Diseases » Petit mal seizures

Seizures

Seizures: Excerpt from The Diagnostic Approach to Symptoms and Signs in Pediatrics

A seizureis a sudden paroxysmal discharge of neurons that causes a transientalteration in neurologic function. This alteration can include changesin level of alertness, sensation, motor activity, and autonomicfunction.

Commission on Classification and Terminologyof the International League Against Epilepsy (1981) revised theclassification of seizures. This chapter describes different typesof seizures and their principal causes.

Classification of Seizure Types

Generalizedseizures

Tonic-clonicseizures

Tonic seizures

Clonic seizures

Absence seizures

Atonic seizures

Myoclonic seizures

Partial seizures

Simple partial seizures

With motorsigns

With somatosensory or special sensorysymptoms

With autonomic symptoms or signs

With psychic symptoms

Complex partial seizures

Simple partialseizures followed by impaired consciousness

With automatisms

Partial seizures with secondary generalization

Unclassified seizures

Generalized Seizures

Tonic-Clonic Seizures

Tonic-clonic seizures begin with tonic contractionof entire musculature and loss of consciousness for 10–30secs. Clonic jerks follow and usually last 30–60 secs.This is usually followed by postictal sleep, which may last minutesto hours. Interictal electroencephalogram (EEG) shows generalizedspikes or irregular spike-wave complexes.

Tonic Seizures

Increased tone of extensor muscles and lossof consciousness characterize tonic seizures, which usually last <60secs.

Clonic Seizures

Clonic seizures, although usually rhythmic,are often asymmetric. Can involve any muscle group but most commonlyinvolve arm, neck, and facial muscles.

Absence Seizures

Absenceseizures (petit mal seizures) usually occur before 10 yrs of agebut seldom before 3 yrs of age.

Often consist of brief lapse of consciousnesswith staring into space and other phenomena (e.g., eye blinking,lip smacking, facial twitching, or head drooping). They start andstop suddenly, usually lasting for a few seconds, but can last upto 30 secs.

Up to 100 or more seizures may occureach day with tendency to diminish in adolescence.

Most children with absence seizureshave no significant intellectual or neurologic deficits.

EEG shows generalized symmetric 3-per-secspike-and-wave pattern often activated by hyperventilation, sleep,or photic stimulation.

Atonic Seizures

Sudden loss of consciousness and diminishedmuscle tone in limb, trunk, and neck muscles characterize atonicseizures (drop attacks). These brief seizures occur without warning,and consciousness returns at end of episode.

Myoclonic Seizures

Brief, bilateral, symmetric muscle contractions,which usually last only a few seconds. Interictal EEG shows generalizedspike-and-wave or polyspike-and-wave complexes arising in randomfashion.

Partial Seizures

Partial(focal) seizures arise from local area of cortex of 1 cerebral hemisphere.

Specific manifestations depend on whichregion of brain is involved.

Impaired consciousness occurs withcomplex partial seizures but not with simple partial seizures.

Simple Partial Seizures

May occurwith motor signs (clonic movements of extremities, facial twitching),somatosensory or special sensory symptoms (distortions of vision,taste, or smell; tingling of extremity), autonomic symptoms or signs(sweating, pallor), or psychic symptoms (hallucinations, anger,fear, emotional disturbances).

Duration is usually <30 secs,and impaired consciousness does not occur, unless secondary generalizationoccurs. There is no postictal phenomenon.

Interictal EEG may be normal or showfocal discharges from specific area of brain.

Complex Partial Seizures

Uncommonbefore 10 yrs of age.

Classic manifestations are impairedconsciousness and automatisms (facial grimacing, lip smacking, repeatingphrases, gestures) that may seem purposeful but are inappropriatefor particular situation.

Duration is usually 30 secs to severalminutes, and in most cases tiredness or confusion follows. Thereis usually amnesia of episode.

Interictal EEG usually shows spike-and-waveor spike pattern localized to specific area of brain.

Sometimes complex partial seizure ispreceded by aura that consists of symptoms (e.g., nausea, vomiting,headache, or abdominal pain). Aura constitutes simple partial seizure,and its spread to involve other areas of brain impairs consciousness.

Principal Causes of Seizures

1. Febrileseizures
2. Hypoxic-ischemic encephalopathy
3. Brain disorders
   1. Cerebralmalformations
   2. Intracranial infection
   3. Intracranial hemorrhage
   4. Other
4. Hypertensive encephalopathy
5. Drugs and toxins
6. Metabolic disorders
   1. Hypoglycemia
   2. Hypocalcemia
   3. Hypomagnesemia
   4. Hyponatremia
   5. Hypernatremia
   6. Uremia
   7. Bilirubin encephalopathy (kernicterus)
   8. Pyridoxine dependency
   9. Inborn errors of metabolism
7. Selected epileptic syndromes
   1. Neonatalseizures
   2. Benign neonatal epilepsy
   3. Infantile spasms (West syndrome)
   4. Lennox-Gastaut syndrome
   5. Benign focal epilepsy with centrotemporalspikes
   6. Temporal lobe epilepsy
   7. Juvenile myoclonic epilepsy
   8. Posttraumatic epilepsy
   9. Childhood absence epilepsy
8. Unknown

Clinical Features and Diagnosis

Febrile Seizures

Can be definedas a seizure occurring in child <6 yrs of age associatedwith a temperature >38°C without evidence of intracranialinfection or acute systemic metabolic disorder. These seizures areuncommon before 6 mos of age.

