Epilepsy I & II Flashcards
Hippocrates view of Epilepsy
- “Sacred disease” - accumulation of phlegm in the veins of the head
- Starts in utero, continues after birth and into adulthood
- Too much - “melted” brain which results in mental illness.
- patient loses speech and chokes causing foam to fall from his or her mouth
What Hippocrates got right
recognized the symptoms and that they derived from the brain
right about juvenile onset
Hippocrates on epilepsy onset
Juvenile Onset b/c young children have small veins, not able to accommodate the increased amount of
phlegm
Hippocrates on epilepsy symptoms
- Shivering
- Loss of speech
- Trouble breathing
- Contraction of the brain
- Blood stops circulating
- Excretion of the phlegm
Seizure
an abnormal, disorderly discharging of the brain’s nerve cells
• abnormal, excessive or hypersynchronous neuronal spiking
• temporary disturbance of motor, sensory, or mental function
- singular event in 10% of people
Epilepsy
refers to a continuum of chronic neurological
syndromes in which a person has heightened risk of
recurrent seizures
Causes for epilepsy
- Causes can be unknown or genetic
* Can result from brain trauma, stroke, brain cancer, drugs
Epilepsy vs. Seizure
Epilepsy is a disease of RECURRENT seizures
seizures can also be singular events (independent of epilepsy)
___ lifetime risk, ___ prevalence
~3% lifetime risk, Prevalence 0.5-1%
prevalence is lower than lifetime risk since many epilepsies resolve (ex. juvenile epilepsy)
Is prevalence reported exact?
No, epilepsy is likely much more prevalent but figures are decreased due to stigma and the heterogenetity of symptoms
Most epilepsy is diagnosed before age___
18 (75-85%)
44% by age 5; 55% by age 10
Children with epilepsy
- 1% of children will have recurrent seizures before age 14
* 50% of cases of childhood epilepsy - seizures disappear (juvenile epilepsy often resolves)
In ___ % of cases, the cause of epilepsy is unknown
50-60%
Cryptogenic vs. idoipathic vs. Symptomatic
Cryptogenic = cause unknown but has suspected orgins Idiopathic = cause unknown Symptomatic = generated by injury (secondary to another event--stroke, trauma, meningitis)
Both cryptogenic and idiopathic epilepsies are thought to be _____
Genetic; but the precise gene itself is unknown
Common causes of epilepsy
- Genetic abnormalities
- brain tumour, stroke, head trauma of any type
- more severe the injury, the greater the chance of developing epilepsy
- aftermath of infection (meningitis, viral encephalitis)
- poisoning, substance abuse (lead, CO, alcohol)
Causes for child onset
- injury, infection, or systemic illness of the mother during pregnancy
- brain injury to the infant during delivery may lead to epilepsy
Seizure’s effect on life expectancy
seizures are not typically fatal, they do reduce life expectancy as well as quality of life (e.g. driving, employment)
Epileptics have __ times higher mortality; depends on _____
3x; depends on control of seizures
If uncontrolled–shorter life expectancy
If controlled–no difference
4 conditions that have risk of death
- status epilepticus (continual seziures)
- suicide associated with depression
- trauma from seizures (ex. trauma from falls)
- sudden unexpected death in epilepsy (SUDEP, 8-17%)
Highest risk of mortality in epilepsy due to
Underlying neurological impairment OR poor control of seizures
Can categorize epilepsies based on
- Seizure types (semiology)
- Etiology
- Electroencephalogram (EEG) findings
- Brain structure
- Age when seizures begin
- Family history of epilepsy or genetic disorder
- Prognosis
Major seizure categories
GENERAL vs FOCAL onset
general = whole brain
focal/partial = only in one part of the brain
and Continuous
General seizure subtypes
Grand mal (generalized motor) Petit mal (absence)--loss of consciousness
Focal seizures subtypes
• Simple partial (focal) seizures (elementary cortex involvement)–w/o loss of consciousness
• Motor cortex (Jacksonian)–seizures move through body according to homunculus representation
• Complex partial seziures (limbic seziures)–w/ loss of consciousness
• Sensory cortex:
–>Somatosensory
–>Auditory-vestibular
–> Visual
–>Olfactory-gustatory (uncinate)
Focal seziures
focal (partial) onset with or
without secondary generalization to major
motor manifestations.
