Epilepsy Flashcards
What is epilepsy?
a tendency to recurrent unprovoked seizures
>2 seizures
What is a seizure? What are the 2 classes?
Paroxysmal synchronised cortical electrical discharges.
Focal
Generalised
What is a focal seizure?
seizure localised to specific cortical region (e.g. temporal lobe). Types: Frontal lobe focal motor Temporal lobe Occipital Frontal lobe complex partial
What is a generalised seizure?
seizure that affects consciousness + whole of brain. Types: Tonic-clonic Absence Myoclonic Atonic Tonic
What are primary epilepsy syndromes?
idiopathic generalised epilepsy
Temporal lobe epilepsy
Juvenile myoclonic epilepsy
What are 10 causes of secondary epilepsy syndromes?
Tumour Infection (e.g. meningitis) Inflammation (e.g. vasculitis) Toxic/Metabolic (e.g. Na imbalance) Drugs (e.g. alcohol withdrawal) Vascular (e.g. haemorrhage) Congenital abnormalities (e.g. cortical dysplasia) Neurodegenerative disease (e.g. Alzheimer's) Malignant HTN or eclampsia Trauma
List 3 conditions that mimic epilepsy
Syncope
Migraine
Non-epileptiform seizure disorder (e.g. dissociative disorder)
What is the pathophysiology of epilepsy?
Imbalance in inhibitory + excitatory currents of neurotransmission
Precipitants include anything that promotes excitation of the cerebral cortex, but individual precipitant often unclear
Describe the epidemiology of epilepsy
COMMON
1% of general population
Typical onset: CHILDREN + ELDERLY
Give 3 characteristics of Frontal lobe focal motor seizures
Motor convulsions.
Jacksonian march (spasm spreading from mouth or digit).
Post-ictal flaccid weakness (Todds paralysis).
What characterises Temporal lobe seizures?
Aura (visceral + psychic symptoms: fear/ deja-vu sensation)
Hallucinations (olfactory, gustatory)
What characterises Frontal lobe complex partial seizures?
Loss of consciousness with associated automatisms + rapid recovery.
What characterises tonic clonic seizures? What are these AKA?
Grand Mal
Vague Sx before attack (e.g. irritability)
followed by tonic phase (generalised muscle spasm),
followed by clonic phase (repetitive synchronous jerks) + associated faecal or urinary incontinence, tongue biting.
After seizure, there is often impaired consciousness, lethargy, confusion, headache, back pain, stiffness
What characterises absence seizures? What are these AKA?
Petit mal
Usual onset in childhood.
Loss of consciousness but maintained posture (stops talking + stares into space for seconds)
Blinking or rolling up of eyes with other repetitive motor actions (e.g. chewing).
No postictal phase.
What characterises non-convulsive status epilepticus?
Acute confusional state.
Often fluctuating.
Difficult to distinguish from dementia.
What signs could you look for in epileptic patients?
Usually normal between seizures
Look for focal abnormalities indicative of brain lesions
What should you establish from the history prior to the seizure?
Rapidity of onset? Duration of episode Alteration of consciousness? Tongue-biting/ incontinence? Rhythmic synchronous limb jerking? Post-ictal period? Drug hx (alcohol, recreational drugs)
What bloods should be taken in epilepsy?
FBC U+E LFTs Glucose Calcium Magnesium ABG Toxicology screen Prolactin: transient increase shortly after seizures
What investigation can help confirm the diagnosis of epilepsy?
EEG: to confirm dx + classify the epilepsy
Ictal EEGs are particularly useful
What other investigations are performed when diagnosing epilepsy?
CT/ MRI: to exclude structural, space-occupying + vascular lesions.
LP to identify infectious aetiology
HIV serology
What is status epilepticus? How is this treated?
seizure > 30min, failure to regain consciousness:
Resuscitate + protect ABC
Check glucose + give if hypoglycaemic. Consider thiamine.
IV lorazepam or IV/ PR diazepam (repeat after 15 min if needed).
If seizures recur or fail to respond, IV phenytoin (15mg/kg) + ECG monitoring.
If these fail, consider GA. Requires intubation + mechanical ventilation.
Treat the cause: e.g. correct hypoglycaemia/ hyponatraemia.
Check plasma levels of all anticonvulsants.
Describe pharmacological management of epilepsy
Only started after 2 unprovoked seizures
FOCAL: lamotrigine or carbamazepine
GENERALISED: sodium valproate
Start tx with only 1 anti-epileptic drug
What is included in the conservative approach of Patient Education for preventing seizures?
Avoid triggers
Use seizure diaries
Supervised swimming/ climbing
Driving permitted once seizure free for 6 months
Anti-epileptic drugs can have teratogenic effects (consider pregnancy)
Drug interactions (e.g. AEDs can reduce effectiveness of OCP)
List 3 complications of anti-epileptic drugs
Gingival hypertrophy (phenytoin)
Neutropaenia + osteoporosis (carbamazepine)
Stevens-Johnson syndrome (lamotrigine)
