How Is Epilepsy Diagnosed?

Epilepsy is a neurological condition characterised by repeated seizures due to abnormal electrical activity in the brain. Diagnosing epilepsy accurately is essential for effective treatment and management, yet it can sometimes be challenging because seizures vary widely in type and cause. If you or someone you know has experienced seizures or unusual episodes, understanding the diagnostic process can help ease concerns and prepare you for medical assessments. This article explains how epilepsy is diagnosed in the UK, outlining the tests and evaluations involved, and what you can expect along the way.

Initial Assessment and Medical History

The first step in diagnosing epilepsy involves a thorough medical history and description of the episodes experienced. Since seizures can look very different from person to person, doctors rely heavily on detailed accounts from the individual and witnesses. They will ask about the type of seizure, how long it lasted, any triggers or warning signs, and what happened before, during, and after the event. It is important to provide as much information as possible, including any injuries sustained, medications taken, and other health conditions. This helps distinguish epilepsy from other conditions that can mimic seizures, such as fainting, migraines, or sleep disorders.

Neurological Examination

Following the initial history, a neurological examination is usually performed. This involves testing reflexes, muscle strength, coordination, balance, and sensation to assess brain and nervous system function. The examination can reveal signs of brain injury or neurological disorders that might explain the seizures. Although the neurological exam itself does not confirm epilepsy, it provides valuable information to guide further investigations.

Electroencephalogram (EEG) Testing

One of the key tools in epilepsy diagnosis is the electroencephalogram, or EEG. This non-invasive test records the brain’s electrical activity through small electrodes placed on the scalp. The EEG can detect abnormal patterns of brain waves that are typical of epilepsy, especially when captured during or shortly after a seizure. Sometimes, additional EEG recordings with video monitoring are done in specialised units to observe seizure activity directly. However, a normal EEG does not rule out epilepsy, as abnormal brain activity may not appear during the test.

Brain Imaging Scans

Imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans are often used to look for structural causes of seizures. These scans can identify abnormalities like brain tumours, scarring, stroke damage, or developmental issues that may trigger epilepsy. MRI is preferred for its detailed images of brain tissue. Imaging helps doctors understand the underlying cause of seizures and plan appropriate treatment.

Additional Tests and Monitoring

In some cases, further tests may be necessary to confirm a diagnosis or explore specific types of epilepsy. These can include blood tests to check for infections, metabolic conditions, or genetic factors. Ambulatory EEGs allow continuous monitoring over 24 hours or longer in a natural setting, increasing the chance of recording a seizure. In specialised epilepsy centres, intracranial EEG monitoring may be performed for surgical candidates, involving electrodes placed directly on the brain surface.

Differential Diagnosis

Diagnosing epilepsy requires careful consideration of other conditions that can resemble seizures. These include syncope (fainting), psychogenic non-epileptic seizures (events triggered by psychological factors), sleep disorders, or transient ischaemic attacks. Differentiating these conditions from epilepsy is crucial because treatments differ significantly. A multidisciplinary approach, involving neurologists, psychologists, and other specialists, can improve diagnostic accuracy.

When Is Epilepsy Diagnosis Confirmed?

Epilepsy is typically diagnosed after a person has had at least two unprovoked seizures occurring more than 24 hours apart. In some cases, a single seizure may lead to a diagnosis if there is a high risk of recurrence based on EEG, brain imaging, or other clinical factors. Early diagnosis is important to begin treatment and reduce the risk of further seizures and related complications.

Emotional Impact of Diagnosis

Receiving a diagnosis of epilepsy can be overwhelming, raising questions about lifestyle, safety, and the future. It is important to have access to support and clear information throughout the diagnostic process. Healthcare providers often refer patients to epilepsy nurses, counsellors, or support groups to help manage the emotional and practical aspects of living with epilepsy.

When to Seek Medical Advice

If you experience unexplained seizures, loss of consciousness, or unusual episodes of altered awareness, it is important to seek prompt medical evaluation. Early assessment and diagnosis improve treatment options and reduce risks. If you have already been diagnosed but notice changes in seizure patterns or frequency, consult your healthcare professional for review.

Final Thoughts

Diagnosing epilepsy involves a careful and often multi-step process that includes a detailed medical history, neurological examination, EEG testing, and brain imaging. While diagnosis can sometimes be complex, advances in medical technology and specialist care have improved accuracy and treatment outcomes. Understanding the diagnostic journey empowers individuals to engage actively in their care and access the support needed to live well with epilepsy.