46 - Patho of Seizure Disorders Flashcards
> ___ % of all patinets with epilepsy will experience their first seizure by age 20
- a second peak occurs in the ___
80%
elderly
Generalized seizures (nono-absence types)
Myoclonic
- ___ like contraction of ___
- isolating jerking of head, trunk, body
shock
muscles
Generalized seizures (non-absence types)
Tonic
- these seizures occur in ___
- involve ___ as a result of increased tone in extensor muscles
- children
- rigidity
Generalized seizures (non-absence types)
Clonic
- these occur in ___ and young ___
- involve ___ , repetitive motor activity
babies, children
rigidity
Generalized seizures (non-absence types)
atonic
- sudden loss of ___ tone
- patients fall if standing (“drop attacks”)
jello moment
muscle
Generalized seizures (non-absence types)
tonic-clonic
- ___ phase immediately followed by ___ phase
- referred to as “ ___ ___ “
- characteristic of epilepsy
tonic, clonic
grand mal
Definitions
Seizure - ___ disorder of the CNS characterized by abnormal cerebral neuronal dischargers with or without loss of consciousness
- disordered, ___ , and rhythmic firing of population of brain neurons
Paroxysm - ___ attack or outburst
paroxysmal
synchronous
sudden
Definitions
Convulsion - specific seizure type where the attack is manifested by ___ muscle ___
Epilepsy - ___ seizures due to damage, irritation, and/or chemical imbalance. Leads to sudden, excessive, synchronous ___ discharge
involuntary, contractions
repeated, electrical
T or F: a seizure can cause cell ischemia because the brain is using more energy than it can manufacture
T
Seizure classifications
focal onset
- aware or impaired awareness
- motor onset or non-motor onset
- may progress from focal to ___ tonic-clonic
generalized onset
- motor:tonic clonic or other motor
- non-motor ( ___ )
unknown onset
- motor: tonic clonic or other motor
- nonmotor
- unclassified
bilateral
absence
Seizure classification
Focal
- about __ %
- only part of the brain is affected
- begin focally in cortical region, example: ___
- usually due to lesion from head trauma, tumor, stroke, hypoxia at birth, metabolic disorder, infections, malformations
- frequently process to generalized seizure ( focal to ___ )
- 60%
- temporal lobe
- bilateral
Seizure classification
generalized
- __ % of seizures
- loss of ___
- both brain ___ involved
- referred to as primary of idiopathic (if not evolved from ___ seizures)
- most are presumed to be ___
- 40%
- consciousness
- hemispheres
- focal
- genetic
pathways for the propagation of focal and generalized seizures
Partial seizure - seizure activity spreads from a focus in one part of the brain ( ___ )
Secondary generalization - focal seizures frequently progress to secondary generalized seizure via projections to the thalamus (latest classification” focal to ___ seizure)
Primary generalized seizure - propagate via diffuse interconnections between the thalamus and cortec (no discrete ___ ). the earliest clinical signs show involvement of ___ brain hemispheres
- focal
- bilateral
- focus, both
brain waves
T or F: focal and generalized seizures yield different EEG pattens
F
focal - aware
focal seizures can be of the “aware: type or involved impaired awareness
aware type (previosuly referred to as simple partial)
- 25% of focal seizures
- limited convulsions (jerking of ___ limb or body part)
- limited sensory disturbance
- no loss of ___
- subjective experiences ( ___ ) also occur - abdominal discomfort, sense of fear, unpleasant small, result of abnormal electrical activity
single
consciousness
aura
seizure focus and inhibitory surround
electrical discharge spreads thrpugh the sizure focus but is contained as a result of inhibtion in a neighboring zone called the ___ ___
- an excitatory pyramidal neuron (A) activating another pyramidal neuron (B), whereas neuron (C) in the surround inhibited regions is ___ because of GABAergic inhibition
inhibitory surround
- hyperpolarized
electrophysiological basis for the tonic and clonic phases of a generalized tonic-clonic seizure
- evolution from focal to bilateral involves a loss of ___ and surround inhibition
- tonic phase: ___ mediated inhibition disapperas, whereas ___ mediated AMPA and NMDA receptor (via influx of cations) activity increase
- clonic phase: ___ mediated inhibition (via influx of ___ ions) gradually returns, leading to period of oscillation
- as GABA mediated inhibtion breaks down during the ___ phase, action potentials propagate to distant neurons, leading to spread of seizure activity from focus to distant sites in the brain
- hyperpolarization
- GABA, glutamate
- GABA, Cl
- tonic
potential triggers of status epilepticus
underlying conditions in the brain:
- prenatal injury
- cerebrovascular disease
- brain tumors
- head trauma
- infection
- hemorrhage
- anoxia
- drugs
general perturbations
- metabolic disturbances (hyperventilation, blood gas/pH, hypoglycemia
- sleep deprivation
- stress
- alcohol withdrawal
- withdrawal or sudden D/C of ___
- repetitive light stimulation (strobes)
AEDs
