Does a seizure always equal epilepsy?
A seizure does not always equal epilepsy, yet epilepsy always equals seizures.
A single seizure or recurrent seizures due to correctable or avoidable circumstances dose not necessarily have epilepsy
A seizure is a single entity
Epilepsy: a condition which a person has recurrent seizures due to a chronic underlying process
Epilepsy is a clinical phenomenon
Paroxysmal event secondary to abnormal excessive or synchronous neuronal activity in the brain.
Depends on distribution of discharges (seizures manifests in various ways)
What percent of population will have at least one seizure?
5 - 10%
Factors that influence incidence and prevalence of seizures?
- 1. Fever
- 2. CNS infection
- 3. Head trauma
- 4. Drugs
What is Epilepsy?
- Chronic disorder with recurrent unprovoked seizures
- -2 or more unprovoked seizures separated by 24 hrs
What is the estimated new diagnosed cases of epilepsy?
What % of population has epilepsy?
125,000 new cases diagnosed
1% of general population has epilepsy
What is the distribution of Epilepsy?
- 1. First peak in newborns and young children
- 2. Second peak in patients >65 yrs old
What are epileptic Syndromes?
Syndromes which epilepsy is predominant feature and there is sufficient evidence to suggest a common underlying mechanism
What are examples of Epilepsy Syndromes?
- Juvenile Myoclonic Epilepsy
- Lennox-Gastaut Syndrome
- Lesial Temporal Lobe Epilepsy Syndrome
Causes of Seizures and Epilepsy
- -result of shift in the normal balance of excitation and inhibition within the CNS
- -intricacy of the nervous system with numerous properties that control balance
- -result from a dynamic interplay between endogenous factors, epileptogenic factors, and precipitating factors
- -Definitive mechanisms remains rudimentary
What are some specific causes of seizures/epilepsy?
- Other disease states
The most important factor in determining incidence of seizures/epilepsy
- 1. Late infancy/early childhood- Febrile seizures
- -prevalence 3-5%
- -Occur 3 months and 5 years with peak incidence 18-24 months
- 2. Childhood: age at which many of the well-defined epilepsy syndromes present
- 3. Adolescence/early adulthood:Epilepsies secondary to acquired CNS lesions begin to predominate
- 4. Older adults: CVD
Causes regardless of age:
- Metabolic disturbances
- Renal Failure
- Hepatic Failure
- 1. Beta-lactam antibiotics
- 2. Quinolones
- 3. Alkylating agents (busulfan, chlorambucil)
- 4. Antimalarials (chloroquine)
- 5. Meperidine
- 6. Tramadol
- 7. Psychotropics (antidepressants, antipsychotics, Lithium)
- 8. Theophylline
- 9. Amphetamine
Seizure type essential for diagnosing cause, therapy, and prognosis
- International League against Epilepsy:
- Based on clinical features associated with EEG, Seizures may be focal or generalized
What are focal seizures?
- -originate within neuronal networks limited to one hemisphere
- -results in asymmetric motor manifestations
- -described as having motor, sensory, autonomic, cognitive features
- -focal seizures are classified with/without dyscognitive features
Can focal seizures become generalized?
- may evolve into generalized seizures
- -progress to include both hemisphere of brain
- -may still be referred to as secondarily generalized
Presentation of Focal Seizures without dyscognitive features
- 1. no loss of consciousness
- 2. altered motor fxn, sensory or somatosensory symptoms or automatism
- 3. Simple Partial Seizures
Focal Seizures with dyscognitive features
- -transient loss of awareness/consciousness
- -begin with an aura
- autaomatisms, periods of memory loss, or aberrations in behavior (start of ictal phase often a sudden arrest of motionless state)
- -Postictal amnesia
- -Complex partial seizures
What are generalized seizures?
- Involve both cerebral hemisphere and result in bilateral motor manifestations
- -associated with loss of consciousness
- -Several types:
- Absence (petit mal): Typical and Atypical
- Tonic-Clonic (grand mal)
- Pure clonic
- Pure tonic
What is Typical Absence (generalized seizures)?
- -sudden, brief lapses of counsciousness w/o loss of postural control
- -lasts for seconds
- -No postictal confusion
What is Atypical Absences (generalized) seizures?
- -longer lapses of counsciousness
- -less abrupt onset and cessation
- -more obvious motor signs
What characterizes Tonic-clonic (grand mal) generalized seizures?
- -seizures with convulsive episodes
- -initial phase is tonic contraction
- -after 10-20 secs, seizure evolves into clonic phase (periods of muscle relaxation on tonic muscle contraction)
- -Ictal phase last no more than 1 min
- -Postictal phase- unresponsiveness (mins to hrs), and possible bladder/bowel incontinence
- -Postictal confusion: H/A, fatigue, muscle ache (hours)
What characterizes Pure Clonic seizures?
- -repetitive clonic jerking with loss of consciousness
- -No initial tonic component
What characterizes Pure clonic seizures?
repetitive clonic jerking accompanied by a loss of consciousness, No initial tonic component
What characterizes Pure tonic seizures?
Continuous muscle contraction, no clonic phase, accompany respiratory arrest resulting in cyanosis
What characterizes Atonic seizures?
- -sudden loss of muscle tone
- -described as head drop, dropping of a limb or slumping to the ground
- -consciousness is usually impaired, but w/o postictal confusion
- -often need protective head gear
What characterizes Myoclonic seizures?
- -brief lightening-like jerking muscular contractions of one part or entire body
- -isolated or repetitive
How are seizures diagnosed?
A thorough Patient history and physical examination
Complete neurologic exam
What is involved in a detailed patient interview of seizures?
- -Time of occurence
- -Presence of aura
- -Ictal activity
- -Postictal state
What should the patient history for seizures focus on?
Risk Factors & Predisposing events
- RF: h/o of febrile seizures, FH of seizures, h/o of head trauma, stoke, tumor
- Precipitating factors: sleep deprivation, systemic diseases, electrolyte imbalances, acute infection, drugs that lower seizure threshold or illicit drug use
What laboratory tests can be used to diagnose seizures?
- -No diagnostic lab tests for epilepsy
- -Serum prolactin levels may be transiently elevated following generalized tonic-clonic seizures
- -Lab tests are done to help r/o treatable causes of seizures (hypoglycemia, infection, altered electrolyte concentrations)
What can be useful to help diagnose various seizure disorders?
- -confirms diagnosis of epilepsy
- -classify seizures
- -locate site of seizure
- -Selection of best antiepileptic drug (AED)
What is the MRI and CT useful in evaluating?
brain tumor and cerebral hemorrhage
Goals of seizure treatment?
- -treat underlying conditions
- -avoid precipitating factors (sleep deprivation, systemic diseases, electrolyte imbalances, acute infection, drugs that lower seizure threshold or illicit drug use)
What are the treatment goals for epilepsy?
No seizures, no side effects, and an optimal quality of life
Control or reduce frequency of seizures and ensure compliance (30-35% of patients are refractory to treatment)
Provide optimal quality of life and allow the patient to live as normal as possible (driving, social relationships, future plans, safety, social stigma)
Balance tolerability, efficacy, and side effects
Accurately diagnose seizure type and classification to determine appropriate AED
Treatment of epilepsy involves:
Suppression of recurrent seizures with AED or surgery
-AED for all patients with recurrent seizures of unknown or unremovable causes