Deep brain stimulation ( DBS ) is a neurosurgical procedure which was introduced in 1987, in this procedure a neurostimulator sometimes it is referred to as “brain pacemaker“, which sends electrical impulses, through implanted electrodes, to some specific targets in the brain for the treatment of movement and neuropsychiatric disorders. Deep brain stimulation has provided therapeutic benefit for treatment resistant disorders such as Parkinson’s disease, essential tremor, dystonia, chronic pain, major depression, and obsessive compulsive disorder. Deep brain stimulation has had a long history but despite it, the principles and mechanism of it are not clear.
The Food and Drug Administration ( FDA ) approved Deep brain stimulation as a treatment for essential tremor and Parkinson’s disease in 1997, dystonia in 2003, and OCD in 2009. Deep brain stimulation is also used in research studies to treat chronic pain, PTSD, and has been used to treat various affective disorders, including major depression, but none of these applications has been approved by the FDA.
Components of Deep Brain Stimulation
The Deep brain stimulation system consists of three components which are the following:
- The implanted pulse generator ( IPG),
- The lead and
- An extension.
The IPG is a battery-powered neurostimulator which is encased in a titanium housing, which sends electrical pulses to the brain that interferes with neural activity at the target site. This lead is coiled wire insulated in polyurethane with four platinum-iridium electrodes and is placed in one or two different nuclei of the brain. Then the lead is connected to the IPG through an extension.
Then according to the problem or symptoms to be addresses the Deep brain stimulation leads are placed. For non-Parkinsonian essential tremor, the lead is placed in the ventrointermediate nucleus ( VIM ) of the thalamus;
For Dystonia and symptoms associated with Parkinson’s disease the lead may be placed in either the globus pallidus internus or the subthalamic nucleus, all of this are medical terms and many of us do not know the meaning of it but the information should be given.
Applications: Deep brain stimulation
Parkinson’s disease is a neurodegenerative disease whose primary symptoms are the following:
- And, postural stability.
Deep brain stimulation does not cure Parkinson’s but it can improve the condition of the patient and the quality of their life. At present deep brain stimulation is used or recommended to those patient’s on whom the medications does not work or those who faced side-effects because of medications. By sending high frequency electrical impulses into specific areas of the brain, it can decrease the side-effects or the need of medications for the patient.
Area on which deep brain stimulation would be targeted is based on an individual person, after going through the patient need and condition. Traditionally, there are two common sites for deep brain stimulation, these are following:
- Subthalamic nucleus ( STN )
- Globus pallidus interna ( Gpi ).
In the United States, deep brain stimulation is approved by the Food and Drugs Administration ( FDI ), for the treatment of Parkinson’s.
Deep brain stimulation has shown results on different kinds of chronic pain and these are the following:
Periqueductal gray and periventricular gray for nociceptive pain.
Internal capsule, ventral posterolateral nucleus, and posterolateral nucleus for neuropathic pain.
Major depression and obsessive-compulsive disorder
Deep brain stimulation is used in cases of treatment-resistant depression, this term was coined in 1974 and it is a term used in clinical psychiatry to describe the cases of major depressive order that do not respond to two cases of antidepressants.
Depression is a disease whose treatment is not yet found. Deep brain stimulation was used on patients, nine for OCD, seven for the treatment of TRD and one for both the diseases, and the patients showed a lot of improvement. Deep brain stimulation proved to be as beneficial as anti-depressants for patients suffering from TRD. There were common side-effects of deep brain stimulation on certain patients such as wound infection, perioperative headache and irritating mood kind of suicidal.
Deep brain stimulation has been used to treat adults suffering from Tourette syndrome, only those who does not respond to conventional treatment.
Adverse side-effects of deep brain stimulation
Though deep brain stimulation had worked for some patients but it also had shown some serious side-effects such as the following:
- Cognitive syndrome
As the brain can shift during surgery, there is a sight possibility that the electrodes can become displaced or dislodged from their position.
This may cause some more profound complications such as personality changes, bleeding within the brain. Brain deep stimulation is still being tried