There are a number of different types of seizures, including the following:
Partial Seizure (also called focal seizure) is a seizure which affects initially only one localised area of the brain and has a clinical pattern influenced by that location, for example:
- Seizures of motor cortex present with unilateral motor features (jerking or twitching movements occurring on one side of the body) but no other features.
- Temporal lobe seizures may present with complex sensory or emotional presentations such as fearfulness, deja-vu experience, abnormal taste or smell sensation or with stereotypical patterns such as staring, lip smacking, repeated chewing or episodic confusion.
- Frontal lobe seizures typically present overnight or in mornings, with a variety of patterns, some influenced by proximity to motor cortex, or behavioural patterns (e.g. motor agitation or automatisms, strong emotional sensations; which may be accompanied by vocalisations or laughter/crying, features that may be misinterpreted as being psychogenic.
Simple Seizure: a seizure without loss of consciousness.
Complex Seizure: a seizure with loss of consciousness.
- These terms may be combined e.g. a complex partial seizure is a partial seizure that includes loss of consciousness.
Generalised Seizure (also referred to as Diffuse or Tonic-Clonic seizures): a seizure that affects both sides of the brain and has a clinical pattern that involves all limbs.
- Partial seizures are said to become secondarily generalised if they initially present with a focal seizure pattern, but evolve during the course of a seizure into a generalised pattern
- Patterns of generalised seizures may include:
- Tonic seizures: predominant motor pattern is one of limb stiffness or rigidity
- Atonic seizures: predominant motor pattern is one of loss of muscle tone, resulting in a pattern described as “drop attacks”.
- Clonic and/or myoclonic seizures: present with rapidly alternating contraction and relaxation or “jerking”of a muscle
- Myoclonic seizures often only last for a fraction of a second and you might have a single jerk or clusters of several jerks.
- Absence seizures typically present as brief loss of consciousness which may appear to be daydreaming or ‘switching off’ possibly with blinking or slight jerking of body or limbs.
- Prodrome (aura, the phase before a seizure): the person may experience a sense of déjà vu, altered sensory perceptions or abdominal rising sensation.
- Epileptic attack: tonic phase and/or rhythmic jerking or complex movements may occur during the seizure. The person may also be incontinent.
- Post-ictal (phase after seizure): The person may experience confusion, fear, exhaustion, self-injury and transient neurological deficits.
Status Epilepticus: a seizure lasting greater than 30 minutes. It is a medical emergency with risks of arrhythmia, reduced cerebral oxygenation, cerebral oedema or muscle damage leading to renal failure
Triggers for Seizures include:
- Missed anticonvulsant medication.
- Alcohol excess/withdrawal.
- Cocaine, ecstasy or other substance abuse/withdrawal.
- Interacting medications (antidepressants, antipsychotics
and oral antispasticity medications are the most commonly prescribed medications in TBI patients, but you should consult British National Formulary for complete list.
- Lack of sleep.
- Illness (febrile or afebrile).
- Menstrual cycle.
- Flickering lights.
For further information consult:
Epilepsy Scotland www.epilepsyscotland.org.uk
National Society for Epilepsy www.epilepsysociety.org.uk