epilepsy Flashcards
questions to ask
prodrome? loss of urine/BM? tongue biting? describe seizure (witnesses?) occupation?
seizure old def
paroxysmal event due to abnormal, excessive, hypersynchronous discharges from aggregate of CNS neurons
seizure new def
transient disturbance of cerebral function due to an abnormal paroxysmal neuronal discharge in the brain
epiplepsy
prevalence?
causes??
Recurrent seizure due to genetically or acquired brain disorder
0.5 to 1 % of pop
50% have a cause:
Head trauma, brain tumor, stroke, infection in brain, congenital
what is NOT considered epilepsy
etOH, metabolic derangements (PROVOKED)
seizure initiation phase
High frequency APs and hypersynchronization (all at same time)
Long lasting depol. of membrane due to influx of calcium which opens voltage dependent sodium channels–>repetitive action potentials
(abnormal e- activity)
location of activity determines type
if gets better w. prednisone
reduces vasogenic edema from brain mass
seizure propagation phase
can go all over from initial location
??? can lower seizure threshold by inhibiting (antagonizing) the effects of ??? at the receptors
PCN (dangerous!)
GABA
structural/metabolic causes
Pediatric – congenital
Metabolic – withdrawal alcohol, drugs, hypoglycemia
Trauma – post trauma, may not imply future seizure
Tumors – all patients > age 30 with seizure must have head imaging, focal seizures
Vascular – usually advanced age, >60
Infectious – AIDS, meningitis, encephalitis, syphilis, cysticercosis
hypoglycemic seizures are
reversible, give sucrose
assess for meningitis
nuchal rigidity
Kernig: flex knee and hip
Bruzinski: flex neck
stretching meninges
partial seizure: simple
motor, sensory, autonomic, or psychic signs
-preservation of consciousness
Jacksonian march: spread over larger regions of motor cortex
Todd’s paralysis: loc. paresis after seizure
partial seizure: complex
loss of consciousness
Frequently begins with aura
Automatisms:
Chewing, lip smacking, picking
EEG will be abnormal during seizure
partial with secondary generalization
Focal onset may not be clinically evident, but EEG would capture spikes/waves
Difficult to distinguish from generalized tonic clonic seizure
primarily generalized seizures: absence (petit mal)
“staring off into space”
Brief lapse of consciousness without loss of postural control
Frequently lasts seconds
Usually begins in childhood, ages 4-8
Can occur hundreds of times a day
Decline in school performance? Daydreaming?
primarily generalized seizures: tonic clonic (grand mal)
~10% of patients with epilepsy have this type
Most frequent type from metabolic derangements
Tonic contraction of muscles of expiration and larynx cause “ictal cry”
EEG will be abnormal during seizure
what worry about: airway, aspiration, most dangerous
other primarily generalized seizures:
tonic: stiffening
atonic: limp
myoclonic: shaking
unclassified:
neonatal
infantile
simple partial seizure symptoms
paresthesia, flashing lights, vertigo, flushing, altered smell/hearing
EEG will be abnormal during seizure, but hard to classify unless actually having seizure- use 24 hr EEG
how to provoke? sleep deprivation
generalized seizure arise from..
both hemispheres simultaneously
Juvenile Myoclonic Epilepsy
Bilateral myoclonic jerks single or repetitive
Most frequent in AM, worse with sleep deprivation
Respond well to anti convulsive therapy
-roll on side
hypoglycemic?
Lennox-Gastaut Syndrome (triad)
1) multiple seizure types (ie: generalized tonic clonic, atonic, atypical)
2) an EEG showing slow spike and wave discharges
3) impaired cognitive function
a normal brain is…
capable of having a seizure, there are differences in the threshold or susceptibility
i.e. 2 kids w/ fevers, 1 gets seizure, other doesn’t
a variety of conditions have high chance of chronic seizure disorder
i. e. penetrating brain trauma, 50% chance of epilepsy
- ppx anticonvulsants
seizures are ??
episodic
May go months to years between episodes
things to exclude
syncope TIA (stroke-like, resolves w.in 24 hrs) migraine acute psychosis (pseudo seizure) other causes of episodic cerebral dysfunction
how to dx pseudoseizure??
dx of exclusion
24 hr EEG
HAVE episode, NORMAL EEG
trick: “hand drop” doesn’t fall on face
ddx syncope from seizure
(convulsant syncope can pass out and shake gray vision, lightheaded) see slide 21 seizures longer biting of tongue
hit ground fast with no prodrome
cardiac arrhythmia
if hx of epilepsy
consider tx, SEs, serum levels e-lytes (hypoNa) CBC (leukocytosis) L/RFTs tox screen (ecstasy: hypothermic, thirsty-->hypoNa)
no hx epilepsy
same labs + serum glucose, Ca, Mg, UA
do what first?
head CT w. w.out contrast
contrast better for masses
no contrast better for bleeds
+ metab. screen
metab/inf disorder
no hx epilepsy, neg metab. screen
MRI scan or EEG ? if neg: idiopathic seizure if pos: mass, stroke, etc-tx underlying disorder for both: controversial: antiepileptic meds
ddx seizure
TIA
Panic Attack
Syncope
Psychogenic Nonepileptic Seizure (PNES):
Check prolactin, which can be high 15-30 minutes after a tonic-clonic seizure in most patients
CK may also be high post convulsion
check ?? level after seizure
why ??
CK rhabdomyalgia (tightened musc.)
chance my child will have it again?
It is possible, but unlikely
childhood febrile seizure
Simple febrile – brief, symmetric
Complex febrile - >15 minutes, focal features
1/3-1/2 of children will have another seizure, but
evaluation
ABCs Hx/exam (neuro focus) lab studies EEG brain imaging psychogenic seizure prolactin level (rises in seizure)
lab studies
CMP, Magnesium, UDS
LP if meningeal signs on exam
HIV patient? Must do LP.
EEG
Recording electrodes on scalp, potential differences recorded
Normal awake, 8-13Hz alpha rhythm, variable faster >13Hz beta waves
Sleep deprivation helps induce seizure, consider 24 hour continuous EEG; may be normal 60% of the time
brain imaging
Almost all patients, except children may not need this
*MRI better than CT to detect any anatomical abnormalities
status epilepticus
how does it wreak havoc?
Repeated seizures without recovery between them; a fixed and enduring epileptic condition lasting > or = 30 minutes
Medical Emergency: can “fry” brain, airway issues
May lead to irreversible neuronal injury
seizure tx
Treat underlying cause if metabolic
Avoid alcohol if alcoholic
Single seizure, started AED is controversial
status epilepticus tx
Typically intubation, lorazepam (ativan), and AED (anti-epileptic drugs)
all together
If no IV, can give rectal diazepam (valium)
resp. depression is issue with lots of benzos-intubate–>ventilator
first line tx: tonic-clonic
valproic acid
lamotrigine
FLD: partial
carbamazepine
phenytoin (dilantin)
lamotrigine
valproic acid
FLD: absence
valproic acid
ethosuximide
“sucks to have an absence seizure”
FLD: atypical absence, myoclonic, atonic
valproic acid
phenytoin (dilantin) OD SEs
diplopia, skin rashes (SJS), ataxia, nystagmus, gingival hyperplasia
carbamazepine (tegretol, carbatrol) OD SEs
leukopenia, aplastic anemia
valproic acid OD SEs
thrombocytopenia, hepatic toxicity
can you ever stop the medicine?
it depends
after 2 yrs seizure free
Lamictal SEs OD
SJS, skin rash
