Upload
feregodoc
View
231
Download
0
Embed Size (px)
Citation preview
7/27/2019 Parametros Practicos Evaluacion TGD
1/60
Practice parameter:
Evaluation of the child with
global developmental delay
Report of the Quality Standards Subcommittee of the AmericanAcademy of Neurology and
The Practice Committee of the Child Neurology Society
M. Shevell, MD; S. Ashwal, MD; D. Donley, MD; J. Flint, MD; M.Gingold, MD; D. Hirtz, MD; A. Majnemer, PhD;
M. Noetzel, MD; and R.D. Sheth, MD.
Published in Neurology2003; 60:367-380
7/27/2019 Parametros Practicos Evaluacion TGD
2/60
Objective of the guideline:
To make evidence-based recommendations
concerning the evaluation of the child with a non-
progressive global developmental delay.
7/27/2019 Parametros Practicos Evaluacion TGD
3/60
Methods of evidence review: Literature searches were conducted with the assistance of the
University of Minnesota Biomedical Information Services for
relevant articles published from 1980 to 2000. Databases
searched included MEDLINE, Healthstar, ERIC and CINAHL.
A bibliography of the 160 articles identified and reviewed forpreparation of this parameter is available at the American
Academy of Neurology Web site (http://www.aan.com/).
Each article was reviewed, abstracted, and classified by a
committee member. A four-tiered classification scheme for
diagnostic evidence recently approved by the Quality
Standards Subcommittee was utilized as part of this
assessment.
7/27/2019 Parametros Practicos Evaluacion TGD
4/60
AAN evidence classification
scheme for a diagnostic articleClass I:Evidence provided by a prospective study in a broad
spectrum of persons with the suspected condition, using a gold
standard for case definition, where the test is applied in a blinded
evaluation, and enabling the assessment of appropriate tests ofdiagnostic accuracy.
Class II:Evidence provided by a prospective study of a narrow
spectrum of persons with the suspected condition, or a well
designed retrospective study of a broad spectrum of persons withan established condition (by gold standard) compared to a broad
spectrum of controls, where test is applied in a blinded evaluation,
and enabling the assessment of appropriated tests of diagnostic
accuracy.
7/27/2019 Parametros Practicos Evaluacion TGD
5/60
AAN evidence classification
scheme for a diagnostic article
Class III:Evidence provided by a retrospective study where either
persons with the established condition or controls are of a narrow
spectrum, and where test is applied in a blinded evaluation.
Class IV:Any design where test is not applied in blinded evaluation
OR evidence provided by expert opinion alone or in descriptive
case series (without controls).
7/27/2019 Parametros Practicos Evaluacion TGD
6/60
AAN system for translation of
evidence to recommendations
Translation of evidence to
recommendations
Rating of recommendations
Level Arating requires at leastone convincing class I study or
at least two consistent,
convincing class II studies
A = Established asuseful/predictive or not
useful/predictive for the given
condition in the specified
population
Level Brating requires at leastone convincing class II study or
overwhelming class III evidence
B = Probably useful/predictive ornot useful/predictive for the
given condition in the specified
population
7/27/2019 Parametros Practicos Evaluacion TGD
7/60
AAN system for translation of
evidence to recommendations
Translation of evidence to
recommendations
Rating of recommendations
Level Crating requires at leasttwo convincing class III studies
C = Possibly useful/predictive ornot useful/predictive for the
given condition in the specified
population
U = Data inadequate or
conflicting. Given currentknowledge, test, predictor is
unproven
7/27/2019 Parametros Practicos Evaluacion TGD
8/60
Introduction
Developmental disabilities are a group of related chronicdisorders of early onset estimated to affect 5% to 10% ofchildren.
Global developmental delayis a subset of developmentaldisabilities defined as significant delay in two or more of thefollowing developmental domains:
gross/fine motor
speech/language, cognition
social/personal activities of daily living
Significant delay is defined as performance two standarddeviations or more below the mean on age-appropriate,standardized norm-referenced testing.
7/27/2019 Parametros Practicos Evaluacion TGD
9/60
IntroductionThe term global developmental delay is usually reserved foryounger children (i.e., typically less than 5 years of age),whereas the term mental retardation is usually applied to olderchildren when IQ testing is more valid and reliable.
