EPILEPSY

Abstract

I. SEIZURE CLASSIFICATION (TABLES 12-1 AND 12-2)A. Seizure 1. Abnormal focal or generalized neuronal discharge, oftenwith physical manifestationsB. Epilepsy 1. Refers to a condition in which a person experiences twoor more seizuresC. Partial (focal) Seizures 1. Simple partial seizuresa. A spontaneous, uncontrolled neuronal discharge from a focal area of the brain without loss of consciousnessb. Motor seizures: clonic, tonic (asymmetrical, e.g., supplementary motor seizures), automatisms, focal negative myoclonusc. Sensory seizures 1) Elementary sensory symptoms: a simple sensationinvolving one sensory modality, e.g., tingling, a visual sensation, odor, or tasteTable 12-1. Terms Used to Describe Seizures and Their DefinitionsTerm DefinitionTable 12-2. Simplified Outline of the International Classification of Epileptic Seizures2) Experiential sensory symptoms a) Temporoparieto-occipital junction b) Complex perceptions ± affective experience, similarto experiences in life but recognized by the subject as occurring out of context, e.g., déjà vu, jamais vu, flashbacks, feelings of depersonalizationd. Autonomic seizures: involve autonomic functions, e.g., unpleasant abdominal sensation, bradycardia, tachycardia, asystole, drooling, piloerectione. Psychic seizures: disturbance of higher cerebral functions f. Gelastic seizures1) Bursts of laughter 2) Related to hypothalamic lesions (usually hamartoma)2. Complex partial seizures a. Spontaneous, uncontrolled neuronal discharge from afocal area of the brain with loss of consciousness b. Temporal >> frontal > parietal or occipital lobe c. May begin as a simple partial seizure d. May have automatisms: involuntary complex motoractivity during impaired consciousness 1) Examples are gum chewing, nose wiping, drinkingfrom cup, lip smacking 2) Usually occur with complex seizures, occasionallywith absence seizures 3) Usually occur ipsilateral to the epileptic focus 4) May be de novo automatisms, in which the complexmotor activity begins after the onset of seizure; reactive automatisms, in which the activity also begins after the onset of seizure but is a reaction to an external stimulus; or perseverative automatisms, which are a continuation of the motor activity that was initiated before seizure onset3. Partial seizures evolving into secondarily generalized seizures4. Partial status epilepticus a. Epilepsia partialis continua b. Aura continua c. Limbic status epilepticus (psychomotor status) d. Hemiconvulsive status with hemiparesisD. Generalized Seizures 1. Generalized tonic-clonic seizuresa. With or without premonition (rare, hours-days) b. Tonic phase: eyes open and roll up, pupils dilate, elbowsflex, arms pronate, incontinence, moaning, cyanosis and apneac. Clonic phase: generalized clonic movements, frequency gradually decreases, amplitude gradually increases, atonic between jerks, tongue biting, cyanosis and apnead. Postictal state: drowsy, confused, lethargy, regular respiration resumes, headache, muscle soreness2. Generalized tonic seizures a. Axial, proximal limbs, or axial + proximal + distal limbsinvolved b. Less common than tonic-clonic seizures c. Typically lasts seconds, can persist (status)3. Generalized clonic seizures: same clinical significance as generalized tonic-clonic seizures4. Absence seizures a. Usually occur in children with normal intelligence b. Generalized 3-Hz spike-and-wave electroencephalogram(EEG) c. Brief duration, usually a few seconds d. Abrupt recovery e. No postictal phase f. Absence with atonic components: primarily affects axialmusculature, causing head drop or slumping of the trunk (falls are rare)g. Absence with tonic components: asymmetric or symmetric contraction of the flexure or extensor musclesh. Absence with automatisms: purposeful or semipurposeful movements occurring without awareness (patient is amnestic for the movements)i. Absence with mild clonic movements: clonic movements may sometimes occur with prolonged spells 1) Are of variable duration and severity 2) Often involve the eyelids or corner of the mouthj. Absence with impairment of consciousness only: no other features5. Atypical absence seizures a. Longer duration than typical absence seizures: may lastseveral minutes b. Less abrupt