Epilepsy (N) Flashcards
Define epilepsy.
Common neurological condition characterised by recurrent seizures
How many seizures are needed for a diagnosis of epilepsy?
Need to have had 2+ seizures (>24 hours apart) for a diagnosis of epilepsy
Define a seizure.
Excessive activity of cortical neurons resulting in transient neurological symptoms
What are some causes of epilepsy? (7)
- primary epilepsy is idiopathic
- secondary causes:
- tumour
- meningitis
- vasculitis
- alcohol withdrawal
- haemorrhage
- metabolic
What conditions have association with epilepsy? (3)
- cerebral palsy (around 30% have epilepsy)
- tuberous sclerosis
- mitochondrial diseases
What are some causes of non-epileptic seizures? (3)
- febrile convulsions - children (3%), early in viral infection as temperature rises rapidly, seizures brief and generalised tonic/tonic-clonic
- alcohol withdrawal seizures - peak incidence 36h after alcohol cessation, due to decreased GABA+increased NMDA glutamate, patients given BZs to reduce risk
- psychogenic non-epileptic seizures (pseudoseizures) - Hx mental health problems/personality disorder
Describe the pathophysiology of epilepsy.
- result from an imbalance in inhibitory and excitatory currents or neurotransmission in the brain
- precipitants include anything that promotes excitation of cerebral cortex
- often unclear why the precipitants cause seizures
What 3 key features is the basic seizure classification (epilepsy) based on?
- where seizures begin in the brain
- level of awareness during a seizure (important as can affect safety)
- other features of seizures
What are the two main types of seizure?
- focal (previously termed partial)
- generalised
Describe the features of focal seizures.
- start in a specific area, on one side of the brain
- level of awareness can vary:
- focal aware (previously termed simple partial)
- focal impaired awareness (previously termed complex partial)
- awareness unknown
- further to this focal seizures can be classified as being:
- motor (e.g. Jacksonian march)
- non-motor (e.g. deja vu, jamais vu)
- other features e.g. aura
What are examples of focal seizures? (4)
- frontal lobe seizure
- temporal lobe seizure
- occipital lobe seizure
- parietal lobe seizure
Describe the features of generalised seizures.
- engage or involve networks on both sides of the brain at onset
- consciousness lost immediately (level of awareness classification not needed)
- generalised seizures can be further subdivided into motor (e.g. tonic-clonic) and non-motor (e.g. absence)
What are the specific types of generalised seizures? (6)
- tonic-clonic (grand mal) - limbs stiffen (tonic), jerking (clonic)
- tonic
- clonic
- atonic - sudden loss of muscle tone = fall
- myoclonic - brief, rapid muscle jerks of limb/face/trunk
- typical absence (petit mal) - brief pauses
What is a focal to bilateral seizure?
- starts on one side of the brain in a specific area before spreading to both lobes
- previously termed secondary generalised seizures
What is status epilepticus?
Seizure lasting >5 minutes, or 2+ seizures within a 5-minute period without the person returning to normal between them
In status epilepticus, what do we rule out with investigations?
Hypoxia and hypoglycaemia
How do we treat status epilecticus? (2)
IV lorazepam or PR diazepam (treatment initiated after 5-10min of seizure)
What is the most common type of focal seizure?
Temporal lobe seizure
What information should we collect from witnesses about seizures? (9)
- rapidity of onset
- duration of episode
- alteration in consciousness
- tongue-biting/incontinence
- rhythmic synchronous limb jerking
- triggers
- post-ictal abnormalities - exhaustion, confusion
- drug Hx - alcohol/recreational
- Jacksonian march - aware, focal seizure, moves around body
What are the features of a frontal lobe (focal) seizure? (4 + 1)
- motor features - head/leg movements
- posturing
- post-ictal flaccid weakness (Todd’s palsy)
- Jacksonian march (clonic movements starting in 1 extremity and moving proximally through body) - usually starts as twitching/tingling of little toe/finger
- frontal impaired awareness seizure - loss of consciousness, involuntary actions, rapid recovery
What are the features of a frontal lobe impaired awareness seizure? (3)
- loss of consciousness
- involuntary actions/disinhibition
- rapid recovery
What is the most common type of focal seizure?
Temporal lobe seizure
What are the features of a temporal lobe (focal) seizure? (4)
- aura - weird smells, involuntary movements, deja vu, abdominal pain
- lip smacking/plucking/grabbing (automatisms)
- post-ictal dysphasia
- hallucinations
How long do temporal lobe (focal) seizures usually last?
Around one minute - with automatisms (e.g. lip smacking/plucking/grabbing)
What are the features of an occipital lobe (focal) seizure?
Visual disturbances - floaters/flashes
What are the features of a parietal lobe (focal) seizure?
Sensory issues - paraesthesia
What are the features of tonic-clonic seizures? (6)
- vague symptoms before attack e.g. irritability
- tonic phase (generalised muscle spasm - goes stiff + falls to floor)
- clonic phase (repetitive synchronous jerks)
- urinary incontinence
- tongue biting
- post-ictal phase - impaired consciousness, lethargy, confusion
What are the features of an absence seizure? (6)
- onset in childhood
- loss of consciousness but maintained posture (do not fall down)
- no post-ictal phase
- begins abruptly without warning + ends abruptly
- patient has no recollection of episode
- stares blankly into space
What would EEG show for absence seizure?
3 Hz spike and wave
How do we treat absence seizures?
