Epilepsy Flashcards
Define epilepsy
Paroxysmal electrical disturbance of cerebral neurons which may give rise to dysfunction of the motor, sensory system, behaviour, conciousness and autonomic function.
How would motor system seizures present (6)
Tonic attack Tonic-clonic Myoclonic Atonic Disturbance of maintenance of posture with hypotonia Automatism
How would sensory seizures present? (5)
Visual, auditory, olfactory, taste or somatosensory auras
How would seizures affecting behaviour present? (3)
Anxiety, fear, elation (rare)
How would seizures affecting consciousness present? (2)
LOC for seconds eg petit mal
10-45 minutes following grand mal seizure
How would seizures affecting autonomic function present? (4)
BP / pupillary changes, facial pallor, tachycardia
What is a focal seizure?
Limited to a part of one cerebral hemisphere , localised
3 types of focal seizures
Focal aware
Focal unaware (clouded conciousness)
With secondary generalisation (“focal to bilat”)
6 types of generalised seizures
Absence Myoclonic Clonic Tonic-clonic Atonic Tonic
Where is lesion usually in focal unaware seizure
Temporal or frontal lobe
Definition generalized epilepsy
Bilateral involvement of cortex at the onset. LOC. Usually no warning
Where does the abnormal electrical impulse probably begin in generalised seizures?
Diencephalon or rostral brainstem (then spreads to both hemispheres)
Define tonic-clonic seizure or “grand mal” seizure (stages)(6)
- Immediate LOC
- Tonic phase: fall and stiff. About 30 seconds, urinary incontinence can occur (EEG = spike discharges)
- Clonic phase: rapid, rhythmic symmetrical myoclonic jerks. About 30 seconds. (EEG - spike and slow wave pattern)
- Period of muscle relaxation : respiration gradually return. 30s.
- Period of sleep
- Regain consciousness with headache, tired, muscle pain, injury, confusion. = postictal period
Characteristics of absence/petit mal seizures (6)
Sudden onset
Vacant stare with disturbance of conciousness
Disruption of ongoing psychic activity
Short duration usually less than 30s, most <10s
Eyes rotate up
Normal alertness when conciousness regained
(EEG=3s spike and wave activity)
Myoclonus definition
Sudden, brief shock-like involuntary jerking movements of muscles, usually sufficient to move joint
Causes myoclonus (4)
Juvenile myoclonic epilepsy
Infantile myoclonic epilepsy (West syndrome) (trunk myoclonus with flexion-extension)
Hypoxia in liver and renal failure
Slow virus infections: subacute sclerosing panencephalitis (SSPE) caused by measles, Creutzfel t-Jacob disease
Atonic seizure characteristics
“Drop attacks”
Fall to ground suddenly without warning, with or without loss conciousness (1-2s)
Tonic seizure characteristics
Increase in tone in arms, legs, trunk. Often results in extension of whole body. May or may not fall.
What is partial epilepsy?
Presence of aura or warning before seizure
When is epilepsy treatment considered? (3)
At least 2 attacks
Unprovoked
Attacks more than 24 hours apart
Definition status epilepticus (3)
Seizure longer than 30 minutes
Seizures recur without patient regaining conciousness between seizures
Frequent occurence tonic clonic seizures without clinical recovery for a period exceeding 20 minutes
Define epilepsia partialis contua
Recurrent motor epileptic seizures that are focal (hands and face), which recur every few seconds or minutes for extended periods (days or years)
Treatment status epilepticus?
- First dose benZo: lorazepam iv/ diazepam iv or rectal / midazolam IM /in/ buccal
No respond after 5 min…
- First dose antiepileptic (phenytoin/valproate)
- 2nd dose benzo
- 2nd dose antiepileptic (phenytoin/valproate)
- Anaesthetic
Name 3 benzos that can be used to treat status epilepticus and doses
Lorazepam 0.1mg/kg (max 4mg)
Diazepam 0.5-2mg/kg (max 19 mg) IV
OR
RECTAL 10MG
MIDAZOLAM 10MG IM/buccal
Dose lorazepam status epilepticus?
0.1 mg/kg IV
maximum 4mg
Dose diazepam status epilepticus? (Valium)
IV: 0.15-2mg/kg (max 10mg)
Rectal: 10 mg
Dose midazolam status epilepticus?
10 mg IM/buccal
Max 20 mg
Name a benefit and disadvantage of using lorazepam for status epilepticus
+ rapid onset, longer duration compared to diazepam
- need IV access; risk injection site reaction
Name a benefit and disadvantage of using diazepam for status epilepticus
+ rapid onset when given IV. Effective also as rectal if no iv access
- risk of accumulation. Rectal route has short duration of action and less effective than other options
Name a benefit and disadvantage of using midazolam for status epilepticus
+ rapid onset action. IM route has best efficacy if all the benzos with little risk accumulation
- short duration action
Dose phenytoin for status epilepticus
20 mg/kg at 50 mg/min
Max 2000mg
Dose valproate (epilim) for status epilepticus
30 mg/kg at 10mg/kg/min
Max 3000 mg