onset and offset c. Often loss of postural tone (more pronounced than mildhead drop)Atypical absence seizures differ from absence seizures in that duration is often longer, onset and offset can be less abrupt, and loss of postural tone may be more prominentAutomatisms are involuntary complex motor activity during impaired consciousnessThey can occur with complex partial or absence seizuresd. Associated with other seizure types and mental retardation e. Slow generalized spike-and-wave (<2.5 Hz) when seen inthe context of Lennox-Gastaut syndrome (see EPILEPSY SYNDROMES)f. May have mild clonic, atonic, tonic, or autonomic activity or automatisms6. Myoclonic seizures a. Shocklike jerk1) Cortical reflex myoclonus: discharge from sensorimotor cortex2) Reticular reflex myoclonus: discharge from brainstem reticular formation3) Primary generalized epileptic myoclonus: diffuse bursts of polyspike and wave or spike and wave4) Nonepileptic myoclonus: most common 7. Atonic seizuresa. Drop attacks b. Duration: seconds c. Spectrum: from head drop to complete loss of tone inentire body 8. Akinetic seizuresa. Similar to atonic seizures, but tone is preserved b. Brief loss of consciousness, motionless9. Infantile spasms (see description under EPILEPSY SYNDROMES)10. Variations of generalized seizures (examples are myoclonic atonic, massive myoclonic, tonic-clonic beginning with clonic phase)11. Generalized status epilepticus a. Generalized tonic-clonic seizure b. Clonic seizure c. Absence seizure d. Tonic seizure e. Myoclonic seizureII. EPILEPSY SYNDROMES (TABLE 12-3)A. Localization-related (focal, local, partial) Cryptogenic or Symptomatic (secondary) Epilepsy (otherwise unclassified)1. Temporal lobe seizuresa. Initial behavioral arrest and automatisms (usually with complex partial temporal lobe seizures); initial speech arrest and aphasia (usually with dominant temporal lobe seizures)b. Associated with epigastric rising sensation, nausea, olfactory hallucinations (usually unpleasant smell, “uncinate fits”), sensation of fear and terror and other changes of affect (intense pleasure or intense depression), gustatory hallucinations (with deep opercular focus), and autonomic symptomsEpileptic myoclonus includes cortical reflex myoclonus (sensorimotor cortex), reticular reflex myoclonus (reticular formation of brainstem), and primary generalized epileptic myoclonus (diffuse epileptic discharge)Table 12-3. International Classification of Epilepsy Syndromesflashes of light, geometric objects (positive or negative visual symptoms)b. Versive eye movementsB. Neonates 1. Benign neonatal seizuresa. Can be idiopathic with no family history or familial (benign familial neonatal seizures)b. Also called “fifth-day fits” c. Clinical presentation1) Clonic or myoclonic seizures and apneic events during first few weeks after birth2) Seizures usually stop by 6 weeks after birth, no longterm sequelae3) Normal development 4) Later, some of the children have epilepsy (10%-15%)or febrile seizures (33%) 5) Treatment is often unnecessary, may prescribe pheno-barbital for 1 month, then taper d. Generalized epilepsy e. EEG1) Normal interictally 2) EEG findings are variablea) There may be focal, multifocal, or bilateral sharp waves, spikes, spike-and-wavesb) There may be a pattern of unreactive, asynchronous theta activity with interspersed spikes (theta point alternant)f. Benign familial neonatal convulsions is an autosomal dominant channelopathy (Table 12-4)g. Voltage-dependent potassium channel mutations 1) Mutations in two genes have been identified:KCNQ2 on chromosome 20 and KCNQ3 on chromosome 82) These impair potassium-dependent repolarization, thus causing hyperexcitability3) Mutation of the KCNQ1 gene causes the long QT syndrome (which also is related to impaired repolarization)c. May arise from mesial temporal lobe (amygdala, hippocampus, associated with mesial temporal sclerosis) or lateral neocortical temporal lobed. Auditory hallucinations (superior temporal gyrus) e. Vertigo and perception of motion f. Memory misperceptions: dreamy state, déjà vu (percep-tion of familiarity with previously unfamiliar people or events), déjà entendu (perception of unfamiliarity with previously familiar people), jamais vu (perception of