Can be categorized as simple or complex.Most febrile seizures are simple and consist of single, brief, generalizedseizures with tonic-clonic or clonic movements lasting several minutes,although they can last as long as 15 mins. If they occur in a series,duration is <30 mins. Complex febrile seizures last >15mins, can occur in a prolonged series for several hours, and maybe focal.

Common clinical dilemma, especiallyin infants, is whether febrile seizure could indicate presence ofmeningitis or encephalitis. Lumbar puncture should be performedif these infections are suspected. This is especially importantin infants <18 mos of age, when physical exam is not asreliable as in older children.

Hypoxic-Ischemic Encephalopathy

Most commoncause of neonatal seizures is hypoxic-ischemic encephalopathy.

In most cases asphyxia occurs beforeor during delivery. History of toxemia, abruptio placenta, cordprolapse, fetal bradycardia, meconium staining, or prolonged failureto establish spontaneous respiration can be presumptive evidenceof intrauterine hypoxia.

In infants and children, hypoxic-ischemicencephalopathy may occur from suffocation, near drowning, shock,and cardiorespiratory arrest from any cause.

Brain Disorders

Cerebral Malformations

Seizures may arise from malformations ofthe brain. Some examples are polymicrogyria, holoprosencephaly,and cortical heterotopias. MRI is diagnostic.

Intracranial Infection

Infections (e.g., bacterial meningitis, encephalitis,and brain abscess) may be associated with seizures. See Chap. 3, Alteration in Consciousness.

Intracranial Hemorrhage

Hypoxiais major factor in development of intraventricular hemorrhage inpreterm infants, whereas subarachnoid hemorrhage usually occursas result of difficult labor or delivery in near-term infants.

In infants and children, head traumais most common cause of intracranial hemorrhage.

Head U/S, CT, and MRI areuseful in localizing and defining extent of hemorrhage. Study performeddepends on age of child and clinical circumstances. ≥1 modalitymay be necessary.

Other

Brain tumors, cerebrovascular disorders,neurocutaneous disorders, and neurodegenerative diseases also maycause seizures. See Chap. 3,Alteration in Consciousness; Chap. 13, Developmental Delay;and Chap. 25, Headache.

Hypertensive Encephalopathy

Severe generalizedheadache and visual disturbances (e.g., blurring of vision) maybe symptoms of severe hypertension.

Seizures also may occur; however, itis impossible to predict at what BP level seizures will occur.

BP should be measured in every individualwho has a seizure (see Chap.32, Hypertension).

Drugs and Toxins

Ingestionof the following substances may produce seizures: theophylline,phenothiazines, tricyclic antidepressants, camphor, glutethimide,benzene, acetylsalicylic acid, morphine, codeine, cocaine, heroin,amphetamines, and lead.

History and physical exam may be diagnostic.

Urine or serum level of implicateddrug, chemical, or heavy metal confirms diagnosis.

Metabolic Disorders

Hypoglycemia

Can be definedas blood glucose concentration of <40 mg/dL afterinitial 2–3 hrs of life.

Clinical manifestations of hypoglycemiain the neonate include jitteriness, tremors, lethargy, poor feeding,apnea, seizures, and alteration of consciousness. In infancy andchildhood, clinical findings include anxiety, hunger, headache,vomiting, sweating, fatigue, lassitude, seizures, and alterationof consciousness.

Principal Causes of Hypoglycemia

1. Transientneonatal hypoglycemia
   1. Associated with decreased substrate or enzymefunction
   2. Associated with hyperinsulinemia
2. Persistent hypoglycemia in infants,children, or adolescents
   1. Hyperinsulinemia
   2. Hormone deficiency
   3. Ketotic hypoglycemia
   4. Drugs or toxins
      1. Insulin
      2. Salicylates
      3. Propranolol
      4. Alcohol
      5. Oral hypoglycemic agents
   5. Hepatic disease
      1. Hepatitis
      2. Cirrhosis
      3. Reye syndrome
3. Metabolic disorders
   1. Glycogenstorage diseases (types O, I, III,VI)
   2. Disorders of gluconeogenesis
   3. Galactosemia
   4. Hereditary fructose intolerance
   5. Maple syrup urine disease
   6. Tyrosinemia
   7. Propionic acidemia
   8. Methylmalonic acidemia
   9. Medium-chain acyl-CoA dehydrogenasedeficiency
4. Systemic disorders
   1. Septicemia
   2. Malnutrition
   3. Malabsorption
   4. Burns
   5. Shock

Transient Neonatal Hypoglycemia

Transienthypoglycemia may occur in neonates because of inadequate substrate(liver glycogen, muscle protein, body fat) or lack of fully developedenzyme systems to sustain glucose production.

