The deep brain stimulation is a treatment technique in which electrodes are placed in a specific region of the brain. These regions are selected based on the symptoms being treated. The electric terminals are placed on both the left and right sides of the brain through small holes or incisions made at the top of the cranium or skull. The electrodes are connected by long cables that travel under the skin and down the neck to a battery-powered stimulator placed under the skin of the chest, which when turned on, sends electrical pulses to block the faulty nerve signals causing rigidity, tremors, and other symptoms.

In the correctly selected patients, DBS is quite safe and efficient but there are some risks. There is an estimated two to three percent risk of brain hemorrhage that may either be of no significance or may cause paralysis, speech impairment, stroke, or other major problems. There is also a small risk of leakage of cerebrospinal-fluid that can lead to headaches or meningitis. According to the research and surveys, there is approximately 15 percent risk of a minor or temporary problem with implantation which also includes infection.

The circuit inside our brains responsible for controlling our movements is called the basal ganglia and is made up of several different groups of brain cells that connect and communicate to each other to fine- tune movement. In Parkinson’s, the key families of brain cells involved in the movement circuit stop working properly as the dopamine-producing cells in the substantia nigra slowly stop producing optimal level of dopamine. Without the injection of dopamine, it becomes harder to get moving and to maintain movements, and so, things like stride length can get shorter over time. This is where DBS comes into the picture. Although we still do not fully understand how this electrical stimulation works to improve movement, scientists and doctors now believe that the stimulation may disrupt abnormal electrical activity in the basal ganglia and may help to regain the movement control.

If the patient is selected carefully, the DBS can be highly effective and reduce the symptoms by 70%.

Yes, DBS is completely reversible and can be turned off or can be removed if necessary.

Studies have reported that DBS can reduce off Parkinson's related symptoms by 60-70%.

Dystonia is a type of movement disorder where a person's muscles contract uncontrollably, which causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures. DBS surgery does not cure dystonia but when the simulator is turned on and is functioning well, it can eliminate the symptoms related to dystonia.

The possible risk factors of dementia after DBS surgery is negligible.

The duration of the operation depends on the technique used by the hospital, but surgery usually lasts between 3-6 hours from start to finish.

There are a few side effects of DBS, and they may include the following:

• Temporary tingling in the face or limbs
• Temporary pain/swelling at the implantation site
• Allergic reaction to the implant
• Slight paralysis
• Jolting or shocking sensation
• Speech or vision problems
• Loss of balance
• Reduced coordination
• Concentration difficulties
• Dizziness

DBS or Deep Brain Simulation surgery is performed by a neurosurgeon specialized in functional neurosurgery.

Deep brain stimulation is regarded as an established treatment for people with movement disorders, such as essential tremor, dystonia, Parkinson's disease, and psychiatric conditions, such as obsessive-compulsive disorder.

DBS surgery in India can cost 7.5 - 9 Lac Rupees.

DBS surgery help in obsessive-compulsive disorder. Deep brain stimulation (DBS) has been approved for OCD treatment under a Humanitarian Device Exemption. But not everyone can avail to DBS to treat their OCD. Their OCD must be considered chronic, severe, and treatment-resistant for them to be eligible for DBS therapy.

Usually, the battery of the stimulator is needed to be replaced every 2 to 5 years. But some DBS systems have stimulators with rechargeable batteries that may last up to 9 years.

The surgical implantation of leads or electrodes within certain areas of the brain is known as deep brain stimulation therapy.

A small device is placed inside a person’s chest, that sends electrical impulses to the electrodes implanted in the brain. These electrical impulses change or block the abnormal activity of a person with a neurological (nerve-related) disorder.
The different parts of the deep brain stimulation therapy system are:
Lead: It is a thin wire that is placed in a certain part of the brain that is causing symptoms.
Pulse generator: This is a pacemaker-like device that sends electrical signals to the lead.
Extension lead: It is a wire that connects the lead to the pulse generator.
Hand-held programmer device: It is a remote control used to control the system, and switch it on and off. It is the only part of the device that lies outside the body.

A deep brain stimulation therapy can be used to treat the following conditions:

• Parkinson’s disease: It is a type of neurological disorder affecting the ability of an individual to control movement.
• Epilepsy: Events of altered brain function that are caused due to abnormal or excessive electrical discharges from the brain cells, leading to epileptic seizures is known as epilepsy.
• Essential tremor: The rhythmic trembling of the different parts of the body are known as essential tremors.
• Dystonia: An involuntary contraction of muscles is known as dystonia. 
• Obsessive-compulsive disorder: It is a type of mental illness that causes uncontrollable obsessions.
• Multiple sclerosis: It is a condition of the central nervous system (brain and spinal cord) causing a disability.
• Intractable pain: This is a type of pain that cannot be relieved by treatment.
• Stroke: A stroke is a condition in which the blood supply to the brain stops. 
• Addiction: An uncontrollable compulsion to use certain things.
• Tourette syndrome: It is a disorder that causes uncontrollable movements and some vocal sounds, called tics.
• Alzheimer’s disease: It is a brain disorder that affects the memory, learning, and thinking, and of a person.
• Anorexia nervosa: It is a type of eating disorder in which an individual limits the intake of food.
• Depression
• Traumatic injury to the brain

The following symptoms may be noticed due to a neurological disorder or a movement-related disorder, which could indicate the need for a deep brain stimulation therapy:

• Tremors
• Stiffness
• Abnormal walking
• Bradykinesia (slow movement)
• Tremors
• Confusion
• Staring spells
• Loss of consciousness
• Fear
• Anxiety
• Jerking movements of the legs or arms
• Involuntary muscle contractions
• Muscle contractions worsening with fatigue, anxiety, or stress
• Fear of germs
• Fear of contamination
• Excessive cleaning 
• Aggressive thoughts
• Checking things again and again
• Compulsive counting
• Having things in the perfect order

A group of the following specialists can work together to provide deep brain stimulation therapy:

• Neurologist
• Neuropsychologist
• Neurosurgeon
• Psychiatrist

A good candidate for deep brain stimulation therapy is the one whose:

• Symptoms are not controlled well despite taking medicines
• Side effects cannot be tolerated using current medicines
• Symptoms are negatively impacting the quality of life of the patient.