familiarity with previously unfamiliar auditory experience), and jamais entendu (perception of unfamiliarity with previously familiar auditory experience)g. Associated with postictal confusion h. Interictal personality: emotionality, hypermorality andhyperreligiosity, increased philosophical interest, humorlessness, hypergraphia, circumstantiality of speech, altered libido (hyposexuality more than hypersexuality)2. Frontal lobe seizures a. Characterized by abrupt onset, brief duration spellsoccurring with high frequency (tendency to occur during sleep) with minimal or no postictal confusionb. Associated with frequent falls during the seizure c. More frequently associated with secondary generalizationand status epilepticus than temporal lobe seizures d. Prominent motor movements such as clonic jerking ofone body part that spreads to involve other body parts, termed “jacksonian march,” because of spread of epileptic activity in motor cortex 1) Head or eyes may turn opposite to side of epilepticfocus 2) Tonic posturing of one limb or “fencer’s posturing”(see below) is often seen with seizures arising from supplementary motor cortex3) There may be motor or gestural automatisms, such as bicycling or pedaling movements of the lower limbs, sexual gesturinge. Most common extratemporal partial epilepsy f. Postictal paralysis (Todd’s paralysis): transient paralysisthat may follow a partial motor seizure 3. Parietal lobe seizuresa. Associated with positive or negative sensory phenomena b. There may be tingling (positive), which often starts inbody parts with larger cortical representation such as the face or the tonguec. There may be negative phenomena such as asomatognosia (loss of awareness for a body part or whole side of the body) or metamorphopsia (both usually representing a nondominant parietal focus)4. Occipital lobe seizures a. Elementary visual hallucinations, often bright lines,Benign familial neonatal convulsions is an autosomal dominant disorder caused by mutation of KCNQ2 or KCNQ3, both genes encoding for potassium channel proteinsThese mutations impair potassium-dependent repolarization, resulting in hyperexcitability2. Early myoclonic encephalopathy a. Also called “early-onset progressive encephalopathy withmigrant, continuous myoclonus” b. Clinical presentation1) Erratic, focal myoclonus: migrates randomly to different body parts2) Occurs in early infancy (occasionally within first few hours after birth)3) The infant may have other seizure types (partial, widespread myoclonus, tonic spasms), but these usually occur later in the course of the disorderc. Generalized, symptomatic, or cryptogenic 1) Multiple causes, a nonspecific diagnosisa) Metabolic (nonketotic hyperglycemia) b) Inherited (autosomal recessive) c) Various developmental malformationsd. Often cryptogenic e. EEG1) Generalized or focal epileptiform discharges 2) EEG often shows burst suppression (as in Ohtaharasyndrome)3) Myoclonus often does not have an EEG counterpart and EEG may be normal initiallyf. Similar to severe myoclonic epilepsy and Ohtahara, Lennox-Gastaut, and West’s syndromes (described below) 1) In all the epileptiform abnormalities thought to con-tribute to decline in cerebral function 2) Severe psychomotor delay 3) Burst suppression pattern may evolve into hypsar-rhythmia later in life g. Poor prognosis1) More than 50% die, others have profound psychomotor delay3. Ohtahara syndrome a. Also called “early infantile epileptic encephalopathy withsuppression bursts” b. Clinical presentation1) Frequent tonic spasms ± partial seizures 2) Onset is usually within first 10 days after birth (other-wise, <3 months) 3) Difficult-to-control seizures 4) Clinical course is marked by neurologic deteriorationc. Symptomatic or cryptogenic: usually structural brain abnormality, multiple causesd. EEG: burst-suppression pattern e. The EEG is the same in Ohtahara syndrome and earlymyoclonic encephalopathy, causing the two to be confused f. Difference: no myoclonic seizures in Ohtahara syndrome g. Seizures are difficult to control, vigabatrin may be benefi-cial in early stages h. Poor prognosis, 50% die within first few months i. Often progresses to West’s syndrome or Lennox-Gastautsyndrome phenotypes 4. Migrating partial seizures of