Most common in infants who are premature,small for gestational age, or the smaller of twins, but it alsocan occur in infants born to toxemic mothers and infants who experiencesevere respiratory distress.

Maternal diabetes mellitus and perinatalasphyxia are most common causes of transient neonatal hyperinsulinemia.

Resolution of hypoglycemia usuallyoccurs in 2–3 days with milk feedings or infusion of intravenousglucose.

Persistent Hypoglycemia in Infants, Children, or Adolescents

Hyperinsulinemia

Most commoncause of persistent hypoglycemia in infancy is hyperinsulinism,which can occur from birth to 18 mos of age.

It should be suspected in a macrosomicinfant with severe nonketotic hypoglycemia who requires glucoseinfusion of >10–15 mg/kg/minto maintain normal serum glucose concentration. When blood glucoseconcentration is <40 mg/dL, inappropriate increasein serum insulin (>10 μU/mL) is considereddiagnostic.

Once presence of hyperinsulinemia hasbeen established through spontaneous or fasting-induced hypoglycemia,specific cause should be investigated by clinical, biochemical,and molecular genetic means.

Causes include genetic defects of beta-cellregulation and focal lesions (islet cell adenoma, focal islet cellhyperplasia).

Hormonal Deficiency

Causes ofhypoglycemia associated with endocrine deficiency include adrenalinsufficiency with or without growth hormone deficiency.

When hypoglycemia is discovered, bloodsample should be drawn for possible cortisol, growth hormone, thyroidhormone (thyroxine), thyroid-stimulating hormone, insulin, and adrenocorticotropichormone measurements. These tests should be performed if other clinicalsigns suggest hormonal deficiency or if no other cause can be foundfor hypoglycemia.

Ketotic Hypoglycemia

Hypoglycemiaassociated with ketonuria may occur in children 18 mos–5yrs of age as response to prolonged fast.

At time of hypoglycemia, serum insulinconcentration is appropriately low (≥5–10 μU/mL),which excludes hyperinsulinism.

Prolonged fast of 12–18 hrsusually reproduces hypoglycemia in susceptible individuals.

Drugs or Toxins

Insulinin excessive dosage may cause severe hypoglycemia. So may salicylateintoxication, which increases insulin secretion and may possiblyinterfere with gluconeogenesis.

Propranolol, a beta-adrenergic blockingagent, may cause hypoglycemia in children who have decreased oralintake from prolonged fasting or illness.

Because ethyl alcohol impairs gluconeogenesis,hypoglycemia may occur 6–8 hrs after acute alcohol ingestionor as early as 1 hr after ingestion in a young child, especiallyif the child has not been fed for several hours. In this circumstance,a blood alcohol level confirms diagnosis.

Hepatic Disease

Hepatitis, cirrhosis, and Reye syndrome alsomay be associated with hypoglycemia. See Chap. 3, Alteration in Consciousness; Chap. 30, Hepatomegaly;and Chap. 36, Jaundice.

Metabolic Disorders

Glycogen Storage Diseases (Types O, I, III, VI)

Glycogenstorage disease type 0 is autosomal-recessive disorder caused bydeficiency in enzyme activity of hepatic glycogen synthetase.

Gene locus has been mapped to chromosome12p12.2.

Hypoglycemia and seizures occur withfasting. Serum insulin concentration is appropriately low.

Liver biopsy with enzyme assay confirmsdiagnosis.

Hypoglycemia and hepatomegaly may occurwith glycogen storage diseases types I, III, and VI (see Chap. 30, Hepatomegaly).

Disorders of Gluconeogenesis

Fructose 1,6-Diphosphatase Deficiency

Resultsin hypoglycemia only during caloric restriction (e.g., with intercurrentillness or in fasting state).

Gene locus of this autosomal-recessivedisorder has been mapped to chromosome 9q22.2-q22.3.

Characteristic features include hepatomegaly,failure to thrive, ketonuria, and lactic acidosis.

Liver biopsy with enzyme assay is diagnostic.

Phosphoenolpyruvate Carboxykinase Deficiency

Severe fastinghypoglycemia, which may occur during first day of life, can occurwith this enzyme deficiency.

Diagnosis is made by enzyme assay fromliver biopsy.

Other

Galactosemia, hereditary fructose intolerance,maple syrup urine disease, tyrosinemia, propionic acidemia, methylmalonicacidemia, and fatty acid oxidation disorders (especially medium-chainacyl-CoA dehydrogenase deficiency) are discussed in Chap. 3, Alteration in Consciousness,and Chap. 36, Jaundice.

Systemic Disorders

Septicemia, malnutrition, malabsorption,burns, and shock also may be associated with hypoglycemia.

Hypocalcemia

May be definedas total serum calcium concentration of <7 mg/dLin preterm infants and <8 mg/dL in infants andchildren. Ionized calcium concentration of <3 mg/dLis also abnormal.