The following preparation may be required for deep brain stimulation therapy:
A group of specialists evaluates the patient’s condition. The patient discusses his/her case with the specialists and evaluates the pros and cons of a deep brain stimulation therapy, before deciding to go ahead with the procedure or not.
The surgeon advises an MRI scan of the brain to be taken before the procedure, to help in predetermining where the device will be placed.
The surgeon should be informed about any medical diseases that the patient may be having.
The surgeon should know about any medications, supplements, or herbs that the patient may be taking.
Inform the surgeon if the patient is having any allergies.
The patient should stop smoking at least fifteen days before the procedure.
The surgeon generally advises the patient to stop blood-thinning medications like aspirin and warfarin a couple of days before the procedure.
The patient’s head will be shaved off the day before the surgery.
In case of the procedure being performed under general anesthesia, the patient will be instructed to not eat or drink anything the day before the surgery.
Any medication that needs to be taken before the surgery, should be taken with small sips of water.

The procedure is performed in two stages:
1. Brain surgery:
The patient is fitted into a stereotactic head frame, to keep the head stable during the surgery. 
A brain MRI or CT scan is used for identifying the area of electrode insertion in the brain.
A local anesthesia (a numbing agent) is injected into the scalp area. 
There are no pain receptors in the brain and therefore, it does not need require anesthesia.
The electrodes are normally placed by the surgeon when the patient is alert so that the effects of stimulation can be tested.
The procedure may sometimes be done under general anesthesia, where the patient is made to fall asleep during the procedure.
A thin wire lead with several electrodes at the tips is implanted by the surgeon into a part of the brain or one lead each is implanted into either side of the brain.
A wire runs under the skin to a pulse generator, that is implanted near the collarbone.

2. Chest wall surgery:
The second part of the therapy involves the implantation of the pulse generator under the skin in the chest, near the collarbone.
This procedure is done under general anesthesia.
The wires from the electrodes in the brain are guided down to a battery-operated pulse generator.
The pulse generator is programmed to send continuous electrical pulses to the brain.
The patient has control over the pulse generator and can turn it on or off with a special remote control.

• The patient will normally be discharged from the hospital one or two days after the procedure.
• The stitches will be removed 10 to 14 days after the procedure.
• The wound area should be covered by band-aids till they are dry. These band-aids can be changed every day as required.
• The patient can gently shampoo his/her hair the day after the stitches are removed.
• The patient is instructed not to scratch the wound area.
• The patient should avoid any kind of sexual activity for two weeks following the surgery.
• Complete rest for two weeks is advised after the surgery.
• Physically strenuous activities should be avoided for four to six weeks after the procedure.
• Avoid bending over, raising the arms above the shoulders, and stretching of the neck.
• The patient can usually return to work four to six weeks following the procedure.

Call the doctor immediately if the following symptoms are noticed:

• High fever
• Bleeding from the incision
• Persistent, severe headaches
• Loss of vision or change in vision
• Redness in the incision area
• Increased swelling in the incision area
• A magnet will be provided to the patient for activating and deactivating the stimulator. This magnet should be kept at a distance of a minimum of one foot from computer discs, credit cards, and televisions, as the magnet can cause damage to these devices.
• Metal detectors can cause the pulse generator to switch on or off, causing worsening of the symptoms. The patient should always carry an identification card provided by the surgeon to request assistance in bypassing these devices.
• Home appliances like cell phones and computers usually do not interfere with the implanted pulse stimulator.

The various benefits of a deep brain stimulation therapy are:
The procedure does not usually cause any permanent damage in any part of the brain.
The electrical stimulation activity is reversible and adjustable as per a change in the disease of the patient or the response of the patient changes bought about by medications.
Use of innovative, not-yet-available treatment modalities is possible.
The pulse stimulator can be switched off if the deep brain stimulation therapy leads to excessive side effects without any long-term consequences.

The various complications associated with deep brain stimulation therapy include:
  1. Surgical complications:

• Brain infection
• Brain hemorrhage (bleeding in the brain)
• Misplaced or wrong location of the leads

 2.Hardware complications:

• Movement of the leads
• Lead failure
• Failure of a part of the deep brain stimulation system
• Battery failure
• Infection around the device
• Device breaking through the skin, as the skin becomes thinner with age

 3. Stimulation-related complications:

• Dyskinesia (unintended movements)
• Speech disturbances
• Freezing (the feet feel as if they are stuck to the floor)
• Balance and gait become worse
• Involuntary contraction of muscles
• Paresthesia (tingling and numbness)
• Diplopia (double vision)

Batteries in rechargeable battery devices can last up to 9 years, whereas, batteries in non-rechargeable devices can last for 3 to 5 years. A simple procedure is required to replace the battery.
A rechargeable battery can usually be charged for half an hour daily, or for four hours every 10 to 14 days.

The cost of deep brain stimulation therapy varies across different hospitals and amongst different doctors. The cost normally varies from INR 5,00,000 to INR 15,00,000.