Seizure Definition Flashcards
Age distribution of seizure
Bimodal with two peaks
- infants <1y (a/w febrile seizures)
- older adults >60y (a/w conditions post-stroke, dementia)
Risk of premature death amongst people with epilepsy is increased 2-3 fold; highest within first 12 months of diagnosis
What are 4 causes of epilepsy-related death?
- Sudden unexplained death in epilepsy (SUDEP)
- Status epilepticus
- Unintentional injuries (drowning, head injuries, burns)
- Suicide
What is SUDEP?
- How is it found?
- What precedes?
- Unwitnessed, sleep related
- Prone position, with evidence of recent seizure
- Preceded by convulsion, followed shortly be apnea and asystole
Risk factors for SUDEP
- Presence and frequency of generalized tonic-clonic seizures
- Nocturnal seizures
- Lack of seizure freedom
What is a seizure?
Transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain
What is epilepsy?
Disease of the brain defined by any of the following conditions:
- At least two unprovoked seizures occurring >24h apart
- One unprovoked seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years
- Diagnosis of an epilepsy syndrome
T/F
All patients with seizures have epilepsy
False
Etiologies of epilepsy
- Structural (37%)
- E.g., hippocampal sclerosis, brain tumors
- Genetic/presumed genetic (20%)
- Infectious (3%)
- Meningitis, encephalitis, neurocysticercosis (parasitic infection)
- Neurodegenerative (2%)
- Alzheimer’s dementia
- Metabolic (2%)
- Mitochondrial disorders, metabolism errors
- Unknown (36%)
What is an acute seizure?
Acute seizures are provoked seizures
- Seizures that occur due to an immediately recognizable stimulus or cause, with close timely association ~1 week to the acute brain insult
What are some causes of an acute seizure?
- Metabolic
- Hypoglycemia (~24h)
- Hyponatremia (e.g., thiazide diuretic), hypocalcemia, hypomagnesemia
- High urea
- Toxic
- Illicit drug use (cocaine, amphetamines)
- Alcohol (withdrawal, intoxication, delirium tremens)
- Benzodiazepine (withdrawal, need to taper gradually)
- Drugs that lower seizure threshold (e.g., TCA, carbapenems, baclofen)
- Structural
- Acute traumatic brain injury/lesion
- Stroke
- Infection/inflammation
- CNS infection - meningitis, encephalitis
Does acute seizure require treatment?
- May be sufficient to just address the cause of seizure (treat seizure provoking factors)
- If tx needed, short-term is sufficient (e.g., short term benzodiazepines)
What is a remote seizure?
Remote seizure is an unprovoked seizure
- Seizures that occur longer than 1 week following a disorder that is known to increase the risk of developing epilepsy
- E.g., a seizure that occurs 6 months after a traumatic brain injury or stroke
What is an unprovoked seizure?
Seizures occurring in the absence of a potentially responsible clinical condition or beyond the interval estimated for the occurrence of acute symptomatic seizures
Consists of cryptogenic seizures and symptomatic remote seizures
FYI:
Cryptogenic seizure - unknown etiology, not a/w previous CNS insult
What is a non-epileptic event?
Abnormal paroxysmal psychic, sensory, and/or motor manifestations which resemble (at least in part) to epileptic seizures, but are not related to abnormal epileptiform discharges in the brain
NO NEUROLOGICAL ORIGIN, EEG is normal
non-epileptic seizures will not be characterized as tonic, clonic etc.
Describe psychogenic non-epileptic seizures (PNES)
- Partial alteration of level of consciousness, partial preservation of awareness
- Caused by stressful psychological experiences or emotional trauma
- Involuntary (caused by stressors)
- Involvement of psychologist and psychotherapy
