Epilepsy is a chronic disorder that affects brain and causes recurrent seizures. It can affect people of all ages and can happen due to the following reasons:
• Brain Injury – as result of car or other serious accident
• Infectious diseases – like AIDS, meningitis and viral encephalitis etc.
• Genetic – some people can get this condition from their parents
• Development disorder – such as autism, neurofibromatosis
• Prenatal trauma – can occur due to infection in mother, poor nutrition or oxygen deficiency that can damage the brain damage before the birth of the babies.
Epilepsy causes seizures that can lead to some risk and complications like falling, drowning during swimming, car accidents, complications at the time of pregnancy, psychological problems such as depression, anxiety and in extreme cases suicide tendency also.
Epilepsy surgery is the right option when the medications cannot control seizures. It can control seizures, make them less severe and improve quality of life. Epilepsy surgery is done to safely remove the part of the brain that causes uncontrollable seizures without causing any harm to the brain.
There are different types of epilepsy surgeries that depend on the type of seizures and part of the brain being affected such as:
1. Temporal lobectomy - cerebrum is the largest part of the brain that is divided into four paired sections known as lobes – the frontal, parietal, occipital and temporal lobes. In temporal lobe surgery, brain tissue in temporal lobes which causes seizures within this area of the brain is cut away to remove the seizure focus.
2. Extratemporal resection – brain tissue in other parts of the brain or areas outside the temporal lobe that causes seizures is removed.
3. Lesionectomy – in this surgery, brain lesions such as area of injury, defect, tumor or abnormal blood vessel causes seizures are removed or cut away. Generally, seizures get stopped once the lesion is removed.
4. Hemispherectomy – in this type of surgery, doctor may remove whole hemisphere or half of the brain. In functional hemispherectomy, doctor will disconnect the hemisphere from the rest of the brain without removing it entirely. This type of surgery is mostly performed on children less than the age of 13 who have one hemisphere that doesn’t work properly.
5. Corpus Callosotomy – a band of nerve fibers that connects the two parts (hemispheres) of the brain is called corpus callosum. This surgery is also called split- brain surgery, in which doctor will cut away the connections between both the hemispheres which stop spreading of the seizures from one hemisphere to the other. Corpus callosotomy works best for the people having extreme and uncontrollable epilepsy seizures that can lead to serious damage or injury.
6. Multiple subpial transaction – this surgery can help control the seizures in irremovable part of the brain. Surgeon will make some shallow incisions (transections); in the brain tissue which will interrupts the flow of seizures without disturbing normal brain activity.
7. Vagus nerve stimulation – a device that sends an electronic jolt to the vagus nerve which controls activity between the brain and other major internal organs will be placed under the patient’s skin to lower a seizure activity in some people with partial seizures.
8. Responsive neurostimulation device – doctors will place a small neurostimulator under the patient’s scalp which is linked to one or two wires placed either in the part of the brain where seizures start or on the surface of the patient’s brain. This device detects abnormal electrical activity in the part and sends an electric current to stop the process that leads to a seizure.
Some tests are suggested by doctor before choosing the right type of surgery for the patient to detect the intensity of seizures and other symptoms such as:
1. Electroencephalogram (EEG) – A technician put harmless electrodes on patient’s scalp, using a special glue or sticky tape. The electrodes are then connected to the EEG machine to record the electrical signals from the brain. Doctors can also see from where in the brain seizures are coming in video telemetry that is done at the same time of EEG. This test can be performed while the patient is awake or asleep, or both.
2. MRI scan – strong magnetic field and radio waves create pictures of tissues, organs and other parts inside the body on computer to see if there is any structural cause for epilepsy.
3. PET scan – this test uses a radioactivity substance (tracer), to see how the brain is working.
4. SPECT scan – Patient will get a radioactivity dye injection that will go to his/her brain. Different parts of the brain are shown in different colors to see how much blood flow is in each part of the brain in SPECT scan. Seizures will occur where there is highest blood flow in the part of the brain.
5. Neuropsychology tests – this test is for detecting if the patient has any memory or learning problem. This can help surgeon to plan out the kind of surgery patient might need.
6. Neuropyschiatry assessment – this important if the patient has psychiatric illness along with seizures. This test is check what are the other problems caused by epilepsy.
Depending on the type of surgery done, some people can get completely free of seizures whereas, others can still get seizures but less often. Post surgery patient need to keep taking anti-seizure medications for a year or more or till the time seizures are under controlled.
Doctor will suggest second surgery/reoperation if the patient still has a seizure just after the surgery which usually means surgeon did not cut away all the brain tissues that are causing seizures.