Disease and Clinical Features of Epilepsy Flashcards
What is the definition of an epileptic seizure?
A transeint event experienced by a subject as a result of a synchronous and excessive discharge of cerebral neurones
What do the following mean?
Prodrome
Aura
Post-ictal
Prodrome - hours/days - may rarely precede seizure: change in behaviour
Aura - part of the seizure, where the patient is aware - strange feeling in gut, dejavu, strange smells/flashing lights
Post-ictal - symptoms follow seizure -
- headache, confusion, myalgia, sore tongue
- temporary weakness after focal seizure in motor cortex (Todd’s Palsy)
- Dysphasia - following focal seizure in temporal lobe
What are strong clues when assessing whether someone has had an epileptic seizure?
Tongue biting and slow recovery
What is a primary generalised seizure?
Simultaneous involvement of both hemispheres, associated with Loss of consciousness/awareness
What are the different types of generalised seizures?
Absence
Tonic Clonic
Myoclonic
Tonic
Atonic
Infantile
What is an absence seizure?
Begins in childhood
Loss of awareness and vacant expression <10s, return to normal as if nothing has happened
May go on to develop generalised convulsive seizures
What is a tonic clonic seizure and what are the stages involved?
Prodrome - Often no warning, may be aura if 2o generalised seizure
Tonic-clonic - Tonic stiffening ⇆ clonic synchonous jerking of the limbs → until convulsion stops
Eyes remain open, tongue bitten, incontinence
Post-ictal phase - flaccid unresponsiveness → gradual return of awareness with confusion and drowsiness +/- headache
What is a myoclonic seizure?
Brief contractions of muscle or muscle groups → sudden involuntary twitch of finger/hand
What is a tonic seizure?
Consistent stiffening of the body, without jerking
What is an atonic (akinetic) seizure?
Sudden loss of muscle tone → fall, without LoC
What are infantile spasms?
West syndrome - a triad of:
Infantile spasms
- Severe myoclonic convulsions
- Nodding attack (head drawn inward)
- Salaam/Jackknife - bending neck and raising arms
EEG (hypsarrhythmia)
Developmental regression
What is a partial seizure?
Electrical discharge restricted to a limited part of cortex of one cerebral hemisphere
What are the different types of partial seizure?
Simple
Complex
Secondary generalisation - starts as partial seizure, spreads widely
What is a simple partial seizure?
Without LoC
e.g. focal motor seizure (Jacksonian)
- Originate in motor cortex
- Jerking begins in one side of mouth/hand → spread (march of the seizure)
- Local temporary paralysis sometimes follows (Todd’s)
With frontal seizures, can get forceful, sustained turning to one side by eyes, head or body = Adversive seizure
What is a complex partial seizure?
Loss of consciousness
Arise from temporal lobe or frontal lobe
Awareness impaired
Temporal lobe → post-ictal confusion (takes time)
Frontal lobe → rapid (fast) recovery
What are the characteristics of a Temporal Seizure?
Automatisms - complex motor phenomena, impaired awareness and no recollection afterwards
Abdominal rising sensation/pain
Dysphasia
Memory phenomena
Emotional disturbance - Hippocampus - sudden terror
Uncal involvement - hallucinations or taste or smell and dream like state
Delusional behaviour
What characterises frontal lobe seizures?
Motor features - posturing, versive movements of head and eyes
Jacksonian march
Motor arrest - Dysphasia or speech arrest
Subtle behavioural disturbance
Post-ictal Todd’s palsy
What characterises occipital lobe seizures?
Visual phenomena - spots, lines, flashes
What characterises parietal lobe seizures?
Sensory disturbances - tingling, numbness, pain
Motor symptoms
What structural changes can causes epilepsy?
Cortical scarring (head injury)
Developmental (tumour)
Space-occupying lesion
Stroke
Hippocampal sclerosis
Valscular malformations
What are non-epileptic causes for seizures?
Trauma, Stroke, Haemorrhage, raised ICP,
alcohol/benzo withdrawal,
metabolic disturbance, liver diease,
infections: meningitis, encephalitis, syphilis, HIV,
raised temperature,
drugs: tricyclics, cocaine, tramadol, theophylline
What are the differentials for epilepsy?
Syncope - Reflex (vasovagal) or cardiogenic
Non-epileptic attacks (psychogenic)
Panic attacks
Sleep disorders, Migraines, TIAs, Hypoglycaemia
What investigations are conducted for epilepsy?
ECG - rule out cardiac cause
EEG - low sensitivity, high specificity. Useful for classification, localisation. Video EEG = Gold standard
Imaging - find cause, response to anti-epileptic drugs, prognosis
What causes of epilepsy are associated to onset at the following ages?
