Epilepsy in brief

INTRODUCTION

EPILEPSY is a chronic noncommunicable disease of the brain that affects around 50 million people worldwide. It is characterized by recurrent seizures, which are brief episodes of involuntary movement that may involve a part of the body (partial) or the entire body (generalized) and are sometimes accompanied by loss of consciousness and control of bowel or bladder function.

Seizure episodes are a result of excessive electrical discharges in a group of brain cells. Different parts of the brain can be the site of such discharges. Seizures can vary from the briefest lapses of
attention or muscle jerks to severe and prolonged convulsions. Seizures can also vary in frequency, from less than 1 per year to several per day.

Please note: Seizure and Epilepsy are not the same thing. Seizure is the sudden onset of an epileptic attack while Epilepsy is defined as having two or more unprovoked seizures.

Signs and symptoms of Epilepsy

Characteristics of seizures vary and depend on where in the brain the disturbance first starts, and how far it spreads. Temporary symptoms occur, such as loss of awareness or consciousness, and disturbances of movement, sensation (including vision, hearing and taste), mood, or other cognitive functions.

CAUSES OF EPILEPSY

Epilepsy is not contagious. Although many underlying disease mechanisms can lead to epilepsy, the cause of the disease is still unknown in about 50% of cases globally. The causes of epilepsy are divided into the following categories: structural, genetic, infectious, metabolic, immune and unknown. Examples include:

1. Brain damage from prenatal or perinatal causes (e.g. a loss of oxygen or trauma during birth, low birth weight)

2. Congenital abnormalities or genetic conditions with associated brain malformations

3. Severe head injury

4. Stroke that restricts the amount of oxygen to the brain

5. Infection of the brain such as meningitis, encephalitis or neurocysticercosis

6. Certain genetic syndromes

7. Brain tumour.

Types of Seizure

There are two major types of Seizure via: (a) Generalized seizure and (2) Focal seizure

Generalized Seizures  -  In this type of seizure the nerve cells on both sides of your brain misfire. They can make you have muscle spasms, black out, or fall.

Focal Seizures - These start in a particular part of your brain, and their names are based on the part where they happen. They can cause both physical and emotional effects and make you feel, see, or hear things that aren’t there. About 60% of people with epilepsy have this type of seizure, which is sometimes called a partial seizure. Sometimes, the symptoms of a focal seizure can be mistaken for signs of mental illness or another kind of nerve disorder.

GENERALIZED SEIZURES

There are 6 types of Generalized Seizures

1. Tonic-clonic (or grand mal) seizures: These are the most noticeable. When you have this type, your body stiffens, jerks, and shakes, and you lose consciousness.

2. Clonic seizures: Your muscles have spasms, which often make your face, neck, and arm muscles jerk rhythmically. They may last several minutes.

3. Tonic seizures: The muscles in your arms, legs, or trunk tense up. These usually last less than 20 seconds and often happen when you’re asleep.

4. Atonic seizures: Your muscles suddenly go limp, and your head may lean forward. If you’re holding something, you might drop it, and if you’re standing, you might fall. These usually last less than 15 seconds, but some people have several in a row. Because of the risk of falling, people who tend to have atonic seizures may need to wear something like a helmet to protect their heads.

5. Myoclonic seizures: Your muscles suddenly jerk as if you’ve been shocked. They may start in the same part of the brain as an atonic seizure, and some people have both myoclonic and atonic seizures.

6. Absence (or petit mal) seizures: You seem disconnected from others around you and don’t respond to them. You may stare blankly into space, and your eyes might roll back in your head. They usually last only a few seconds, and you may not remember having one. They’re most common in children under 14.

FOCAL SEIZURES

This is classified basically into three

1. Simple focal seizures: They change how your senses read the world around you: They can make you smell or taste something strange, and may make your fingers, arms, or legs twitch. You also might see flashes of light or feel dizzy. You’re not likely to lose consciousness, but you might feel sweaty or nauseated.

2. Complex focal seizures: These usually happen in the part of your brain that controls emotion and memory. You may lose consciousness but still look like you’re awake, or you may do things like gag, smack your lips, laugh, or cry. It may take several minutes for someone who’s having a complex focal seizure to come out of it.

3. Secondary generalized seizures: These start in one part of your brain and spread to the nerve cells on both sides.

DIAGNOSIS OF SEIZURE

To figure out if you have epilepsy and what type you have, your doctor will do some or all of these tests:

1.Electroencephalogram (EEG).- This is the most common test. Your doctor places sensors on your scalp that record electrical activity in your brain. If they see changes in your normal brain wave pattern, that’s a symptom. Many people with epilepsy have abnormal EEGs.

2. Computerized tomography (CT) scan.- It uses X-rays to create images of your brain. This can help your doctor rule out other seizure causes, like tumors, bleeding, and cysts.

3. Blood tests.- They also help discount other reasons for seizures, like genetic conditions or infections.

4. Neuropsychological tests.- The doctor will test your speech, thinking, and memory skills to see if those areas of your brain have been affected by seizures.

Others include PET scan, FMRI, MRS SPECT etc

TREATMENT OF EPILEPSY/SEIZURES

Medications are mainstays in controlling epileptic seizures although there are other ways through which they can be treated.

Other ways of treating Epilepsy include:

1.Vagus Nerve Stimulation
For this epilepsy treatment, a doctor implants a pacemaker-like device in your body to stimulate the vagus nerve, which runs from your brain to your torso.

2. Multiple Subpial Transection (MST)
Multiple subpial transection (MST) is a surgery used to control brain seizures in people with epilepsy who don't respond to medication.

3. Temporal Lobe Resection
In this surgery for epilepsy, brain tissue in the temporal lobe is cut away to remove the seizure focus. etc.
Please take note, a procedure called Corpus callosotomy is performed in patients with extreme and uncontrollable forms of Epilepsy
Finally, the following drugs are currently in use for the treatment of Epilepsy:

1. Felbamate (Felbatol) 2. Gabapentin (Neurontin), 3. lamotrigine (Lamictal) 4. Levetiracetam (Keppra)
5.Oxcarbazepine (Oxteller XR)
6.Tiagabin hydrochloride (Gabitril) 7. Topiramat (Topamax)
8. Zonisamide (Zonegran)