Clinical features include poor feeding,tremulousness, lethargy, vomiting, cramps, abdominal distension,seizures, apnea, and tetany (in non-neonates).

Suspicion of hypocalcemia should beconfirmed with measurement of total and ionized serum calcium. Agentsthat complex calcium in blood (e.g., citrate and long-chain freefatty acids) can reduce serum ionized calcium without a decreasein serum calcium.

In neonatal period, hypocalcemia mayoccur during first 1–2 days of life (early) or toward endof first week of life (late). Early form can occur in very-low-birth-weightinfants, infants with perinatal asphyxia, and infants of diabeticmothers. Hypoparathyroidism and maternal hyperparathyroidism areother causes of early hypocalcemia.

Late occurrence of hypocalcemia maybe due to intake of high-phosphate milk, decreased calcium intestinalabsorption, hypoparathyroidism, and hypomagnesemia. Failure of hypocalcemiato respond to intravenous calcium should suggest coexisting hypomagnesemia.

Principal causes of hypocalcemia ininfants and children include decreased intake (nutritional), diminishedintestinal absorption of calcium, excessive calcium excretion (hypercalciuria),chronic renal failure, drugs (furosemide), excessive use of sodiumphosphate enemas, hypoparathyroidism, and vitamin D deficiency.The latter 2 disorders are discussed in the next section.

Hypoparathyroidism

Causes includefamilial hypoparathyroidism, DiGeorge syndrome, postsurgical hypoparathyroidism,autoimmune disease, resistance to parathyroid hormone, and idiopathic.

Diagnosis is confirmed by low serumcalcium, high serum phosphorous, and low serum parathyroid hormoneconcentrations. Specific cause needs to be investigated.

Vitamin D Deficiency

Deficiencyof vitamin D intake or defect in its metabolism may lead to hypocalcemia. Resultof these disturbances is rickets, which involves failure of bonemineralization. Most infantile rickets occurs in exclusively breast-fedterm babies who are not exposed to the sun.

Other causes of rickets include

Vitamin Dmalabsorption

Defective vitamin D synthesis (acquired25-hydroxylase deficiency from liver disease)

Congenital l-alpha-hydroxylase deficiency(also called vitamin D–dependent rickets)

Acquired l-alpha-hydroxylase deficiency(chronic renal failure)

Altered vitamin D metabolism from anticonvulsanttherapy (phenobarbital, phenytoin)

Hypophosphatemia (familial vitaminD–resistant rickets)

Dietary phosphate deficiency

Multiple renal tubular defects (Fanconisyndrome)

Clinical manifestations of ricketsdepend on age of child and degree of mineral depletion. Mild involvementmay only cause biochemical changes, whereas more severe involvementusually produces some of the following physical findings: frontalbossing, craniotabes, delayed closure of the fontanelles and sutures,enlarged costochondral junctions, enlarged wrists and ankles, bilateralbowing of the legs, lumbar lordosis, and diminished growth.

Radiographic changes include cuppingand fraying of metaphyses of rapidly growing bone, decreased densityof shafts of long bones, and pathologic fractures.

Lab findings in rickets include normalor low serum calcium, low serum phosphorus (except with renal osteodystrophy),and high serum alkaline phosphatase.

Specific cause must be investigated.

Hypomagnesemia

Occurs whenserum magnesium concentration is <1.5 mg/dL.

Clinical signs include tremors, nystagmus,seizures, and muscle weakness (chronic).

Causes of neonatal magnesium deficiencyinclude

Decreasedmagnesium intake (maternal magnesium deficiency, small-for-gestational ageinfants)

Diminished intestinal absorption (extensivesmall intestine resection)

Increased magnesium losses (chronicdiarrhea, extrahepatic biliary atresia, neonatal hepatitis, decreasedrenal tubular reabsorption)

Drugs (aminoglycosides, diuretics)

Maternal hyperparathyroidism

Increased phosphate intake

In infants and children, causes include

Chronic diarrhea

Intestinal malabsorption

Chronic renal disease, drugs (aminoglycosides,diuretics, cisplatin, cyclosporine)

Diabetes mellitus

Hyponatremia

Definedas serum sodium concentration of <130 mEq/L.

In low-birth-weight infants, diureticsgiven for chronic lung disease is common cause.

Other causes in neonates include excessivehypotonic replacement of fluid losses, hypovolemia with loss ofsodium in excess of water, and inappropriate secretion of antidiuretichormone. The latter may occur with hypoxic-ischemic encephalopathy,intracranial hemorrhage, and bacterial meningitis.

Frequent cause in young infants isfeeding of large amounts of water without any electrolyte. Anothercause is persistent diarrhea with loss of sodium in excess of water.

Hypernatremia

Definedas serum sodium >150 mEq/L.

In low-birth-weight infants, hypernatremiais usually due to severe insensible water loss or treatment of metabolicacidosis with large amounts of sodium bicarbonate.

