Neuro Emergencies: Seizures Flashcards
Acute Symptomatic Seizures can occur from the following?
Head Trauma
Brain Tumors
Intracranial Infection
Congenital brain malformations
Hypo/hyperglycemic
Hyper/hyponatremia
Hypocalcemia
Hypomagnesemia
Withdrawal states
Hypoxic brain injury
Stroke
Vascular malformations
Eclampsia
Hypertensive encephalopathy
Hyperthyroidism
Toxic/metabolic
AED non-compliance
Differential Diagnosis for seizure like symptoms
Syncope
Tremors
Rigors
Nonepileptic seizures
Dyskinesia
TIA
Types of Generalized Seizures
Convulsive
Absence
Tonic
Atonic
Myoclonic
Types of Generalized Absence Seizures
Typical
Myoclonic Absence
With eyelid myoclonia
Atypical
Types of Generalized Myoclonic Seizures
Negative Myoclonus
Myoclonic-Atonic
A generalized seizure is conceptualized as originating at some point within, and rapidly engaging, bilaterally distributed networks
Can include cortical and subcortical structures, but do not necessarily include the entire cortex
Although individual seizure onsets can appear localized, the location and lateralization are not consistent from one seizure to another
Can be asymmetric
What type of Seizure?
Generalized
Typically bilateral and symmetric although variants with asymmetry including head and eye deviation can be seen
A tonic clonic seizure is a seizure consisting of a tonic and a clonic phase, typically in this order, however variations such as clonic-tonic-clonic are also seen
A clonic seizure is a seizure involving bilaterally rhythmic jerking and may occur alone or in combination with tonic activity where there is bilaterally increased tone of the limbs typically lasting seconds to a minute
The jerking in a clonic seizure is more sustained and rhythmic than seen in a myoclonic seizure
What type of Seizure?
convulsive
Seizure is a generalized seizure with abrupt onset and offset of altered awareness which can vary in severity
Memory for events during the seizures is usually impaired although there may be some retained awareness particularly for adolescents
Clonic movements of eyelids, head, eyebrows, chin, perioral or other facial parts may occur
Myoclonus of limbs can rarely occur
Oral and manual automatisms are common and there may be perseveration of behaviors occurring prior to seizure onset
Absence seizures were previously known as ‘petit mal’ seizures
Absence status epilepticus can occur
What type of Absence Seizure?
Typical
Rhythmic myoclonic jerks of the shoulders and arms with tonic abduction that results in progressive lifting of the arms during the seizure
The myoclonic jerks are typically bilateral but may be unilateral or asymmetric
Perioral myoclonias and rhythmic jerks of the head and legs may occur
Seizures last 10-60 seconds and typically occur daily
Level of awareness varies from complete loss of awareness to retained awareness
What type of Absence Seizure?
Myoclonic Absence Seizure
Absence seizures accompanied by brief, repetitive, often rhythmic, fast (4-6 Hz) myoclonic jerks of the eyelids with simultaneous upward deviation of the eyeballs and extension of the head
Seizures are typically very brief (<6s in duration) and multiple seizures occur on a daily basis
Mostly awareness is retained
What type of Absence Seizure?
Absence with eyelid myoclonia seizure
Seizure has less abrupt onset and offset of loss of awareness than typical absence seizures
They are often associated with other features such as loss of muscle tone of the head, trunk or limbs (often a gradual slump) and subtle myoclonic jerks
Often occur in individuals with intellectual impairment
The loss of awareness may be minimal with the patient continuing an activity, but more slowly or with mistakes
What type of Absence Seizure?
Absence Atypical Seizure
Involves bilaterally increased tone of the limbs typically lasting seconds to a minute
They often occur out of sleep and in runs of varying intensity of tonic stiffening
The individual is unaware during these events
At the beginning with more intense stiffening, individuals may make an expiratory sound
More severe and prolonged seizures may have a vibratory component which may be confused with clonic jerking
Often occur in individuals with intellectual impairment
What type of seizure?
Tonic Seizure
Involves sudden loss or diminution of muscle tone without apparent preceding myoclonic or tonic features
Very brief (<2 seconds) and may involve the head, trunk or limbs
Often occur in individuals with intellectual impairment
What type of seizure?
Atonic Seizure
A single or series of jerks (brief muscle contractions)
Each jerk is typically milliseconds in duration
Status epilepticus of this type is characterized by ongoing (> 30 minutes) irregular jerking, often with partially retained awareness
What type of Seizure?
