14 I Fall 2004 The Child’s Doctor

Educational ObjectivesAt the conclusion of thisactivity, participants will beable to:

• Describe the underlyingcauses of cerebral palsy

• Direct the initial assessmentof a child with cerebral palsy

• Recognize when a referral toa pediatric neurologist isrequired in the evaluationand management of a childwith cerebral palsy

DiagnosisCP is usually recognized early in life when achild fails to reach motor milestones at theappropriate chronological age. Diagnosis is basedon detailed history and physical examination,including a neurological evaluation.

Since CP is distinguished from degenerativebrain disorders, medical history must establishthat the child is not losing previously acquiredfunction. However, some neurological disorders,due to slow progression of symptoms, mayinitially be mistaken for CP (eg, dopa-responsivedystonia, hereditary spastic paraplegia, ataxiatelangiectasia). These conditions may be suggestedby unusual complaints, a history of progressingdeficits, characteristic abnormalities onneuroimaging studies, or a family history ofchildhood neurologic disorder with associated CP.

During examination, pediatricians should checkdevelopmental reflexes, muscle tone, deeptendon reflexes, and plantar responses.Attention should be paid to reflexes that areretained for abnormally long periods, which iscommon for children with CP. The Moro reflex,for example, tends to be seen beyond the usual6 months in children with CP. However,children with CP may develop hand preferencemuch earlier than usual (age 3).

It is also useful to classify the clinical type of CP,since this has implications regarding etiologyand associated conditions, as discussed in moredetail below. In one study, 44% of the CPpopulation were spastic diplegic, 33% spastichemiplegic, and 6% spastic quadriplegic. Evenless common presentations include ataxic anddyskinetic CP.2

EtiologyThe brain abnormality resulting in CP mayhave been caused by various antenatal, perinataland postnatal events. In the past, the mostcommon cause of CP in the term or near terminfant was thought to be intrapartum hypoxic-ischemic injury, often called perinatal asphyxia.It is now known that hypoxia-ischemia is notthe only cause of neonatal encephalopathy, andthat CP is rarely caused by hypoxia-ischemia.Epidemiological studies have established thatantenatal factors account for as much as 70% ofacute neonatal encephalopathy.3

Furthermore, not all cases of neonatalencephalopathy result in CP. Mild encephalopathyis invariably associated with favorable prognosis,and normal outcome is seen in about 75%-80%infants with moderate encephalopathy.4 Allinfants with severe encephalopathy stringentlydefined have a poor outcome.4

According to the essential criteria developed bythe American College of Obstetricians andGynecologists,3 in order to attribute CP tointrapartum hypoxia, the child born at 34 ormore weeks of gestation must have had theclinical signs of severe or moderate neonatalencephalopathy, defined as seizures, abnormaltone, poor feeding, and a depressed level ofconsciousness within the first 24 hours of life.Computed tomography (CT) scan andelectroencephalogram (EEG) if obtained will beabnormal. In addition, evidence of a metabolicacidosis in fetal umbilical cord arterial bloodobtained at delivery (pH<7 and base deficit≥12mmol/L) is needed, as well as exclusion of otheridentifiable etiologies such as trauma,

C M E F E A T U R E

Initial Assessment of a Child with Cerebral Palsy

Cerebral palsy (CP), defined as a nonprogressive disorder of posture or movement due to a

lesion in the developing brain, occurs annually in about 10 000 infants born in the U.S.1 To help

pediatricians assess a child with this common disorder, this review will highlight the latest

findings on pathogenesis of CP, summarize the new recommendations for diagnostic testing,

and discuss the prognostic implications of various types of brain injury responsible for CP.

LEON G. EPSTEIN, MD

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coagulation disorders, infectious conditions, or genetic disorders.Finally, the only forms of CP attributable to acute hypoxicintrapartum events are spastic quadriplegic and, less commonly,the dyskinetic type.

