Epilepsy

🔍 When to Suspect

Episode of altered awareness or abnormal movements, possibly with an aura, loss of consciousness, motor features, tongue biting, or incontinence, followed by post-ictal confusion

From the full topic in The Ocean Library: Epilepsy

🧭 When to suspect

Epilepsy is a clinical diagnosis, and the single most valuable piece of information is a clear eyewitness account of the event. A patient typically presents after an episode of altered awareness or abnormal movements that someone else has witnessed.

The diagnosis rests on the description, not on a test – Electroencephalogram (EEG) and imaging support classification and aetiology, but neither confirms nor excludes epilepsy.

Suspect an epileptic seizure where there is:

• A preceding aura (a rising epigastric sensation, an unusual smell or taste, or déjà vu)

• Loss of awareness

• Characteristic motor features such as rhythmic jerking or stiffening

• Lateral tongue biting

• Incontinence

• Followed by a distinct period of post-ictal confusion or drowsiness

Be alert too to subtle focal seizures – brief, stereotyped, repetitive episodes of tingling, specific smells or tastes, or staring spells – which are easily missed but equally warrant urgent assessment.

In primary care, separate epilepsy from its mimics:

• The commonest pitfall is misdiagnosing syncope as a seizure.

• Brief myoclonic jerks are common in convulsive syncope and do not make it epileptic.

• Dissociative (non-epileptic) seizures are also frequently mistaken for epilepsy.

Feature	Epileptic seizure	Syncope
Onset	• Often abrupt • May have an aura	Prodrome of light-headedness, nausea, greying vision, sweating
Posture/trigger	• Any posture • Can occur in sleep	• Usually upright • Prolonged standing, pain, heat
Motor features	Prolonged rhythmic jerking or stiffening	Brief, irregular myoclonic jerks (convulsive syncope)
Tongue biting	Lateral – fairly specific	Tip of tongue, or none
Recovery	Prolonged post-ictal confusion, drowsiness, Todd's paresis	Rapid (seconds to minutes)

For clarity, epilepsy means either:

• Two or more unprovoked seizures occurring more than 24 hours apart.

• A single unprovoked seizure where the risk of recurrence is high (for example a structural brain lesion or unequivocal epileptiform EEG).

A single seizure is therefore not in itself a diagnosis of epilepsy – but every first suspected seizure still needs urgent specialist assessment.

Seizures are classified by where they begin (the International League Against Epilepsy [ILAE] 2017 framework). The label matters because it drives drug choice and counselling – but the underlying diagnosis still rests on the clinical description.

Category	What to recognise
Focal onset	Arise in one area of one hemisphere. • Classified as aware or with impaired awareness. • Classified as motor (jerking, automatisms such as lip-smacking) or non-motor (sensory, autonomic, or psychic features like déjà vu). • May evolve to a bilateral tonic-clonic seizure.
Generalised onset	Engage both hemispheres from the start. Motor: tonic-clonic, tonic, atonic, myoclonic, clonic, epileptic spasms. Non-motor: absence seizures (brief loss of awareness with staring).
Unknown onset	• Used when the onset was not witnessed or cannot be determined • Reclassify once more information is available
Epilepsy type	A separate level: focal, generalised, combined focal and generalised, or unknown.
Common syndromes	Juvenile myoclonic epilepsy, childhood absence epilepsy, infantile spasms (West syndrome), Lennox-Gastaut syndrome, and Dravet syndrome.

Source: NICE NG217

---