Deep brain stimulation (DBS) in Parkinson’s disease (PD)

Host: Hello and Welcome to PACE Hospitals Podcast. Today we delve into the remarkable world of Deep Brain Stimulation (DBS) and its profound impact on Parkinson’s disease.

Joining us today Dr Sandhya Manorenj - Consultant Adult and Pediatric Neurologist having wide expertise in treating and managing Parkinson's disease (PD). In today’s episode she would like to uncover the transformative potential of this innovative therapy, offering hope and relief to millions around the globe.

Dr Sandhya thank you for joining us at PACE Hospitals, Hitech City.

Host: Dr Sandhya Manorenj thank you for joining us lets understand exactly what is Parkinson’s disease?

Doctor:  Parkinson's disease is the second most common neurodegenerative disease after Alzheimer's disease. It usually affects the older individuals after the age of 50 years. The average age of onset of Parkinson's disease in India is around 51 years which is very much younger than the world population.

The average age of onset of PD in the world is above 60 years of the age. We also found that the 10% of the Parkinson's disease occur in the young individual, that is before 50 years and there have been associated genetic abnormality, it was found that the study from NIMHans observed that 45% of the Parkinson's disease patients in India occurred in younger age group between 22 years to 49 years, so that is the important role of deep brain stimulation in this age group of patients.

Host:  What are motor and non-motor symptoms of Parkinson's disease?

Doctor:  The disease is categorized by motor and non-motor symptoms. The non motor symptoms start around 10 to 30 years prior to the motor symptoms. The non motor symptoms are loss of smell, constipation, depression. 

Sometime the patient can also present with sleep disturbance, etcetera while the motor symptoms are bothersome and it is characterized by shaking or tremor initially of one side of the body involving the upper part of the body, that is upper extremities followed by lower extremities and later on slowness or bad kinesia, tightness of the limbs or rigidity and later poster instability. Hence person is unable to do his activity of daily living and he becomes slow at workplace and there is slowness of thought also and he lost his job.

Host:  What is deep brain stimulation?

Doctor:  DBS is a surgical therapy used to treat certain aspects of Parkinson's disease and it helps patient to be asymptomatic most of the day, that is 80% of the day the patient becomes on.

Host:  So, doctor, what is DBS surgery?

Doctor:  The surgery is done in two stages. The first stage is planning and appropriately making the site for electrode insertion. This is done using a stereotypic frame and imaging brain to localize the subthalamic nucleus or the globus peldus internal.

These are the deeper structures of the brain where we are going to introduce the electrode and this takes this procedure takes around 3 hours.So what happen in the DBS surgery, a electrode are inserted into a target area of the brain that is, as I already told, the subthalamic nucleus and globus pallidus using MRA brain and the entire procedure is done in the awake state of the individual and local anesthesia is given at the insertion site of the electrodes.

Now coming to the second stage, the second stage is done in the next day, after the first day and it is under general anesthesia and this procedure is performed to implant an impulse generator battery, that is, it is a brain pacemaker which is similar to a heart pacemaker and it is approximately the size of a stopwatch and this is placed under the collarbone or in the abdomen and it delivers an electrical stimulation to the targeted areas in the brain that control movement. Those who undergo DBS surgery are given a controller to turn the device on or off and review basic parameters such as battery life.

Host:  When is DBs indicated or advised in PD patient?

Doctor:  When they have levodopa responsiveness, when the age of the patient is between 30 to 70 years and there is no dementia or there is no memory impairment or no psychosis and then patient is already on medication, and he developed drug induced excess movements that is called as dyskinesia, or the patient is not able to tolerate the medications and there is medication related side effects. So, these are the indication of DBS.

Host:  Can DBS improve non motor symptoms of PDE? 

Doctor:  Yes. DBS may also improve some of the non-motor symptoms that include sleep, pain and urinary urgency. It is important for everyone to keep in mind that DBS can only help relieve symptoms, not cure or stop disease progression.

Host:  Is DBS an approved treatment in PD?

Doctor:  Yes, DBS is the approved treatment in Parkinson's disease. It was first approved in 1997 to treat Parkinson's tremor, that is shaking in patients with Parkinson's disease. In 2002, it was approved to treat advanced Parkinson's symptoms.

Advanced Parkinson symptoms usually occur in those patients after five years of onset of motor symptoms. In 2016, it was advised for the early stages of PD. For people who have PD for at least four years and have motor symptoms which are not controlled with medications, who will benefit maximum with DBS surgery, it is most effective for people who experience disabling tremors, wearing of spel and medication induced dyskinesias.

Host:  How long the benefit of DBS lasts?

Doctor:  Studies showed that benefit lasts at least five years. It depends upon the type of pacemaker and battery used. There are two types of battery available, non-rechargeable and rechargeable battery. So in non-rechargeable battery it works for three to five years and battery has to be removed and replaced after doing small incision below the collarbone where the pacemaker was implanted.

Now in case of rechargeable type, it can be charged and used even up to 15 years and some devices up to 25 years. It is not right choice for every person with Parkinson's disease to undergo DBS as certain non-motor symptoms like speech, swallowing, difficulty thinking or gait freezing does not respond to DBS therapy.

