DEEP BRAIN STIMULATION (DBS) IN PARKINSON’S DISEASE

DEEP BRAIN STIMULATION (DBS) IN PARKINSON’S DISEASE

Major Symptoms of Parkinson’s disease

Parkinson’s disease (PD) is a progressive neurological disease, characterised by tremors, rigidity, slowness of movements and postural imbalance. Though it is more common after the age of 40, people younger than 40 can also get affected (when it is known as young onset PD).

Other symptoms of PD include low volume speech (sometimes totally incomprehensible), expressionless face, reduced blink rate, reduced arm swing while walking, stooped posture, small handwriting (called micrographia), short-shuffling steps, tendency to fall forwards. Many people also have pain and aches in the affected limbs. Sleep disturbance and restless leg syndrome are common comorbid illnesses in people with PD. Severe memory impairment is NOT a feature of PD, however, in advance PD, mild memory impairment may occur in about 10% of patients. Similarly, loss of bladder control or erectile dysfunction is not a feature of PD. When these features are present, one should suspect multiple system atrophy (MSA).

Diagnosis of PD

The diagnosis of PD is still best made on the basis of clinical examination by an experienced neurologist (preferably trained in movement disorders, though not a must). PET and DaT scans are available to help in the diagnosis of PD, but they are not superior to a good clinical examination by an experienced neurologist.

Treatment of PD

Treatment of PD is still primarily medical and DBS is not the first option.

The most effective medicine is levodopa-carbidopa combination. If a patient does not respond to levodopa treatment, we should doubt the diagnosis (it may not be PD). Even though levodopa is the most effective medication, we should delay starting it by 2-3 years, to avoid side effects and lack of efficacy later on. Other medications in use are pramipexole, ropinirole, trihexiphenydyl, selegiline, rasagiline, amantadine, entacapone, safinamide, etc.

Role of Deep Brain Stimulation (DBS) surgery in PD

DBS was approved for PD in 2002. In the past 15 years, about 1,35,000 patients worldwide have undergone DBS for PD.

What does DBS surgery involve?

A neurosurgeon places the leads (thin wires) that carry electrical signals to specific areas of the brain. Then, the surgeon places a battery-run neurostimulator (like a pacemaker) under the skin of the chest.

The surgeon may use a programming device to adjust the settings. You may have a device, similar to a remote control, which allows you to turn the system on and off and check the battery. You may also be able to adjust the stimulation within options programmed by your doctor.

A neurologist initially evaluates a patient to determine whether he or she is the right candidate for DBS surgery. Then, further evaluations include brain imaging (MRI, CT, PET, etc), neuropsychological testing, UPDRS scoring, etc. Once the patient is found to be suitable for DBS, he is referred to the neurosurgeon.

Which patients are likely to benefit from DBS surgery?

1.     The diagnosis of PD should be definite.

2.     Patient has had PD for five years or more.

3.     Patient continues to respond to levodopa, even though the response may or may not be good.

4.     There are motor fluctuations, such as on-off phenomena, with or without dyskinesia.

5.     Various medical treatments have not had desired benefit.

6.     PD symptoms are severe enough to interfere with activities of daily living.

Which patients are NOT likely to benefit from DBS surgery?

1.     Patients with atypical Parkinsonian symptoms,

2.     Patients with multiple system atrophy (where bladder and sexual dysfunction are prominent symptoms),

3.     Patients with progressive supranuclear palsy,

4.     Patients with dementia or severe cognitive impairment,

5.     Patients with unstable psychiatric illnesses,

6.     Patients with advanced PD, who are confined to bed/wheelchair; despite being on medications,

7.     Patients with NO response to levodopa therapy,

Who are the best candidates for DBS surgery in PD?

1.     Excellent response to levodopa therapy,

2.     Younger age,

3.     Mild or no cognitive impairment,

4.     Few or no axial (affecting neck or trunk) motor symptoms,

5.     Absence of or well controlled psychiatric disease.

Are there any complications of DBS surgery?

DBS surgery is generally safe if performed by a trained group of specialists. However, complications may occur in upto 3% of patients, which include:

1.     Bleeding (hemorrhage) in the brain,

2.     Infection,

3.     Stroke,

4.     Speech impairment

5.     Erosion, migration or fracture of the lead,

6.     Death

What to expect after DBS surgery?

Most patients report a reduction in severity of symptoms after surgery. Tremors, dyskinesia, slowness all respond to the surgery.

PD medications, however, can not be stopped even after DBS. Most patients still need to take medications, however, at much lower doses.

The benefits are seen at five years after surgery, however, the effect tends to wane in later years.

DBS does not alter the disease progerssion, and disease continues to get worse even after DBS.

Is MRI safe after DBS?

Yes, MRI can be safely done after DBS surgery.

What is the cost of DBS surgery ?

The cost of surgery is approximately INR 9,00,000 to 10,00,000.

Dr Sudhir Kumar MD (Med) DM (Neuro)

Senior Consultant Neurologist

Apollo hospitals, Hyderabad

http://www.facebook.com/bestneurologist/

drsudhirkumar@yahoo.com

04023607777/60601066

PARKINSON'S DISEASE

PARKINSON’S DISEASE (PD)

What is Parkinson’s disease (PD)?

Parkinson’s disease is a disease of the brain, which is caused by selective degeneration of nerves in the basal ganglia, leading to deficiency of dopamine in brain.

What are the symptoms of Parkinson’s disease?

The most typical symptoms of this disease include:

1. Tremors- shaking of hands and feet,
2. Slowness of all activities,
3. Stiffness of arms and legs,
4. Loss of balance while standing or walking.

A patient may have only one or some or all of these at onset. However, as the disease progresses, all of them would eventually develop all these symptoms.