Prevalence:
The precise prevalence of global developmental delay isunknown.
Estimates of 1% to 3% of children younger than 5 years of age
are reasonable given the prevalence of mental retardation in thegeneral population.
Based on approximately 4 million annual births in the UnitedStates and Canada, between 40,000 to 120,000 children borneach year in these two countries will manifest globaldevelopmental delay.
7/27/2019 Parametros Practicos Evaluacion TGD
10/60
Clinical Question
What is the diagnostic yield of metabolic and genetic
investigations in children with global developmental
delay?
7/27/2019 Parametros Practicos Evaluacion TGD
11/60
Analysis of the Evidence
Metabolic testing in children with globaldevelopmental delay
Reference Class N
Results
(% patients with abnormal screening)
33 II 151 26% for mild delay; 77% for severe
delay; genetic etiology in 28%, 5%
were metabolic disorders
34 III 1,087 0.6%.; standardized biochemicalscreening
7/27/2019 Parametros Practicos Evaluacion TGD
12/60
Analysis of the Evidence
Metabolic testing in children with globaldevelopmental delay
Reference Class N
Results
(% patients with abnormal screening)
35 III 1,568 1.3%; standardized
biochemical screening
7 III 60 63% with all testing but less than 1%
for metabolic testing
36 III 281 5< 5%; nonstandardized evaluation;
etiologic yield of 72% for whole group
7/27/2019 Parametros Practicos Evaluacion TGD
13/60
Analysis of the Evidence
Metabolic testing in children with globaldevelopmental delay
Reference Class N
Results
(% patients with abnormal screening)
28 III 99
7/27/2019 Parametros Practicos Evaluacion TGD
14/60
Conclusions
Routine screening for inborn errors of metabolism in children
with global developmental delay has a yield of about 1% that
can, in particular situations such as relatively homogeneous
and isolated populations or if there are clinical indicators,
increase up to 5%. When stepwise screening is performed the
yield may increase to about 14%.
7/27/2019 Parametros Practicos Evaluacion TGD
15/60
Analysis of the Evidence
Cytogenetic studiesreporting cytogenetic andfragile X
Reference Class N Results
% of patients with abnormal results on
cytogenetic studies
41 III 2,757 2.93% (2.61% also had FraX)
42 III 256 3.9%
43 III 274 4.7% (9.1% also had FraX)
44 III 166 5.4%
7/27/2019 Parametros Practicos Evaluacion TGD
16/60
Analysis of the Evidence
Cytogenetic studiesreporting cytogenetic andfragile X
Reference Class N Results
% of patients with abnormal results on
cytogenetic studies
28 III 99 7.1 %
29 III 120 11.6% (2.3% also had FraX)
7 IV 60 10%
45 IV 170 3.5%
7/27/2019 Parametros Practicos Evaluacion TGD
17/60
Analysis of the Evidence
Cytogenetic studiesreporting on fragile Xprevalence
Reference Class N Results
% of patents with fragile X (FraX)
47 II 1,581 0.7% FraX overall with 1.0% in males,
0.3% in females, and 7.6% in males
with clinically pre-selected criteria
48 II 80 0% females with FraX
49 II 20 0% females with FraX
50 II 278 0.3% females with FraX
7/27/2019 Parametros Practicos Evaluacion TGD
18/60
Analysis of the Evidence
Cytogenetic studiesreporting on fragile Xprevalence
Reference Class N Results
% of patents with fragile X (FraX)
51 II 128 3.9% females with FraX
52 II 50 4.0% females with FraX
53 II 194 4.1% females with FraX
54 II 35 11.4% females with FraX
7/27/2019 Parametros Practicos Evaluacion TGD
19/60
Analysis of the Evidence
Cytogenetic studiesreporting on fragile Xprevalence
Reference Class N Results
% of patents with fragile X (FraX)
55 III 103 3.9% FraX
56 IV 4,940 5.3% FraX
7/27/2019 Parametros Practicos Evaluacion TGD
20/60
Analysis of the EvidenceCytogenetic studiestesting for Rett syndrome
Patients with classic Rett syndrome appear to develop normally
until 6 to 18 months of age, then gradually lose speech and
purposeful hand use, and develop abnormal deceleration of
head growth that may lead to microcephaly.
