Epilepsy Flashcards
What is epilepsy
A recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain, manifesting as a seizure
What are convulsions the motor signs of?
Electrical discharges
What does an aura imply?
A focal seizure
What symptoms may be present post-ictally from a seizure in the motor cortex
Headache
Confusion
Myalgia
Temporary weakness
What is post ictal weakness often called?
Todd’s palsy
What symptom may be present post-ictal from a seizure in the temporal lobe
Dysphasia
What proportion of seizures are idiopathic
2/3
List some other causes of seizures
Cortical scarring - head injury years before onset
Developmental - dysembryoplastic neuroepithelial tumour or cortical dysgenesis
Space occupying lesion
Stroke
Hippocampal sclerosis
Vascular malformations
Tuberous sclerosis
Sarcoidosis
SLE
PAN
Antibodies to voltage gated potassium channels
How is epilepsy diagnosed?
Diagnosis is difficult due to the heterogenous nature of the disease
All patients with a seizure must be referred for specialist assessment and investigation within 2 weeks
What must be established in the history of a seizure?
Tongue biting
Collateral from witness
Slow recovery
Funny turns/odd behaviour
Deja vu and odd episodic feelings of fear may be relevant
Any triggers? Alcohol, stress, flickering lights, TV. Triggering attacks tend to recur
List the 3 types of focal seizure
Simple - without impairment of consciousness
Complex - with impairment of consciousness
Secondary generalised - Evolving to bilateral, convulsive seizure
Describe the features of a simple seizure
Awareness unimpaired
Focal motor, sensory, autonomic or psychic symptoms
No post ictal symptoms
Describe the features of a complex seizure
Awareness is impaired
Either at seizure onset or following a simple partial aura. Most commonly arise from the temporal lobe in which post ictal confusion is a feature
Describe the features of a secondary generalised seizure
In 2/3 patients with partial seizures, the electrical disturbance, which starts focally, spreads widely, causing a generalised seizure, which is typically convulsive
Describe focal seizures
Originating within networks linked to one hemisphere and often seen with underlying structural disease
Describe generalised seizures
Originating at some point within and rapidly engaging bilaterally distributed networks leading to simultaneous onset of widespread electrical discharge with no localising features referable to a single hemisphere
List some examples of generalised seizures
Absence seizure Tonic-clonic seizure Myoclonic seizure Atonic (akinetic seizure) Infantile spasms
Describe absence seizures
Brief (<10s) pauses
Presents in childhood
Describe tonic-clonic seizures
Loss of consciousness
Limbs stiffen (tonic) then jerk (clonic)
May have one without the other, Post ictal confusion and drowsiness
Describe myoclonic seizures
Sudden jerk of the limb, face and trunk
The patient may be suddenly thrown to the ground or have a violently disobedient limb
Describe atonic seizure
Sudden loss of muscle tone causing fall
No LOC
What are infantile spasms commonly associated with?
Tuberous sclerosis
Give some features of a temporal lobe seizure
Automatisms Dysphasia De ja vu Emotional disturbance Hallucinations of smell, taste and sound Delusional behaviour Bizarre associations
Give some features of a frontal lobe seizure
Motor features such as posturing or peddling movements of the legs
Jacksonian march - spreading focal motor seizure with retained awareness often starting with the face or thumb
Motor arrest
Subtle behavioural disturbance
Dysphasia or speech arrest
Post ictal todds palsy
Give some features of a parietal lobe seizure
Sensory disturbance - tingling, numbness, pain
Motor symptoms - due to spread to the pre central gyrus
Give some features of occipital lobe seizure
Visual phenomena such as spots, lines and flashes
Describe non-epileptic attack/pseudo seizure
Gradual onset Prolonged duration Abrupt termination Closed eyes Resistance to eye opening Rapid breathing Fluctuating motor activity Episodes of motionless unresponsiveness CNS exam, CT, MRI and EEG are normal May coexist with true epilepsy
List some provoking causes of seizures
Trauma Stroke Haemorrhage Increased ICP Alcohol Benzo withdrawal Metabolic disturbance Infection High temp Drugs
What investigations are done to investigate seizures
CT/MRI EEG Drug levels if on anti-epileptics Drugs screen LP - if considering infection
How long must someone abstain for driving for
> 1 year seizure free
What does antiepileptic drug choice depend on?
Seizure type Epilepsy syndrome Comorbidities Lifestyle Patient preferences
Describe focal seizure antiepileptic drug choice
1st line - Carbamazepine and Lamotrigine
2nd - levetiracetam or topiramate
Describe generalised tonic clonic seizure drug choice
1st line - sodium valproate or lamotrigine
2nd line - carbamazepine, clobazam, levetiracetam or topiramate
Describe absence seizure drug choice
1st line - sodium valproate or ethosuximide
2nd line - lamotrigine
Describe myoclonic seizure drug choice
1st line - sodium valproate
2nd line - Levetiracetam or topiramate
Describe tonic or atonic seizure drug choice
Sodium valproate or lamotrigine
How long should antiepileptic drugs be built up over
2-3 months until seizures are controlled or maximum dosage is reached
When should antiepileptic drugs be switched?
If ineffective or not tolerated, switch to next appropriate drug
How do you switch between antiepileptic drugs?
Introduce the new drug slowly and only withdraw the first drug when established on the second
When can antiepileptics be stopped
> 2years seizure free and after assessing the risks and benefits for the individual
How do you stop antiepileptics
Decrease dose slowly (over 2-3 months) or >6months with benzodiazepines and barbiturates
Describe sudden unexpected death in epilepsy
More common in uncontrolled epilepsy
May be related to nocturnal seizure associated apnoea or asystole
List the side effects of carbamazapine
Leucopenia Diplopia Blurred vision Impaired balance Drowsiness Mild generalised erythematous rash SIADH (rare)
List the side effects of lamotrigine
Maculopapular rash TENS/SJS Diplopia Blurred vision Photosensitivity Tremor Agitation Vomiting Aplastic anaemia
List the side effects of levetiracetam
D&V Dyspepsia Drowsiness Diplopia Blood dyscrasia
List the side effects of sodium valproate
Teratogenic Nausea Liver failure Pancreatitis Hair loss Oedema Ataxia Tremor Thrombocytopenia Encephalopathy
List the side effects of phenytoin
Toxicity - nystagmus, diplopia, tremor, dysarthria, ataxia
Which antiepileptics are liver enzyme inducing
Carbamazepine
Phenytoin
Barbiturates
How much folic acid should women of child bearing age take?
5mg/day
Which antiepileptic is preferred in pregnancy and breast feeding?
Lamotrigine
How do oestrogen containing contraceptives effect lamotrigine?
Decrease lamotrigine levels
How do liver inducing enzymes affect progesterone containing contraception?
Make it less reliable
