Alterations of Neurologic Function in Children Chapter 19 Mosby items and derived items © 2010,...

Alterations of Neurologic Function in Alterations of Neurologic Function in ChildrenChildren

Chapter 19Chapter 19

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.

2Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.

Embryonic Development of the Embryonic Development of the Neural SystemNeural System

Dorsal (posterior) inductionDorsal (posterior) induction Ventral (anterior) induction Ventral (anterior) induction Proliferation Proliferation Migration Migration OrganizationOrganization Myelination Myelination


Structure and Function of the Structure and Function of the Nervous System in ChildrenNervous System in Children

Develops from a dorsal thickening of the Develops from a dorsal thickening of the ectoderm (neural plate)ectoderm (neural plate) Neural groove and foldsNeural groove and folds Neural tubeNeural tube Neural crestNeural crest

Mesoderm Mesoderm Blood vessels, microglial cells, dural and Blood vessels, microglial cells, dural and

arachnoid layers of the meninges, the capsule of arachnoid layers of the meninges, the capsule of some peripheral nerve endings, and nerve some peripheral nerve endings, and nerve coveringscoverings



Sulcus limitansSulcus limitans Basal plateBasal plate Alar plateAlar plate SuturesSutures FontanelsFontanels Myelin sheathMyelin sheath

A lipid-protein sheath A lipid-protein sheath


Neural Tube Defects (NTD)Neural Tube Defects (NTD)

Caused by an arrest of the normal Caused by an arrest of the normal development of the brain and spinal cord development of the brain and spinal cord

Occurs in about 3000 U.S. pregnancies/yr Occurs in about 3000 U.S. pregnancies/yr Strong association of fetal death Strong association of fetal death

Reduces the actual prevalence of neural defects Reduces the actual prevalence of neural defects at birthat birth

Maternal folate deficiency Maternal folate deficiency Periconceptional supplementation with folic acid Periconceptional supplementation with folic acid

can reduce NTD by up to 70% can reduce NTD by up to 70%


Structural MalformationsStructural Malformations Defects of neural tube closureDefects of neural tube closure

AnencephalyAnencephaly EncephaloceleEncephalocele MeningoceleMeningocele MyelomeningoceleMyelomeningocele

• Arnold-Chiari type II malformationArnold-Chiari type II malformation

• Tethered cord syndromeTethered cord syndrome


Structural MalformationsStructural Malformations


Axial Skeleton MalformationsAxial Skeleton Malformations

Spina bifida occultaSpina bifida occulta Vertebral defect that allows the protrusion of the Vertebral defect that allows the protrusion of the

neural tube contentsneural tube contents Cranial deformitiesCranial deformities

AcraniaAcrania CraniosynostosisCraniosynostosis MicrocephalyMicrocephaly Congenital hydrocephalusCongenital hydrocephalus

• Macewen sign (“cracked pot” sign)Macewen sign (“cracked pot” sign)


EncephalopathiesEncephalopathies

Static encephalopathiesStatic encephalopathies Cerebral palsy: a diverse group of nonprogressive Cerebral palsy: a diverse group of nonprogressive

syndromes that affect the brain and cause motor syndromes that affect the brain and cause motor dysfunction beginning in early infancy dysfunction beginning in early infancy • Static cerebral palsyStatic cerebral palsy

• Dyskinetic cerebral palsyDyskinetic cerebral palsy

• Ataxic cerebral palsyAtaxic cerebral palsy


Inherited Metabolic Disorders of Inherited Metabolic Disorders of the Central Nervous Systemthe Central Nervous System

Defects in amino acid metabolismDefects in amino acid metabolism Phenylketonuria (PKU)Phenylketonuria (PKU)

• HyperphenylalaninemiaHyperphenylalaninemia

Defects in lipid metabolismDefects in lipid metabolism Lysosomal storage diseasesLysosomal storage diseases Tay-Sachs diseaseTay-Sachs disease


Seizure DisordersSeizure Disorders EpilepsyEpilepsy

Partial seizuresPartial seizures Generalized seizuresGeneralized seizures Unclassified epileptic seizuresUnclassified epileptic seizures

• Infantile spasmsInfantile spasms

• Lennox-Gastaut syndromeLennox-Gastaut syndrome

• Juvenile myoclonic epilepsyJuvenile myoclonic epilepsy


Benign Febrile SeizuresBenign Febrile Seizures

Occur in 2% to 5% of childrenOccur in 2% to 5% of children Brief and self-limited Brief and self-limited Often between ages 6 months and 5 yearsOften between ages 6 months and 5 years

Peak incidence at 14 to 18 monthsPeak incidence at 14 to 18 months Pathogenesis unknown Pathogenesis unknown

Influencing factors: age, degree and rate of Influencing factors: age, degree and rate of temperature elevation, nature of illness temperature elevation, nature of illness


Status EpilepticusStatus Epilepticus Continuing or recurring seizure activity Continuing or recurring seizure activity

Recovery from seizure activity is incompleteRecovery from seizure activity is incomplete Seizure activity is unrelenting Seizure activity is unrelenting