Myoclonic Seizure
Is a seizure with brief cessation of background muscle tone, lasting less than 500 milliseconds
The resulting movement produced can have two components, an initial loss of posture caused by the negative myoclonus, and a subsequent voluntary, compensatory movement to restore posture
May occur in isolation or in a series
What type of Seizure?
Negative Myoclonic Seizure
Is a myoclonic seizure followed by an atonic seizure
Sometimes a series of myoclonic jerks occurs prior to the atonia
The head and limbs are affected, typically resulting in rapid fall
The myoclonic jerk may be subtle
Myoclonic-Atonic Seizure
Focal Seizure features include
Aura
Motor
Autonomic
Dyscognitive
Focal seizures are conceptualized as originating within
networks limited to one hemisphere
Focal Seizures distribution may be?
discretely localized or more widely distributed
Focal seizures may originate in
subcortical structures
Focal Seizuers
For each seizure type, ictal onset is what?
with preferential propagation patterns that can involve what?
consistent from one seizure to another
the ipsilateral and/or contralateral hemisphere
Focal seizures can be described by their
semiology (features)
The features that occur may reflect the regional networks involved what?
often enabling what?
in the seizure origin or propagation
these areas of the brain to be identified
Some features allow identification of what?
others allow identification of what?
the hemisphere involved
the discrete area of the brain (for example a lobe) that is involved
Auras are subjective and may be?
sensory or experiential
Auras reflect the initial what?
seizure discharge
An aura may be an isolated phenomenon or progress to a focal seizure with
objective features (with or without altered awareness) or to a bilateral convulsion
An aura is also known as a?
Warning
A sensory aura involves what?
A sensation w/o an objective clinical sign
Characterized by sensory phenomena including tingling, numbness, electric-shock like sensation, pain, sense of movement, or desire to move
occur in seizures involving the sensorimotor cortex
Somatosensory Aura
Characterized by elementary visual hallucinations such as flashing or flickering lights, spots or other shapes, simple patterns, scotomata, or amaurosis
More complex hallucinations such as seeing formed images are considered experiential aura.
Occur in seizures involving the occipital lobe, and are often colored in nature
Visual Aura
Characterized by elementary auditory phenomena including buzzing, ringing, drumming or single tones
More complex hallucinations such as voices are considered experiential seizures
Occur in seizures involving auditory cortex in the lateral superior temporal lobe
Auditory Aura
Characterized by phenomena - usually an odor, which is often unpleasant
Occur in seizures involving the mesial temporal or orbitofrontal regions
Olfactory Aura
Characterized by taste phenomena including acidic, bitter, salty, sweet, or metallic tastes
Occur in seizures involving the parietal operculum and the insula
Gustatory Aura
Characterized by upper abdominal phenomena including discomfort, emptiness, tightness, churning and a sensation that may rise up to the chest or throat
Occur in seizures involving the mesial temporal lobe
Epigastric Aura
Characterized by a sensation in the head such as light-headedness or headache
Cephalic Aura
An experiential aura involves affective, mnemonic (memory) or perceptual subjective phenomena including depersonalization and hallucinatory events; these may appear alone or in combination Experiential aura include the following types
Affective
Mnemonic
Hallucinatory
Illusory
Characterized by phenomena such as fear, depression, joy and anger.
Affective Aura
Characterized by memory phenomena such as feelings of familiarity (déjà vu) and unfamiliarity (jamais vu)
Mnemonic Aura
Characterized by imagined complex sensory phenomena that may involve visual (e.g. formed images), auditory (e.g. hearing voices) or other sensory modalities, without change in awareness
The sensory phenomena may be accompanied by associated emotion or interpretation e.g. may be experienced as persecutory
Hallucinatory Aura
Characterized by an alteration of actual perception involving visual, auditory, somatosensory, olfactory, and/or gustatory phenomena, without change in awareness
Illusory Aura
A motor feature involves motor activity and may consist of
Motor features may be?
an increase (positive) or decrease (negative) in muscle contraction
elementary or complex
Involves a stereotyped contraction of a muscle or group of muscles. Such motor features may be predominantly convulsive (e.g. hemiclonic), myoclonic, tonic, epileptic spasm, versive or dystonic.
