Diagnosing epilepsy: understanding the process

Epilepsy is a common neurological condition that affects the brain’s electrical activity, leading to recurring seizures. Diagnosing it accurately requires careful assessment, as many other conditions can mimic its symptoms. This article by a consultant neurologist explains the process of diagnosing epilepsy, and how the different possible causes can inform the treatment plan.

What is epilepsy?

Epilepsy is defined as a tendency to have recurrent, unprovoked seizures. A seizure occurs when there is a sudden burst of abnormal electrical activity in the brain, disrupting normal function. Depending on where in the brain this activity begins, seizures can cause a wide range of effects — from brief lapses in awareness to full-body convulsions.

There are many types of seizures, such as:

• Focal seizures with preserved awareness. With these seizures, people don’t lose consciousness or awareness. They may experience unusual feelings such as feeling a ‘flip’ in the stomach (like when on a roller coaster ride or plane suddenly descending), a déjà vu, tingling, unusual tastes or smells, or stiffness and twitching in a part of the body.
• Focal seizures with impaired awareness. With these seizures, people are not aware of having a seizure. They may suddenly look blank/vacant, will not be responsive during the event and will not retain memories of it. They may make involuntary and repetitive movements like rubbing their hands, swallowing or smacking their lips.
• Focal to bilateral tonic-clonic seizures: They happen in two stages, the tonic, where the individual loses consciousness and their body goes rigid, and the clonic, where there is involuntary jerking and shaking. These seizures are dangerous, and people can sustain injury. Some individuals may bite their tongue or lose control of their bladder and bowels. They tend to last a few minutes, and afterwards, the individual will likely feel drained and confused, with no recollection of what just happened.

What causes epilepsy?

In many people, the exact cause of epilepsy cannot be found. However, certain factors can increase the risk. These include structural changes or brain injuries, such as those caused by head trauma, stroke, infections like meningitis, or developmental abnormalities. Genetic factors also play a significant role, with some forms of epilepsy running in families.

In older adults, epilepsy can sometimes develop after a stroke or other acquired brain injury. In children, it may appear without any clear underlying cause, suggesting a genetic predisposition to abnormal brain activity. Identifying the cause helps to guide treatment and improve long-term outcomes.

How epilepsy is diagnosed

The diagnostic process begins with a detailed history. The neurologist will ask the patient, and ideally someone who has witnessed the events, to describe exactly what happens before, during, and after a suspected seizure. The description of movements, awareness, duration, and recovery is often the most valuable information available.

A neurological examination follows, looking for signs of underlying brain disease or focal weakness. However, between seizures, most people with epilepsy have completely normal findings.

The next step is usually an electroencephalogram (EEG), which records electrical activity in the brain. Abnormal patterns, called epileptiform discharges, may confirm a diagnosis of epilepsy. Yet, it is important to understand that EEG results can appear normal, even in people with definite epilepsy. Because of this, the test may need to be repeated, sometimes using techniques such as sleep-deprived or prolonged video EEG monitoring to capture subtle abnormalities.

Brain imaging, usually by magnetic resonance imaging (MRI), is also essential. It allows doctors to look for structural causes such as scarring, malformations, or tumours. In some cases, the MRI can appear normal even when seizures are clearly occurring, which highlights the importance of combining multiple investigations and clinical judgment.

Blood tests may be performed to rule out metabolic or genetic conditions that can cause similar symptoms. Occasionally, other specialist investigations, such as lumbar puncture or functional imaging, are arranged if the diagnosis remains uncertain.

Through this thorough, step-by-step approach, a neurologist aims to ensure that no other condition is mistaken for epilepsy, such as fainting, panic attacks, or sleep disorders.

The importance of accurate diagnosis

Diagnosing epilepsy is a process that demands patience, precision, and experience. Because tests can appear normal and seizures can mimic other conditions, a single normal result does not rule out epilepsy. Careful observation, repeated testing, and expert interpretation are essential to reach the right conclusion.

An accurate diagnosis not only ensures the most effective treatment but also helps patients understand their condition, make informed choices, and live with confidence and independence.

How epilepsy can be treated

Once a diagnosis is confirmed, the mainstay of treatment is anti-seizure medication, tailored to the specific type of epilepsy and the individual’s circumstances. These medicines help to control seizures in most people, often allowing them to lead full and active lives.

If seizures continue despite medication, further assessment may be required to explore alternative treatments. Options include epilepsy surgery, vagus nerve stimulation, or dietary therapies such as the ketogenic diet, depending on the type and cause of epilepsy.

Lifestyle adjustments, such as maintaining good sleep, avoiding excessive alcohol, and managing stress, also play an important role in reducing seizure frequency.