Main causes in infancy and childhoodinclude diarrhea with water losses out of proportion to sodium losses,extensive burns, diabetes insipidus, and chronic renal disease.

Uremia

Various factors may cause seizures in childrenwith uremia, including uremia itself, hypocalcemia, hyponatremia,and hypertension.

Bilirubin Encephalopathy (Kernicterus)

Infants with kernicterus often have high-pitchedcry, poor feeding, decreased movements, opisthotonus, and seizures.Survivors usually have deafness, choreoathetosis, spasticity, andpsychomotor retardation (see Chap.3, Alteration in Consciousness).

Pyridoxine Dependency

Pyridoxine(vitamin B₆) dependency, a rare cause ofintractable neonatal seizures, usually presents in neonatal period,often during first day of life. Biochemical defect is unknown.

Seizures can be of any type. If noimmediate cause of neonatal seizures can be found and if they failto respond to usual therapy, trial of intravenous pyridoxine maybe given.

Cessation of seizures under EEG monitoringis best way to confirm diagnosis.

Inborn Errors of Metabolism

These disorders include galactosemia, hereditaryfructose intolerance, glycogen storage diseases, disorders of gluconeogenesis,and organic acidemias (maple syrup urine disease, disorders of fattyacid oxidation). They are mentioned in the section Hypoglycemia and discussedin Chap. 3, Alteration in Consciousness,and Chap. 13, Developmental Delay.

Selected Epileptic Syndromes

In addition to conditions discussed below,childhood absence epilepsy causes seizures. There are also unknowncauses.

Neonatal Seizures

Manifestationsof seizures in neonates may be different from those in infants andchildren. Neonatal seizures are often subtle and change from momentto moment. They rarely occur as isolated events but usually occurrepeatedly over a few hours or days. Generalized tonic-clonic seizuresrarely if ever occur in neonates. Main seizure types in neonatesare subtle (associated motor automatisms), clonic (focal or multifocal),tonic (focal or generalized), and myoclonic (focal, multifocal,generalized).

Mostcommon type of neonatal seizure is subtle, which may involve eyechanges (conjugate eye deviation, eye fluttering, blinking), mouthmovements (chewing, sucking, drooling, tongue thrusting), autonomicchanges (tachycardia, BP changes, pupillary dilatation), or apnea.Usually unassociated with ictal EEG changes, except when tonic eyedeviation occurs.

Clonic seizures involve rhythmic jerkingof 1 part of body that may be focal or multifocal. Focal seizurein neonates does not necessarily signify focal brain pathology.Can occur with generalized metabolic disturbance (e.g., hypoglycemia).Ictal EEG usually shows rhythmic discharges.

Tonic seizures involve extension oflimbs and are usually generalized. Seen most commonly with severebrain injury (hypoxic-ischemic encephalopathy, intracranial hemorrhage)and is usually not accompanied by ictal EEG changes.

Myoclonic seizures are characterizedby rapid isolated jerks of entire body or body parts. Usually signifiessevere brain injury (e.g., hypoxic-ischemic encephalopathy). Mayevolve into infantile spasms. Generalized myoclonic seizures areusually associated with abnormal ictal EEG, whereas it is unusualto see ictal changes with focal or multifocal myoclonic seizures.

Benign Neonatal Epilepsy

Benign formof neonatal seizures has been described in some families. Genetictransmission is autosomal-dominant and 2 genetic loci have beenmapped.

Seizures are often mixed, with tonicand clonic movements and motor automatisms.

Neurologic exam is normal.

Spontaneous remission usually occursafter several months.

Infantile Spasms (West Syndrome)

Infantilespasms, a form of generalized epilepsy, usually begin at 4–8mos of age.

The flexor spasm (salaam or jackknifeattacks) with sudden flexion of head, neck, and trunk, lasts a fewseconds and tends to occur in repetitive series of attacks, whichmay number up to several hundred episodes in 1 day.

Usual EEG finding is hypsarrhythmiapattern, which consists of high-voltage, irregular slow waves withspike-and-wave complexes.

Hypoxic-ischemic encephalopathy, perinatalinfections, cerebral dysgenesis, and various genetic (tuberous sclerosis)and metabolic disorders (phenylketonuria) are common causes of thistype of epilepsy.

Lennox-Gastaut Syndrome

Characterizedby seizures, developmental delay, and characteristic EEG pattern.It is not a pathologic entity, but rather diffuse encephalopathywith many causes (e.g., perinatal asphyxia, cerebral malformation,head trauma, CNS infection, metabolic disorders, and neurodegenerativediseases).

Seizures usually begin in children <3yrs of age and are difficult to control.

More than 1 seizure type may occur,and most common types are tonic-clonic, tonic, and myoclonic.

EEG usually shows bilateral, generalized,synchronous sharp and slow-wave discharges.

Benign Focal Epilepsy with Centrotemporal Spikes

Most commonsyndrome of simple partial epilepsy in childhood. Onset is usually2–14 yrs of age, with peak at 9–10 yrs.