Elementary Motor
rhythmic jerking (clonic activity) that may occur alone or in combination with tonic activity
Convulsive Motor
a single or short cluster of brief muscle contractions (jerks)
Myoclonic Motor
increased muscle tone
Tonic Motor
sudden flexion, extension or mixed flexion-extension of proximal truncal muscles, lasting 1-2 seconds, typically occurs in a series
Epileptic spasm Motor
sustained, forced conjugate ocular, cephalic, and/or truncal rotation or lateral deviation from the midline
Versive Motor
sustained contractions of both agonist and antagonist muscles producing athetoid or twisting movements, may produce abnormal postures
Dystonic
involves complex movement patterns. Three types are recognized, hypermotor, negative motor and automatism.
Complex motor feature
Involves proximal limb or axial muscles, producing irregular large amplitude ballistic movements, such as pedaling, pelvic thrusting, jumping, thrashing and/or rocking movements
Hypermotor
Characterized by reduced motor activity
Negative Motor
Coordinated, repetitive motor activity usually occurring when cognition is impaired and for which the subject is usually amnesic afterward. This often resembles a voluntary movement and may consist of an inappropriate continuation of pre-ictal motor activity.
Automatism
Automatism
Lip smacking, lip pursing, chewing, swallowing, clicking
Oroalimentary
Automatism
Bilateral or unilateral distal or proximal movements, including fumbling, tapping, manipulating movements of hands or feet
Manual or pedal
Automatism
Often unilateral, fumbling or exploratory movements with the hand intended to lend emotional tone to communication
Gestural
Automatism
Bursts of laughter or giggling, usually without appropriate affective tone and described as ‘mirthless’
This is characteristic of seizures arising in the hypothalamus, but can occur in seizures arising in the frontal or temporal lobes
Gelastic
Automatism
Single or repetitive sounds such as shrieks or grunts
Vocal
Automatism
Single or repetitive words, phrases or brief sentences
Verbal
Automatism
Outbursts of crying
Dacrystic
Characterized by phenomena, which can involve cardiovascular, gastrointestinal, vasomotor, and thermoregulatory functions
Examples include palpitations, nausea, butterflies, hunger, chest pain, urge to urinate or defecate, goosebumps, sexual sensation, feeling hot or cold, pilo-erection, pallor, tachycardia or bradycardia/asystole, flushing, pupillary changes and lacrimation
What type of Focal Seizure Feature?
Autonomic
Involves altered awareness or responsiveness
Degree of loss of awareness or responsiveness may vary
What type of Focal Seizure Feature?
Dyscognitive
Old Guideline International League Against Epilepsy classification of seizures:
Consciousness is not impaired
Only part of the cortex is disrupted by the seizure
Simple Partial Seizures
Old Guideline International League Against Epilepsy classification of seizures:
Abrupt loss of consciousness
May stare or engage in repetitive behaviors
Complex Partial Seizures
Old Guideline International League Against Epilepsy classification of seizures:
Usually occur in childhood
Frequently occur in clusters
Sudden staring with impaired LOC
May have eye blinking or lip smacking
Absence or petit mal
Old Guideline International League Against Epilepsy classification of seizures:
AKA Grand Mal seizure
Abrupt loss of consciousness
Muscles become stiff followed by jerking and twitching
Generalized tonic-clonic seizures
Old Guideline International League Against Epilepsy classification of seizures:
Rhythmical jerking muscle contractions
Usually involve the arms, neck and face
Clonic Seizures
Old Guideline International League Against Epilepsy classification of seizures:
Sudden brief muscle contractions
Occur singly or in clusters
Consciousness usually not impaired
Myoclonic seizures
Old Guideline International League Against Epilepsy classification of seizures:
Sudden muscle stiffening (falling to ground)
Impaired LOC
Tonic Seizures
Old Guideline International League Against Epilepsy classification of seizures:
Sudden loss of control of the muscles
Usually of the legs
Atonic Seizures
Period following the seizure
Recovery period for the brain
May last minutes to hours
Postictal State
History Taking for Diagnostic purposes, ask about?
Epilepsy
Recently d/c’d meds
recreational drug use
precipitating events
aura
seizures semiology
incontinence
tongue biting
post ictal state
Physical Exam for Diagnostic purposes, look for?
Post ictal paresis
eye deviation
fluctuating LOC
Observe for s/sx of NCSE
Diagnostic Tests that should be completed?
EEG
LP
Imaging that should be completed?
CT or MRI
Laboratory studies that should be completed?
Blood glucose
BMP
Mg
Phos
CBC
UA
UDS
AED levels
Laboratory studies specific to LP that should be completed?
Cell count
glucose
protein
cultures
Predisposing factors for status epilepticus include?
AED noncompliance
Withdrawal Syndromes
Acute structural injury
Metabolic abnormalities
Drugs
Anoxia
Status Epilepticus is defined as?
