What Causes Seizures in Epilepsy?

Epilepsy is a neurological condition characterised by recurrent seizures caused by abnormal electrical activity in the brain. Seizures are the hallmark of epilepsy, but understanding what triggers these episodes can be complex. Seizures occur when there is a sudden, excessive surge of electrical signals among brain cells, disrupting normal brain function. This article explores the causes of seizures in epilepsy, the brain mechanisms involved, and factors that can provoke seizures, drawing on trusted UK health information to provide clear and accessible insights.

The Brain’s Electrical Activity and Seizures

The brain functions through carefully balanced electrical impulses transmitted between nerve cells. In epilepsy, this balance is disrupted, causing groups of neurons to fire excessively and synchronously. This abnormal electrical activity interferes with normal brain processes and results in seizures. The type, severity, and symptoms of seizures depend on where in the brain this abnormal firing begins and how far it spreads.

Underlying Causes of Seizures in Epilepsy

Seizures arise from various underlying causes that affect brain function. These include genetic factors that influence how nerve cells communicate, structural brain abnormalities such as scars or tumours, brain injuries from trauma or stroke, infections like meningitis or encephalitis, and metabolic or developmental disorders. In many cases, the exact cause remains unknown, termed idiopathic epilepsy.

Genetic Influences on Seizures

Certain gene mutations can make nerve cells more excitable or affect brain development, increasing seizure susceptibility. These genetic factors often contribute to epilepsy syndromes that begin in childhood or adolescence. While genetics do not cause seizures directly, they create a predisposition that, combined with other triggers, can lead to seizures.

Structural Brain Abnormalities

Damage or changes to brain structure can disrupt electrical pathways and provoke seizures. Brain injuries, strokes, tumours, or areas of scarring interfere with normal neuron function, creating ‘hotspots’ where seizures originate. The location of these abnormalities influences seizure type and symptoms.

Triggers That Precipitate Seizures

Seizure triggers do not cause epilepsy but can provoke seizures in susceptible individuals. Common triggers include sleep deprivation, stress, alcohol consumption, flashing lights (in photosensitive epilepsy), missed medication, illness, or hormonal changes. Avoiding or managing these triggers helps reduce seizure frequency.

How Seizures Spread in the Brain

Seizures may start in a small, localized area (focal seizures) and sometimes spread to involve larger regions or both sides of the brain (generalised seizures). The spread influences the severity and consciousness level during the seizure. Understanding this helps in diagnosis and treatment.

Why Seizures Vary Between Individuals

Seizure causes and patterns differ widely among people with epilepsy. Factors such as age, type of epilepsy, brain health, and seizure triggers shape how seizures appear. This variability means epilepsy management must be personalised.

The Role of Chemical Imbalances

Neurotransmitters, chemicals that transmit signals between neurons, also play a role. Imbalances in excitatory and inhibitory neurotransmitters can lead to excessive brain activity and seizures. Some epilepsy treatments target these chemical pathways to stabilise electrical activity.

When to Seek Medical Advice About Seizures

If you experience unexplained seizures or changes in seizure patterns, it is essential to seek prompt medical evaluation. Accurate diagnosis of the cause helps guide effective treatment and seizure control.

Final Thoughts

Seizures in epilepsy result from abnormal electrical activity in the brain caused by a range of genetic, structural, and environmental factors. While the precise cause may not always be identifiable, understanding these mechanisms helps tailor treatment and manage seizure risk. Avoiding triggers and adhering to prescribed therapies are key to reducing seizure frequency and improving quality of life.