Seizure disorders Flashcards
What can cause blackouts?
Circulation - Syncope (most common) -hypotension -cardiogenic Neurological - epilepsy -psychogenic -sleep disorders -raised ICP Metabolic disorder
Define an epileptic seizure.
Paroxysmal even in which changes of behaviour, sensation or cognitive processes are caused by excessive, hypersynchronous neuronal discharges in the brain.
(lecture 21.1.18)
Describe the symptoms and signs of an epileptic seizure.
30-120 seconds
- positive ictal (during seizure) symptoms: hallucinations
- lateral tongue bite
- deja vu
- negative post-ictal symptoms
- Todd’s paralysis
What causes an epileptic seizure?
There is an imbalance between the parts of the brain trying to initiate a seizure and those trying to stop it. It can be brought on during sleep because the latter parts are less active.
How would you define a seizure in which there is unilateral movement and stiffness, which gradually changes to bilateral rhythmic convulsions?
Secondary generalised seizure.It starts focal (hence ‘secondary’), and as the discharges decrease in amplitude and the seizure spreads across the corpus collosum, the stiffness becomes bilateral rhythmic jerking.
(lecture - video)
What does a temporal lobe focal seizure look like?
Deja vu, dysphasia, automatisms, fear, derealisation, olfactory/ gustatory hallucinations.
What does a frontal lobe focal seizure look like?
Motor, dysphasia.
What does syncope look like?
5-30 seconds
- vasovagal - when it is hot, occurs from sitting or standing
- cardiogenic - less warning, history of heart disease.
- presyncopal symptoms
- swift recovery and re-orientation compared to seizures.
What does a parietal lobe focal seizure look like?
Numbness, tingling, pins and needles.
Describe the characteristic features of a non-epileptic/ dissociative seizure.
Situational
1-20 minutes
Eyes closed
Dramatic motor phenomena, prolonged atonia
Ictal crying and speaking
Slower post-ictal recovery
Associated with psychiatric illness and somatoform disorders.
Describe the management of focal epilepsy.
Correct diagnosis is essential for effective treatment - eg carbamazepine worsens myoclonic seizures but helps focal epilepsy.
Lamotrigine
Carbamazepine
Describe the management of generalised/ tonic-clonic epilepsy.
Lamotrigine, Sodium valproate (teratogenic - beware pregnancy)
Give 3 consequences of misdiagnosed epilepsy.
Treatment with anticonvulsants
Stopped from driving
Actual problem not treated, diagnosis delayed.
Describe the management of myoclonic seizures.
Levetiracetam
Valproate
Define focal epilepsy.
Common type of epilepsy associated with focal brain abnormality. It may start at any age and can be simple (with awareness) or complex (loss of awareness). Can spread to become a secondary generalised seizure.
Define genetic generalised epilepsy.
Common type of epilepsy, usually affecting under 30s. Includes myoclonic, absence or primary generalised tonic-clonic.
(lecture)
What is a myoclonic seizure?
A type of genetic generalised epilepsy.
Describe the management of a non-epileptic attack.
Parents: rectal benzodiazepine or buccal midazolam to prevent an attack.
Ambulance: lorazepam
ABCDE
Hospital: IV phenobarbital or phenytoin; anaesthesia.
How does lamotrigine work and what can it be used to treat?
Sodium channel inhibitor in the presynaptic neurone, decreasing firing rate. Can treat focal and generalised epilepsy.
How does levetiracetam work and what can it be used to treat?
Inibits neurotransmitter release from synaptic vesicles. Used to treat myoclonic seizures.
What is refractory epilepsy and how is it treated?
Seizures persist despite treatment, especially temporal lobe epilepsy. Often monotherapy (lowest possible dose) used to reduce side-effects. Temporal lobectomy works for some patients with hippocampal sclerosis.
When would vagal nerve stimulation be used?
28% mean seizure reduction, used for palliative treatment.
What investigations would you do if you suspect epilepsy?
MRI if focal or considering surgery. CT if secondary to injury EEG ECG Glucose, U&E, LFT, calcium - exclude metabolic causes.
What are absence seizures and how are they treated?
Short seizures with staring spells.
Treatment: Valproate, ethosuximide.