Spastic quadriplegia, however, may result from causes other thanintrapartum hypoxia. Also, purely dyskinetic or ataxic CP,especially with an associated learning difficulty, commonly has agenetic etiology and is rarely caused by intrapartum orperipartum asphyxia.

Spastic hemiplegia and spastic diplegia are almost always due toantepartum events, the latter occurring almost exclusively inpreterm babies.5 Generally, infants born very prematurely or withlow birth weight are at higher risk for CP, compared to term ornear-term infants.

CP with antenatal origins is often due to infections duringpregnancy (eg, rubella, cytomegalovirus, toxoplasmosis), stroke,toxemia, or placental abruption.6 Other antenatal factorsassociated with CP include intrauterine growth restrictions,multiple pregnancies, coagulation disorders, antepartumbleeding, congenital or genetic anomalies, and infertilitytreatments.3 In addition to hypoxic-ischemic encephalopathy,other causes of CP with perinatal onset include kernicterus andtrauma.6 Postnatal causes of CP include brain infections (eg,bacterial meningitis, viral encephalitis), progressive hydrocephalus,or brain injury from car accidents, falls, or child abuse.6

Diagnostic testingThe role of diagnostic testing is to clarify the etiology andsuggest the prognosis based on the type and severity ofconfirmed brain injury. In the recently published guidelines fromthe American Academy of Neurology and the Child NeurologySociety,6 neuroimaging is recommended as the initial diagnosticstudy in children with CP. See images 1-4 on page 16 forexamples of neuroimaging studies used as diagnostic tools in CPevaluation. The guidelines do not recommend routine use ofmetabolic and genetic testing, coagulation studies, or EEG.However, since 70% of children with CP have associatedconditions,1 early screening is advised for potential cognitivedelay, vision and hearing impairments, speech and languagedisorders, and swallowing disorders.

MRI or CT: The AAN/CNS review of research concluded thatmagnetic resonance imaging (MRI) is preferable to CT, sinceMRI was abnormal in 89% of children with CP, compared to77% of cases with abnormal CT findings. MRI also is moresensitive than CT in detecting periventricular leukomalacia,other perinatally acquired lesions, and subtle congenital

anomalies of brain development, and is more useful indetermining whether the brain injury was antenatal, perinatal, orpostnatal. Periventricular white matter damage (eg, periventricularleukomalacia) is frequently found in children with CP who werepreterm births. A child with CP who was a preterm birth andsuffered severe cerebral hypoperfusion during early fetal life,however, will usually have injury that is mostly in the deep graymatter and brain stem nuclei. In term births, severe reduction tocerebral blood flow more commonly causes injury to subcorticalwhite matter and cerebral cortex.7

Genetic and metabolic testing: Since the introduction ofneuroimaging, congenital brain malformations have beendiscovered in some children with CP (12% on MRI and 7% onCT).6 These malformations include lissencephaly, schizencephaly,and pachygyria, which have been associated with specific geneticdisorders (eg, lissencephaly/Miller-Dieker syndrome/chromosome 17p13.3, Zellweger syndrome). Also, somemetabolic disorders may appear as CP. These disorders includeglutaric aciduria (type 1), Lesch-Nyhan syndrome, 3-methylglutaconic aciduria, pyruvate dehydrogenase deficiency,and female carriers of ornithine transcarbamylase deficiency. If abrain malformation is found in a child with CP, or ifneuroimaging does not show a specific structural abnormality,genetic or metabolic testing is warranted.

Coagulopathies: Diagnostic testing for coagulation disordersshould be considered only in children with spastic hemiplegicCP, since neuroimaging shows high incidence of unexplainedcerebral infarction in these children. Coagulation disorders mayinclude Factor V Leiden deficiency, the presence of anticardiolipinor antiphospholipid antibodies, and Protein C or S deficiency.

Epilepsy and EEG: Although epilepsy accompanies cerebral palsyin 45% of cases,6 routine EEG is not useful during initialevaluation, since it does not help to determine the etiology ofCP. An EEG is recommended only when epileptic features arepresent. Epilepsy is seen more often in children with spasticquadriplegia or hemiplegia, compared to children with othertypes of CP.

