w9 seizures Flashcards
what are seizure disorders?
Is a symptom of disease, not a specific disease
what is a seizure?
is a sudden, transient disruption in brain electrical function caused by abnormal excessive discharges of cortical neurons
what is epilepsy?
is a recurrence of seizures and a disorder for which no cause can be found
what is convulsion?
-is a tonic-clonic (jerky, contract-relax) movements associated with some seizures
what are conditions that are associated w/ seizure disorders?
any conditions that affect the CNS or neuronal environment
- metabolic disorders
- congenital malformations
- genetic predispositions
- perinatal injury
- postnatal trauma
- myoclonic syndromes
- infection
- brain tumour
- vascular disease
- drug/alcohol abuse
- some environmental stimuli (blinking lights) known to imitate seizures
types of seizures -generalized seizures
affect neurons bilaterally
types of seizures-focal (partial) seizures-
affect neurons unilaterally
types of seizures-epilepsy syndromes
-usually a genetic or developmental cause
types of seizures-unclassified epileptic seizures-
the etiology is unknown
what is status epilepticus?
is a medical emergency !!
-continuing/recurring seizures w/ incomplete recover, unrelenting seizure activity that lasts 30 minutes or more
what are the 6 causes of epilepsy?
- genetic
- structural
- metabolic
- immune
- infections
- unknown
patho of epilepsy
- is the interaction of complex genetic mutations w/ environmental effects
- abnormalities synaptic transmission
- imbalance in the brain’s neurotransmitters
- development of abnormal nerve connections after injury
what is epileptogenic focus -epilepsy
- Group of neurons that appear chronically hyperexcitable; fire more frequently and with greater amplitude
- Cortical excitation spreads when the intensity threshold is reached
what is the tonic phase -epilepsy
A state of muscle contraction in which there is excessive muscle tone
- Excitation of subcortical thalamic and brainstem areas
- Associated with loss of consciousness
what is the clonic phase in epilepsy?
(alternating contraction and relaxation of muscles)
- Inhibitory neurons in cortex, anterior thalamus, and basal ganglia react to cortical excitation –> muscle contractions gradually cease
- Epileptogenic neurons exhausted
what is the postictal phase -epilepsy
- following an epileptic seizures and pt returns to baseline
- Headache, confusion, aphasia, memory loss, and paralysis, lip-biting
what are the consequences of epilepsy?
- cerebral blood flow increase
- cerebral oxygen consumption is increased by 60%
- glucose depletion
- accumulation of lactate in brain tissues
- potential for progressive brain injury and irreversible damage
what is prodroma?
Early clinical manifestations, such as malaise, headache, or a sense of depression, that may occur hours to a few days before the onset of a seizure
what is aura?
-A focal seizure experienced as a peculiar sensation preceding the onset of a generalized seizure or complex partial seizure that may take the form of gustatory, visual, or auditory experience; a feeling of dizziness or numbness; or just “a funny feeling”
-sensation that occurs that is a warning sign of a seizure
“smelling, lip-smacking
what is ictus?
The episode of the seizure
Relaxation of urinary and bowel sphincters → incontinence
treatment of seizures
- Antiseizure medication
- Ketogenic diet for epilepsy
- Surgery; vagal nerve stimulation
what is the ketogenic diet?
- high in fat, moderate in protein, and low in carbohydrates
- limits water intake to avoid ketone dilution and carefully controls caloric intake
- used when seizures cannot be controlled through pharmacotherapy or when the adverse effects of an antiepileptic drug (AED) are unacceptable
- equally effective for every seizure type but not all clients respond to the diet
what is drug therapy for seizure disorders? goal
- goal of antiseizure pharmacotherapy is to suppress neuronal activity just enough to prevent abnormal or repetitive firing
- drug choice depends on the type of seizure
- drug therapy: pt is placed on an initial low dose
- amount is gradually increased until seizure control is achieve or drug side effects prevent additional increase
- if seizure activity continues, different medication in small dose increments are added while reducing the initial dose of the first drug
what are the 3 vernal mechanisms of drug therapy for seizures?
- Stimulate a influx of chloride ions → potentiates GABA (inhibitory)
- Delay an influx of sodium ions
- Delay an influx of calcium ions
what are the 3 vernal mechanisms of drug therapy for seizures?
- Stimulate a influx of chloride ions → potentiates GABA (inhibitory)
- Delay an influx of sodium ions
- Delay an influx of calcium ions
Benzodiazepines: diazepam
- Indication: Anxiety, adjunct in seizure disorders
- Mechanisms of action: binds to GABA (inhibitory) receptor-chloride channels through the CNS. Suppresses abnormal neuronal activity in the limbic system and subsequent impulses to the reticular activating system that may seizures.
- Desired effects: Decreased seizures, anxiety, restlessness
Benzodiazepines: diazepam-adverse effects
Dizziness, headache, hypotension, blurred vision, constipation, nausea & vomiting, neutropenia, respiratory depression
Gamma-aminobutyric acid (GABA) Inhibitors: valproic acid
- Indication: Seizures
- Mechanisms of action: desensitizes sodium channels in the CNS that are responsible for neuronal responsibility. Desensitization prevents the spread of disruptive electrical charges in the brain the produces seizures.
- Desired effects: Decreased symptoms of epilepsy, bipolar disorder
Gamma-aminobutyric acid (GABA) Inhibitors: valproic acid-adverse effects
sedation, drowsiness, GI upset, and prolonged bleeding time
-Other effects: visual disturbances, muscle weakness, tremor, psychomotor agitation, bone marrow suppression, weight gain, abdominal cramps, rash, alopecia, pruritus, photosensitivity, erythema multiforme, and fatal hepatotoxicity
Anticonvulsants: Succinimides: ethosuximide
- Indiciation: seizure disorders
- Mechanisms of action: delay entry of Ca++ = increase the electrical threshold and decrease neurons from firing too quickly
- Desired effects: absence of seizures
ethosuximide -adverse effects
: psychosis or extreme mood swings, depression with suicidal intent, dizziness, headache, lethargy, fatigue, ataxia, sleep pattern disturbances, attention difficulty, and hiccups
what is generalized absence seizure?
- last seconds- no change in muscle tone
- may occur over several times in a day
- appears as if they are daydreaming
- more common in children and often misdiagnosed w/ ADHD
what is tonic-clonic?
may begin w/ an aura- “I smell burnt toast” - a warning sign
tonic phase- muscle stiffness and rigidity last 10-20 seconds, followed by unconsciousness
clonic phase- hyperventilation and jerking of the extremities - last about 30 seconds
what is atonic or akinetic “drop attacks”
-sudden loss of muscle tone
what is myoclonic?
it is jerking or stiffening of the extremities
-may fall from the seizure
what is simple partial?
- produces sensory and motor symptoms localized or confirmed to an area
- remains consciousness and may result in aura
- no post-ictal phase
what is complex partial?
psychomotor seizures
- temporal lobe is most often involved
- altered behaviour of the client- loss of consciousness for a few seconds -altered behaviour in these pt’s
- has a post-ictal phase
interventions for seizures
- ensure patent airway -support airway, prepare to suction
- first thing–> make sure pt are on the floor and protecting the head and body, never restrain the pt
- side-rail are paded-
- make sure nothing is in the mouth
- preventing injury at this time, removing/loosen restrictive clothing
- assess behaviour at the onset of the seizure- the client has experienced an aura, if a change in facial expression occurs
- if client is sitting/standing plane on the floor and protect head/body
- turn client to the side to allow secretions to drain
- note type, character and progression of seizure
