contains the limbic system, which is concerned with your emotional responses such as rage, fear and joy, and ‘unconscious’ physical responses, such as changes in heart rate and blood pressure.
The aim of each procedure is to disrupt connections between nerves in very small areas of the limbic system that seem to be creating or contributing to persistent depression or obsessive thinking.
What does the procedure involve?You are given a general anaesthetic. A specially constructed apparatus called a stereotactic frame is attached to your skull to hold the surgical tools firmly in position, so that the surgery can be very exact. The frame is attached through tiny cuts in your scalp, using skin folds wherever possible. Your hair is shaved only in these small areas.
A small hole (called a burr hole), is made in your skull using a special drill, and then a fine probe is put through this hole. Computer software is used alongside imaging, such as magnetic resonance imaging (MRI), to guide the probe precisely to the target spot within the brain (to an accuracy of one millimetre). When the probe is in the right place, an electrical current is passed through it. This generates heat to destroy a very small area of brain tissue at the end of the probe. The probe and the frame are then removed, and the cuts in the scalp are stitched and/or glued.
Neurosurgery for mental disorder (NMD) usually takes about one and a half hours, most of which is taken up by scans to monitor the position of the probe.
There is no international agreement on the best target site for the probe, and different techniques are used at different treatment centres. The following operations are used in the UK:
Two probes are inserted via burr holes made in your forehead, and guided to a part of your brain called the caudate nucleus. A very small part of this target area is then destroyed using an electrical current as described above.
Bilateral anterior capsulotomy
Two probes are passed via incisions on each side of the midline on top of your head into your part of the brain called the internal capsule, which is close to the caudate nucleus. The target area is then destroyed using an electrical current as described above.
Bilateral anterior cingulotomy
This procedure involves a similar technique to capsulotomy, but targets an area of your brain called the anterior cingulate gyrus.
Two days after the operation you should be able to sit out of bed; on the third day, you should be able to start moving about. Rehabilitation must be gradual, because recovery is a slow process."
[Dundee Advanced Interventions Service uses Anterior Cingulotomy:
"photo of 'Normalised' T1 MRI Scan showing targets for Anterior Cingulotomy"]