Dr. Kodeeswaran Marappan
M.B.B.S., M.R.C.S.(I), M. CH. (NEUROSURGERY)
DEEP BRAIN STIMULATION
DBS is a surgical procedure used to treat a variety of disabling neurological symptoms.
DBS Surgery Technique
>> MRI Brain is done one day before surgery to see the deep nuclei (subthalamus) of brain.
>> Patient is kept off medication for 12 hrs.
>> This surgery is done under local anesthesia and sedation.
>> On the day of surgery Stereotactic frame (Leksell, ZD Frame) is fixed under local anesthesia, and then patient is taken to Radiology Department for CT Scanning.
>> The subthalmic target is calculated by fusing CT Scan and MRI images on work station.
>> In the operation theatre two small holes in th skull are made, Micro electrode recording is done using 5 channel MER. After analyzing the recording of MER, the track which has longest and strongest signal of sub thalamus chosen for the stimulation. If stimulation confirms the reduction of tremor,stiffness and slowness in operation theatre DBS lead is placed in that track using C-arm.
>> DBS lead is placed in that track using C-arm.
>> DBS lead is connected to IPG (Kinetra, Libra XP “Non Reahcrgeable” and Braio “Rechargeable”) under general anesthesia. This procedure is done on the same day or can be done after one day under general anesthesia.
>> After the Deep Brain Stimulation electrodes implantation, the next important step of this surgery is programming. Initial programming is done in two weeks time and later-on further programming is done as out patient basis in subsequent visits.Patient can himself programme using hand held patient’s programmer under guidance of a neurologist or programming assistant.
How DBS works?
DBS(Deep Brain Stimulation) uses a surgically implanted medical device, similar to a cardiac pacemaker, to deliver electrical stimulation to precisely targeted areas within the brain. Stimulation of these areas blocks the signals that cause the disabling motor symptoms of Parkinson’s disease. The electrical stimulation can be noninvasively adjusted to maximize treatment benefits. As a result, many individuals may achieve greater control over their body movements. DBS System consists of three implanted components :
>> Lead – A lead consists of four thin coiled insulated wires with four electrodes at the lead tip. The lead is implanted in the brain.
>> Extension – An extension connects to the lead and is threaded under the skin from the head, down the neck and into the upper chest.
>> Neurostimulator – The neurostimulator connects to the extension. This small, sealed device, similar to a cardiac pacemaker, contains a battery and electronics. The neurostimulator is usually implanted beneath the skin in the chest below the collarbone (depending on the patient, a surgeon may implant the neurostimulator in the abdomen).
Sometimes called a “brain pacemaker,” it produces the electrical pulses needed for stimulation.These electrical pulses are delivered through the extension and lead to the targeted areas in the brain. The pulses can be adjusted wirelessly to check or change the neurostimulator settings.
Parkinson Disease is an Idiopathic, Chronic, Progressive, Degenerative disorder affecting the elderly people. However it is also seen in young people. Parkinson Disease occurs when certain nerve cells (neurons) in substantia nigra that produces dopamine chemical die or become impaired. When approx. 80% of these nerve cells(dopamine producing cells) are damaged, the symptoms of Parkinson disease appear.
PARKINSON DISEASE SYMPTOMS
- Tremor of the hands, arms, legs
- Rigidity or stiffness of the limbs and trunk
- Bradykinesia or slowness of movement
- Postural instability or impaired balance and freezing.
- Disease slowly progress over years.
Those Patients who can not affored the cost of DBS can benefit from pallidotomy. In Pallidotomy for Parkinson disease a small Thermocoagulation (circuit break) is done at postero-ventral part of Pallidum using stereotactic technique . Pallidotomy helps the patient on the controlateral side of surgery. It improves tremor, stiffness and drug induced side effects.
Bilateral Pallidotomy is also possible but is avoided in lieu of more side effects related to surgery.Surgery is done under local anesthesia patient is discharged after 48 hours.
The spasms may spread to involve twisting contractions of other parts of the body.Early-onset generalized dystonia is characterized by the twisting of the limbs and torso.
They have genetic pattern and runs in family.
Respond to medications but if not controlled then Pallidal deep brain stimulation is a good alternative.
Secondary dystonia are secondary to some other disorder like trauma, Wilson disease etc. These are treated by treating the cause. They are not the good candidate for deep brain stimulation.
Epilepsy is the tendency to have repeated seizures that start in the brain.Epilepsy is usually only diagnosed after a person has had more than one seizure.The incidence of Epilepsy in general population is 0.5-1%.
- 15% of all Epilepsy patients do not respond to combination of three medications and are labelled as intrectable.
- For such cases either surgery or Deep brain stimulation is a good alternative.
- Very few 4-5% are good case of surgery. Rest 90-95 % of intrectable epilepsy
- Patients continue to have seizure despite medications. Deep Brain Stimulation is a good alternative in such cases
- DBS is very effective in all kind of refractory epilepsy
We expect improvement in the range of 50-70% in seizure control and medication are gradually reduce over period of time.
Tremor is a normal phenomenon which is experienced by everyone. Normal tremor is referred to as “physiological tremor” and it is the slight tremor that any person will see when they, for instance, put out their hands. This tremor can be exaggerated in certain situations such as those associated with anxiety and fatigue. This is usually referred to as “exaggerated or enhanced physiological tremor”.
Essential Tremor is a neurological disorder in which patients exhibit a rhythmic trembling of the hands, head, legs, trunk and/or voice, which is more visible during movement or with arms outstretched, than at rest. It is recognisable when seen in postural (voluntarily maintaining a position against gravity) and kinetic (performing any kind of movement) positions. Thus, essential tremor is considered an “action” tremor. It is not believed to be associated with any disease or condition.It can affect persons of any age, gender (both genders are equally affected) and race, it can start in adolescence or adulthood and in the majority of cases, it is inherited. The mean age at onset is 45 years. While more commonly seen in older individuals, ET can begin as early as birth. The age of onset, body part(s) affected and the severity of the tremors, typically differ from patient to patient, even within the same family. This difference from patient to patient holds true for benefits received from drug therapy as well. When tremor begins ins the very elderly it has sometimes been called senile tremor The condition is slowly progressive and tremor will worsen overtime. Some individuals may have to change occupations (i.e. dentists and draftsman) or have to take early retirement.Tremor may involve different body parts. Most often the hands are affected. Usually the dominant hand is first affected and eventually both hands may be involved. Handwriting becomes less legible and drinking liquids is difficult to manage. The individual may have to use both bands or use a straw to drink. Eating soup may become impossible. It may no longer be possible to sign a cheque in a bank or serve coffee at a luncheon. Dysfunction with fine manipulation and embarrassment are also problems. Tremor of the head may also occur. The shakiness may be a ‘yes-yes” or a “no-no” movement. Embarrassment and social withdrawal may result from head tremor. Shakiness of the voice may occur which gives a quavering intonation to speaking. Tremor of the trunk and legs is seen in some patients.Tremor Surgical Treatment
Obsessive Compulsive Disorder (OCD)
Millions of people suffer in silence affected by a disorder that affects about 2% of the population. Obsessive Compulsive Disorder (OCD) patients have a tendency to keep the disorder secret, suffering for months or years because they feel too humiliated or do not wish to be considered mad. Surveys have shown that it is not that rare a condition-it is the fourth commonest psychiatric illness.