seizures / epilepsy / convulsions Flashcards
WHAT IS STATUS epilepticus ?
seizures lasting for >30min, or repeated seizures without intervening
consciousness. Mortality and the risk of permanent brain damage increase with the
length of attack
time threshold after which a seizure is considered SE differs according to the type of a seizure:
≥ 5 minutes for tonic-clonic seizures
≥ 10 minutes for focal seizures with impaired consciousness
10–15 minutes for absence seizures
what is the difference between seizure , epilepsy and convulsion?
seizure - abnormal electrical discharge in your brain
single seizure doesn’t mean you have epilepsy
Epilepsy is defined as having chronic seizures
characterized by a predisposition to seizures
convulsion - general term that people use to describe uncontrollable muscle contractions
Not all seizures are characterized by convulsions. if you have a seizure you can simply feel confused without a physical reaction
for epilepsy to be diagnosed what needs to be demonstrated ?
Two or more unprovoked or reflex seizures separated by more than 24 hours
or
unprovoked or reflex seizure in an individual with a high risk of subsequent seizures (e.g., after traumatic brain injury, stroke, CNS infections)
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A single seizure or multiple provoked or triggered seizures (e.g., febrile seizures) without an underlying predisposition to seizures do not suffice for the diagnosis of epilepsy.
what is the aetiology of seizures ?
Seizure triggers are stimuli that can precipitate seizures both in people with and without epilepsy.
Excessive physical exertion Alcohol consumption Fever (febrile seizures) Sleep deprivation Flashing lights (e.g., strobe lights, video games) Music Hormonal changes - after menopause
etiology of epilepsy ?
genetic
Genetic mutations affecting ion channels or transmitter receptors
Chromosomal abnormalities (e.g., Angelman syndrome, Prader-Willi syndrome, Rett syndrome)
Genetic metabolic disorders (e.g., PKU !!!!, congenital disorders of glycosylation, lysosomal storage diseases,
Mitochondrial diseases (e.g., MELAS)
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structural - cerebral lesion or abnormality
Perinatal injury, e.g., hypoxic-ischemic injury Brain tumors and metastases Traumatic brain injury (TBI) Hippocampal sclerosis Tuberous sclerosis
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Metabolic
Inborn errors of metabolism - PKU
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Immune: autoimmune encephalitides
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Infectious: chronic CNS infection (e.g., toxoplasmosis, malaria, neurocysticercosis) or complication of acute CNS infection
what is the classification of seizure according to location
1) location of abnormal activity
focal - Originates within the networks of a single hemisphere
Generalized - Originates from both hemispheres
Unknown
Focal to bilateral tonic-clonic: focal progresses to a tonic-clonic pattern (characteristic of bilateral brain involvement)
what are the different types of seizures according to clinical manfestation ?
Simple partial (focal)
no loss of consciousness
seizures or ‘auras’
“rising” feeling in your tummy – like the sensation in your stomach when on a fairground ride
can be motor - jerking movements of a foot, the face, an arm or another part of the body
sensory - hearing problems, hallucinations
unusual smells or tastes
Autonomic : may cause changes in blood pressure, heart rhythm, or bowel or bladder function
psychic
a feeling that events have happened before (déjà vu)
tingling in your arms and legs
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Complex partial (focal) seizures lose your sense of awareness and make random body movements, automatisms such as: smacking your lips rubbing your hands making random noises (grunting shouting) moving your arms around unresponive and have no memory of it
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Tonic-clonic seizures
happen in 2 stages
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Absence
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Myoclonic seizures
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Clonic seizures
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Tonic seizures
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Atonic seizures
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febrile seizures
what are the different types of epilepsy ?
Reflex epilepsy
Epilepsy in which seizures are consistently provoked by a certain trigger (e.g., lights, music, hormonal changes during menstrual cycle). Subtypes can be determined based on the trigger and include:
Photosensitive epilepsy
Musicogenic epilepsy
Catamenial epilepsy
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Drug-resistant epilepsy: epilepsy in which at least two antiepileptic drugs have failed to prevent seizures
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Resolved epilepsy
age‐dependent epilepsy syndrome that has not recurred in individuals who are now past the applicable age.
Under generalised onset seizures what are the common symptoms of all the types of seizures
Symptoms are produced by bilateral cerebral cortex disturbances.
Start with loss of consciousness.
Patients do not recall the seizure.
Aura is uncommon
clinical manifestation of Tonic-clonic seizure (grand mal) ?
ICTAL
Prodromal symptoms
sleep disturbances, lightheadedness, mood changes, anxiety/irritability, impaired concentration
Loss of consciousness (sudden and without warning)
Motor symptoms
1) Tonic phase
Generalized muscle contraction: muscles go stiff
!! ROTATED EYES, APNEA, LATERAL TONGUE BITING !!
pooled oral secretions, cyanosis,
Increased sympathetic tone: dilated, unresponsive pupils,
↑ heart rate,
↑ blood pressure
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Clonic phase: rhythmic muscle twitching
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Bladder or bowel incontinence
Usually lasts 1–3 minutes
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POST - ICTAL
Unresponsiveness - last a few seconds or up to an hour
Confusion Amnesia of the event Aphasia Fatigue Muscular flaccidity and muscle pain
clinical manifestation of clonic seizure ?
ICTAL
Loss of consciousness - if general
Bilateral rhythmic jerking (of the entire body or only a part)
typically lasts a few minutes
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post - ictal
Amnesia of the event
Under generalised motor seizures, what are the clinical manifestation of tonic seizure ?
ICTAL
Often occurs when the patient is drowsy, asleep, or after waking
Loss of consciousness
Muscle stiffening (extension or flexion of the head, trunk, and/or extremities)
can be bilateral or unilateral
Can be accompanied by
autonomic symptoms (e.g., tachycardia, flushing)
This might mean you lose balance and fall over
Can be followed by atypical absence seizure
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POST ICTAL
Amnesia of the event
Drowsiness or confusion may occur
Under generalised motor seizures, what are the clinical manifestation of myoclonic seizure ?
Positive myoclonus: sudden jerk-like muscle twitching
Negative myoclonus: a brief loss of muscle activity during tonic contraction of a muscle
can affect the entire body or only a part.
Myoclonic seizures
often happen soon after waking up.
normally remain awake during them
only last a fraction of a second, but several can sometimes occur in a short space of time.
are nonrhythmic (i.e., jerks occur at different intervals) and irregular (i.e., jerks are asymmetric and may change laterality)
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post ictal
amnesia
Under generalised motor seizures, what are the clinical manifestation of
1) myoclonic - atonic seizure ?
2) Myoclonic-tonic seizure?
3) Atonic seizure (also known as “drop seizure” or “drop attack”?
ICTAL
1) Myoclonus followed by a brief loss of tone
2) Myoclonus followed by a brief increase in tone
3) Sudden loss of muscle tone: sudden head drop or collapse (lasts < 15 seconds)
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post ictal
amnesia
clinical manifestation of Typical Generalized nonmotor seizure (absence seizure)
Sudden onset and stop
They mainly affect children
you lose awareness of your surroundings for a short time.
stare blankly into space
look like they’re “daydreaming”
blank stare, unresponsiveness
with sudden stop in motion
Subtle automatisms (often go unnoticed): lip-smacking, eye fluttering, or head nodding are common.
may fall to the ground.
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Can occur several hundred times a day and usually lasts < 10 seconds
tend to be very brief and They can happen several times a day.
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post ictal
awareness returns rapidly, without any impairment
Amnesia is common
