10. Seizures - epileptic, non-epileptic, syncope Flashcards
Give 5 causes of transient loss of consciousness.
- Syncope.
- Epileptic seizures.
- Non-epileptic seizures.
- Intoxication e.g. alcohol.
- Ketoacidosis/hypoglycaemia.
- Trauma.
Define syncope.
Insufficient blood or oxygen supply to the brain causes paroxysmal changes in behaviour, sensation and cognitive processes.
Give 5 signs that a transient loss of consciousness is due to syncope.
- Situational.
- 5-30s in duration.
- Sweating.
- Nausea.
- Pallor.
- Dehydration.
Define seizure.
A convulsion caused by paroxysmal discharge of cerebral neurones.
Abnormal and excessive excitability of neurones.
Give a definition for a non-epileptic seizure.
Mental processes associated with psychological distress cause paroxysmal changes in behaviour, sensation and cognitive processes.
List 4 non-epileptic causes of seizures.
- Trauma
- Stroke
- Haemorrhage
- Raised ICP
- Alcohol/benzodiazepine withdrawal
- Metabolic disturbance
- Liver disease
- Fever
- Infection - HIV, meningitis, encephalitis, syphilis
- Drugs - tricyclics, cocaine, tramadol, theophylline
Give 5 signs of a non-epileptic seizure.
- Situational.
- 1-20 minutes in duration (longer than epileptic).
- Eyes closed.
- Crying (ictal) or speaking.
- Pelvic thrusting.
- History of psychiatric illness.
- Very fast or very slow post-ictal recovery.
- No cyanosis, tongue biting, incontinence or injury.
What is epilepsy?
The tendency to have seizures.
Give a definition for an epileptic seizure.
Excessive, unsynchronised neuronal discharges in the brain cause paroxysmal changes in behaviour, sensation or cognitive processes.
At what age does epilepsy usually develop?
Before 20 or over 65
Which is likely to last for longer, an epileptic or a non-epileptic seizure?
A non-epileptic seizure can last from 1-20 minutes whereas an epileptic seizure lasts for 30-120 seconds.
Give 5 causes of epilepsy.
- 2/3rds are idiopathic often familial
- Cortical scarring:
* Head injury years before onset
* Cerebrovascular disease e.g. cerebral infraction, haemorrhage or stroke
* CNS infection e.g. meningitis or encephalitis - Space-occupying lesion e.g. tumour
- Tuberous sclerosis
- Alzheimer’s or dementia - epilepsy more common
- Alcohol withdrawal
What are the 3 main elements of a seizure?
- Prodrome
- Precedes the seizures (usually hrs or days before)
- Not part of the seizure, results in change of mood or behaviour
- People with tonic-clonic seizures more likely to have this - Aura
- Part of seizure where the patient is aware and may precede its
other manifestations
- E.G. strange feeling in gut, déjà vu, strange smells, flashing lights
- Often implies a partial focal seizure, but not necessarily from the
temporal lobe - Post-itcal
- The period after the seizure
- Headache, confusion, myalgia and a sore tongue (often bitten)
- Temporary weakness after a focal seizure in motor cortex - Todd’s palsy
- Dysphagia following temporal lobe focal seizure
Give 5 signs/features of an epileptic seizure.
- 30-120s in duration.
- ‘Positive’ symptoms e.g. tingling and movement.
- Tongue biting (lateral)
- Head turning (positive ictal symptoms)
- Muscle pain.
What 2 categories can epileptic seizures be broadly divided into?
- Primary/Generalised epilepsy - the whole brain is affected.
- Partial/Focal epilepsy - only one portion of the brain is involved.
What are primary/generalised epileptic seizures?
- Simultaneous onset of electrical discharge throughout whole cortex (involving both hemispheres), with no localising features referable to only one hemisphere
- Bilateral symmetrical and synchronous motor manifestations
- Always associated with loss of consciousness or awareness
Give 3 examples of generalised epileptic seizures.
- Generalised tonic-clonic seizures (AKA grand-mal)
- Typical absence seizure (aka petit mal)
- Myoclonic seizure
- Tonic seizure
- Atonic (akinetic) seizure
What occurs in the brain during a primary generalised seizure?
Simultaneous onset of electrical discharge throughout cortex with no localised features.
What do the terms tonic, myoclonic and akinetic mean in terms of seizures?
Tonic = intense stiffening of body with no convulsions.
Myoclonic = isolated muscle jerking (rapid repetitions of this = clonic).
Akinetic = cessation of movement, falling and loss of consciousness.
Describe the features of generalised tonic-clonic seizures
- Often no aura
- Loss of consciousness
- Tonic phase (muscle tensing):
* Rigid, stiff limbs - person will fall to floor if standing - Clonic phase (muscle jerking):
* Generalised, bilateral, rhythmic muscles jerking lasting sec-mins - Eyes remain open and tongue often bitten
- There may be incontinence of urine/faeces
- Post-ictal -> drowsiness, confusion or coma for several hours
Describe the features of absence seizures.
- Usually a disorder of childhood
- Child ceases activity, stares and pales for a few seconds only (brief pauses):
I.e. suddenly stops talking in mid-sentence, then carries on where left-off - Often do not realise that they’ve had an attack
- On EEG characterised by a 3-Hz spike and wave activity
- Children with petit mal tend to develop generalised tonic-clonic
seizures in adult life
Describe the features of myoclonic seizures.
- Sudden isolated jerk of a limb, face or trunk
(Isolated muscle jerking) - Patent may be thrown suddenly to the ground, or have a violently disobedient limb