Seizure disorders & anticonvulsant meds Flashcards
We understand a seizure as _____
abnormal electrical activity in a group of CNS neurons that can lead to involuntary movements and/or sensations.
Seizures can also be defined by the
characteristic changes on an
_____ they produce
Electroencephalogram (EEG)
Electroencephalography (EEG)
● Several sensitive electrodes are placed over the scalp. The tracing received during the EEG depicts the electrical activity occurring at the surface of the brain.
● EEG waves are generally classified according to their frequency, amplitude, shape, and the sites of the scalp at which they are recorded.
● This information about waveform frequency and shape is combined with the age of the patient, state of alertness or sleep, and scalp location to determine pathologic or diagnostic significance
EEG is the essential component in the
evaluation of _____
seizures and epilepsy
The diagnostic definition of Epilepsy:
○ Disorder characterized by recurrent
seizures due to a chronic underlying
process.
○ Two or more unprovoked seizures
T/F Just because someone has a seizure, does
not mean they now have the diagnosis of
Epilepsy
T
Common Triggers of Seizures at any age
■ Metabolic disturbances, hypoglycemia, hyperglycemia, significant renal or hepatic failure
■ Medications and abused substances
Common Triggers of Seizures in infancy/early childhood
■ Fever, trauma, CNS infection, congenital CNS abnormalities, metabolic disorders
Common Triggers of Seizures in childhood
■ Epilepsy syndromes, head trauma, CNS infection, rarely CNS tumor
Common Triggers of Seizures in adolescence and early adulthood
■ Head trauma, CNS infection, brain tumor, illicit drugs, alcohol
withdrawal
■ Less commonly, epileptic syndromes
Common Triggers of Seizures in older adults
■ Cerebrovascular disease (stroke), trauma, CNS tumor, neurodegenerative disorders (such as MS)
Generalized vs. focal onset seizures
● Generalized Onset Seizures:
○ Involves both hemispheres of the brain simultaneously
○ From widespread cellular, biochemical, or structural abnormalities
● Focal Onset Seizures:
○ Seizures restricted to discrete areas of the cerebral cortex
○ Usually associated with structural abnormalities
○ Frequently have a prodrome and/or aura
Generalized seizures
- Originate at some point within and rapidly engage bilaterally distributed networks
- Can include cortical and subcortical structures
but not necessarily the entire cortex
Focal seizures
- Originate within networks limited to one hemisphere
- May be discretely localized or more widely
distributed
General onset seizure - Tonic-Clonic (Grand Mal)
○ Abrupt loss of consciousness, no aura.
Types of Seizures - Generalized
○ Tonic Phase:
■ Initial phase of increased muscle tone (tonic
contractions) that lasts 10-20 sec
■ “Ictal cry” (common due to contraction of
larynx), impaired respirations, and cyanosis
○ Clonic Phase:
■ Spasms of muscle contraction and relaxation (clonic phase) that
usually lasts < 1 minute
○ Postictal unresponsiveness, bowel/bladder incontinence, and gradual recovery of consciousness.
○ Generally fatigued after the event.
○ Around 25% of epilepsy
Generalized Onset Seizures - Motor: Atonic
○ Sudden loss of postural muscle
tone lasting 1-2 seconds. Ranges
from quick head drop to collapse
(risk of head injury).
○ Brief impairment of
consciousness, no postictal
confusion.
○ About 1% of epilepsy cases
Generalized Onset Seizures - Motor: Myoclonic
○ Short episodes of muscle contractions lasting generally only a few seconds, brief jerking
of limbs.
○ Usually begin in childhood or early adulthood.
○ About 2-3% of epilepsy.
Generalized Onset Seizures - Nonmotor
● Sudden, brief lapses of consciousness, no loss of postural control, and no postictal confusion
● Begin in childhood or early adolescence, may be confused with “day
dreaming.”
Focal Onset Seizures with normal awareness
● Consciousness is fully preserved
during seizure.
● Motor, sensory, autonomic, or psychic
symptoms without alterations of
consciousness.
● Accounts for about 14% of epilepsy.
● We further classify based on which
symptom appears at the onset of a
seizure (motor or nonmotor)
Focal Onset Seizures with impaired awareness
● Focal seizure accompanied by altered consciousness, ranging from mild
confusion to what appears to be total LOC.
● Often begins with an aura, and commonly includes involuntary automatisms
(chewing, smacking of the lips, display of emotion, running, etc).
○ May or may not have convulsions
● Patient is then confused following the seizure, and full recovery of conscious
takes from a few seconds to an hour.
● Accounts for about 36% of epilepsy cases.
Focal to bilateral seizure
● This is when any type of focal seizure “generalizes” to the whole brain.
Types of Seizures - Focal Onset
○ As the impulses spread and involve
both hemispheres, they produce a
generalized seizure (often
tonic-clonic).
Epilepsy Syndromes - Examples
● West Syndrome
● Dravet Syndrome
● Genetic Febrile Seizures Plus (GEFS+)
● Myoclonic Atonic Epilepsy (Mae) - Commonly known as Doose Syndrome
● Lennox-Gastaut Syndrome (LGS)
● Epileptic Encephalopathy with Continuous Waves During Sleep (CSWS)
● Childhood Absence Epilepsy (CAE)
● Juvenile Myoclonic Epilepsy (JME)
Febrile Seizures
● Seizures in young children with febrile illness.
○ The most common neurologic disorder of infants and young children
Febrile Seizures
● It presents as brief (<15 min), generalized tonic-clonic convulsions.
● While this can be very alarming for the parents of these young babies,
reassurance can generally be provided.
● Diagnostic efforts should focus on the cause of the fever, and treating that
cause
These do not usually lead to a diagnosis of epilepsy
Febrile seizures
Febrile seizure diagnosis
● At times, a Lumbar Puncture is considered if the diagnosis is unclear.
Keep the following in mind when considered a spinal tap:
○ Strongly consider an LP in children younger than 12 months,
because signs and symptoms of bacterial meningitis can be
minimal or absent in this age group, especially if unvaccinated
○ LP should be moderately considered in children 12-18 months of
age, again, because clinical signs/symptoms of bacterial meningitis
may be subtle in this group.
○ In children older than 18 months, the decision to perform an LP
depends on the clinical suspicion of meningitis.
Management of febrile seizures
● Supportive therapy or therapeutic interventions directed at the
condition that caused the fever is the focus of management.
● Several large studies on the risk vs benefits of treating with anticonvulsant medications say “no, not necessary for most.”
○ Neither long-term or intermittent anticonvulsant therapy is indicated for children who have experienced 1 or more simple
febrile seizures.
○ However, if preventing subsequent febrile seizures is essential for the health of the child, PO Diazepam is the treatment of choice
Status Epilepticus (SE)
a life-threatening neurologic disorder that is,
essentially, an acute prolonged seizure crisis.
Status Epilepticus (SE)
● Defined as…
○ Continuous seizures or repetitive, discrete seizures, with impaired
consciousness (seizures > 5 min in duration).