infancya. Clinical presentation 1) Onset less than 6 months after birth (average, firstseizure at 3 months) 2) Progresses over weeks 3) Multifocal seizures, shift from hemisphere to hemi-sphere 4) Seizures are nearly continuous at times, occur in clusters 5) Progressive microcephaly and severe psychomotordeterioration 6) Poor response to anticonvulsantsTable 12-4. Epilepsy Syndromes With Simple Genetic InheritanceEarly myoclonic encephalopathy is characterized by newborn infants with migrant focal myoclonic epilepsy and progressive psychomotor abnormalitiesOhtahara syndrome is early infantile epileptic encephalopathy with tonic spasms and focal seizures associated with a burst-suppression pattern on EEGb. Idiopathic: no identifiable cause 5. Pyridoxine (vitamin B6)-dependent seizures (congenitaldependency on pyridoxine) a. Autosomal recessive disorder b. Some data suggest this condition results from dimin-ished activity of glutamic acid decarboxylase (GAD); diminished action of GAD leads to increased cerebral concentrations of glutamic acid, which may not normalize after initiation of treatment with doses necessary to stop seizuresc. Age at onset: usually neonatal period but may appear up to 1 year of aged. Diagnosis: established by response (remission of seizures) to treatment with parenteral pyridoxine and relapse without ongoing treatmente. Treatment: life-long administration of pyridoxine oral supplements daily 1) If left untreated, the disease is fatal within days tomonths 2) If treatment is delayed, patients develop psychomotorretardation, progressive deterioration of neurologic function, chronic encephalopathyf. This condition needs to be differentiated from 1) Pyridoxine deficiency-related seizures: often resultfrom breastfeeding by malnutritioned mothers and may be recurrent, of abrupt onset, and responsive to vitamin B6 supplementation; in comparison, pyridoxine-dependent seizures occur in setting of normal dietary pyridoxine supplementation, require larger doses of pyridoxine to control seizures, and usually occur earlier than pyridoxine deficiencyrelated seizures2) Pyridoxine-responsive epilepsy (usually infantile spasms): seizure frequency may decrease with pyridoxine supplementation (in addition to other anticonvulsants)C. Infants 1. Infantile spasmsa. This is not an epilepsy syndrome but a seizure typeb. May be symptomatic or idiopathic: poor developmental outcome when symptomatic, mild to no mental retardation in 40% when idiopathicc. Associated with West’s syndrome d. Clinical presentation1) Occurs within first year after birth 2) Sudden tonic extension or flexion of limbs and axialbody a) Flexion spasms: flexion of neck, trunk, and limbs,followed by several seconds of tonic activity, or may be mild head droop or waist flexionb) Extensor spasm: like the Moro reflex 3) Spasms occur in clusters, often after awakeninge. EEG 1) Interictal: hypsarrhythmia (high-amplitude, chaoticslow waves with multifocal spikes and sharp waves), which diminishes during REM sleep2) Seizure: electrodecrement (low-amplitude fast activity) f. Treatment: ACTH, vigabatrin (not currently available inU.S., because of high incidence of retinal toxicity) more effective than other epileptic drugsg. Benign myoclonus of infancy (described below) can mimic infantile spasms; compared with infantile spasms, benign myoclonus 1) Identical to infantile spasms by semiology but normalEEG 2) Clusters occur for weeks or months 3) Usually much less frequent by 3 months, none by2 years 4) Developmentally normal infant 5) Treatment not needed2. West’s syndrome a. Triad: infantile spasms, hypsarrhythmia, developmentalarrest b. Symptomatic or cryptogenic c. Etiology: several prenatal, perinatal, or postnatal insults,such as congenital in utero or acquired infections (e.g., meningitis, encephalitis), hydrocephalus, metabolicBenign myoclonus of infancy appears identical to infantile spasms by semiology, but EEG is normalInfantile spasms may be idiopathic or symptomatic. When idiopathic, sometimes there is mild or no mental retardation (40%)Symptomatic infantile spasms are generally associated with poor developmentWest’s syndrome is a nonspecific diagnosis referring to the triad of infantile spasms, hypsarrhythmia, and developmental