Ethosuximide
What are the features of myoclonic seizures? (2)
- convulsions without muscle tensing (no tonic phase)
- sudden jerking of limb, trunk or face with preserved consciousness
What are the features of atonic seizures? (3)
- sudden muscle relaxation causing patients to fall to the ground and lay motionless
- can also result in incontinence
- can result in post-ictal confusion
What are the features of tonic seizures?
Muscle tensing without convulsions (no clonic phase)
What are the features of convulsive status epilepticus?
Prolonged or repeated tonic-clonic seizures with an altered level of consciousness
What are the features of non-convulsive status epilepticus? (3)
- acute confusional state
- often fluctuating
- difficult to distinguish from dementia
How is diagnosis of epilepsy usually made?
Clinical diagnosis - 2 or more unprovoked seizures 24h apart
What scans do we do for epilepsy? (2)
- electroencephalogram (EEG) - to confirm diagnosis and classify epilepsy - generalised epileptiform activity or focal, localising abnormality
- MRI - look for structural, space occupying or vascular lesions that may cause midline shift, possible if non-epileptic patient presenting with seizures
What type of EEG is useful in epilepsy?
Ictal EEG - during seizure
What bloods do we do for epilepsy and why? (3)
- capillary blood glucose - exclude hypoglycaemia
- electrolytes - to look for hypocalcaemia and hyponatraemia
- prolactin - to tell difference between seizures and pseudoseizures (transient increase in prolactin after seizures)
What are some risk factors for epilepsy? (8)
- poor anticonvulsant therapy adherence
- alcohol-use disorder
- stroke
- toxic/metabolic causes
- Fx of generalised-onset epilepsy
- previous CNS infection
- head trauma
- prior seizure events or suspected seizure events
What are some differential diagnoses for epilepsy? (6)
- syncope
- psychogenic non-epileptic status (normal prolactin, long duration, fluctuating course)
- cardiac arrhythmia
- TIA
- delirium (can mimic non-convulsive status epilepticus)
- coma (can mimic non-convulsive status epilepticus)
What is the 1st-line management for status epilepticus (acute repetitive seizures)?
Benzodiazepine - IV lorazepam (hospital) or PR diazepam (community)
(Progression: repeat in 10min if does not work –> IV phenytoin with ECG monitoring –> general anaesthesia + intubation + mechanical ventilation)
What are some side effects of phenytoin? (3)
- P450 enzyme inducer
- gingival hypertrophy
- peripheral neuropathy
What is the maximum dose of IV benzodiazepines that we can give for epilepsy?
Max of 2 doses (hence we then move on to IV phenytoin)
What is the general medication escalation pattern for epilepsy?
- 1st line - anticonvulsant monotherapy
- 2nd line - alternative anticonvulsant monotherapy
- 3rd line - anticonvulsant dual therapy
What is the general rule in epilepsy about starting anticonvulsants?
Only start after >2 unprovoked seizures
Which anticonvulsant should not be used in females of reproductive age?
Sodium valproate - teratogenic (neural tube defects)
When do NICE suggest starting antiepileptics after first seizure (rather than the second as in most cases)? (4)
- patient has neurological deficit
- brain imaging shows a structural abnormality
- EEG shows unequivocal (without doubt) epileptic activity
- patient/family/carers consider the risk of having a further seizure unacceptable
What is the 1st-line treatment for generalised tonic-clonic seizures in males vs females?
- M - sodium valproate
- F - lamotrigine or levetiracetam
What is the 1st and 2nd-line treatment for absence seizures?
- 1st line - ethosuximide
- 2nd line:
- M - sodium valproate
- F - lamotrigine or levetiracetam
- carbamazepine may exacerbate absence seizures
What is the 1st-line treatment for myoclonic seizures in males vs females?
- M - sodium valproate
- F - levetiracetam
What is the 1st-line treatment for tonic or atonic seizures in males vs females?
- M - sodium valproate
- F - lamotrigine
What is the 1st and 2nd-line treatment for focal seizures?
- 1st line - lamotrigine or levetiracetam
- 2nd line - carbamazepine, oxcarbazepine or zonisamide
What are some side effects of lamotrigine? (2)
- Stevens-Johnson syndrome
- large blistering rash throughout body
What are some side effects of carbamazepine (2nd line for focal seizures)? (5)
- SIADH
- drowsiness
- Stevens-Johnson syndrome
- neutropenia
- osteoporosis
What is important to keep in mind about carbamazepine for epilepsy?
May exacerbate absence seizures
What are some side effects of sodium valproate? (3)
- weight gain
- alopecia (regrowth may be curly)
- teratogenic (avoid in women)
What is the general 1st-line treatment for generalised seizures in men vs women?
- M - sodium valproate
- F - lamotrigine (levetiracetam if myoclonic seizures)
- (absence - ethosuximide; above are 2nd line options)
What does DVLA do in epilepsy? (3)
- 1st unprovoked seizure = 6 months off driving
- if abnormal brain imaging/EEG = 12 months off driving
- no formal diagnosis of epilepsy after just 1 seizure
What do we educate patients about in epilepsy? (4)
- avoiding triggers
- using seizure diaries
- particular consideration for women of childbearing age due to sodium valproate being teratogenic - take folic acid and use lamotrigine instead
- be careful of drug interactions e.g. antiepileptics can reduce efficacy of OCP
When do we consider surgery for epilepsy?
If refractory focal epilepsy
What are some complications of epilepsy? (4)
- fractures from tonic-clonic seizures
- behavioural problems
- sudden death in epilepsy
- complications to anti-epileptic drugs:
- phenytoin - gingival hypertrophy
- carbamazepine - neutropenia and osteoporosis
- lamotrigine - Steven-Johnson syndrome
Describe the prognosis of epilepsy.
50% remission at 1 year