Continuous seizures
- Generalized (status epilepticus)
* Focal (epilepsia partialis continua)
Major seizure classifications (6)
- “Grand Mal” or Generalized tonic-clonic
- Absence “petit mal”
- Myoclonic Sporadic
- Clonic
- Tonic
- Atonic
“Grand Mal” or Generalized tonic-clonic
Unconsciousness, convulsions, muscle rigidity
Absence “petit mal”
Brief loss of consciousness; generalized; still maintain muscle tone; appear to be daydreaming
Myoclonic Sporadic
isolated, jerking movements
Clonic
Repetitive jerking movements
Tonic
Muscle stiffness, rigidity
Atonic
Loss of muscle tone
Typical absence seizure–characterization
petit mal
characterized by 3Hz hyperactivity
Juventile myoclonic seziure (generalized) EEG
high amplitude spiking; disordered
Interictal (b/t seizures) EEG of Infantile Spasm (west symdrome)
Hypsarrythmia–lack of brain rhythm (highly disordered)
Ictial and interictal EEG in mesial temporal love epilespy
Interictal = focal temporal discharges (spikes outside of seizure activity) Ictal = rhythmic theta discharges (5-7 Hz)
Temporal Lobe Epilepsy Symptoms
odd feeling, memory,
sensation
Frontal Lobe Epilepsy Symptoms
seizure symptoms in the
frontal lobes vary widely
frontal lobes responsible for executive function; cognitive performance
Parietal Lobe Epilepsy Symptoms
somatosensory, somatic,
visual, language
Occipital Lobe Epilepsy Symptoms
visual hallucinations
Primary Generalized Epilepsy Syndromes
idiopathic, can be
myoclonic,
grand-mal, or absence
Reflex Epilepsy
in response to specific
stimuli only
Epilepsy syndromes in kids
- Benign Rolandic Epilepsy
- Juvenile Myoclonic Epilepsy
- Infantile Spasms (West Syndrome)
- Childhood Absence Epilepsy
- Benign Occipital Epilepsy
- Landau-Kleffner Syndrome
Benign Rolandic Epilepsy
seizure activity around central sulcus (aka the rolandic fissure)
Outgrown b/t 14-18; peak seizure activity ages ~8-9
Results in infrequent facial seizures and other pharyngal symptoms (ex. hyper salivation)
Juvenile Myoclonic Epilepsy
seizures associated with sleep status–often when tired or waking
often diagnosed b/t 12-18; not benign continues into adulthood
Infantile Spasms (West Syndrome)
idiopathic, symptomatic, or cryptogenic, prognosis varies
sever neuro-developmental disorder
infantile spasms w/ jack-knife convulsions
associated w/ interictal hypsarhytmia
Childhood Absence Epilepsy -
kids 5-9, remission in 80% (mostly benign )
Benign Occipital Epilepsy
positive (ex. hallucinations) or negative (i.e. lack of visual perception) visual
symptoms
Landau-Kleffner Syndrome
loss of language between 3 and 7 (in kids who had normal language development up until age 3)
Includes seizures but they are rare or at night (and often therefore go unnoticed)
Non-genetic causes of epilepsy
Vascular malformations; cerebral tumours (structural abnormalities)
meningitis, encephalitis (infection)
birth asphyxia, cerebrovascular accident (hypoxic-ischemic injury)
mTOR (Mammalian target of
rapamycin)–what is it
protein kinase that regulates cell growth, proliferation, motility, and survival
As well as protein synthesis and transcription
mTOR roles in
- Important in excitatory
synaptic neurotransmission - positive regulator of development, survival and plasticity
- synaptic connectivity (increased spine stability, spine enlargement, role in LTP)
mTOR good and bad
Good= role in learning BAD = likely plays role in epilepsy
mTOR + epilepsy
Aberrant activation (overactivation) of mTOR pathway -->altered excitation/inhibition balance --> susceptibility to seizures reverberating circuit --> epileptogenesis
how to decrease mTOR’s effect on epilepsy
Rapamycin may reduce
seizure activity by preventing mTOR activity