Epilepsy

Also known as partial epilepsy, it originates in and only affects a specific part of the brain. It is usually the most common and the average duration is 1 or 2 minutes. There are 3 types:

Simple focal seizures - the person is conscious and can remember the seizure. Their symptoms depend on the area of the brain affected and may originate in the motor, sensory, autonomic, cognitive or emotional areas of the brain. Depending on the area of origin, the patient may experience uncontrolled or body part movements, strange sensations (such as tingling, dizziness, or hallucinations) and sudden emotional changes.

Complex partial seizures - the person tends to lose consciousness and does not remember the seizure completely. With consciousness they also tend to lose awareness of their surroundings but without losing muscle tone. They usually show a fixed gaze, repetitive movements and automatic behaviours.

Focal seizures with secondary generalisation - occurs when a simple or complex focal seizure spreads to the whole brain. It is important for patients to be informed about the mechanism of seizures and how they start, as this will help the neurologist to know whether the seizures are of focal or localised origin or whole brain at once.

These seizures affect both hemispheres of the brain. They are less common and their duration varies depending on the type of seizure. They are divided into 5 types:

Generalised absence seizures - involve loss of consciousness and loss of connection with the environment. The person usually remains ‘disconnected’ and immobile with a fixed gaze. The average duration is 10-20 seconds and they have a rapid recovery.

Tonic-clonic seizures - have two phases, the tonic phase and the clonic phase. The tonic phase begins with a sudden loss of consciousness with muscle stiffness. This is followed by the clonic phase, which manifests with repetitive seizures in the arms and legs. They last between 1 and 3 minutes and it is important to recognise these seizures, as the affected person may bite their tongue and be injured if there is a fall due to loss of consciousness.

Myoclonic seizures - do not involve unconsciousness and are characterised by sudden, brief jerks of muscles in part or all of the body. They last only a few seconds and tend to be accompanied by other types of seizures.

Atonic seizures - are very brief and last only seconds. They are characterised by a sudden loss of muscle tone, thus causing unexpected falls that can result in more serious injuries. Like myoclonic seizures, they are often accompanied by other seizures.

Tonic seizures - they cause sustained muscle stiffness throughout the body without any other movement. They last between 10 secs and 1 minute.