Seizures are primarily motor and predominantlyaffect face and oropharyngeal musculature, often lasting 30–60secs and occurring usually while asleep or upon awakening.

Neurologic exam is normal. TypicalEEG shows repetitive spike focus in centrotemporal area.

Recurrences after 16 yrs of age areunusual.

Temporal Lobe Epilepsy

Temporallobe seizures are most common cause of partial complex seizuresin adolescents.

Usually preceded by aura, which mayconsist of head deviation and posturing in children <2 yrsof age, epigastric sensation associated with fear in young children,and hallucinations in older children.

Onset is often noted by staring episodes,lip smacking, or chewing movements.

Duration is usually 1–2 mins,which is longer than with absence seizures. Period of confusionor tiredness usually follows.

MRI may reveal anatomic abnormality(e.g., hamartoma, slow-growing glioma, cyst, arteriovenous malformation,or mesial temporal sclerosis).

Juvenile Myoclonic Epilepsy

Usual onsetis 12–18 yrs of age.

Myoclonic jerks affect mainly shouldersand arms and rarely lower extremities.

Consciousness is usually preserved.

Tonic-clonic or absence seizures alsomay occur.

Sleep deprivation and photic stimulationcan trigger this type of seizure.

Characteristic EEG shows generalizedspike/polyspike-and-wake discharges.

Posttraumatic Epilepsy

Head traumacan cause seizures at any age.

Risk of seizures is related to severityof trauma. Children with cerebral contusion, intracerebral hematoma,or loss of consciousness for >24 hrs are at risk for developingseizures.

Generalized or focal seizures can occuras acute reaction of the brain to trauma, in 1–2 wks followingtrauma, or months later.

Diagnostic Approach

Neonatal Seizures

Phenomena That May Be Confused with Seizures

Determining whether a seizure has occurredmay be difficult in some neonates. Seizures may consist of clonicmovements, tonic posturing of extremity, repetitive random or suckingmovements, or eye deviation. Recurrent apnea also may occur as amanifestation of a seizure disorder, but it is rarely the only manifestation.Jitteriness and benign myoclonic phenomena must be distinguishedfrom seizures.

Jitteriness

Jitteriness is stimulus sensitive and hasa tremulous quality. It ceases when extremity is held.

Benign Neonatal Sleep Myoclonus

Occurs duringdrowsiness and sleep but not during wakefulness.

Consists of isolated jerking movementsof arm or leg.

Pathologic myoclonic jerks in newbornsare not related to sleep; face and trunk may be involved, and EEGis abnormal.

Evaluation

Historyand physical exam suggest most likely causes of neonatal seizures.

Certain tests should be performed initially:CBC with differential; blood glucose and urea nitrogen; and serumelectrolytes, creatinine, calcium, phosphorus, and magnesium.

If meningitis or septicemia is suspected,spinal fluid analysis with appropriate cultures, blood culture,UA, and urine culture should be performed.

Imaging of brain with head U/Splus CT or MRI is useful for suspected brain malformations and intracranialhemorrhage.

The following tests should be consideredfor suspected metabolic disorders: serum ammonia, lactate, pyruvate,carnitine, liver function tests, amino acids, blood pH, and PCO₂;urine for reducing sugars, ketones, and organic acid analysis; andcerebrospinal fluid glycine. Simultaneous video-EEG recording mayclarify whether seizures are occurring and if so, what type theyare.

Blood glucose determination confirmspresence of hypoglycemia.

With symptomatic hypoglycemia, intravenousglucose should be given, but before glucose is given, blood sampleshould be drawn and held for subsequent tests.

Serum insulin level of >10μU/mL in presence of hypoglycemia is evidence forhyperinsulinemia.

Serum cortisol level of <10μg/dL suggests adrenal insufficiency. Low serum cortisoland growth hormone levels suggest pituitary disease.

Presence of hepatomegaly suggests galactosemia,hereditary fructose intolerance, or glycogen storage disease (typesI, III, VI). Urine positive for reducing sugars occurs with galactosemiaand hereditary fructose intolerance.

If diagnosis is uncertain and seizuresdo not respond to therapy, 100–200 mg of intravenous pyridoxinemay be given, while monitoring clinical and EEG responses.

Postneonatal Seizures

Phenomena That May Be Confused with Seizures

Clinical phenomena that may be confused withseizures are syncope, breath-holding spells, tics, benign paroxysmalvertigo, pseudoseizures, night terrors, migraine, and spasmus nutans.Manifestations of each are briefly described and contrasted withthose of seizures.

Syncope

May be precededby dizziness or nausea. There is loss of postural tone, and individual collapses.Bradycardia and lowered BP occur in neurocardiogenic syncope (commonfaint).

History may include evidence of anxiety,hyperventilation, systemic illness, fasting, or prolonged standing,especially in warm weather or in closed quarters.

Tonic-clonic movements are uncommon,and urine incontinence is rare.

After episode, confusion is uncommonand amnesia does not occur.

Breath-Holding Spells

Unusualbefore 6 mos of age and usually cease by 6 yrs of age.

