Shining a Light on Epilepsy: Brain Function and Seizure Management.

Seizure is a disorder of the electrical activity of the brain leading to variable forms of symptoms (e.g. clonic contraction of muscles, vertigo, flashes of light…etc.).

Epilepsy is diagnosed if the seizures are repeated (more than two) or if there is a high probability of recurrence (e.g. seizure due to brain tumor).

A seizure can be caused by many medical or surgical conditions. First seizure must be investigated by a brain MRI (epilepsy protocol) and at least a standard EEG (30 minutes). Also, laboratory analysis for possible metabolic imbalance (e.g. low calcium level or high blood sugar) should be done. If the seizure is proven to be provoked by a correctable condition no antiseizure medication is needed for long time and correction of the abnormality will be sufficient to prevent recurrence.

Epilepsy is classified in different ways. The International League Against Epilepsy (ILAE) has released a new classification in 2022. Epilepsy syndromes are mainly classified according to age, neonates and infant, childhood and variable age. This is due to the different presentation and outcome in each age group. Some epilepsies are more benign than others and can disappear with age and others are prone to recur the entire lifetime and need permanent antiseizure medication.

Epilepsy also is classified according to the type of seizure occurring each time. The same type of seizure tends to recur according to the area of the brain affected. If the seizure starts in the area responsible for motor control of the arm the patient will experience a tonic contraction of the same arm. If the seizure occurs in the area responsible for emotions the patient can experience unexplained sudden fear with increased heart rate. If it starts in the visual cortex the patient can experience flashes of light…. etc.

Epilepsy is controlled by antiseizure medications (ASM). The ASM can only prevent seizures from recuring yet there is no medical cure for the epileptic focus. The duration of treatment is variable, yet most patients will need it for life. The medication is chosen according to the classification of epilepsy and seizure type. Some ASM are contraindicated in some seizure type; Not all ASM fit all seizure types. Proper diagnosis is needed before choosing the ASM.

The golden rule is one ASM reaching maximum dose according to patient weight in order to control the seizures. Three trials of single ASM are done before starting to add on another medication.

Some patients experience “Drug Resistant Epilepsy” or “Refractory Epilepsy” that is defined according to the ILAE”

• Drug-resistant epilepsy occurs when a person has failed to become (and stay) seizure free with adequate trials of two antiseizure medications (called ASMs).
• These seizure medications must have been chosen appropriately for the person’s?seizure type,?tolerated by the person, and tried alone or together with other seizure medications.

Patients with refractory epilepsy can benefit from some intervention. Vagal nerve stimulation is used to abort the seizure when it starts. Epilepsy surgery is considered only if the patient has severe drug-resistant epilepsy.

It needs a multidisciplinary team including neurologists, neurosurgeons, neurophysiologists, radiologists and neuropsychologists. Surgery needs thorough preparation, and final decision is made when the team calculate the risk-benefit properly.