What causes epilepsy

Overview

Epilepsy is a neurological disorder characterized by recurrent, unprovoked seizures. A seizure is a sudden surge of abnormal electrical activity in the brain. While the exact cause of epilepsy remains unknown in about half of all cases, a significant portion can be attributed to identifiable factors. These factors can disrupt the delicate balance of nerve cell activity in the brain, leading to the unpredictable electrical discharges that cause seizures.

What Causes Epilepsy?

Genetic Factors

Genetics are a significant contributor to epilepsy. In many instances, epilepsy is inherited. Specific genetic mutations can alter the way brain cells function or communicate, making an individual more susceptible to seizures. These genetic predispositions can be passed down through families. Sometimes, a genetic mutation occurs spontaneously and is not inherited from parents. Research has identified over 100 different genes that may be associated with various forms of epilepsy, underscoring the complex genetic underpinnings of the condition.

Brain Injuries

Traumatic brain injuries (TBIs) are a common cause of epilepsy, particularly in younger individuals. Injuries sustained from accidents, falls, or assaults can damage brain tissue, which can then lead to the development of epilepsy days, months, or even years after the initial injury. The severity and location of the brain injury often influence the likelihood of developing epilepsy. For example, injuries that affect the brain's outer layer (cortex) are more likely to result in seizures.

Brain Infections

Certain infections that affect the central nervous system can also lead to epilepsy. These include meningitis (inflammation of the membranes surrounding the brain and spinal cord) and encephalitis (inflammation of the brain itself). Infections such as viral, bacterial, or parasitic infections can cause inflammation and damage brain cells, potentially triggering seizures. In some parts of the world, neurocysticercosis, a parasitic infection from tapeworms, is a leading cause of epilepsy.

Structural Brain Abnormalities

Abnormalities in the structure of the brain can disrupt normal electrical activity and cause epilepsy. These can include:

• Brain Tumors: While not all brain tumors cause epilepsy, some, particularly those located in the cerebral cortex, can irritate the surrounding brain tissue and lead to seizures.
• Stroke: A stroke occurs when blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain damage from a stroke can cause epilepsy, especially in older adults. It is estimated that up to 50% of new epilepsy cases in people over 60 are due to stroke.
• Congenital Malformations: These are abnormalities in brain development that occur before birth. Examples include cortical dysplasia (abnormal development of the brain's outer layer) or arteriovenous malformations (abnormal tangles of blood vessels).

Other Causes

While less common, other factors can contribute to epilepsy:

• Metabolic Disorders: Certain inherited metabolic disorders can affect brain function and lead to seizures.
• Immune System Disorders: In rare cases, the immune system may mistakenly attack the brain, leading to inflammation and epilepsy.
• Developmental Disorders: Conditions like autism spectrum disorder and cerebral palsy are sometimes associated with a higher risk of epilepsy.

What is Not a Cause of Epilepsy?

It's important to note that epilepsy is not contagious and cannot be 'caught' from someone else. It is also not caused by psychological factors alone, although stress and anxiety can sometimes trigger seizures in individuals who already have epilepsy.

When to Seek Medical Advice

If you or someone you know experiences recurrent seizures, it is crucial to consult a healthcare professional. A proper diagnosis is essential to determine the cause of the seizures and to develop an effective treatment plan. Early diagnosis and management can significantly improve the quality of life for individuals with epilepsy.