Seizures, autistic-like behavior, ataxia, intermittent
hyperventilation, and stereotypic hand movements occur in
most patients.
Rett syndrome is believed to be one of the leading causes of
global developmental delay/mental retardation in females and
is caused by mutations in the X-linked gene encoding methyl-
CpG-binding protein 2 (MECP2). About 80% of patients with
Rett syndrome have MECP2mutations.
7/27/2019 Parametros Practicos Evaluacion TGD
21/60
Analysis of the EvidenceCytogenetic studiestesting for Rett syndrome
The prevalence of Rett syndrome in the general population is
approximately 1 to 3 individuals per 10,000 live births and it
has been estimated that there are approximately 10,000
individuals in the United States with this disorder.
Currently there are insufficient data to estimate the prevalence
of Rett syndrome variants in milder affected females or in
males.
7/27/2019 Parametros Practicos Evaluacion TGD
22/60
Analysis of the Evidence
Cytogenetic studiesMolecular screening forsubtelomeric chromosomal rearrangements
Reference Class Level of mental
retardation
N N (% )of patients
with significant
rearrangements
68 I Controls
Mild
Moderate/Severe
75
182
284
0
1 (0.55)
21 (7.39)
69 I Controls
Unspecified
Mild
Moderate/Severe
150
61
82
46
0
0
0
0
7/27/2019 Parametros Practicos Evaluacion TGD
23/60
Analysis of the Evidence
Cytogenetic studiesMolecular screening forsubtelomeric chromosomal rearrangements
Reference Class Level of mental
retardation
N N (% )of patients
with significant
rearrangements
70 II Unspecified 27 2 (7.4)
71 II Moderate/Severe 29 2 (8.89)
7/27/2019 Parametros Practicos Evaluacion TGD
24/60
Analysis of the Evidence
Cytogenetic studiesMolecular screening forsubtelomeric chromosomal rearrangements
Reference Class Level of mental
retardation
N N (% )of patients
with significant
rearrangements
72 II IQ< 60 254 13* (5.12)
73 II Unspecified 120 5 (4.17)
7/27/2019 Parametros Practicos Evaluacion TGD
25/60
Analysis of the Evidence
Cytogenetic studiesMolecular screening forsubtelomeric chromosomal rearrangements
Reference Class Level of mental
retardation
N N (% )of
patients with
significantrearrangements
74 II Mild
Moderate/Severe
44
117
0
13 (11.11)
75 II Mild
Moderate/Severe
42
28
0
1 (3.57)
7/27/2019 Parametros Practicos Evaluacion TGD
26/60
Analysis of the Evidence
Cytogenetic studiesMolecular screening forsubtelomeric chromosomal rearrangements
Reference Class Level of mental
retardation
N N (% )of patients
with significant
rearrangements
76 II Unspecified 50 3 (6.0)
77 II Mild
Moderate/Severe
29
82
3 (10.3)
7 (8.5)
78 II Unspecified 250 9 (3.6)
7/27/2019 Parametros Practicos Evaluacion TGD
27/60
Conclusions The accumulated data suggest that cytogenetic studies will be
abnormal in 3.7% of children with global developmental delay,
a yield that is likely to increase in the future as new techniques
are employed.
In mixed populations (both males and females), a yield of
between 0.3% and 5.3% (average yield of 2.6%) has been
demonstrated for fragile X testing. The higher range of this
yield exists for testing amongst males.
There is a suggestion that clinical preselection for the fragile X
syndrome amongst males may improve diagnostic testing
beyond routine screening.
7/27/2019 Parametros Practicos Evaluacion TGD
28/60
Conclusions After Down syndrome, Rett syndrome is believed to be the
most common cause of developmental delay in females.
Although milder variants in females and more severe
phenotypes in males recently have been recognized, estimates
of their prevalence are not currently available.
Subtelomeric chromosomal rearrangements have been found
in 6.6% (0-11.1%) of patients with idiopathic moderate to
severe developmental delay.
