Module 8 Part 3 Seizure Disorders Flashcards
T or F seizures are most common pediatric neurological disorder
T
how are seizures caused
caused by excessive and disorderly neuronal discharges in the brain
what do the mnfts of seizures depend on?
depend on the region of the brain in which they originate
what are some mnfts of seizures
may include unconsciousness or altered consciousness; involuntary movements; changes in perception, behaviours, sensations and posture
what is the most common cause of seizures in children
febrile seizures
list the possible causes of seizures
infectious, neurological, metabolic, traumatic, or r/t ingestion of toxins
what is epilepsy
condition characterized by TWO or more unprovoked seizures and can be caused by variety of pathological processes in the brain
what should not be classified as epilepsy?
a single seizure event
what percentage of childhood seizures disappear completely?
50%
how is optimum treatment/prognosis determined for someone with seizures?
optimum Tx and prognosis require an accurate diagnosis and a determination of the cause
what is an acute symptomatic seizure?
associated with an acute insult, such as head trauma or meningitis
what are remote symptomatic seizures?
those w/o an immediate cause but with an identifiable prior brain injury such as major head trauma, meningitis, hypoxia, stroke etc
what are cryptogenic seizures
those occurring with no clear cause
idiopathic seizures are _____ in orgin
genetic
what are the 3 ways abnormal electrical discharges may arise?
- arise from central areas in the brain that affect consciousness
OR - may be restricted to one area of the cerebral cortex producing mnfts specific to that one area
OR - may begin in a localized area of cortex and spread to other portions of the brain
how does seizure activity begin?
begins with a group of neurons in the CNS that, b/c of excessive excitation and loss of inhibition, amplify their discharge simultaneously
what type of physiological stimuli stimulate normal cells in surrounding areas and distant, synaptically related cells during a seizure?
examples such as cellular dehydration, severe hypoglycemia, electrolyte imbalance, sleep deprivation, emotional stress or endocrine changes
how does a generalized seizure develop?
when the neuronal excitation from the epileptogenic focus spreads to the brain stem
what areas of the brain stem are usually affected?
midbrain and reticular formation
what are the midbrain and reticular formation known as? and what are they responsible for?
centrencephalic system and responsible for spread of the epileptic potentials
can discharges happen spontaneously in the centrencephalic system?
yes but they can also be triggered by a focal area in the cortex
what are the 3 classifications of seizures?
partial, generalized and unclassified
what are early systemic changes during a generalized seizure
tachycardia, HTN, hypergylcemia, and hypoxemia
do brief seizures produce side effects?
rarely produce significant durable side effects
in contrast, what can prolonged seizures lead to? and what is the long term cause?
lactic acidosis rhabdomyolysis, hyperkalemia, hyperthermia, and hypoglycemia and can cause LONG term neurological damage
what is a partial seizure
local onset, involve a relatively small location in the brain
what is a generalized seizure
involve both hemispheres and without local onset
what is process of Dx in a child suspected of having epilepsy
- determining whether epilepsy or seizures exist and not an alternative diagnosis
- defining the underlying cause, if possible
what Dx studies/labs may be useful for seizures
- venous lead level
- WBC count for signs of infection
- BG for hypoglycemic episodes
- serum electrolytes
- toxic screen may be done if alcohol or drug use is suspected
- lumbar puncture can confirm specific diagnosis
- CT
- MRI
- EEG
what is the MOST USEFUL Dx test and why
EEG is most useful because it confirms the presence of abn electrical discharges and provides information on the seizure type and the focus
in addition to the EEG, what would you want in along side the EEG?
EEG + thorough clinical description of pt’s behaviour during seizure episode
what are the goals of Tx for seizures?
to control seizures and to reduce their frequency and severity, discover and correct the cause when possible and the help the child live as normal a life as possible
what are the 4 Tx options for mngt of epilepsy
medication therapy, ketogenic diet, vagus nerve stimulation, and epilepsy Sx
when do people with epilepsy have seizures?
when their basal level of neuronal excitability exceeds a critical point; no event occurs if the excitability is maintained below this threshold
administration of antiepileptic medications serves to do what?
to raise the threshold and prevent seizures
main effect of antiepileptic medications?
reducing the responsiveness of normal neurons to the sudden, high-frequency nerve impulses that arise in the epileptogenic focus
when is it safe to d/c an anticonvulsant medication
if complete seizure control is maintained for 2 years with the use of an anticonvulsant and person has no risk factors
what are the risk factors
age of onset over 12, history of neonatal seizures, numerous seizures before control is achieved, and the presence of a neurological dysfunction
when does reoccurrence usually occur after discontinuing an anti seizure med
most frequently within 6 months of discontinuation
whats the benefit of a keto diet with seizures
forces body to shift from using glucose as primary energy source to using fat and the person develops state of ketosis
whats the benefit of vagus nerve stimulation
used an implantable device that reduces seizures of individuals who have not had effective control with med therapy
what is vagus nerve stimulation
its a programmable signal generator implanted in chest where electrodes tunnelled underneath the skin deliver electrical impulses to the left vagus nerve. the pt can activate the device using a magnet at the onset of a seizure
benefits of Sx for seizures
used when seizures are determined to be caused by tumour, hematoma, or other cerebral lesion
what are refractory seizures
persistence of seizures despite adequate trials of three anti-epileptic meds alone or in combination
what is status epilepticus?
continuous seizure that lasts more than 30 min or a series of seizures from which the child does not region a premorbid LOC
what medication is often used instead of IV phenytoin?
because of possible complications and drug interactions associated with IV phen.
if IV phenytoin is used, how should it be administered
via slow IV push at a rate no greater than 50mg/min
for in-hospital management, what three meds are used for status epilepticus
IV lorazepam (Ativan), midazolam or diazepam
what is mortality associated with?
with the severity and frequency of child’s seizures
what is an important nursing responsibility?
observe seizure and accurately document events
should you halt a seizure once it has begun?
NO, because it is impossible but also because it should never be attempted
when a seizure is occurring, what should the nurse do?
place child on side because it facilitates drainage and helps maintain a patent airway
what is one of the most common types of seizures
Febrile seizures
simple febrile seizures occur when?
no pre-exisiting neuro abnormalities and fever greater than 38 deg
when do simple febrile seizures resolve?
within 15 min with a return to alert mental status and no further seizure occurring within the 24hour period
complex febrile seizures occur when?
occur usually with pre-existing neuro impairment
how long do complex febrile seizures last?
lasting more than 15 min that can recur within 24hours and result in neuro deficits after the seizure
what can be used for medication with febrile seizures?
controlling seizure with IV or rectal lorazepam or diazepam and reducing temp with acetamin. or ibuprofen
what is phenytoin
anti-epileptic drug that works against partial seizures and primary generalized tonic-clonic seizures
what is the MOA of phenytoin
causes selective inhibition of sodium channels and slows recovery of sodium channels from inactive state back to active state
what are the TE of phenytoin?
used to treat all major forms of epilepsy except absence seizures
adverse effects of phenytoin
continuous back and forth movement of the eyes, sedation, ataxia, diplopia, and cognitive impairment