Children with CP and epilepsy are classified as havingsymptomatic epilepsy. Children with epilepsy associated with CPare more likely to have neonatal seizures and seizures within thefirst year of life, status epilepticus, and a need for polytherapy.These children are more likely to have partial seizures and are lesslikely to become seizure free. In children with CP and epilepsy,favorable factors associated with a seizure-free period of 1 year ormore include normal intelligence, single seizure type,monotherapy, and spastic diplegia.8

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16 I Fall 2004 The Child’s Doctor

Screening for other associated conditions: Screening forconditions commonly found in children with CP must beincluded in the initial evaluation. Cognitive delay occurs in 52%of children with CP, and it is more likely to be present ifneuroimaging studies are abnormal than if they are normal orhave minor abnormalities.9 Also, type and etiology of CP areassociated with specific disorders. For example, mental impairmenttends be more severe in children with spastic quadriplegia thanin children with spastic hemiplegia or diplegia. Visual problems,found in 28% of cases, are more likely in children whose CP wascaused by periventricular leukomalacia.6 Hearing impairmentoccurs in 12% of children with CP, and is more frequent whenCP is related to very low birth weight, kernicterus, neonatalmeningitis, or severe hypoxic-ischemic insults.6

Prognostic implications of neuroimaging findingsNeuroimaging is helpful in determining prognosis. Outcomes areless favorable in children with bilateral injury involving corticaland subcortical structures usually associated with a spasticquadriparetic type of CP. Neuroimaging findings of atrophy,abnormal gray matter configuration, and marked leukomalaciausually imply severe impairment.10

In very premature infants, selective vulnerability of theperiventricular white matter to ischemic injury produces diplegicCP with greater motor deficit in the lower extremities comparedto the upper extremities. In term infants, white matter lesionswith internal capsule involvement are associated with abnormalmotor outcome, whereas moderate white matter changes withnormal internal capsule are correlated with normal motor function.11

Extensive bilateral cerebral and basal ganglia lesions, associatedwith spastic quadriplegia and the most adverse outcome,commonly signal epilepsy and severe cognitive, motor, visual andauditory impairments.11 Mild basal ganglia lesions, however, arefound in dyskinetic type of CP and indicate minor neuro-motorabnormalities and sometimes normal cognitive development.11

Children with focal ischemic injury (stroke) limited to 1hemisphere will usually have a residual hemiparesis, but are likelyto have normal or nearly normal cognitive function. The MRIwill show loss of brain parenchyma and compensatory increase inthe size of the ventricles and subarachnoid spaces on the involvedside. Partial seizures with or without secondary generalization arealso common with this type of injury.

Although neuroimaging studies help to assess prognosis for achild’s CP, more substantial prognostic information must bederived by considering imaging data in combination with clinicalevaluation.

C E R E B R A L P A L S Y ( c o n t . )

Image 1: MRI axial T2sequence of a 14-month-oldgirl with a right hemiparesis.There is an abnormalhyperintense signal in thewhite matter of the righthemisphere indicating an old(antepartum) infarct.

Image 2: MRI axial T1sequence of a 14-month-oldboy with microcephaly anddelayed motor development.The MRI demonstratesenlarged ventricles and alarge porencephalic cyst in theleft frontal lobe with a thinrim of residual cortex. Thereis also thickened andsimplified cortex (pachygyria)in the right frontal lobe.

Image 3: CT scan of an 18-month-old girl bornprematurely who sustainedan intraventricularhemorrhage. She has a lefthemiparesis and a milddegree of spastic diparesis.The CT scan demonstratesenlargement of the rightlateral ventricle.

Image 4: CT scan of a 5-month-old boy with asevere spastic quadriparesisand acquired microcephalyassociated with anintrapartum hypoxic-ischemicinjury. The scan showsmarked diffuse atrophy andencephalomalacia withsecondary enlargement of theventricles and sulci.

* Note that for all images the left side of the brain appears on the right side of the image.