7/27/2019 Parametros Practicos Evaluacion TGD
29/60
Recommendations1. Given the low yield of about 1%, routine metabolic screening
for inborn errors of metabolism is not indicated in the initialevaluation of a child with global developmental delay providedthat universal newborn screening was performed and the
results are available for review. Metabolic testing may bepursued in the context of historical (parental consanguinity,family history, developmental regression, episodicdecompensation) or physical examination findings that aresuggestive of a specific etiology (or in the context of relativelyhomogeneous population groups) in which the yieldapproaches 5% (Level B; class II and III evidence). If newbornscreening was not performed, if it is uncertain whether a patienthad testing, or if the results are unavailable, metabolicscreening should be obtained in a child with globaldevelopmental delay.
7/27/2019 Parametros Practicos Evaluacion TGD
30/60
Recommendations2. Routine cytogenetic testing (yield of 3.7%) is indicated in the
evaluation of the child with developmental delay even in theabsence of dysmorphic features or clinical features suggestive of aspecific syndrome (Level B; class II and III evidence).
3. Testing for the fragile X mutation (yield of 2.6%) particularly in thepresence of a family history of developmental delay, may beconsidered in the evaluation of the child with global developmentaldelay. Clinical preselection may narrow the focus of who should betested without sacrificing diagnostic yield. Although screening for
fragile X is more commonly done in males because of the higherincidence and greater severity, females are frequently affected andmay also be considered for testing. Because siblings of fragile Xpatients are at greater risk to be symptomatic or asymptomaticcarriers, they can also be screened (Level B; class II and class IIIevidence).
7/27/2019 Parametros Practicos Evaluacion TGD
31/60
Recommendations4. The diagnosis of Rett syndrome should be considered in females
with unexplained moderate to severe mental retardation. If
clinically indicated, testing for the MECP2gene deletion may be
obtained. Insufficient evidence exists to recommend testing of
females with milder clinical phenotypes or males with moderate orsevere developmental delay (Level B; class II and class III
evidence).
5. In children with unexplained moderate or severe developmental
delay, additional testing using newer molecular techniques (e.g.FISH, microsatellite markers) to assess for subtelomeric
chromosomal rearrangements (6.6%) may be considered (Level
B; class II and class III evidence).
7/27/2019 Parametros Practicos Evaluacion TGD
32/60
Clinical Question
What is the role of lead and thyroid screening in
children with global developmental delay?
7/27/2019 Parametros Practicos Evaluacion TGD
33/60
Analysis of the EvidenceLead Screening
Lead is the most common environmental neurotoxin. Studies
over several decades have shown a relation between marked
elevations in serum lead levels, clinical symptoms and cognitivedeficits (but not definitively mental retardation).
Average blood lead levels in the United States have fallen
dramatically from 15g/dL in the 1970s to 2.7g/dL in 1991
through 1994.
It is estimated that there are still about 900,000 children in the
United States between the ages of 1 and 5 years who have blood
lead levels equal to or greater than 10 g/dL.
7/27/2019 Parametros Practicos Evaluacion TGD
34/60
Analysis of the EvidenceLead Screening
It is unlikely at the present time for a child to have symptomatichigh-level lead exposure that would cause moderate to severeglobal developmental delay.
Low-level lead exposure remains possible, and it has beenestimated that each 10 g/dL increase in blood lead level maylower a child's IQ by about 1 to 3 points.
The relation and clinical significance of mildly elevated butnontoxic levels (i.e., those that do not require medicalintervention) to developmental status remains controversial.
In a cohort of children (age 12 to 36 months) identified onroutine screening at a urban public hospital, elevated leadlevels (10 to 25 g/dL) resulted in a 6.2- point decline in scoreson the Mental Developmental Index when compared to childrenwith lead levels below 10 g/dL (class II study).
7/27/2019 Parametros Practicos Evaluacion TGD
35/60
Analysis of the Evidence
Lead Screening
In a study of data drawn from the NHANES III, an inverserelation between blood lead concentration at subtoxic levelsand scores on four measures of cognitive functioning was
demonstrated (class III study). Of 72 children referred to a child developmental center with
developmental and/or behavioral problems compared tocontrols, a significantly higher distribution of leadconcentrations was demonstrated, with 12% of the samplepossessing a concentration greater than 10 g/dL (class II
study).
In a study of children drawn from a population at low risk forlead exposure, 43 children with either developmental delay orattention deficit hyperactivity disorder did not demonstrateelevated lead levels compared to controls (class II study).
