Seizures Flashcards
Define epilepsy
tendency to recurrent unprovoked seizures
Define Seizure
abnormal cortical discharges (creates experience – disturbance in consciousness, behaviour, emotion, motor or sensory function)
What is an acute symptomatic seizure associated with?
associated with alcohol withdrawal, hypoglycaemia are not epilepsy
What are the special seizure syndromes?
single seizures or childhood febrile seizures (6 mths and 6 yo)
What are the main RF for seizures?
- FHx (50% genetic, 50% environmental)
- Childhood febrile seizures e.g. febrile status epilepticus (>30 min seizure)
- Perinatal event or abnormal early development
- Other previous insult: head trauma, stroke, meningitis, encephalitis
What are the types of focal seizures?
A. Focal (seizures starts on one side of the brain)
= Unilateral networks at onset
Subtypes:
• Simple focal
• Focal dyscognitive (if start simple focal but spreads) e.g. arrest of L hand indicates R lobe seizure
• Secondary generalized tonic clonic (if start focal, becomes secondary generalized)
What are the types of primary generalised seizures?
B. Primary Generalised (starts on both sides of brain simultaneously)
Subtypes:
• Absence (hyperventilation often a trigger; very brief episodes; very frequent esp in children; motor arrest; eyelid flickering; uncommon after mid 20s, commonest childhood)
• Myoclonic (increased tone; jerk e.g. when falling asleep)/Atonic (complete relaxation; no tone)
• Tonic (stiffening of limbs and toppling over)
• Primary generalized tonic clonic (sudden tonic stiffening, cry, stiffen with limbs extended, no ventilation (go blue), then after 15-20 s there will be low amplitude high f movements, then those movements will be higher in amplitude but lower in f, then turn into a few jerks)
What are the typical symptoms of temporal lobe focal seizure?
- Olfactory and gustatory hallucinations (noxious and nasty)
- Auditory hallucinations especially machinery humming
- De ja vu
- Autonomic phenomena: (butterflies from stomach that rise up to chest)
- Changes of speech “I couldn’t get any words out” – if in dominant
What is the most common focal seizure location?
Temporal lobe
What are the typical symptoms of frontal lobe focal seizure?
- Olfactory and gustatory hallucinations (noxious and nasty)
- Auditory hallucinations especially machinery humming
- De ja vu
- Autonomic phenomena: (butterflies from stomach that rise up to chest)
- Changes of speech “I couldn’t get any words out” – if in dominant
What are the typical symptoms of occipital lobe focal seizure?
- Visual symptoms
- Coloured circles/patterns
- Occasionally, negative features e.g. blindness
- DDx: migraine – black/white visual disturbance, occipital – coloured hallucinations
What are the typical symptoms of parietal lobe focal seizure?
- Somato-sensory seizures
- Uncommon
- Rapid spread of abnormal sensory feelings (burning, lightning, electric shock, etc) usually from peripherally to centrally
When assessing a paroxysmal episode you must consider the following:
- Background to patient
- Setting
- Prodrome
- Event
- Recovery
- Will consider in detail for syncope, then briefly for psuedoseizures, migraine
- Prioritize what happens before and after over what happens during!
What features favour syncope in terms of • Setting • Prodrome • Event • Recovery
- Setting: rising to upright posture, prolonged standing, pain, needles, cough, micturition, after exercise (vasovagal), during exercise (cardiogenic)
- Prodrome: Nausea, palpitations, dyspnoea, pallor warm sensation, sweating, light headedness, greying of vision, hearing becomes distant
- Event: Pallor, motionless collapse (not always
- Recovery: nausea, rapid recovery to orientation
What features favour seizure in terms of • Setting • Prodrome • Event • Recovery
- Setting: stress, sleep deprivation, photic triggers, drug withdrawal
- Prodrome: hallucinations – auditory, gustatory, visual, olfactory
- Event: tongue biting, head turning, unusual posturing, cyanosis, urinary incontinence in bed (as vasovagal does not usually happen lying down)
- Recovery: Headache, confusion, postictal- amnesia (most useful Q to Ddx syncope and seizure: what is the next thing you remember after your collapse – do not usually remember waking up), and slow recovery to orientation
What are the main features that favour psuedoseizures over seizures?
- Often background abuse, background of unexplained Sx (e.g. pelvic pain)
- Attacks variable
- Attacks often wax and wane
- Flurries of attacks common
- Attacks often prolonged e.g. 20 minutes
What are the main features that favour seizures over psuedoseizures?
- May be background brain injury or FH epilepsy
- Attacks stereotyped
- Attacks evolved then stop
- Attacks usually 1-2/day (except absences, NFLE)
- Attacks > 4 mins uncommon
What are the main DDx for a collapse/blackout?
a. Syncope
• Neurally mediated (reflex) e.g. vasovagal
• Orthostatic hypotension e.g. diuretic induced
• Cardiac arrhythmias e.g. paroxysmal VT
• Structural cardiopulmonary e.g. AS
NB: 70% of ppl who faint jerk
b. Functional Collapses (psuedoseizures)
• Attacks are prolonged app 20-30 minutes
• No sudden onset and no sudden offset, it waxes and wanes
c. Migranous visual aura [occipital seizures]
d. Transient ischaemic attacks: usually negative symptom [focal siezures]
e. Metabolic dysfunction: e.g. hypoglycaemia [focal seizures]
f. Tinnitus [lateral temporal seizures with auditory aura]
g. Physiological déjà vu [mesial temporal seizures]
f. parasomnias [frontal seizures]
g. movement disorders e.g. hemiballismus (after stroke), paroxysmal dyskinesisa) [frontal seizures]
What is the main feature that differentiates a migraine from an occipital seizure?
Migraine visual hallucinations are in B/W
Occipital seizures are coloured hallucinations