arrestdisturbance (postnatal), developmental anomalies (prenatal), tuberous sclerosis, among others (40% cryptogenic)d. Developmental arrest or regression may occur before seizures develope. Treatment: as mentioned, ACTH, corticosteroids, and vigabatrin; the latter is drug of choice for infantile spasms associated with tuberous sclerosis3. Aicardi’s syndrome a. Triad: Infantile spasms, agenesis of the corpus callosum,retinal malformations b. X-linked: occurs predominantly in girls, lethal in boys4. Benign myoclonic epilepsy of infancy a. Clinical presentation1) Normal infant or toddler (4 months-3 years) 2) Spectrum: from subtle head drop to massive wide-spread generalized myoclonus (less intense than infantile spasm)3) Some seizures provoked by intermittent photic stimulationb. Idiopathic, generalized c. EEG1) Normal interictally 2) Generalized spike and polyspike with jerksd. If treated, excellent developmental outcome; some patients have photosensitivity, and some may eventually develop generalized tonic-clonic seizurese. Easily controlled with valproate f. Similar to a younger version of juvenile myoclonicepilepsy g. One-third of infants have a family history (as expectedbecause it is idiopathic, often genetic) 5. Benign infantile seizuresa. Can be subdivided into “benign familial infantile seizures” and “benign nonfamilial infantile seizures”b. Clinical presentation 1) Partial seizures in first 1 to 2 years after birth 2) Often occur in clusters 1 to 3 days, <10/day 3) Seizures last a maximum of a few minutes 4) No postictal stupor or status 5) Normal psychomotor developmentc. Idiopathic 1) Benign epilepsies typically are idiopathic (e.g., benignmyoclonic epilepsy of infancy), but idiopathic epilepsies are not always benign (e.g., severe myoclonic epilepsy of infancy below)d. Usually autosomal dominant inheritance (when familial) 1) Genetic homogeneity 2) Associated with familial choreoathetosis duringinfancy or childhood e. EEG1) Focal epileptiform discharges 2) May secondarily generalizef. Treatment: responds well to anticonvulsants 6. Severe myoclonic epilepsy in infancya. Also called “Dravet syndrome” b. Clinical presentation1) Begins within 1 year after birth 2) No previous brain abnormality except occasionallydiffuse atrophy 3) Myoclonic seizures (begin mild, worsen over time) 4) Partial seizures develop later 5) Often, the first seizure occurs with fever, can haveprolonged febrile seizures (i.e., can evolve from febrile seizures)6) One-fourth of the infants have a family history of seizures7) Developmental delay with psychomotor regression due to severe, progressive neurologic deterioration that may be secondary to recurrent seizuresc. Idiopathic, generalized or focal d. EEG1) General, focal, and multifocal abnormalities 2) May be normal interictally (early in disease course) 3) Photosensitivity is commone. Treatment 1) Seizures are often medically refractory 2) Valproate and benzodiazepines may be triedD. Children 1. Benign childhood epilepsy with centrotemporal spikesa. Also called “benign rolandic epilepsy of childhood” b. Common: accounts for one-fourth of childhood seizures c. Clinical presentationAicardi’s syndrome is the X-linked triad of infantile spasms, agenesis of corpus callosum, and retinal malformationsBenign epilepsy syndromes are generally idiopathicBut not all idiopathic epilepsies are benign, e.g., idiopathic Dravet syndrome (severe myoclonic epilepsy in infancy) causes progressive brain damage1) Onset in childhood, age 4 to 12 years 2) Resolves by middle teens 3) Motor, sensory simple seizures: tonic-clonic move-ments of face or hand, paresthesias of face or hand, drooling, tingling in mouth, speech arrest4) Can have secondary generalization, usually nocturnal 5) Seizures increase with sleep: 70% of patients haveseizures only during sleep (15% awake only, 15% awake and sleep)6) Normal development and neurologic examination d. Idiopathic, focal e. EEG1) Centrotemporal spikes: between central and mid temporal leads (Fig. 12-1)2) Normal background f. Autosomal dominant inheritance, variable penetrance:although half of the close relatives of the patient may demonstrate the EEG abnormality during childhood, only 12% of them have clinical seizuresg. Treatment 