What are some of the other symptoms of Parkinson’s disease?

Other symptoms that may occur in a patient with Parkinson’s disease are:

1. Mask-like facies or expressionless face, (even in situations of happiness, they may fail to express it on the face),
2. Stooped posture, with head & trunk bent forwards,
3. Slurred and low volume speech (it is often difficult to comprehend what they are saying),
4. Slow speed of walking,
5. Reduced swinging of arms while walking,
6. Very small letters while writing, referred to as Micrographia,
7. Reduced blink rate (which makes them give a staring look),
8. Short, shuffling steps while walking,
9. Loss of balance while turning, leading to falling forwards.

Why this disease is called Parkinson’s disease?

This is because the very first description of this disease was given by a doctor named Dr James Parkinson, a neurologist from UK. In his honour, the disease was given his name.

Which age group is commonly affected with Parkinson’s disease?

This disease typically affects people above 40 years of age, and the incidence increases with advancing age.

Occasionally, this can occur in people younger than 40, when it is called young onset Parkinson’s disease (YOPD).

How is Parkinson’s disease diagnosed?

Like many other neurological problem, Parkinson’s disease too is diagnosed on the basis of typical symptoms (as described above).

It may be difficult to diagnose PD in very early stages, as the affected person may have only minor symptoms such as mild tremors of hands, and perfectly well otherwise. However, careful examination by a Neurologist would help confirm its diagnosis in this stage too.

Is there a very specific test for diagnosing Parkinson’s disease, especially in early stage?

In doubtful cases, or in very early stages, PET scan (positron emission tomography) can help in accurate diagnosis of PD. This facility is available in our hospital, and I do use it in some cases.

Can Parkinson's disease be transmitted genetically to the children of patients suffering from this disease?

In about 10% of cases, PD can be genetic in origin. But about 90% of cases of PD are sporadic (they have no family history of Parkinson's disease).

What are the treatment options available for Parkinson’s disease?

The mainstay of treatment of PD is medications. Various medications are available. These include levodopa/carbidopa combination (which provide direct dopamine to the brain); ropinirole & pramipexole (which increase the action of dopamine); trihexiphenidyl, amantadine, entacapone, etc.

The choice of drug depends on the patient’s symptoms as well as the severity & duration of PD.

Your neurologist is the best person to decide the most appropriate medications and their doses.

What are the common side effects with medications used for treating PD?

Though these medications are generally safe, some side effects may occur:

1. Giddiness while sitting up or standing- this is because of drop in BP while standing, which is a side effect of levodopa/carbidopa (syndopa/sinemet),
2. Behavioural disturbances- agitation, hallucinations (seeing something that is not there or hearing something when no one is speaking, etc), sleep disturbances can occur with syndopa, especially if the last dose is taken late (such as after 8 pm). 
3. Nausea, vomiting, loss of appetite may occur with syndopa.
4. Abnormal movements of hands or feet, akin to dancing or rhythmic movements, referred to as dyskinesias.

What are the common precautions while taking medications for PD?

1. Medications for PD should be taken on empty stomach, as presence of food may interfere with their absorption,

2. They should be taken on exact time, as advised by the doctor,

3. Any change in the dosage or timing of the medications should be done only after consulting the neurologist.

How long are the medications required in Parkinson’s disease?

Medications are usually required for lifelong. However, the dose would change as per the severity of disease.

Are botulinum toxin injections (Botox) helpful in treating PD?

In selected cases, where there is increased rigidity or dystonia, botox may be useful. The decision can be made by the neurologist after clinical examination.

Are there any surgeries available for treating Parkinson’s disease?

Deep brain stimulation (DBS) surgery is the standard surgery performed in some cases of PD. This surgery can be compared to pacemaker (of heart); wherein an electrode is placed in the brain.

It should be noted that not all cases of PD require surgery, nor would all cases of PD benefit from DBS surgery.

Patients with predominant tremors of hands may be the best candidates for DBS surgery.

Another group of patients who may benefit are those with inadequate response to levodopa, or those with levodopa-induced dyskinesias (see above under side effects).

The decision regarding the need or usefulness of surgery can be made by the neurologist after detailed clinical evaluation.

Is DBS surgery available in India?

Yes, many centers in India (Mumbai, Bangalore, New Delhi, Hyderabad, Trivandrum, etc) have the facilities for doing DBS surgery in India.

We perform DBS surgery in our institute too.

What kind of outcome can be expected in patients with PD after treatment?

1. There is no cure available for PD,
2. Disease continues to progress despite medical treatment, and the severity of disease would worsen over time,
3. The disease leads to severe motor disability, hampering the activities of daily living and occupation,
4. There is generally no increase in the chances of death, if the patients are looked after well.
5. However, it should be noted that a reasonably good quality of life can be maintained with proper medical treatment and physiotherapy for more than 20 years after the onset of PD symptoms.

Is there a specific diet to be followed by patients suffering from Parkinson’s disease?

Protein content should be reduced by 50%, and protein-rich foods (such as pulses, meat, etc) should be shifted to dinner time (after the last dose of syndopa has been taken). This is to ensure proper absorption of syndopa, as presence of high protein food may interfere with the absorption of levodopa.

Is there any limitation on physical activities?

No, there is none. In fact, it is better for a patient with PD to indulge in regular physical activities, including outdoor games, to maintain good physical fitness & mobility.

If you have any additional queries on Parkinson's disease, please send me an email: drsudhirkumar@yahoo.com

DR SUDHIR KUMAR MD (Medicine), DM (Neurology)

Senior Consultant Neurologist

Apollo Health City, Hyderabad, India

Phone: 0091-40-23607777

Email: drsudhirkumar@yahoo.com