Epilepsy Flashcards
What is an ictus?
Sudden neurological event
What is a seizure?
Transient neurological dysfunction caused by excessive activity of cortical neutrons resulting paroxysmal alteration of behaviour and/or EEG changes.
What is epilepsy?
Tendency to repeated, spontaneous seizures
What are the generalised seizure types?
- Tonic
- Clonic
- Tonic-clonic
- Myotonic
- Atonic
What are the common focal seizure types?
- Dyscognitive
- Evolving to bilateral, convulsive seizure (secondary generalised).
What are the features of the tonic phase of a GTCS?
Tonic phase:
- muscle rigidity
- arms down
- eyes open
- cry
What is the progression of a GTCS?
- Tonic phase
- Clonic phase
- Apnoea
What are the features of a GTCS?
- Last 1-5mins;
- Tonic and clonic phases
- minor injury common (e.g. tongue biting);
- confusion following
What is an absence seizure? What are its feaures?
Alteration of consciousness without loss of postural tone (stay upright); difficult to detect.
May have facial twitch (3Hz blinking, mouth mvt, eyes drift open).
Last 2-10s; generally in children/teens.
What are myoclonic seizures?
Brief contractions localised to muscle groups of one or more extremities, can be single or multiple.
May precede GTCS
What are focal seizures?
Single area of brain without alteration of consciousness. Features depend on location. Usually brief.
What are focal dyscognitive seizures?
Localised region with sufficient spread to impair consciousness. Bilateral temporal lobes involved.
What is the distinction between absence seizures and focal dyscognitive seizures?
Focal dyscognitive similar to absence but are:
- longer
- less distinct offset
- automatisms
- less frequent
- may precede simple seizure
What are the types of genetic generalised epilepsies?
- Childhood absence
- juvenile myoclonic
- juvenile absence
- epilepsy with tonic clonic seizures along
What are genetic generalised epilepsies?
GTCS, absence and or myoclonic seizures with:
-no evidence of brain damage
-epileptiform discharges 3Hz or faster
-response to therapy usually good (80-85%)
(Childhood / or Juvenile Absence Epilepsy; Juvenile Myoclonic Epilepsy; Epilepsy with tonic-clonic seizures alone)
Onset childhood absence epilepsy?
4-8 years (up to 12).
What are the types of seizure in childhood absence epilepsy? How does juvenile absence epilepsy compare?
-Absence (frequent, multiple per day).
-GTCS (40%; adolescence)
Juvenile absence epilepsy has its onset in adolescence (cf 4-12y for childhood)
What are the features of juvenile myoclonic epilepsy?
- Onset 12-18y
- Seizures: myoclonus, GTCS, absence
- Often photosensitive.
- Sleep wake cycle.
Is an ictal EEG useful?
Almost always abnormal in seizure; perfect for pseudo seizure (will appear normal despite appearance of symptoms).
What proportion of people who have a seizure will go on to develop epilepsy?
~50% of people who have single seizure as an adult will never have another
What is the role of ethosuximide?
Basically only absence seizures (e.g. childhood absence)
What is important about valproate?
Teratogenic. Be very careful in women of childbearing age.
In whom should carbamazepine be used with caution?
Asian subcontinent (HLA association with stevens johnson syndrome = toxic epidermal necrolysis).
Features of clonic phase of GTCS?
Repetitive violent jerking of face and limbs, tongue biting, cyanosis, frothing, incontinence
What is a tonic seizure characterised by?
Muscle rigidity in flexion or extension
What is a clonic seizure characterised by?
Repetitive rhythmic jerking movements
Features of a complex focal seizure?
- Pt appears awake but w/ impairment of awareness
- Classically characterised by automatisms (chewing, lip smacking, swallowing etc)
Ix in seizure/?epilepsy workup?
- FBE / UEC / LFTs / CMP / ESR / CK
- Fasting BSL
- Consider tox screen, EtOH
- CT/MRI if new seizure w/o identified cause
- LP if fever or meningism
- EEG
Treatment of epilepsy?
- avoid precipitants
- anticonvulsants if indicated
- psychosocial issues: stigma of seizures, pt/fam ed
- safety issues: driving, swimming, operating heavy machinery
- consider surgical Mx if focal and refractory
What are the indication for medical therapy in management of seizures?
- 2+ unprovoked seizures,
- known organic brain disease, -EEG with epileptiform activity
- episode of status epileptics
- abnormal neurologic examination
What is status epileptics?
Unremitting seizure of greater than 5 min; or successive seizures without a return to baseline state
What are the complications of status epilepticus?
- Anoxia
- Cerebral ischaemia and oedema
- rhabdomyolysis and renal failure
- aspiration pneumonia / pneumonitis
- death
Initial Mx status epilepticus?
- ABCs
- Vitals
- Fingerprick glucose (stat)
- ECG
- Nasal O2
- IV NS, glucose (50mL IV) and thiamine
- ABGs (if cyanotic)
Medications used for seizure termination?
Benzodiazepines
Medications used for acute seizure prophylaxis?
- Benzos
- Phenytoin (Levetiracetam, Valproate)
What is SUDEP?
Sudden Unexpected Death in Epilepsy (SUDEP)
- 1-2/1000 pts sudden death
- ?Cardio-resp arrest, often in sleep
- related to seizure frequency