1) Easily controlled with anticonvulsants2) Often not necessary to treat (physicians often wait until the second seizure)3) Treatment can be stopped after adolescence (only 10% of patients continue to have seizures 5 years after onset)2. Early-onset benign childhood occipital epilepsyBenign childhood epilepsy with centrotemporal spikes is an example of focal idiopathic epilepsyEarly-onset benign childhood occipital epilepsy involves infrequent seizures (autonomic, hemiconvulsive, and generalized)Late-onset childhood occipital epilepsy is characterized by frequent visual seizuresa. Also called “Panayiotopoulos syndrome,” “epilepsy associated with ictal vomiting,” “childhood epilepsy with occipital paroxysms”b. Clinical presentation 1) Most common in children 3 to 6 years old 2) Autonomic seizures and status epilepticus: commonly,ictal vomiting, eye deviation; often progress to partial clonic or generalized tonic-clonic seizures (often nocturnal)3) Visual seizures: elementary or complex visual hallucinations, amaurosis, illusions (such as metamorphopsia), which are often experienced during wakefulness4) Infrequent seizures: most patients, 1 to 3 seizures total 5) Autonomic status epilepticus in almost half of theseizures c. Overlap with benign childhood epilepsy with centrotem-poral spikes (also an idiopathic, benign partial epilepsy) 1) Excellent response to anticonvulsants 2) Variable localization of seizures: frequently extra-occipital, the clinical presentation defines the syndrome rather than occipital spikesd. EEG 1) Interictal EEG: frequent or nearly continuous burstsor trains of high-voltage rhythmic occipital spikes and spike-wave complexes at a frequency of 1 to 3 Hz, localized to unilateral or bilateral occipital regions, with normal background activity, increases during non-REM sleep, and disappears with eye opening2) Ictal EEG: low-voltage fast activity (unilateral or bilateral)e. Treatment 1) Not needed if only one seizure or a few brief seizures 2) Carbamazepine is usually the first-line treatment3. Late-onset childhood occipital epilepsy (Gastaut type) a. Clinical presentation1) Children 4 to 8 years old 2) Visual seizuresa) Hallucinations, blindness: weekly to several per day b) May generalize (rarely) c) Often followed by migraine headache d) Often induced by photic stimulation3) The children commonly have a family history of benign childhood epilepsy with centrotemporal spikes4) Both late-onset childhood occipital epilepsy and benign childhood epilepsy with centrotemporal spikes may be benign childhood seizure-susceptibility syndromes with overlapping causesb. Idiopathic, benign partial epilepsy c. EEG: same as in early-onset benign childhood occipitalepilepsyd. Treatment is recommended because seizures are frequent 4. Epilepsy with myoclonic absencesa. Rare, with unknown cause b. Clinical presentation1) Children, average age at onset is 7 years 2) One-half of the children have developmental delay attime of onset 3) Prolonged (10-60 seconds) absence seizures areaccompanied by bilateral, severe limb myoclonus (may progress to tonic activity) a) Myoclonus is rhythmic, corresponds to the spikesof the 3-Hz spike-and-wave EEG pattern b) Unlike other absence syndromes, no eye twitching4) Most children develop other seizure types a) Generalized tonic-clonic seizures b) Typical absence seizures c) Fallsc. Significance 1) Mental impairment is more common than in otherchildhood absence syndromes 2) Mental deterioration is thought to be due to seizures 3) One-half of the patients continue to have seizures asadults d. High-dose ethosuximide and valproate usually controlthe seizures e. EEG1) Ictal: 3-Hz spike-and-wave pattern 2) Interictal: intermittent bursts of generalized spike-and-waves on a normal background 5. Myoclonic-astatic epilepsy of childhooda. Clinical presentation 1) The first seizure (often a generalized tonic-clonicseizure) usually occurs in a developmentally normal child 2 to 5 years old2) Repeated, sometimes prolonged generalized tonicclonic seizures3) After months of repeated generalized tonic-clonic seizures, other seizure types (myoclonic, absence, and drop-attacks) appear a) Drop attacks are myoclonic or atonic seizures b) Tonic seizures are uncommon (in contrast