5 min or more of continuous clinical and/or electrographic seizure activity.
Repetitive seizures without return to baseline between seizures
Most seizures stop within a few minutes
Any seizure lasting > 5 minutes likely to evolve to what?
Status Epilepticus
Classification of Status Epilepticus
Convulsions that are associated with rhythmic jerking of the extremities
Convulsive
Classification of Status Epilepticus
“Wandering confused” patient
Acutely ill patient with severely impaired MS with or without subtle movements
Non-convulsive
Classification of Status Epilepticus
Status Epilepticus that has not responded to a Benzo and 1 AED
Refractory SE
Classification of Status Epilepticus
Failed secondary treatment
Anesthetic is usually required
Super Refractory SE
Lactic acidosis is what in SE?
And usually is resolved how?
common early
spontaneously once seizures are treated
Intubation usually required more due to?
toxicity of therapies administered to control seizures than due to ongoing seizures themselves
Alternatives to help keep airway patent?
Monitor what?
Oral or nasal airways
Sats, BP, and HR
Avoid what in SE management?
long-acting paralytics
What should always be checked with SE?
blood glucose
Emergent Medications
Benzodiazepines that can be used/dose?
Lorazepam 0.1 mg/kg IV
Diazepam 0.15mg/kg IV (can be given PR)
Midazolam 0.2 mg/kg IM (up to 10 mg) (can be given buccal or intranasal)
Emergent Medications
Fosphenytoin
Dose?
Check what?
Advantage?
Disadvantage?
20 mg/kg IV (at no more than 50 mg/min)
Check post-load level and consider additional bolus
No respiratory depression
CV instability (bradycardia, hypotension)
Emergent Medications
Valproic Acid
Dose?
Useful if? (4)
Can be?
20-40 mg/kg IV (may give additional 20mg/kg)
Patient allergic to phenytoin and/or phenobarbital
High risk for CV instability (old, hypotensive, CVD)
Already taking VPA with sub-therapeutic levels
Generalized (or myoclonic) epilepsy
Hepatotoxic
Emergent Medications
Levetiracetam
Dose?
Useful if? (4)
30-60 mg/kg IV initial load (max dose 4500 mg)
Patient allergic to phenytoin and/or phenobarbital
High risk for CV instability (old, hypotensive, CVD)
Already taking phenytoin with therapeutic levels
Minimal drug interactions
Emergent Medications
Phenobarbital
Dose?
Disadvantage?
20 mg/kg IV (may give additional 5-10 mg/kg)
Respiratory depression and hypotension
Continuous infusions for RSE/SRSE
Midazolam
load with?
maintenance?
Re-bolus prior to?
Goal of therapy?
Higher doses may induce?
0.2-0.4mg/kg
0.1-3mg/kg/hr
increasing
seizure cessation
Burst suppression
Continuous infusions for RSE/SRSE
Propofol
Load with?
maintenance?
Titrate how?
Concern for?
1-2mg/kg bolus
1-10 mcg/kg/min
up quickly
Propofol infusion syndrome
Continuous infusions for RSE/SRSE
Ketamine
Load with?
Maintenance?
1-2 mg/kg IV
1-10 mg/kg/hr
Continuous infusions for RSE/SRSE
Pentobarbital
Load with?
Maintenance?
Half-life is approx.?
5mg/kg
1-10 mg/kg/hr
20 hrs
When to use continuous EEG
Recent clinical seizure or SE without return to baseline
Any patient in RSE on continuous drips
While weaning drips
Coma, including post cardiac arrest
Epileptiform activity (PLEDs or GPEDs) on initial EEG
Intracranial Hemorrhage (ICH, SAH, TBI)
Suspected NCSE in patients with AMS
Cessation of non-convulsive seizures
What % of pts remain unresponsive after successful cessation of convulsive SE still in SE?
14%
Why should we use EEG for pts in RSE on continuous gtt?
Allows titration to goal
When can continuous EEG be discontinued?
if off all anesthetics and no seizures for 24-48 hours
How to periodically reassess?
Spot EEG
What % of comatose patients, including post cardiac arrest, have NCSE?
20-60%
What % of patients with epileptiform activity (PLEDs or GPEDs) are at risk for NCSE?
40-60%
Duration of therapy for SE
Continue achieved target (seizure control or burst-suppression) for?
Wean infusions over? and observe EEG closely for?
Optimize what?
Success =?
24-48hrs
12-24 hrs; recurrence of seizures
underlying maintenance regimen
off gtts and seizure free > 24 hrs
