Lecture 1-seizures Flashcards
seizure definition
A sudden, excessive electrical discharge in the brain characterized by a variety of
symptoms, including uncontrolled
movements of the body, disorientation,
confusion, or loss of consciousness.
epilepsy definition
condition in which a person has recurrent
seizures due to a chronic, underlying process.
– At least 2-3 seizures w/o clear precipitatingfactors.
– Epilepsy may be considered a “syndrome”
consisting of several events (seizures).
• A person with a single seizure, or a recurrent seizure due to a correctable circumstance
does not necessarily have “epilepsy.”
Seizure etiologies
Trauma: birth trauma (hypoxia), head injury
• Congenital defects
• Metabolic: hypoglycemia, hyponatremia, hypo- or hypercalcemia, uremia, Reye’s syndrome.
• Infection: meningitis, encephalitis, abscess
• Drugs: theophylline, lidocaine, cocaine, etc.
• Drug w/drawal: EtOH, narcotics, anxiolytics, anticonvulsants, steroids.
• Other toxins: lead, organic phosphates, etc.
Neoplasia: primary and metastatic lesions.
• Vascular: CVA (ischemia vs. hemorrhage),
arteritis, sickle cell disease, hypertension, A-V malformation.
• Degenerative neurologic disease
• Childhood febrile seizures
– 3-5% of normal children.
ictal
during the seizure
interictal
between seizures
postictal
after the seizure
repetitive flexion/extension movements
clonic
rigid posturing/continuous muscle tension
tonic
tonic/clonic
combo of tonic and clonic movements
factors that lower the seizure threshold making seizures more likely
epileptogenic
having characteristic seizure activity (spiking) on EEG
epileptiform
types of partial seizures
simple partial
complex partial
partial with secondarily generalized
types of generalized seizures
generalized tonic-clonic absence tonic atonic myoclonic
arise from a focal area of the brain and progress in a manner consistent with the area of irritation (what type of seizure is this)
partial seizure
do simple partial seizures have alteration of consciousness?
no; patient is able to interact with others and remember the event
do complex partial seizures have alterations in consciousness?
yes; impaired consciousness; unable to respond to visual or verbal commands; reduced awareness in postictal period
what type of seizure can become secondarily generalized
complex parial
SPS (simple partial seizure) motor symptoms
start in motor cortex, can be a twitch or include jacksonian march or todds paralysis
clonic movements starting in hand or foot and progressing to involve whole limb (seizure type?)
jacksonian march (SPS)
paralysis that lasts minutes to hours (cant move arm/leg; may be mistaken for stroke) seizure type?
todds paralysis (SPS)
SPS sensory cortex symptoms
parathesias, numbness, tingling of arm, face etc.
SPS temporal lobe symptoms
deja vu, epigastric discomfort
SPS occipital lobe symptoms
flashing lights, visual changes
CPS (complex partial seizure) clinical picture
Combination of focal motor and focal sensoryactivity, with alteration of consciousness.
(also called “psychomotor seizures”)
• May exhibit bizarre behavior.
• Exaggerated emotions.
• Episodic fluctuations in attitude, attention, behavior, and memory.
• Epigastric and abdominal sensations.
CPS seizure progression
Seizure may begin with an aura.
• Ictal phase
– Sudden behavioral arrest or motionless stare.
– Automatisms: involuntary, automatic behaviors, eg. chewing, lip smacking, swallowing, hand movements, emotionaloutburst, running, etc.
• Postictal: confusion, amnesia
Bilateral generalized electrical discharge arising from both cerebral hemispheres simultaneously (seizure type?)
Generalized
Absence or petit mal seizure clinical picture
Characterized by sudden brief loss of consciousness without loss of postural control.
– Lasts only a few seconds.
– Consciousness returns promptly.
– No postictal confusion.
– automatisms
– May be confused with “daydreaming.”
Almost always begin in childhood or early adolescence.
• Person is “absent” to higher cortical function during the attack.
• May occur hundreds of times per day!
Characteristic EEG pattern for absence seizures
generalized spike and wave pattern
main seizure type in 10% of people with epilepsy
Generalized Tonic-Clonic
most common seizure type due to metabolic problems
generalized tonic-clonic
GTC (generalized tonic clonic) typical presentation
Usually begins abruptly, w/o warning.
• Occasional promonitory signs beforehand.
