Epilepsy Flashcards
seizure
*the clinical symptom of an abnormal, hypersynchronous discharge of a population of cortical neurons
*may produce clinical symptoms or may only be apparent as electrical activity on the EEG
*a singular event!
epilepsy
*RECURRENT seizures (2+) which are not provoked by systemic or acute neurologic insults
focal (partial) seizures
*affect one area of the brain (BEGINS in one area on EEG)
*commonly originate from temporal lobe
*may be preceded by a seizure aura
*can be focal aware or focal impaired awareness
focal aware seizures
*no alteration of consciousness
*can be motor, sensory, autonomic, psychic
focal impaired awareness seizures
*impaired consciousness (may range from mild confusion to loss of consciousness)
*clinical manifestations vary with site of origin and propagation of electrical activity through brain
*duration typically < 2 minutes
*often present as “staring spells”
focal to bilateral tonic-clonic seizures
*BEGINS focally, with or without obvious focal neurological symptoms
*variable symmetry, intensity, and duration of tonic (stiffening) and clonic (jerking) phases
*typical duration 1-3 minutes
*postictal confusion, somnolence, with or without transient focal deficit
non-motor generalized seizures (typical absence seizures)
*brief staring spells with impairment of awareness
*3-20 seconds
*sudden onset & sudden resolution
*often provoked by hyperventilation
*onset typically between 4 and 14 years of age
*often resolve by 18 years of age
*normal development and intelligence
*EEG: generalized 3 Hz spike-wake discharges
what is the EEG finding for non-motor generalized seizures (typical absence seizures)
generalized 3 Hz spike-wave discharges
what type of seizure is characterized by generalized 3 Hz spike-wave discharges
non-motor generalized (typical absence seizures)
motor generalized seizures
*associated with loss of consciousness and post-ictal confusion/lethargy
*duration 30-120 seconds
* tonic phase: stiffening and fall; may be associated with ictal cry
*clonic phase: rhythmic extremity jerking
*EEG: generalized polyspikes
etiologies of seizures and epilepsy - infancy and childhood onset
-prenatal or birth injury
-inborn error of metabolism
-congenital malformation
etiologies of seizures and epilepsy - childhood and adolescence onset
-idiopathic/genetic syndrome
-CNS infections
-trauma
etiologies of seizures and epilepsy - adolescence and young adult onset
-head trauma
-maturation effects of structural foci
-drug intoxication and withdrawal
etiologies of seizures and epilepsy - older adult onset (50+)
-STROKE
-brain tumor
-acute metabolic disturbances
-neurodegenerative
Lennox Gastaut Syndrome
*multiple seizure types
*slow (< 3 Hz) spike and wave on EEG
*developmental delay
examples of structural causes of epilepsy
-medial temporal sclerosis
-migration abnormality
evaluation after a first seizure
-history and physical
-blood tests
- +/- lumbar puncture
-blood or urine screen for drugs
-EEG (best if pt is sleep deprived)
-MR brain scan
seizure precipitants
-metabolic and electrolyte imbalance
-sleep deprivation
-ASM non-compliance
-hormonal variations
-stress
-fever/infection
-head injury
-stimulants and other drugs
medications that can trigger a seizure
*wellbutrin
*diphenhydramine (benadryl)
*tramadol
*some stimulants or antibiotics
key metabolic abnormalities associated with triggering a seizure
1) hyponatremia (low sodium in blood)
2) hypoglycemia
electroencephalogram (EEG)
*graphical depiction of cortical electrical activity, usually recorded from the scalp
*advantage of high temporal resolution, but poor spatial resolution of cortical disorders
*most important neurophysiological study for the diagnosis, prognosis, and treatment of epilepsy
background abnormalities on EEG
significant asymmetries and/or degree of slowing inappropriate for clinical state or age, may not relate to seizures
interictal abnormalities associated with seizures and epilepsy
**spike-wave complexes are pathognomonic for epilepsy
-spikes (< 70 msec)
-sharp waves (< 200 msec)
psychogenic non-epileptic spells
*NOT seizures (“functional neurologic disorder”)
*females > males; h/o abuse; may coexist with epilepsy
*psychiatric mechanism - dissociation, conversion - malingering is rare
*common association with physical, emotional, or sexual abuse
*NO EEG CORRELATION
cellular mechanisms for seizure generation
*too much excitation
-ionic: inward Na+ and Ca++ currents
-neurotransmitter: glutamate and aspartate
*too little inhibition
-ionic: inward Cl-, outward K+ currents
-neurotransmitter: GABA
vagus nerve stimulator
*intermittent programmed electrical stimulation of left vagus nerve
*may improve seizures, etc
ethosuximide only works for what type of seizures
absence seizures
epidiolex (CBD) for seizures
*only approved for:
1) Dravet syndrome (SCM1A)
2) tuberous sclerosis complex
3) Lennox Gastaut syndrome
Stevens-Johnson Syndrome (SJS)
-blisters and erosions of the skin, particularly palms and soles and mucous membranes
-fever and malaise
-rare condition
-rapid titration of lamotrigine especially in combination with valproate increases risk
surgical treatment for epilepsy - potentially curative
-resection of epileptogenic region avoiding significant new neurologic deficit
-laser thermal ablation
surgical treatment for epilepsy - palliative
-partial or staged resection of epileptogenic region
-disconnection procedures to prevent seizure spread (callostomy)
surgical treatment for epilepsy - devices
-responsive neurostimulation
-deep brain stimulation
status epilepticus
*a medical emergency
*traditionally, > 30 minutes of convulsive seizure activity or 2+ sequential seizures without full recovery between seizures for > 30 minutes
*current: defines earliest time when treatment should be started (t1) and the time when long term consequences are increasingly likely (t2)
t1 = 5 min and t2 = 30 min
sudden unexpected death in epilepsy (SUDEP)
sudden, unexpected, witnessed or unwitnessed, nontraumatic and non-drowning death in a patient with epilepsy where the autopsy does not reveal any other cause of death
