Epilepsy Flashcards
Prevalence of epilepsy in Canada
Epilepsy affects about 1% of the Canadian population and about 50 million persons worldwide
About ___ of cases enter long-term remission with treatment
65-85%
Causes of epilepsy
- May be genetic
- May be secondary to tumors, infection, head injury, lack of oxygen (for example, at birth), metabolic factors, alcohol abuse and stroke
- In >50% of cases, the cause is unknown
Tonic
stiffening of muscles
atonic
limp
Clonic
repeated jerking movements
Absence
interruption of consciousness, with blank stare, possibly with some motor symptoms
What is the focal onset of seizure types
Focal onset
Motor Non-motor
Focal to bilateral tonic-clonic
Motor symptoms
may be tonic, clonic or aclonic, or brief muscle twitching
automatisms
like clapping or rubbing of hands, lipsmacking or chewing, pacing in circles
Non-motor symptoms of seizures
changes in sensation, emotions, thinking or cognition, autonomic functions (such as gastrointestinal sensations, waves of heat or cold, goosebumps, heart racing, etc.), or lack of movement (behavior arrest).
What do frontal lobe seizures generally do?
Cause loss of motor control and changes in behavior or change language expression
What do Occipital lobe seizures generally do?
Multi shapes, loss of vision
What do Parietal lobe seizures do?
Numbness or tingling
What do Temporal lobe seizures do?
Odd smell tase buzzing or ringing in the ear
Excessive Excitation What is a seizure?
- Inward sodium and calcium currents
- Excitatory neurotransmitters: glutamate , spartate
Not enough inhibition What is a seizure?
- Inward chloride and outward potassium curents * Inhibitory neurotransmitters: GABA (A, B)
Sodium channel blockers
They slow the rate of recovery so it extends the period of absolute refractive period.
What are High-voltage activated calcium channel used for?
Focal seizures usually
What are T-type slow calcium channels
used for?
Use for absence seizures
Calcium channel blockers (Two types)
T-type slow calcium channels
High-voltage activated calcium channel
Focal seizures usually
Drugs that inhibit glutamate receptors and SV2A
AMPA: glutamate receptor (excitatory), also ion channel for sodium and potassium
NMDA: glutamate receptor (excitatory), also ion channel for calcium, sodium and potassium
Drugs that enhance GABA-mediated inhibition
Benzodiazepines (diazepam, lorazepam, midazolam, clonazepam), barbiturates (phenobarbital), vigabatrin
What are myoclonus motor symptoms?
Brief muscle twitching common
What is surround inhibition?
Gabaergic neurons block the signal to surrounding neurons so we don’t have massive movements (Moving a finger vs a hand)
Sodium channel blockers work how?
They slow the rate of Sodium moving into the neuron