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R E F E R E N C E S

[1.] Boyle CA, Yeargin-Allsopp M, Doernberg NS, et al. Prevalence ofselected developmental disabilities in children 3-10 years of age: theMetropolitan Atlanta Developmental Disabilities Surveillance. MMWR1996;45:1–14.

[2.] Hagberg B, Hagberg G, Beckung E, et al. Changing panorama ofcerebral palsy in Sweden. VIII. Prevalence and origin in the birth yearperiod 1991–94. Acta Paediatr 2001;90:271–277.

[3.] American College of Obstetricians and Gynecologists Task Force onNeonatal Encephalopathy and Cerebral Palsy. Neonatal Encephalopathyand Cerebral Palsy: Defining the Pathogenesis and Pathophysiology.Washington, DC: ACOG; 2003.

[4.] Volpe JJ. Neurology of the Inborn. 4th ed. Philadelphia, PA: WBSaunders; 2001.

[5.] Nelson KB, Grether JK. Potentially asphyxiating conditions andspastic cerebral palsy in infants of normal birth weight. Am J ObstetGynecol 1998;179:507-513.

[6.] Ashwal S, Russman BS, Blasco PA, et al. Practice Parameter:Diagnostic assessment of the child with cerebral palsy: Report of theQuality Standards Subcommittee of the American Academy of Neurologyand the Practice Committee of the Child Neurology Society. Neurology2004;62(6):851-863.

[7.] Barkovich AJ, Hallam D. Neuroimaging in perinatal hypoxicischemic injury. Ment Retard Dev Disabil Res Rev 1997;3:28-41.

[8.] Wallace SJ. Epilepsy in cerebral palsy. Dev Med Child Neurol2001;43:713-717.

[9.] Schouman-Claeys E, Picard A, Lalande G, et al. Contribution ofcomputed tomography in the aetiology and prognosis of cerebral palsy inchildren. Br J Radiol 1989;62:248-252.

[10.] Yokochi K, Hosoe A, Shimabukuro S, et al. Gross motor patterns inchildren with cerebral palsy and spastic diplegia. Pediatr Neurol1990;6:245.

[11.] Mercuri E, Barnett AL. Neonatal brain MRI and motor outcome inschool age children with neonatal encephalopathy: A review of personalexperience. Neural Plasticity 2003;10(1-2):51-57.

LEON G. EPSTEIN, MD

Derry A. and Donald L. Shoemaker Professor of PediatricNeurology, Division Head, Neurology, Children’s MemorialHospital; Deputy Director for Clinical Research, Children’sMemorial Research Center; Associate Director of General ClinicalResearch Center, Feinberg School of Medicine, NorthwesternUniversity; Chicago, Illinois

lepstein@childrensmemorial.org

Pediatric neurology consultationIn evaluation and management of a child with cerebral palsy,consultation with a pediatric neurologist should be consideredwhen there are questions about accuracy of the diagnosis, todetermine the underlying cause, or if there are unusual clinicalfeatures to suggest that the child may have a progressive ratherthan a static condition. A pediatric neurologist may also helpto inform parents about initial evaluation, interpretation ofneuroimaging studies, and prognosis. Severe cases can bereferred to a pediatric neurologist for regular evaluations onannual or semiannual basis, and for coordination of therapywith physical, occupational and speech therapists, and withorthopedic specialists. Finally, a referral is needed when thereare associated neurological problems, in particular seizures,which may be difficult to control.

Conclusion CP is common and will be seen in most pediatric practices.There are multiple causes of CP and the pediatrician shouldnot assume that minor events in the intrapartum period areresponsible without careful consideration of the criteria forneonatal encephalopathy and a thorough investigation forother causes. There are medical-legal implications to casualcomments or written notes regarding the etiology of CP evenif these are not well founded. Neuroimaging, in particularMRI, is the most useful diagnostic tool for children with CP.Neurological consultation is most often justified to helpestablish the type of cerebral palsy and to discuss prognosiswith the child’s parents. ■

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