toEpilepsy with myoclonic absences is characterized by long absence seizures with bilateral limb myoclonusHowever, unlike atypical absence seizures, EEG shows 3-Hz spike-and-wave activityLennox-Gastaut syndrome, in which tonic seizures are a prominent seizure type)b. Idiopathic, likely polygenic c. EEG: 2 to 3-Hz spike waves (often faster than inLennox-Gastaut syndrome) d. Treatment: valproate, ethosuximide, benzodiazepine,lamotrigine e. Some authorities suspect this is a mild or early form ofLennox-Gastaut syndrome 6. Lennox-Gastaut syndromea. Clinical triad: mental retardation, characteristic slow spike-and-wave (2 Hz) EEG, multiple seizure typesb. Clinical presentation 1) Children, age at onset is 2 to 8 years 2) Boys affected more often than girls 3) The first seizure type is usually drop attacks 4) Many patients have severe mental retardation preced-ing onset of seizures 5) Later, multiple seizure types evolve, often in associa-tion with status epilepticus, progressive psychomotor deterioration a) Tonic seizures (last a few seconds)i) Head/neck flexion or ii) Neck extension/arm abduction or iii) Generalized tonic stiffening sudden fallb) Atypical absence seizure i) Gradual onset and offset (unlike typical absence) ii) Longer duration than a typical absence seizure iii) May be brief postictal decrease in alertness(unlike typical absence seizure) c) Atonic seizure: neck only or whole body d) Generalized tonic-clonic seizure e) Less common seizure types: partial tonic-clonic,myoclonic f) Consider myoclonic-astatic epilepsy if prominentmyoclonic seizures c. Cryptogenic or symptomatic d. Prognosis is usually poor, especially if symptomatic e. Progressive deterioration is thought to be related to fre-quent subclinical epileptic discharges (epileptic encephalopathy)f. EEG 1) Interictal “slow spike-and-wave”: double meaning ofname (Table 12-5) a) Spikes are slow (150 ms, longer than a true spike,which should be <70 ms) b) Spike-and-wave rate is also slow (1.5-2.5 Hz) com-pared with typical absence seizures (3 Hz) 2) Ictala) Tonic seizure: rhythmic fast activity followed byhigh-amplitude slow activity b) Absence seizure: slow spike-and-wave dischargeg. Treatment 1) Valproate: all seizure types 2) Lamotrigine, felbamate: especially for drop attacks 3) Carbamazepine and phenytoin: may help generalizedtonic-clonic seizures but may worsen atypical absence seizures7. Landau-Kleffner syndrome a. Clinical presentation1) Acquired aphasia (word deafness): the main feature of the syndrome2) Seizures, may be multiple types: 20% of patients do not have seizures a) Generalized tonic-clonic seizures b) Partial seizuresTable 12-5. Syndromes Associated With Characteristic EEG PatternsSyndrome EEG patternThe “slow spike-and-wave” pattern characterizes Lennox-Gastaut syndrome, occurring during atypical absence seizures and interictally“Slow” refers to both the prolonged duration of “spikes” (150 ms) and the slow rate of spike-andwave activity (1.5-2.5 Hz)Carbamazepine and phenytoin can worsen atypical absence seizuresLandau-Kleffner syndrome refers to acquired epileptic aphasia in childrenc) Myoclonic seizures 3) Children, age at onset: 3 to 8 years oldb. Symptomatic, nonspecific (variety of lesions) c. Magnetic resonance imaging (MRI): usually normal;functional imaging shows temporal abnormalities d. EEG: variable, multifocal spikes, most commonly temporal e. Outcome is variable1) Seizures usually are controlled with medication, seizure disorder resolves with time2) Persistent language problems in about half the children f. Treatment1) Antiepileptic drugs (valproate and lamotrigine) may help decrease seizure frequency and improve cognitive function2) Corticosteroids have been tried with some success in small series, but data are inadequate8. Epilepsy with continuous spike-and-wave pattern during slow wave sleep, also referred to as “electrical status epilepticus during sleep” a. Clinical presentation1) First seizure occurs in childhood (peak age at onset: 5 years)2) Multiple seizure types, partial or generalized 3) Seizures occur infrequently, often during sleep 4) Then, seizures accelerate and EEG changes to charac-teristic pattern (electrical status during slow wave sleep)5) Psychomotor deterioration (language and