Seizures Flashcards
What is syncope?
Loss of consciousness due to a sudden decrease in cerebral blood flow
- Majority of patient seen in first seizure clinics are there due to hypoxic seizure
- Syncope is often followed by syncopal/ hypoxic seizure
Types of syncope
1. Reflex/ vasovagal syncope: most common form in the young, occurs in response to overstimulation of vagus nerve which slows down the heart
Triggers: prolonges standing, rising, emotional trauma, pain
Features: gradual onset, light-headedness, nausea, sweating, palpitations, greying of vision, feeling distant, cold skin, pallor, rapid recovery with no confusion
2. Orthostatic syncope: common in older age, medications, autonomic neuropathy, autonomic failure
Features: occurs upon standing or changing posture, rising, after meals
3. Carotid sinus syncope: hypersensitivity of the carotid sinus, attributable to pressure on the neck
4. Reflex anoxic attacks: occurs in children, excessive activity of the vagus nerve briefly stops the heart, triggered by pain, fear, anxiety
5. Cardiac syncope: often occurs with no prodrome and in any posture
Tachyarrhythmia: ineffective CO leading to syncope
Bradyarrhythmia: heart block, sick sinus syndrome
Structural heart disease: aortic stenosis, HOCM, mitral stenosis, atrial myxoma, ischaemic heart disease
6. Respiratory syncope: cough syncope, valsalva manoeuvre, breath holding spells, hyperventilation
7. CNS syncope: rare, raised ICP, autonomic dysreflexia
Behavioural causes of syncope
Hyperventilation
Psychogenic, non-epileptic attacks
Seizure vs syncope
What is juvenile myoclonic epilepsy?
Usually begins between 12-16yrs
Slightly more common in girls
Seizures often occur when patient is tired, as they wake up or when having breakfast
Key: patients with JME are more likely to have seizures when they don’t get enough sleep or when they drink excessive amounts of alcohol
What is West syndrome?
AKA infantile spasms
Affects 350-400 children in the UK per year
In 90% the spasms occur in the first year of life
Episodes last 1-2 seconds - looks like body is seizing, can occur in clusters
EEG shows hypsarrhythmia (chaotic, disorganised electrical activity with no pattern)
Can cause developmental delay
Patient: 7 months old, showeing abnormal spasms in clusters, EEG shows totally chaotic pattern (hypsarrhythmia), following spasms baby is off food and irritable
Diagnosis?
West syndrome
Treatment for West syndrome?
Steroids and AEDs (specifically vigabatrin which prevents GABA breakdown)
What is Dravet syndrome?
Rare form of epilepsy that beings within 1st year of life
Causes developmental delays and learning difficulties along with behavioural challenges
Seizures most often associated with high temperature and involve one side of the body
Seizure occur for a prolonged period of time
80% have a mutation in SCN1A
Dravet is drug resistant, some commonly used medications e.g. lamotrigene can cause an increase in seizure frequency
Dravet is the only form of epilepsy in which to use of 3 medications is beneficial
Prognosis is poor and children usually need supportive care throughout life
Epileptic seizure + learning difficulties + developmental delay
Diagnosis?
Dravet syndrome
What is Lennox Gastaut syndrome?
Childhood epilepsy syndrome
Usually begins between 3-5yrs
Causes ‘drop attacks’: atonic or tonic seizures where patient falls to floor suddenly (compared to puppet strings being cut in atonic and tree falling down in tonic)
Can also cause absence seizures
Causes learning difficulties
Treatment resistant - ketogenic diet may help
How can the age of onset give an idea of the cause of a seizure?
- 0-2yrs: birth trauma, congenital defects, familial epileptic syndrome/ channelopathy
- 2-12yrs: idiopathic generalised epilepsy, trauma, infections, accidental poisoning
- 12-30yrs: trauma, alcohol, toxins
- 50+yrs: trauma, alcohol, toxins, tumours
- 70yrs+: dementia
What is status epilepticus?
State of prolonged, uncontrolled seizures
A single seizure that lasts >5mins or multiple seizures without a full neurological recovery between seizures
Aetiology of status epilepticus
1/3 of patients will have an underlying background of chronic epilepsy and SE occurs most commonly due to treatment non-compliance
1/3 patients: SE wwill represent the onset of epilepsy
1.3 patients: episode occurs in isolation with no prior or future seizures
Investigations in status epilepticus
All patients presenting to ED should have an IV cannula inserted and blood sent for U&E, magnesium, calcium and a FBC
Blood gas for determining metabolic status
Further investigations will then depend on individual circumstances e.g. CT brain, blood cultures, serum anticonvulsant levels, lumbar puncture etc
