seizures Flashcards
prevalence of seizures vs febrile convulsion vs epilepsy in childhood
seizures = 2-5%
febrile convulsion = 1 in 30 = 3%
epilepsy = 0.5%
examples of generalised onset seizures
- GTC
- tonic
- myoclonic
- typical absence
- atonic
aetiology of epilepsy
- genetic epilepsy
- structural - malformation/focal epileptogenic lesion
- infection e.g. neurocystercercosis
- inflammation / immune e.g. ADEM
- metabolic
describe key features of seizures arising from the frontal vs temporal vs occipital cortces
frontal = MOTOR, nocturnal
temporal = most common focal epilepsy = oromotor automatisms (lipsmacking), weird psych stuff e.g. fear / deja vu, olfactory/auditory
occipital = visual
what can and shouldn’t be used to distinguish syncope vs GTC
don’t use convulsions / incontinence
post-confusion is good (<30s for syncope, 2-20mins GTC)
trigger is also RARE in seizure
what determines what kinds of investigations you need to do if you suspect epilepsy?
how likely it is that there is a sinister cause:
idiopathic focal (BOE, BRE): nothing
idiopathic generalised (CAE, JAE, JME): mostly nothing
symptomatic focal - imaging
symptomatic generalised (infantile spasms / lennox gastaut): consider all
most common cause of focal epilepsy worldwide
neurocystercercosis
what kind of epilepsies are the following provocation procedures for EEG used for?
1. hyperventilation
2. photic stimulation
- Hyperventilation – stimulates absence seizures
- Photic stimulation – idiopathic generalised epilepsy
following correspond to what EEG pattern?
1. absence seizures
2. BRE
3. BOE
4. juvenile myoclonic
5. Infantile spasms
6. lennox-gastaut
- absence seizures = 3Hz spikes
- BRE = centro-temporal sharp waves
- BOE = right occipital spikes
- juvenile myoclonic = 4-6Hz
- Infantile spasms = hypsarrhythmia
- lennox-gastaut = < 2.5 Hz sharp/slow
which types of epilepsy classically have normal inter-ictal EEGs
FLE, TLE, IGE
% of autistic children with epilepsy
30%
what are the four seizure syndromes to know about in the neonatal period
• Benign neonatal seizures
• Benign familial neonatal seizures
• Early myoclonic encephalopathy (EME)
• Ohtahara syndrome (early infantile epileptic encephalopathy - EIEE)
key features of benign neonatal seizures
- ‘fifth day fits’
- resolve by 2 weeks
- everything is fine - no fhx, neuro exam ok, eeg fine
key features of benign familial neonatal seizures
- within 1st week onset; self-resolve in early infancy
- AD inheritance, usually KCh channelopathy
- everything else fine
differentiate EME vs EIEE
EME
present as neonate
metabolic/genetic
abnormal at birth/at seizure onset
starts as myoclonic > infantile spasms
progressive into vegetative state; death in infancy
EIEE
present in first 3 months
anoxia / genetic
always abnormal at birth
tonic > west/ lennox-gastaut
static: causes mental retardation + quadriplegia, last slightly longer
EEG pattern of EME and EIEE
suppression burst
clinical triad of west syndrome
i. Epileptic spasms (seizures type)
ii. Hypsarrythmia (EEG)
iii. Arrest of psychomotor development/regression (clinical)
peak age of onset for infantile spasms
3-7mo
classic spasms of infantile spasms
- most commonly after waking
- sudden, brief, bilateral and symmetric contraction of the muscles of the neck, trunk and extremities, occurring in clusters
first line treatment for infantile spasms
1st line = high dose pred
if tuberous sclerosis, 1st line = vigabatrin
if treatable metabolic condition, treat
common causes of infantile spasms (and most common)
malformations
1. cortical dysplasia = most common > can treat
2. Cerebral dysgenesis = Aicardi syndrome
3. Lissencephaly = Miller-Dieker syndrome
tuberous sclerosis
T21
infections
metabolic
genetics
dravet syndrome also known as…?
severe myoclonic epilepsy of childhood
3 key features of dravet
- pleomorphic triggered by fever/ warm temps/ lights
- seizures in first year, but dev delay + abnormal EEG at 2-3y
- hypotonia, ataxia
- multifocal spikes on EEG - 90% from SCNA1 mutation
major causes of mortality in dravet
SUDEP
status
accidents e.g. drowning
infections
Mx options in dravet? what Rx to avoid?
- avoid triggers
- initially - valproate +/- clobazam
** 90% from SCNA1 mutation, so avoid Na blockers e.g. carbamazepine!
name the three benign focal epilepsies of childhood
- childhood epilepsy with centrotemporal spikes (CECTS) = BRE = BECTS
- BOE of childhood early onset = panayiotopoulos
- BOE of childhood late onset = gastaut
key features of BRE
- asleep/about to wake
- up to 2mins with rolandic complex i.e. oropharyngeal sensorimotor seizures: numbness/tingling, hypersalivation, guttural vocalisation
- fully conscious
- start ~6-8yo, remit by puberty
incidence of BRE
most common childhood epilepsy- 15%
Rx for BRE
1st line valproate
Carbamazepine, phenobarbital and lamotrigine CONTRA-INDICATED
early BOE key features for exam and 1st line Rx
- peak onset 3-5yo, spontaneous remission 2-3y after onset
- focal autonomic (vomiting**, pallor, sweating, apnoea, HR) > generalised
- infrequent seizures, but status typical
- 1st line if having more seizures- carbamazepine
late BOE features that distinguish it from early BOE
- 8-9yo onset, and remission less likely
- vomiting uncommon; eye features more common
- daytime not night (cf early)
- more frequent and shorter seizures (cf early)
- EEG markedly activated by eye closure
key features of childhood absence epilepsy
- peak onset 5-6y; remission in 80% after Rx
- impaired consciousness e.g. staring WITHOUT loss of body tone
- induced by hyperventilation
- 3Hz EEG
Rx to give and avoid in CAE
- ethosuxamide, 2nd lamotrgine
AVOID carbamazepine, vigabatrin, gaba - they aggravate the seizures!!
