Deep brain stimulation
121 millions are people depressed found globally and 15 to 30% do not respond to treatment. In 2005 researchers conducted experiments on six people. These six people were suffering from clinical depression and did not respond to treatment. Treatment is a term inclusive of medication, psychotherapy and electroconvulsive therapy and non response means that medication was ineffective though they were under treatment for durations ranging from 1.5 to 10 years.
People who do not respond to treatment often suffer this disabling infliction life long. Research reported that patients who were non responsive to treatment were those who had a metabolically active area in the brain called as Brodmann 25.
The procedure of DBS explained
The procedure requires two surgeries to be performed. One surgery is in the brain and the other is in the chest (in case of men) and for women it is in the stomach.
The brain surgery is performed under local anesthesia. The patient is first kept in a particular posture. Local anesthesia is given for the patient has to be awake to tell the exact response. The surgeon drills two holes in the skull. Guided by imaging techniques the surgeon implants hair thin electrodes in both sides of the brain. Helen Mayberg a neuroscientist at Atlanta has pinpointed an area of 2.5 cm wide in the Subgenual cingulated region (SCR region.) This is the lowest part of a deep band of tissue that runs in the central part of the brain. This modulates our negative thoughts. Excess activity in this region is related to depression. When the activity is prevented depression stops.
Surgery in the chest is the second part of the procedure. The surgeon places neurotransmitters in the chest. Wires from the brain are attached to the neurotransmitters in the chest. The neuro transmitter sends electrical signals to the brain thus stimulating it.
The neurotransmitter can be programmed from outside. Stimulation is continuous for 24 hours a day. Depending on the requirement the dosage is adjusted.
Benefits of DBS
- Sufferers of depression linked their disorder to darkness. When the stimulation was given via the neurotransmitter the depressed people felt a sudden surge of relief. The treatment they felt was like lifting the blanket and they are free of the darkness. Their depression vanished immediately and remained vanished.
- Upon stimulation by DBS the patients felt a heightened sense of awareness and a calmness of mind.
- They also reported an increase in the speed of speech.
Risks of DBS
Chances of seizure, brain infection or hemorrhage are possible complications.
These experiments are still in their infancy. It was noticed that when the electrodes were switched off the patient lost some of the positive effects they felt. But four out of the six patients who were experimented upon were free of depression for six months at a stretch (quite an encouraging result.)