Every year, National Epilepsy Day is observed on November 17 to raise awareness about the condition. A brain illness, it is marked by periodic fits or seizures.
What happens at the end of an epileptic episode? Unlike other diseases, epilepsy has no end stage; however, the severe stage is often referred to as intractable epilepsy. In epilepsy, intractable epilepsy occurs when medications/drugs fail to control the condition and are unable to provide a stable quality of life for the patient. The expectations of the quality of life with intractable epilepsy differ from one patient to the next. The frequency of seizures increases over time in this stage, and since the regular dose of medication does not work, the dosage of medication is disproportionately increased. “A neurologist examines these symptoms and determines whether a surgical procedure to be suggested for patients’ benefits. The surgical procedure can be an open surgery known as resection or disconnection surgery, or it can be done through neuromodulation, in which deep brain stimulation is used to stop seizures,” says Dr. Anirban Deep Banerjee, Associate Director, Neurosurgery, Institute of Neurosciences, Medanta Hospital, Gurugram.
How deep brain stimulation surgery help in treating epilepsy?
Deep brain stimulation (DBS) is a medical procedure in which a small electrical current is delivered to a specific area of the brain. This procedure aids in the reduction of seizure frequency. DBS is also known as a brain pacemaker because, like a heart pacemaker, it helps regulate irregular heartbeats. Similarly, DBS can help treat irregular seizures caused by uncontrollable brain disruption. “DBS helps in reducing the frequency of seizure episodes by 50% in 50% of the patients, also known as the thumb rule of 50-50, which means that 50% of the patients who undergo DBS surgery and among them up to 50% of the seizures episodes are reduced, allowing the doctor to gradually deescalate the seizures medication,” adds Dr Banerjee.
Criteria of performing DBS
When a patient is diagnosed with epilepsy, there are certain criteria to look for before consulting with someone about DBS. The criteria consider the patient’s age, for example, a person over the age of 18 can only undergo DBS using an FDA-approved procedure. Aside from age, another factor that a doctor considers is the type of epilepsy the patient has; this can only be used to treat patients with partial onset epilepsy. Patients are only given the option of DBS.
Success rate of DBS surgery
The success rate is defined by the 50-50 rule. Deep brain stimulation can cure 50% of patients who receive it, and it can reduce seizure episodes in 50% of those patients.
Preparing patient for surgery?
Before the surgery, the patient has to undergo a routine check-up and a specialized MRI known as the Deep Brain Stimulation Protocol. It allows the doctor to see specific anatomical areas deep within the brain. “We now have advanced MRI to delineate the areas prior to surgery which runs in a few millimetres only. This procedure is performed prior to surgery to assist the doctor in determining where the wires should be precisely placed during surgery to achieve the best results,” opines Dr Banerjee.
The patients are usually discharged a day after surgery for few days after surgery. The patients are asked to adhere to medications after surgery, at least for one year until the doctor changes the course. Only after one year, the medications deescalated by the neurologist based on the condition of the patient, until that time, a process called brain pacemaker programming sessions, is suggested to patients by the doctor. The process helps the doctor modulate the pacemaker, which is implanted in the patient’s body by an external source, so that the doctor can moderate the voltage, and strength of the current. These adjustments can be fine-tuned in the pacemaker based on the patient’s response to ensure maximum benefit. These sessions are held on a periodic basis for three months, and after a year, the medications are gradually reduced as seizure episodes are brought under control.
Dr Banerjee explains the pros and cons of DBS
It reduces seizure episodes by half
It may reduce a person’s need for medication
During surgery, bleeding can occur, which causes a deep-seated haemorrhage. The likelihood of a deep seated haemorrhage occurring is less than 1%.
Patients may get infected as a result of the transplantation because of implanted foreign material into their bodies. However, the chances are minimal and can be managed by antibiotic