7/27/2019 Parametros Practicos Evaluacion TGD
36/60
Analysis of the Evidence
Lead Screening
The recently published guidelines of the American Academy of
Pediatrics, candidates for targeted screening include children 1 to
2 years of age living in housing built before 1950 situated in an
area not designated for universal screening, children of ethnic orracial minority groups who may be exposed to lead-containing
folk remedies, children who have emigrated (or been adopted)
from countries where lead poisoning is prevalent, children with
iron deficiency, children exposed to contaminated dust or soil,
children with developmental delay whose oral behaviors placethem at significant risk for lead exposure, victims of abuse or
neglect, children whose parents are exposed to lead
(vocationally, avocationally, or during home renovation), and
children of low-income families.
7/27/2019 Parametros Practicos Evaluacion TGD
37/60
Analysis of the Evidence
Thyroid Screening
Unrecognized congenital hypothyroidism is a potentially treatable
cause of later developmental delay. Delay in diagnosis and
treatment beyond the newborn period and early infancy has been
clearly linked to later often substantial, neurodevelopmentalsequelae.
Implementation of newborn screening programs has been
extremely successful in eliminating such sequelae.
In some countries, where comprehensive newborn screening
programs are not yet in place, congenital hypothyroidism hasbeen found to be responsible for 17/560 (3.8%) cases of cognitive
delay evaluated in a pediatric neurology clinic (class II Study).
Many of these children also had prominent systemic symptoms.
7/27/2019 Parametros Practicos Evaluacion TGD
38/60
Conclusions
Low-level lead poisoning is associated with mild cognitive
impairments but not with global developmental delay.
Approximately 10% of children with developmental delay and
identifiable risk factors for excessive environmental leadexposure may have an elevated lead level. In the absence of
systematic newborn screening, congenital hypothyroidism may
be responsible for approximately 4% of cases of cognitive
delay.
7/27/2019 Parametros Practicos Evaluacion TGD
39/60
Recommendations
1. Screening of children with developmental delay for lead toxicity
may be targeted to those with known identifiable risk factors for
excessive environmental lead exposure as per established
current guidelines (Level B; class II evidence).
2. In the setting of existing newborn screening programs for
congenital hypothyroidism, screening of children with
developmental delay with thyroid function studies is not
indicated unless there are systemic features suggestive of
thyroid dysfunction (Level B; class II evidence).
7/27/2019 Parametros Practicos Evaluacion TGD
40/60
Clinical Question
What is the diagnostic yield of EEG in children with
global developmental delay?
7/27/2019 Parametros Practicos Evaluacion TGD
41/60
Analysis of the Evidence
EEG
The vast majority of articles on EEG and global developmentaldelay are class IV studies on small cohorts of children with analready established diagnosis (e.g., sub-acute sclerosing
panencephalitis or progressive myoclonic epilepsy
) that isoften a progressive encephalopathy rather than a staticencephalopathy such as global developmental delay.
Two class III studies (n=200 children with global developmentaldelay) who had EEG have been reported.
In one study, the EEG did not contribute to determining theetiology of developmental delay.
In the second study, 10 of 120 children were found to haveepileptic syndromes. It is likely that all of these children alreadyhad overt seizures and a recognized epilepsy for which anabnormal EEG result is expected.
7/27/2019 Parametros Practicos Evaluacion TGD
42/60
Analysis of the Evidence
EEG
Another class III prospective study of 32 children withsignificant developmental dysphasia with or without associatedglobal developmental delay revealed nonspecific epileptic
abnormalities in 13 of 32 children (40.6%), a finding of unclearetiologic significance.
A retrospective class IV study of 60 children with globaldevelopmental delay, 83% of whom had EEG, yielded anetiologic diagnosis based on the EEG results in 2.0% of thecohort (specifically one child with ESESelectrographic status
epilepticus during slow wave sleep). Although the yield on routine testing is negligible, if there is a
suspected epileptic syndrome that is already apparent from thehistory and physical examination (e.g., Lennox- Gastautsyndrome, myoclonic epilepsy, Rett syndrome), the EEG hasconfirmatory value.
