Epilepsy and seizures Flashcards
Define epilepsy
Idiopathic recurrent tendency to have seizures, chronic disorder (minimum of 2 more than 24 hrs apart)
Define seizures
Spontaneous, intermittent, uncontrolled electrical brain activity
Define prodrome
Nonspecific symptoms that precede an epileptic attack
Define aura
- Sensory disturbances that precede an attack, usually by minutes
- More specific
Define ictus
The epilepsy attack
Describe the pathophysiology of epilepsy
Normal balance between GABA (-) and glutamate (+) shifts towards glutamate
- More excitatory, glutamate stimulation increased, GABA inhibition
What is the epidemiology of epilepsy?
- Common
- Age dependent: Highest below 20 and after 60
What are the risk factors of epilepsy?
- Familial inherited
- Dementia (10x more likely)
What are causes of seizures?
VITAMIN DE
Vascular
Infection
Trauma
Autoimmune
Metabolic (eg hypocalcaemia)
IDIOPATHIC
Neoplasms
Dementia + drugs (cocaine)
Eclampsia
How long do epileptic seizures last?
Under 2 minutes
Describe the lead up to an epileptic seizure and afterwards
- Prodrome - mood change, days before
- Aura - minutes before, deja vu + automatisms (lip smacking, rapid blinking), not always present, mostly seen in temporal lobe epilepsy
- Ictal event - seizure
- Post ictal period
What symptoms are seen in the post ictal period in epilepsy?
- headache
- confusion, reduced GCS
- Todd’s paralysis - if motor cortex affected, may have temporary paralysis + muscle weakness
- Dysphasia
- Amnesia
- SORE TONGUE - only in epileptic seizures (often bitten) not in syncope
What are the 2 main types of seizures?
Primary generalised + Partial/focal seizures
Describe features of generalised seizures
- Generalised – 30-40%
- Originates in the midbrain or brainstem
- Electrical discharge in both hemispheres (bilateral)
- Associated with LOC or awareness
(can be anywhere in the brain)
Describe features of partial/focal seizures
- Partial/focal – 60-70%
- Focal onset, electrical discharge is restricted to one area of the brain
- May develop into generalised (secondary)
(only in one specific area)
What are 2 further types of generalised seizures?
- Tonic-clonic (grand-mal)
- Absence (petit-mal)
Describe tonic-clonic seizures
- Often no aura
- Tonic phase (10-60 secs) – Rigid, fall to the floor, tongue biting, incontinence, no breathing during this phase
- Clonic phase (seconds-minutes) – Convulsions, limb jerking, eye rolling, uncoordinated breathing
- These seizures are usually self-limiting
- Physical injuries are common, drowsy, confused, headache
Describe absence seizures
- Childhood onset
- Moments of staring blankly into space (secs-mins) then carrying on where they left off
- Can occur many times a day and be debilitating
- Conscious but unresponsive
- Normal function resolves quickly
- 3Hz spike on EEG
What are the 3 features of generalised seizures?
- Tonic
- Myoclonic
- Atonic
Define tonic
Just rigid
- Sudden increased tone, rigid
- No jerking
Define myoclonic
Just jerking limbs
- Sudden isolated jerk of a limb, face, trunk
- May fall suddenly to the ground
Define atonic
Sudden floppy limbs + muscles
- Sudden loss of muscle tone + movement
- Resulting in a fall
Describe the further types of focal/partial seizures
- Simple
- Complex
- Secondary generalised
Describe simple partial seizures
- NO loss of consciousness or memory
- Isolated limb jerking
- Head turning (away from side of the seizure)
- Isolated paresthesia
- Todd’s paralysis – temporary paralysis/weakness
Describe complex partial seizures
- Most commonly from temporal lobe
- Can have LOC
- Can affect awareness/memory before, during or after
- Visual/auditory hallucinations
- Lip smacking
- Automatism
- Post ictal confusion/drowsiness is common
- Symptoms depend on lobe involved
Describe secondary generalised seizures
- Partial seizures that spread to lower brain areas, which initiates a generalised seizures
- Usually tonic-clonic
What are symptoms of seizures that suggests temporal lobe?
Aura, dysphasia, post ictal period
What are symptoms of seizures that suggests frontal lobe?
Jacksonian march + Todd’s palsy
What are symptoms of seizures that suggests parietal lobe?
Paraesthesia
What are symptoms of seizures that suggests occipital lobe?
Vision changes
How do you diagnose epilepsy?
Must have 2 or more that are 24+hrs apart
What investigations do you do for epilepsy?
- EEG
- MRI/CT
- Bloods – FBC, U&Es, LFTs, BM (to look for a potential cause, infection)
What is seen on EEG for epilepsy?
- 3H2 wave in absence seizures
- Not diagnostic
- Support diagnosis, can determine type of epilepsy
- May be falsely negative
What is seen on CT/MRI for epilepsy?
- examine hippocampus
- can show focal lesions to identify cause
What is the treatment for epilepsy?
- Sodium valproate to all types
EXCEPT females of childbearing age (15-45) as it’s teratogenic - Instead give lamotrigine
What is a complication of epilepsy?
Status epilepticus
NEURO EMERGENCY
What is status epilepticus?
- Seizure which lasts longer than 5 minutes or more than one seizure within 5 minutes (without returning to normal consciousness between) - Can lead to permanent brain damage and death
How do you treat status epilepticus?
Benzodiazepines –> LORAZEPAM 4mgIV
If doesn’t work phenobarbital then phenytoin
