Epilepsy

• Epidemiology:
• Cumulative lifetime incidence of seizure is 9%
• Cumulative lifetime incidence of epilepsy is 3.1% by age 80
• Prevalence of seizure is 5-8/1,000 per year
• Onset of epilepsy is more common among the elderly (60+ years) then in children (0-9 years)
• Etiology:
• Infant (0-2 years):
• Paranatal hypoxemia and ischemia, intracranial birth injury, acute infection, metabolic disturbances (hypoglycemia, hypocalcemia, hypomagnesemia, pyridoxine deficiency), congenital malformation, genetic disorder
• Child (2-12 years):
• Idiopathic, acute infection, trauma, febrile convulsion
• Adolescent (12-18 years):
• Idiopathic, trauma, drug/alcohol withdrawal, arteriovenous malformation
• Young adult (18-35 years):
• Trauma, alcoholism, brain tumor
• Older adult (>35 years):
• Brain tumor, cerebrovascular disease, metabolic disorders (uremia, hepatic failure, electrolyte abnormality, hypoglycemia), alcoholism
• Common causes of provoked seizures:
• Massive sleep deprivation, excessive use of stimulants, withdrawal from sedative drugs and alcohol, substance abuse, high fever, hypoglycemia, electrolyte imbalance, hypoxia
• International Classification of Epileptic Seizures:
• Partial Seizures - Begin locally in a specific region, then spread

§ Simple partial seizure

· No alteration of consciousness

· May have motor signs, somatosensory symptoms, autonomic symptoms, or psychic symptoms

· Usually last only a few seconds

• Complex partial seizure (psychomotor seizure, temporal lobe seizure)
• Involve an impairment of consciousness
• Most last for 1-3 minutes (occasionally longer) with a following period of confusion (which lasts for several minutes)
• Automation occurs during event of which patient has no memory (frequently involves socially embarrassing behavior)
• May secondarily generalize
• Generalized Seizures – Those that are generalized from the start
• Absence seizure
• Most common seizure of childhood
• Involves impairment of consciousness, eye blinking, staring, and other minor facial movements
• Last only a few seconds to a minute, but may occur many times per day in rapid succession
• Myoclonic seizure
• Composed of quick muscle jerks
• May be unilateral or bilateral
• Consciousness generally not impaired
• Tonic seizure
• Composed of tonic spasms of truncal and facial muscles associates with flexion of the upper extremities and extension of the lower extremities
• Most common in childhood
• Clonic seizure
• Resemble myoclonus except that there is a loss of consciousness and the repetition rate is slower
• Most common in childhood
• Tonic-Clonic seizure
• Generalized contraction of trunk muscles is interrupted by short periods of relocation which become more frequent
• Accompanied by marked increases in heart rate and blood pressure
• Last 1-2 minutes, but may occur in rapid succession (status epilepticus)
• After seizure, incontinence may occur as the sphincter muscles relax
• Full consciousness might not return for 10-15 minutes, and confusion/fatigue may persist for hours for days
• Atonic seizure
• Sudden loss of tone in postural muscles
• Most commonly seen in children with Lennox-Gastaut syndrome
• Generally last only a few seconds and may occur without any loss of consciousness
• Frequently associated with injuries from falls
• Benign Rolandic Epilepsy

• Self-limited – ends by adolescence
• Autosomal dominant, onset age 5-9 years
• Nocturnal tonic clonic seizures with focal onset followed by clonic contractures of one side of face (or arm or leg)
• EEG shows high voltage spikes in contralateral rolandic (centrotemporal) area
• Spikes in EEG are greatly accentuated by sleep
• Febrile Seizures
• Seizure in the setting of fever and no evidence of another cause
• Epidemiology:  Occur in approximately 4% of all children
• Occur typically among children 3 months to 5 years of age
• Up to 20% of patients have family history (family/siblings)
• 7% develop epilepsy by age 25
• Risk factors – family history of later epilepsy, pre-existing neurologic abnormality, complex febrile seizure (>15 min duration, >1 febrile seizure in 24 hours), focal febrile seizure
• Not associated with increased risk of mental retardation or serious neurologic impairment
• Risk of recurrence is approximately 35%
• 50% in those <12 months of age
• Lennox-Gestaut – childhood epilepsy; tonic, atonic, absence of myoclonic seizures; with mental retardation
• EEG shows 1-2 Hz spike and wave (slower than typical absence)
• Treat with depakote
• West Syndrome – infantile spasms; short tonic seizures with mental retardation, hypsarrthmia on EEG, myoclonus
• Onset 6-8 months of age
• Treat with ACTH