Host:  So, doctor, is there any risk of doing DBS surgery?

Doctor:  Like all brain surgeries, deep brain stimulation surgery does carry a small risk of infection, stroke, bleeding or seizure. DBS surgery may be associated with reduced clarity of speech or even slight changes in finding the right word. A small number of people living with PD have experienced cognitive decline after DBS surgery, this occurs most often in patients who already have some cognitive impairment prior to surgery.

Host:  What are the components of the DBS system?

Doctor:  So, there are three components, the lead, which is inserted into the deep brain structures of the brain, its extension wires and the neurostimulator, which is kept outside under the skin below the collarbone.

Host:  Which brain targets should be used to implant the DBS lead?

Doctor:  There are two target choices which was approved by FDA, that is subthalamic nucleus and the globus peldus interna are the most common site.

Host:  How long does the procedure of DBS surgery takes?

Doctor:  It takes four to 5 hours.

Host:  What is the frequency at which target organs are stimulated in DBS?

Doctor:  Usually in treatment of Parkinson's disease, high frequency DBS that is more than 100 hz are recommended for the treatment of PD.

Host:  When does the effect of DBS start? Immediately after DBS surgery or later?

Doctor:  Programming generally begins after a few weeks of DBS surgery. At least four weeks after the surgery, the device is turned on and therapeutic stimulation occurs. Symptom relief can take months. Meantime, medication of the PD can be reduced.

Host:  Does TBS permanently damage brain tissue?

Doctor:  The effects of deep brain stimulation are reversible and do not permanently damage the brain tissue.

Host:  What is the honeymoon period of PD?

Doctor:  The initial five years after the onset of motor symptom of PD is called as the first honeymoon period. During this period, patient respond well to medication with levodopa therapy after five years drug induced dyskinesia that is abnormal movements shaking off phenomena, the drug does not work, and side effects of medication occurs. So if the patient undergo DBS which is done during this period, that is after five years, there is second honeymoon period in them.

Doctor:  As the DBS improves the motor symptoms, tremor and bradykinesia and it prevent dyskinesia and patient remains on, that is normal moment in most of the day. Around 80% of the day the patient remains on and he can do his activities of daily living and he can go for his work.

Host:  How often a patient undergoing TBS surgery need to visit doctor? 

Doctor:  initially four weeks after surgery programming is done where brain pacemaker device is turned on which is otherwise called as the IPG. Subsequently, reprogramming is done after three months and the revisit every year or two. If the PD patient require frequent reprogramming, it indicates either DBS surgery is not done properly or the doctor who does programming did not do it well.

Host:  Does the DBS device should be turned off during night?

Doctor:  No, the device is turned on throughout the day and night. Usually, the adjustment and reprogramming is done only by the doctor that is a neurologist or neurosurgeon.

Host:  What precautions to be taken after undergoing DBS surgery?

Doctor:  Person can lead a normal life. He needs to avoid exposure to high electromagnetic field region like MRA row. However, with recent advances, MRI compatible DBS devices are available.

Secondly, while taking ECG, the electrode has to be kept posterior as a pacemaker is kept below the left clavicle. Thirdly, when a person goes through metal detector while entering the shopping mall, they should show their card of DBS device so that they are devoid of metal detector.

Fourthly, while undergoing other surgeries where a doctor needs to stop bleeding from blood vessels by cauterization, they need to avoid monopolar dithermy in patients with DBS which is an electric current. In such circumstances, bipolar diathermy is safe in patient with DBS device.

Host:  Can a person undergo MRI study while on DBS device or brain pacemaker?

Doctor:  MRI is usually avoided in patients with DBS device as most of the devices are MRA non compatible but there are MRA compatible device too. Hence a person need to discuss regarding the same with diabetic, neurologist or neurosurgeon before going for MRA.

Host:  Can a person with TBS device use electronic devices like cell phone, fridge or iron box?

Doctor:  Yes, they can use it safely. Only precaution taken while undergoing other surgeries as I already mentioned, bipolar diathermy should be preferred to arrest bleeding.

Host:  What are the things a patient with DBS device should avoid?

Doctor:  Avoid a metal detector test at shopping mall or at a high security zone. Need to show that device can avoid MRI scan.

Host:  So, doctor, overall, what does DBS do in patients with PD?

Doctor:  DBS surgery provides a person to forget that he is a patient of Parkinson's disease. It helps to lead an independent life, self-care, driving, going to his work, without any dyskinesia, without any medication related side effects. It provides a quality living from 2 hours to 14 to 18 hours of the day, thus providing second honeymoon period in patients life.

Host:  Thank you, Dr Sandhya, for shedding light on the transformative potential of Deep Brain Stimulation in Parkinson’s disease to our listeners.

Doctor: I hope this information can be valuable for the listeners to know more about the importance of deep brain stimulation in patients with Parkinson's disease.

If any of you have any further questions regarding Deep Brain Stimulation in Parkinson’s disease please don’t hesitate to consult a neurologist and remember, advancements in medical science continue to pave the way for improved treatments and quality of life for Parkinson’s patients.

We will be back soon with another episode on PACE Hospitals Podcast, until next time, Stay informed, stay connected and keep seeking knowledge and support, take care. Thank you