-sudden LOC, falls to ground, has tonic then clonic, then postictal phase
Tonic Phase of GTC
– Tonic phase (lasts 10-40 sec):
• generalized tonic contractions - body rigid; jaw clenched; loud moan or cry; eyes roll back.
• Increased BP, HR, pupil size; cyanosis.
Clonic phase of GTC
– Clonic phase (30 sec to 3 min):
• Muscle groups relax & contract; jerky movements.
• May froth at the mouth; lose bowel/bladder control.
Postictal phase of GTC
Postictal phase (minutes to hours): • confused, sleepy; c/o HA, body ache; amnesia.
Continuous seizures, or recurrence without regaining consciousness is called (seizure type?)
status epilepticus
automatisms
Accompanied by subtle, bilateral motor
signs such as rapid eye-blinking, chewing, slight rapid movements of hands (automatisms).
status epilepticus is a medical emergency bc it can lead to:
cardiorespiratory dysfunction
• metabolic derangements
• hyperthermia
• irreversible brain damage after 2 hours.
what do status epilepticus seizures look like as they continue?
Seizures can be more subtle as they last longer. Beware continued
unresponsiveness.
Sudden, brief generalized muscular contraction, of limbs and trunk. (seizure type)
generalized myoclonic
causes of generalized myoclonic seizures
- metabolic disorders
- degenerative CNS diseases
- anoxic brain injury
benign form of myoclonus (localized or generalized)
sudden jerking movements experienced by some normal people as they are falling asleep.
atonic seizure clinical picture
Sudden loss of postural tone lasting 1-2 seconds.
– Consciousness briefly impaired.
– No postictal confusion.
– May cause brief drop of head or nodding mvmt.
longer atonic seizures will result in
falls to the ground
what seizure type is usually associated with other forms of epilepsy?
atonic seizures
where do you look for injuries that may have occured during a seizure?
Scalp, tongue, neck, back, extremities.
while obtaining a history from a pt that had a seizure what is really important?
talking to someone that witnessed an event
labs to order for a seizure patient?
- CBC, U/A
• Comprehensive metabolic panel (CMP): glucose, electrolytes, Ca++, renal & liver tests. - Serum magnesium
- Toxicology screen
– prescription & illicit drugs
– drug levels (eg. theophylline, anticonvulsants) - Serology - syphilis screen
all new onset seizure patients need
imaging studies: cranial CT, MRI, CXR
Key diagnostic test for seizures
EEG
specialized test that may be needed in patients with refractory seizures
PET or SPECT
acute seizure treatment
ABC’s: Airway, Breathing, Circulation
– Do not try to put anything in patient’s mouth.– Turn patient on side; protect head from injury.
Status epilepticus treatment
- I.V. access--anticonvulsant I.V. – 50% Glucose (50cc). - Narcotic antagonist? - Thiamine 100mg i.v. – Review STAT lab work. - Cardiac monitoring
IV anticonvulsant used for status epileticus
IV lorazepam/diazepam or iv phosphenytoin or phenytoin: loading dose followed by continuous infusion
if seizure persists: phenobarbital IV/ midazolam infusion
Chronic epilepsy treatment
Treat underlying condition.
- Avoid precipitating factors (video games, stress, sleep deprivation)
- Antiepileptic Drug Therapy (AED Tx).
- Neurologist consultation (suggested for most cases of epilepsy)
- Counseling re: driving, vocational issues, and depression.
anti-epileptic drug therapy general considerations
- Antiepileptic drugs of choice for each type of seizure disorder
- AED Therapy is almost ALWAYS started with a SINGLE DRUG, titrated upwards.
- Follow blood levels to keep in therapeutic
range.
• Patient education is CRUCIAL - to promote compliance with regular use of AED’s.
• Be alert to potential drug interactions.
myoclonic/atonic seizure first line drug
valproic acid
focal onset seizures first line drugs
- carbamazepine
- phenytoin
- valproic acid
GTC first line drugs
- valproic acid
- carbamazepine
- phenytoin
absence seizure first line drugs
- ethosuximab
- valproic acid
% of epileptic patients resistant to medical tx
20%
refractory epilepsy tx options
- surgery: temporal lobectomy, lesionectomy, corpus callosotomy
- Vagal nerve stimulation
temporal lobectomy outcomes
70% seizure-free and 15-25% have 90% reduction in
seizures.
Vagal nerve stimulation
pacemaker like device for partial seizures