lennox-gastaut key features
- peak onset 3-5y
- seizures severe AF - pleomorphic and everyday (WEAR HELMET)
- developmentally normal BEFORE first seizure
- slow spike+wave <2.5Hz EEG
- no drug is great
ketogenic diet esp effective in which epilepsy?
epilepsy with myoclonic-atonic seizures (EMAS) = doose syndrome
key features of EMAS / Doose syndrome
- peak 2-4y
- WEAR HELMETS (as well as lennox-gastaut)
- myoclonic / drop seizures
- ketogenic diet v effective (many GLUT1 defect)
- 50% do well
landau-kleffner syndrome (LKS) - key features
- a/w sleep
- EEG: CT spikes+waves > continuous when asleep i.e. ESES
- normal until 3-6y, when they lose language (later than autism)
- no tx effective
gelastic seizures - what are they, and what causes them
= sudden laughing/crying
hypothalamic hamartoma - can have surgery
juvenile myoclonic epilepsy- key features, Rx and which to avoid
- 12-15y peak onset; low remission - lifelong tx
- triggers: sleep dep, alcohol, lights
- morning myoclonic jerks, and absence/GTC on waking
- 1st valproate, AVOID carbamazepine/phenytoin
which is the key chromosomopathy associated with epilepsy
T21
which Rx need levels and monitoring
phenytoin
phenobarb
very rarely carbamazepine/valproate
biggest risk factors for SUDEP
- poorly controlled tonic-clonic seizures ***
- male
- longstanding epilepsy
- younger age at onset
risk factors for febrile convulsion
Major
i. Age <1 year
ii. Duration of fever <24 hours
iii. Fever 38-39 degrees
Minor
i. Family history of febrile seizures / epilepsy
iii. Complex febrile seizures
iv. Daycare
v. Male gender
vi. Low sodium at the time of presentation
definition of complex febrile convulsion
i. Focal features at onset or during seizure
ii. Duration of >15 minutes
iii. Recurrence within the same febrile illness
iv. Incomplete recovery in an hour
risk factors for development of epilepsy with febrile convulsion
one risk factor = 2%, >1 factor = 10% risk:
family history of epilepsy
any neurodevelopmental problem
prolonged or focal febrile seizures
febrile status epilepticus
1st line treatment:
- for most seizures
- neonatal seizures
- focal seizures
- most childhood epilepsies = valproate
- neonatal = phenobarb
- focal epilepsy = carbamazepine
first line Rx for:
- most seizures
- neonatal
- partial
- most = valproate
- neonatal = phenobarb
- partial = carbamazepine
MOA classes of the anti-epileptics and their broad side effects
NaCl blockers - CBZ, PHT, VPA, LTG
- esp CNS (drowsy, ataxia, tremor, vom etc)
GABAergic - PB, BZP, VGA, VPA
- esp behavioural (aggression, irritability etc)
specific side effects they want you to know for exams:
- CBZ
- valproate
- phenytoin
- lamotrigine
- vigabatrin
- topiramate
- oxcarbazepine
- CBZ: hypoNa, saliva, SJS/DRESS in azeans
- valproate: pancreatitis/liver failure
- phenytoin: serum sickness, gums, hirsutism, OP, megaloblastic anaemia
- lamotrigine: SJS
- vigabatrin: retinopathy, psychosis
- topiramate: nephrolithiasis, glaucoma
- oxcarbazepine: hypoNa
lamotrigine - what reduces and increases its half-life?
CBZ/phenytoin reduces
valproate increases
which triple combo of AED works well
LTG + VPA + CLB
which AED will exacerbate BRE/BOE and IGE
CBZ and OXC
asians - beware of which AEDs and why
CBZ, OXC, PHT, LTG, HLA-B*15:02 allele
which AEDs are weight gain, weight neutral and weight loss
Weight gain = carbamazepine, oxcarbazepine, valproate, and the gabas
Weight neutral = lamotrigine, keppra, phenytoin
Weight loss = topiramate
when to withdraw AED generally
after 2 years seizure free therapy in unspecified epilepsy syndrome
teratogenic effects of AEDs - which 3 do we not like, and which is the worst?
valproate worst; NTD
CBZ = spina bifida
phenytoin = clefts
first sign of CBZ toxicity
diplopia
which drug to avoid in mitochondrial disorders
valproate
which drug to avoid in dravet
lamotrigine
vagal nerve stimulation in epilepsy - success rates
50% have >=50% seizure reduction
<10% chance of seizure freedom
what is the thought process behind ketogenic diet
4 fat: 1 protein/carb > body burns fat more than CHO/protein > ketones produced > brain uses these for glucose»_space; (dunno how) raises the seizure threshold
when is the ketogenic diet CI?
metabolic diseases with fat oxidation deficits and/or lactic acidosis