Pallid breath holding, which is consideredvariant of neurocardiogenic syncope, usually follows acute painor an injury. Infant or child becomes pale and loses consciousness;however, complete recovery occurs in 1–2 mins.

More common is cyanotic breath-holdingspell, where infant or child cries, holds breath during expiration,and turns dusky until breathing occurs again. Prolonged episodemay result in tonic-clonic movements and loss of consciousness.

Tics

Recurrent involuntary movements that maymimic seizures. No loss or change in consciousness or postictalphenomena occur. Verbal tics also occur, especially in Tourettesyndrome.

Benign Paroxysmal Vertigo

Usuallydevelops in children 2–6 yrs of age.

Sudden episodes are associated withfalling, refusing to walk, nausea, vomiting, and nystagmus. Duringthe episode, ability to communicate and talk is retained.

Episodes may last seconds to minutesand can occur daily or every few months.

Pseudoseizures (Nonepileptic Events)

Typicallyoccur at 10–18 yrs of age and are more common in girls.They may be seen, however, in children as young as 4–6yrs of age.

These events represent a form of conversionreaction, sometimes as a result of physical or sexual abuse.

Episodes can mimic generalized tonic-clonic,tonic, and complex partial seizures, but they differ from true seizuresin several ways. Onset of movements gradually builds up to paroxysmcompared with sudden onset of epileptic attack. Motor movementsare not true clonic movements but range from quivering to flailingof extremities. Postures and verbalizations are unusual.

Afterward, most individuals becomeimmediately responsive and do not experience postictal state.

Urination and tongue biting are infrequentbut may occur. Episodes never occur during sleep and only infrequentlywhen child is alone.

Ictal EEG shows no paroxysmal discharges.

Pseudoseizures also can occur in individualswho have true seizures.

Night Terrors

Common in children 5–7 yrs of age,particularly in boys, and occur during slow-wave sleep. Childrenscream, thrash around, and appear frightened. Seem unaware of theirparents and surroundings. Difficult to console and do not rememberepisode. In contrast, nightmares occur during rapid eye movement sleep,and children can often recall episode.

Migraine

Transientconfusional states and focal neurologic signs may occur during migraine episode.

Family history of migraine usuallyexists.

Migraine and seizures may occur insame individual, so careful evaluation is important.

Spasmus Nutans

Characterized by triad of head nodding, nystagmus,and torticollis.

Evaluation

Once ithas been established that a seizure has occurred, seizure type andcause must be determined if possible. Direct observation or carefulhistory may permit physician to determine seizure type, but thisis not always possible, and EEG is often helpful.

Age of onset, type of seizure, medicalhistory, circumstances in which seizure occurs, and physical examhelp determine whether patient has epileptic syndrome. Importantto recognize particular epileptic syndrome to determine appropriatetherapy and prognosis as well as to assess genetic risk.

Child who presents with fever and seizureusually has either febrile seizure or intracranial infection (meningitisor encephalitis).

Lumbar puncture should be performedin any child with suspected meningitis or encephalitis.

Because clinical exam is more reliablein child >18 mos of age than in younger infant, lumbarpuncture may not be necessary in older child with simple febrileseizure who appears otherwise well and has normal physical exam.

With occurrence of nonfebrile seizure,serum sodium, glucose, calcium, magnesium, creatinine, and bloodurea nitrogen should be measured. Approach to hypoglycemia has alreadybeen discussed. EEG should be performed except for child with typicalfebrile seizure.

History of head trauma suggests presenceof contusion, skull fracture, or intracranial hemorrhage. Childabuse is frequent cause of head trauma, and other clues (e.g., obviousbruising) may be seen. Shaking injury may produce extensive traumawith no visible evidence of injury.

With history of head trauma and seizure,CT should be performed.

With evidence of increased intracranialpressure or focal findings including focal seizures, intracranialmass lesion should be suspected and CT or MRI should be performed.MRI is preferred over CT for diagnosis of small hamartomas or othermalformations, neuronal migrational disorders, and mesial temporalsclerosis.

Drug or poison ingestion is anotherpossible cause of acute seizure, and history may be diagnostic.Otherwise, urine toxicology screen may confirm diagnosis.

Cerebral angiography is useful in thediagnosis of a vascular lesion (e.g., cerebral aneurysm or arteriovenousmalformation).

Other tests should be ordered, dependingon presence of other findings (e.g., progressive neurologic syndrome).

If uncertain whether seizures are occurring,simultaneous video-EEG recording can be performed. Although EEGis useful to help confirm diagnosis of epilepsy and classify typeof seizures, normal interictal EEG may occur with epilepsy and abnormalEEG does not confirm diagnosis unless seizure has been clinicallyrecognized. EEG should be recorded during wakefulness and sleep,and maneuvers that may activate seizure activity (e.g., hyperventilation,photic stimulation, and sleep deprivation) should be performed.