• Usually lasts for 30+ minutes Usually lasts for 30+ minutes

• Any seizure activity can evolve into status epilepticusAny seizure activity can evolve into status epilepticus

Status epilepticus is a medical emergency that Status epilepticus is a medical emergency that requires immediate intervention requires immediate intervention


Acute EncephalopathiesAcute Encephalopathies Reye syndromeReye syndrome

Usually associated with influenza B or varicella virus Usually associated with influenza B or varicella virus infections in children who have taken aspirin infections in children who have taken aspirin

Pathology unknown Pathology unknown Inborn errors of metabolism are a contributing factor Inborn errors of metabolism are a contributing factor Profound hypoglycemia, hypoketonemia, Profound hypoglycemia, hypoketonemia,

hyperammonemia, increase in serum short-chain fatty hyperammonemia, increase in serum short-chain fatty acidsacids

Liver shows diffuse deposits of lipids and absence of Liver shows diffuse deposits of lipids and absence of any inflammatory reaction or necrosis any inflammatory reaction or necrosis

Fatty degeneration of the kidneys leads to azotemia Fatty degeneration of the kidneys leads to azotemia (excess urea in the blood) (excess urea in the blood)

Brain is extremely edematousBrain is extremely edematous


Acute EncephalopathiesAcute Encephalopathies MeningitisMeningitis

Inflammation of the meningeal coverings of the Inflammation of the meningeal coverings of the brain and spinal cord brain and spinal cord • Bacterial meningitisBacterial meningitis

6000 cases per year; half in children younger than 18 6000 cases per year; half in children younger than 18

• Viral meningitisViral meningitis Hallmark of viral meningitis or aseptic meningitis is a Hallmark of viral meningitis or aseptic meningitis is a

mononuclear response in the CSF and the presence of mononuclear response in the CSF and the presence of normal blood glucose levelnormal blood glucose level


Children and HIVChildren and HIV HIV infections in childrenHIV infections in children

Perinatally through the placentaPerinatally through the placenta Exposure to infected maternal blood and vaginal Exposure to infected maternal blood and vaginal

secretionssecretions Postpartum ingestion of breast milkPostpartum ingestion of breast milk


Cerebrovascular DiseaseCerebrovascular Disease Cerebrovascular disease in children differs in Cerebrovascular disease in children differs in

adults in three waysadults in three ways Absence of predisposing factorsAbsence of predisposing factors Differences in the clinical responseDifferences in the clinical response Anatomic site of the pathologic conditionAnatomic site of the pathologic condition

Occlusive cerebrovascular diseaseOcclusive cerebrovascular disease Hemorrhagic cerebrovascular diseaseHemorrhagic cerebrovascular disease


Childhood TumorsChildhood Tumors Most common solid tumor and second most Most common solid tumor and second most

common primary neoplasm common primary neoplasm Primary is leukemiaPrimary is leukemia

~50% of solid tumors are nonmalignant ~50% of solid tumors are nonmalignant Account for 20% of all childhood cancers Account for 20% of all childhood cancers

Annual incidence of 2.4 to 4 per 100,000 Annual incidence of 2.4 to 4 per 100,000 2000 cases are diagnosed each year2000 cases are diagnosed each year

The leading cause of death from disease in The leading cause of death from disease in children 1 to 15 years children 1 to 15 years


Childhood TumorsChildhood Tumors Brain tumorsBrain tumors

MedulloblastomaMedulloblastoma EpendymomaEpendymoma AstrocytomaAstrocytoma Brainstem gliomaBrainstem glioma Optic nerve gliomaOptic nerve glioma


Childhood Brain TumorsChildhood Brain Tumors


Childhood TumorsChildhood Tumors Embryonal tumorsEmbryonal tumors

Neuroblastoma (aggressive tumor)Neuroblastoma (aggressive tumor)• Originates in neural crest cells (develop into sympathetic Originates in neural crest cells (develop into sympathetic

nervous system) nervous system)

• Most diagnosed during first 2 years Most diagnosed during first 2 years

• 75% found before child is 5 years75% found before child is 5 years

• Abdomen (65%) most often in the adrenal medulla Abdomen (65%) most often in the adrenal medulla

• Mediastinum (15%)Mediastinum (15%)


Childhood TumorsChildhood Tumors Embryonal tumorsEmbryonal tumors

Retinoblastoma (rare congenital eye tumor)Retinoblastoma (rare congenital eye tumor) Rarely diagnosed after age 5 Rarely diagnosed after age 5 40% inherited as autosomal dominant disorder40% inherited as autosomal dominant disorder Prognosis for most children is excellent, with a Prognosis for most children is excellent, with a

greater than 90% long-term survivalgreater than 90% long-term survival• Children with bilateral or metastatic disease have a poor Children with bilateral or metastatic disease have a poor

prognosis prognosis • About 75% have useful vision in the treated eyeAbout 75% have useful vision in the treated eye


Childhood TumorsChildhood Tumors

Alterations of Neurologic Function in Children Chapter 19 Mosby items and derived items © 2010,...

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