Infants
Children/Adolescent
Young adults
30-50
50+
Infants - Developmental malformation, perinatal injury, infection
Children/Adolescent - Idiopathic Generalised Epilepsy
Young adults - IGEs, Various: head injury, alcohol, vascular malformations, hippocampal sclerosis
30-50 - brain tumours
50+ - Cerebrovascular disease, mass lesions - neoplasms
What is idiopathic generalised epilepsy?
Mixture of generalised seizures
Start in childhood, teen or young adulthood
Imaging normal (structurally)
EEG abnormal - abnormal firing
Seizures triggered by alcohol excess and sleep deprivation
[Juvenile Myoclonic Epilepsy, Childhood Absence Epilepsy]
What is Juvenile Myoclonic Epilepsy? And how is it treated?
Upper limb jerks, GTCS, Absences
Seizures on waking, precipitation by alcohol excess and sleep deprivation
EEG - spike and wave, photosensitivity common
MRI normal
Treatment: Sodium Valporate; (2nd) Lamotrigine; (3rd) Levetiracetam
What is hippocampal sclerosis?
Scarring and atrophy to the hippocampus and surrounding cortex
Main cause of temporal lobe epilepsy
Childhood febrile convulsions are the main RF
visible on MRI
Refractory epilepsy - resection of damaged temporal lobe may be an option
What is a hamartoma?
Benign local malformation which resembles a neoplasm
How may traumatic brain injury be linked to epilepsy?
May cause epilepsy, sometimes years after event
Risk does not increase after mild injury
Depressed skull, penetrating injury, intracranial haemorrhage increase risk significantly
How is cerebral palsy related to epilepsy?
1/3 of children with cerebral palsy have epilepsy
How does prematurity and foetal hypoxia relate to epilepsy?
They may cause periventricular leukomalacia which can cause early-onset epilepsy
In which part of the brain are mass lesions likely to cause epilepsy?
The grey matter
After age 60, what is the commonest cause of epilepsy?
Stroke and small vessel cerebrovascular disease
what is a cavernoma?
Cavernomas (cluster of abnormal dilated vessels) usually present with epilepsy
How are inflammatory conditions related to epilepsy?
Often seizures are presenting feature of encephalitis, cerebral abscesses or tuberculomas
Also in chronic meningitis
What does pork tapeworm cause?
Neurocyticercosis - major cause of seizures in countries where pork tapeworm is endemic
How are alcohol and drugs related to epilepsy?
Chronic alcohol use - whilst drinking heavily/during period of withdrawal
Alcohol-induced hypoglycaemia/head injury can also → seizures
Drugs: Antipsychotics, SSRIs, Lithium, Lidocaine, Ciclosporin, Cocaine
Withdrawal of anti-epileptics or benzodiazepines may cause seizures
What metabolic abnormalities can cause seizures?
Hypoglycaemia, hypocalcaemia, hyponatraemia
Acute hypoxia
Uraemia, hepatic encephalopathy
Pophyria (abnormal metabolism of Hb)
What are the treatments for Generalised TC seizures?
1 - Sodium Valporate/Lamotrigine
- Carbamazepine (Na+ channels)/Topiramate
Others: Levetiracetam, oxycarbazepine, clobazam
What are the treatments for Absence Seizures?
Sodium Valporate
Lamotrigine
Ethosuximide
What is the treatment for tonic, atonic or myoclonic seizures?
- Sodium valporate/Lamotrigine
- Topiramate
Other: Levetiracetam, Clobazam
(same as GTCS, but avoid carbamazepine/oxcarbazepine)
What is the treatment for partial seizures?
- Carbamazepine
- Sodium Valporate/Lamotrigine/Oxcarbazine/Topiramate
Others: Levetiracetam, GABApentin, Tigabine, Phenytoin, Clobazam
What is status epilepticus?
Seizure or series of seizures lasting for 30mins without regaining consciousness
MEDICAL EMERGENCY
Seizures lasting >5min need treating
Mortality 20%
What is the immediate management for status epilepticus?
Secure airway, monitor vital signs
IV access
Oxygen
U+Es, Ca, Mg, ABGs, ECG +/- anti-epileptic drug levels
IV glucose and thiamine (if alcohol suspected)
What are the treatments for early, established and refractory status epilepticus?
Early - IV Lorazepam 4mg, repeated once after 10 mins
- alternatives: Diazepam, Buccal Midazolam
Established - IV Phenytoin - Monitor BP and Cardiac
- alternatives: valporate, levetiracetam, phenobarbitone
Refractory - ITU, GA. IV Propofol, Thiopental, Midazolam
EEG, continue treatment + existing AEDs
What is non-convulsive status epilepticus?
Electrographic status (diagnose with EEG), but no convulsions
Confusion, reduced GCS, psychiatric symptoms
Responds well to benzodiazepines
What is SUDEP?
Sudden Unexpected Death in Epilepsy
- non-traumatic unwitnessed death
- post-mortem normal
- Cardiac arrhythmias, perictal hypoxia, postictal cerebral depression → hypoventilation and bradycardia