References

1. Aicardi J. Epilepsy in children, 2nded. New York: Raven, 1994.
2. Aicardi J. Diseases of the nervous system in childhood,2nd ed. London: Mac Keith Press, 1998.
3. Avery GB, et al, eds. Neonatology: pathophysiologyand management of the newborn, 5th ed. Philadelphia: LippincottWilliams & Wilkins, 1999.
4. Behrman RE, et al., eds. Nelson textbook of pediatrics,16th ed. Philadelphia: WB Saunders, 2000.
5. Chasnoff IJ. Newborn infants with drug withdrawal symptoms.Pediatr Rev 1988;9:273–277.
6. Commission on Classification and Terminology of theInternational League Against Epilepsy. Proposal for revised clinicaland electroencephalographic classification of epileptic seizures.Epilepsia 1981;22:489–501.
7. Finegold DN, et al. Glycemic response to glucagon duringfasting hypoglycemia: an aid in the diagnosis of hyperinsulinism.J Pediatr 1980;96:257–259.
8. Fleisher GR, Ludwig S, eds. Textbook of pediatric emergencymedicine, 4th ed. Philadelphia: Lippincott Williams & Wilkins,2000.
9. Freeman JM. Febrile seizures: a consensus of theirsignificance, evaluation and treatment. Pediatrics 1980;66:109–111.
10. Online Mendelian Inheritance in Man (OMIM). McKusick-NathansInstitute for Genetic Medicine, Johns Hopkins University (Baltimore,MD) and National Center for Biotechnology Information, NationalLibrary of Medicine (Bethesda, MD), 2000. World Wide Web URL: http://www.ncbi.nlm.nih.gov/omim.
11. Rudolph AM, ed. Rudolph's pediatrics, 20thed. Stamford, CT: Appleton & Lange, 1996.
12. Schwartz RP. Neonatal hypoglycemia: how low is toolow? J Pediatr 1997;131:171–173.
13. Sperling MA. Pediatric endocrinology. Philadelphia:WB Saunders, 1996.
14. Stafstrom CE. Neonatal seizures. Pediatr Rev 1995;16:248–255.
15. Stanley CA. Hyperinsulinism in infants and children.Pediatr Clin North Am 1997;44:363–374.
16. Swaiman KF, Ashwal S, eds. Pediatric neurology: principlesand practice, 3rd ed. St. Louis: CV Mosby, 1999.
17. Volpe JJ. Neurology of the newborn, 4th ed. Philadelphia:WB Saunders, 2001.

'>>>>>>>>>>>>>>>

Book Source Details

• Book Title: The Diagnostic Approach to Symptoms and Signs in Pediatrics
• Author(s): Paul S. Bellet
• Year of Publication: 2006
• Copyright Details: The Diagnostic Approach to Symptoms and Signs in Pediatrics, Copyright © 2006 Lippincott Williams & Wilkins.

More About Petit mal seizures

• Back to disease: Petit mal seizures: Introduction
• Next Book Extract About Petit mal seizures: Carpopedal spasm (Nursing: Interpreting Signs and Symptoms)
• More Book Extracts: All Online Books for Petit mal seizures

More Medical Textbooks Online about Petit mal seizures

Review other book chapters online related to Petit mal seizures:

Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.

---

More About This Book: Title: The Diagnostic Approach to Symptoms and Signs in Pediatrics Authors: Paul S. Bellet Publisher: Lippincott Williams & Wilkins Copyright: 2006 ISBN: 0-78172-899-1

 » Next page: Carpopedal spasm (Nursing: Interpreting Signs and Symptoms)

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• Carpopedal spasm (Nursing: Interpreting Signs and Symptoms)
• Fasciculations (Nursing: Interpreting Signs and Symptoms)
• Level of consciousness, decreased (Nursing: Interpreting Signs and Symptoms)
• Myoclonus (Nursing: Interpreting Signs and Symptoms)
• Seizures, generalized tonic-clonic (Nursing: Interpreting Signs and Symptoms)

Tools & Services:

• Bookmark this page
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

homepage | back to top

Common Health Mistakes

Choose ... Alzheimers & Dementia Asthma Child ADHD ADHD in Adults Allergy Hypertension Bipolar Breast Cancer Celiac Disease Crohns Disease Colon Cancer Contraception Diabetes Cancer Depression Erectile Disorder Cholesterol COPD GERD Heartburn/Reflux Metabolic Syndrome Migraine/Headache Multiple Sclerosis Obesity Osteoporosis Overactive Bladder Psoriasis Sexual Disorder Sleep Disorders Smoking The Pill Ulcerative Colitis All Common Mistakes

Symptom
Checker

Choose... Fever Rash Pain Headache Fatigue Cough Other symptoms

Search Specialists by State and City

Choose... GENERAL PRACTICE CARDIAC HEALTH WOMEN'S HEALTH CANCER CARE RADIOLOGY MENTAL HEALTH PATHOLOGY EAR, NOSE, THROAT MEDICINE GENETICS NEUROLOGY DIALYSIS CARE SURGERY ORTHOPEDICS/SPORTS MEDICINE CHILDREN'S HEALTH OTHER SPECIALTIES