Week 232 - Epilepsy Flashcards
Define an epileptic seizure
A transient event experienced by a subject as a result of synchronous and excessive discharge of cerebral neurones (arising due to variety of pathologic processes)
List some key differential diagnoses for epilepsy
Syncope (vasovagal or cardiogenic); Non-Epilectic Attacks (psychogenic); Sleep disorders (narcolepsy/cataplexy/parasomnias); Migraine; TIA; Hypoglycaemia
List causes of seizure that may be mistaken for epilepsy or cause LOC
Metabolic: low calcium, magnesium, glucose; deranged LFTs
Toxic: tricyclics, MAOIs, Alcohol
Infections/Inflammation: meningitis, abscess, febrile convulsion (paeds)
Vascular / Respiratory: TIA / CVA, hypoxia
Tumours
What 3 types of epilepsy classification are there?
1) Seizure type
2) Localisation
3) Aetiology
What two seizure types are there?
Generalised or Partial AKA Focal
(Generalised spreads throughout the brain and always results in altered consciousness
Partial affects part of the brain and so causes localised symptoms)
What two forms of partial seizure can occur?
Simple (remain fully conscious) or Complex (altered or lost consciousness)
When classifying epilepsy by location what is meant?
The lobe of the brain being affected (in a partial seizure epilepsy)
What 3 principle aetiologies can all epilepsy be categorised into?
- Idiopathic (no know reason)
- Symptomatic (clearly identifiable cause)
- Cryptogenic (characteristics suggestive of underlying cause but not yet found)
What features of a vasovagal syncopal episode would be suggestive of such?
3Ps: posture, provocation and prodrome
Standing; heat, venesection, micturition; nausea, clammy, tinnitus, blurring or loss of vision, deafness
Rapid orientation with prolonged fatigue as well as a few myoclonic jerks are common; usually last no more than 30s
What are the Red Flags for cardiogenic syncope?
Occur on exercise FHx sudden death PMH of IHD No warning Rapid recovery
Describe the common features of a generalised tonic-clonic seizure
Sudden onset, tonic stiffening followed by synchronous clonic mvmts
Cyanosis
Stertorous breathing (harsh snoring/gasping)
Tongue-biting (lateral) ;incontinence; injuries
Post-ictal period (altered state of conc after), prolonged recovery
Absence seizures are a form of what type of epilepsy, generalised or partial?
Generalised
In what patient group are absence seizures most common?
Children (uncommon in adults)
They usually grow out of it.
Describe the typical features of an absence seizure including frequency, duration, behaviours and recovery
Can happen several times in a day
Rarely last more than ~20 secs
Individual often stares blankly
Alert immediately after with no knowledge of the seizure
Describe the typical features of a Temporal Lobe (complex partial) seizure including prodrome, frequency, duration, behaviours and recovery
3As > PRODROME Aura (rising epigastric sensation, olfactory and gustatory, déjà vu) BEHAVIOR - Arrest (motor / speech), Automatism (lip-smacking, semi-purposeful actions)
Rarely > couple times a week; up to several mins
Post-ictal period of confusion
List some features of a likely Non-Epileptic Seizure
Awareness retain; gradual onset; prolonged; Frequent; no response it AEDs; Preceded by autonomic arousal; Asynchronous movements; Eyes closed and resist opening; Back arching; Carpet burns; Biting tip of tongue
What is Status Epilepticus?
A medical emergency
When a seizure lasts >5 mins (some say >30 mins but intervention should have occurred well before then as they can lead to brain damage and death)
What clinical signs often present with epileptic seizures?
Pupil dilatation Increased BP and Tachycardia, cyanosis Up going plantars Fall in pO2 and pH Rise in creatinine kinase levels
What examinations would be sensible to perform with suspected epilepsy?
Neurological examinations (peripheral, cranial nerve)
Lying and standing BP
Cardio
Check for injuries and neurocutaneous lesions (e.g. From neurofibromatosis)
What investigations should be performed?
ECG (all blackouts)
EEG
Imaging (cranial - CT for masses/CVA; MRI
Give 3 reasons for imaging the brain in epilepsy
1) to find the cause
2) for treatment: response to AEDs or surgery
3) important for prognosis
(All new-onset unprovoked seizures need imaging)
Give 3 major causes of epilepsy in infants
Developmental malformations
Perinatal injuries
Infections
What is the major cause / type of epilepsy among children/adolescents?
Idiopathic Generalised Epilepsy
Besides idiopathic generalised epilepsy give 4 possible causes of epilepsy in young adults
head injury, alcohol, vascular malformations, hippocampal sclerosis