7/27/2019 Parametros Practicos Evaluacion TGD
43/60
Conclusions
Available data from two class III and one class IV study
determined an epilepsy-related diagnosis in 11 of 250 children
(4.4%). However, the actual yield for a specific etiologic
diagnosis occurred in only 1 patient (0.4%).
7/27/2019 Parametros Practicos Evaluacion TGD
44/60
Recommendations
1. An EEG can be obtained when a child with global
developmental delay has a history or examination features
suggesting the presence of epilepsy or a specific epileptic
syndrome (Level C; class III and IV evidence).
2. Data are insufficient to permit making a recommendation
regarding the role of EEG in a child with global developmental
delay in whom there is no clinical evidence of epilepsy (Level
U; class III and IV evidence).
7/27/2019 Parametros Practicos Evaluacion TGD
45/60
Clinical Question
What is the diagnostic yield of neuroimaging in
children with global developmental delay?
7/27/2019 Parametros Practicos Evaluacion TGD
46/60
Analysis of the Evidence
Neuroimaging
Reference Class N Results
(% patients with abnormal studies)
7 III 60 31.4% (CT, a few had MRI)
28 III 99 27% (CT); 41.2% when done on an
indicated basis vs 13.9% when on a
screening basis
100 III 23 4.3% (CT)
101 III 76 27.6% (CT) with 71.4% of these with
nonspecific atrophy
102 III 37 81% (CT)
7/27/2019 Parametros Practicos Evaluacion TGD
47/60
Analysis of the Evidence
Neuroimaging
Reference Class N Results
(% patients with abnormal studies)
103 III 79 63% (CT)
45 IV 170 30% (CT); 65.5% (MRI); 19/29
patients who had MRI showed an
abnormality
104 III 224 48.6% ( MRI)
105 III 40 92.5% (MRI)
106 IV 3 100% (MRI) but small number of
patients
7/27/2019 Parametros Practicos Evaluacion TGD
48/60
Analysis of the Evidence
Neuroimaging
Reference Class N Results
(% patients with abnormal studies)
107 III 13 100% (MRI) but small number ofpatients
108 III 21 Amount of abnormal cerebral white
matter on MRI correlated with degree
of mental impairment.
7/27/2019 Parametros Practicos Evaluacion TGD
49/60
Conclusions
Available data primarily from class III studies show that CT
contributes to the etiologic diagnosis of global developmental
delay in approximately 30% of children, with the yield
increasing if physical examination findings are present. MRI is more sensitive than CT, with abnormalities found in
48.6% to 65.5% of children with global delay with the chance of
detecting an abnormality increasing if physical abnormalities,
particularly cerebral palsy, are present.
7/27/2019 Parametros Practicos Evaluacion TGD
50/60
Recommendations
1. As the presence of physical findings (e.g., microcephaly, focal
motor findings) increases the yield of making a specific
neuroimaging diagnosis, physicians can more readily consider
obtaining a scan in this population (Level C; class III evidence).
2. If available, MRI should be obtained in preference to CT
scanning when a clinical decision has been made that
neuroimaging is indicated (Level C; class III evidence).
Neuroimaging is recommended as part of the diagnostic
evaluation of the child with global developmental delay (Level
B; class III evidence).
7/27/2019 Parametros Practicos Evaluacion TGD
51/60
Clinical Question
Are vision and hearing disorders common in children
with global developmental delay?
7/27/2019 Parametros Practicos Evaluacion TGD
52/60
Analysis of the Evidence
Vision and hearing disorders In two class III studies totaling 365 children with global
developmental delay, abnormalities on vision screening werefound in 13%to 25% of children.
Refractive errors (24%), strabismus (8%), and a number oforganic ocular diseases (8%) were also detected in one ofthese reports.
Supporting these findings is a class IV retrospective review thatestimated the frequency of primary visual sensory impairmentin children with global developmental delay to range between
20% and 50%. Appears to be an increased prevalence of additional visual
developmental disability among individuals with syndromesfeaturing significant sensory impairment.
7/27/2019 Parametros Practicos Evaluacion TGD
53/60
Analysis of the Evidence
Vision and hearing disorders In one class III study (n=260) with severe global developmental
delay in whom vision and audiologic screening were
performed, 18% of children were found to be deaf.
Another class III study (n=96) clinically suspected hearing lossfound that 91% had hearing loss as detected by behavioral
audiometry or brainstem auditory evoked response testing.
Retrospective analysis of legally mandated universal newborn
screening program (53,121 newborns over 4 years)
demonstrated the utility of a two-stage otoacoustic emissionevaluation process in accurately detecting early hearing loss in
a population not amenable to audiometric testing (class II
study).
7/27/2019 Parametros Practicos Evaluacion TGD
54/60
Conclusions
Several class III studies have shown that children with global
developmental delay are at risk to have primary sensory
impairments of vision and hearing. Estimates of vision
impairment or other visual disorders range from 13% up to 50%whereas significant audiologic impairments occur in about 18%
of children based on data in one series of patients.
7/27/2019 Parametros Practicos Evaluacion TGD
55/60
Recommendations1. Children with global developmental delay may undergo
appropriate vision and audiometric assessment at the time oftheir diagnosis (Level C; class III evidence).
2. Vision assessment can include vision screening and a fullophthalmologic examination (visual acuity, extra-oculo-movements, fundoscopic) (Level C; class III evidence).
3. Audiometric assessment can include behavioral audiometry orbrainstem auditory evoked response testing when feasible(Level C; class III evidence). Early evidence from screeningstudies suggest that transient evoked otoacoustic emissionsshould offer an alternative when audiometry is not feasible(Level A; class I & II evidence).
7/27/2019 Parametros Practicos Evaluacion TGD
56/60
Future Research
Recommendations1. Further prospective studies on the etiologic yields of various
diagnostic tests need to be undertaken on large numbers ofyoung children with global developmental delay including controlsubjects. These should include newer molecular genetic and
MRI technologies. With this information, prospective testing ofspecific evaluation paradigms would be possible.
2. Features (i.e., markers) present on the history and physicalexamination at intake need to be identified that will improvespecific evaluation strategies and enhance etiologic yield.
3. The timing of actual testing in children with global developmentaldelay needs to be addressed. Specifically, it should bedetermined at what age and on what basis one can be certainthat a child has a global developmental delay sufficient to justifytesting as well as at what age the yield from testing will beoptimal.
7/27/2019 Parametros Practicos Evaluacion TGD
57/60
Future Research
Recommendations4. Alternative strategies of conducting testing simultaneously or
sequentially need to be critically assessed. This should help
reduce unnecessary testing and provide cost-effective evaluations
and more accurate diagnostic yields.
5. Additional studies are needed to evaluate the role of EEG in a child
with global developmental delay in whom there is no clinical
evidence of epilepsy.
6. Additional studies are needed to better characterize visual and
auditory deficits in children with global developmental delay.
Further investigation of the sensorimotor impairments of children
with global delay are also needed to better determine how early
intervention therapies might improve the overall function of children
who are likely to have multiple needs.
7/27/2019 Parametros Practicos Evaluacion TGD
58/60
Future Research
Recommendations7. Issues related to quality of life and social support of families who
have children with developmental delay need further study.
Included in this should be the benefits that medical testing confer
by reducing parental concerns related to determining a specific
etiology and by providing important information regardingprognosis, genetic counseling, alleviation of parental anxiety, and
planning future educational and treatment needs.
7/27/2019 Parametros Practicos Evaluacion TGD
59/60
Acknowledgements
The committee thanks the following individuals for their
willingness to review early versions of this manuscript: David
Coulter MD, Child Neurology Society and the American
Association of Mental Retardation; Nancy Dodge MD, AmericanAcademy of Pediatrics, Chair Section on Children with
Disabilities; William Lord Coleman, MD, American Academy of
Pediatrics, Chair Section on Developmental and Behavioral
Pediatrics; Thomas B. Newman, MD, MPH, American Academy
of Pediatrics; Committee on Quality Improvement; RichardQuint, MD, MPH, Clinical Professor in Pediatrics, UCSF; Carl
Cooley, MD; Constance Sandlin, MD; Clinical Medical Director,
Genzyme Genetics.
7/27/2019 Parametros Practicos Evaluacion TGD
60/60
To view the entire guideline and additional AAN
guidelines visit:
www.aan.com/professionals/practice/index.cfm
Published in Neurology2003; 60:367-380