Neurodevelopmental Assessment and Care of Premature Infants

Ma. Teresa C. Ambat, MD Neonatology-TTUHHSC 10/28/2008

Introduction

 PCPs should be vigilant in following outcomes of prematurely born child  Should integrate and adapt assessments of development, neurologic status and bahavior for each child at each encounter

Neurodevelopmental and Behavioral Outcomes

 Long-term outcome arises from complex interplay of biologic, genetic, social and environmental factors  Additional or shifting developmental dysfunction over time, as more subtle disabilities become increasingly apparent and testable “new morbidities”

Risk Factors for Developmetal and Behavioral Problems in the Preterm Infant



Prenatal

LBW GA <28 wks IUGR Male gender 

Postnatal

Neonatal seizures Abnormal HUS (white matter injury, PVL, Grade 3-4 IVH) CLD Prolonged mechanical vent Infections (NEC, sepsis, meningitis) Feeding problems >34 wks PMA ECMO Low economic status Maternal depression

Prevalence of Significant Disabilities in VLBW

Mental retardation CP Blindness Deafness Motor delay Language problems ADHD Need for special education Psychological/behavioral problems 10-20% 5-21% 2-11% 1-3% 24% 23-42% 7-10% 9-28% 25%

Correction for Prematurity

 Correction for prematurity up to 2-3 years of age when considering neurologic, developemental or behavioral issues, otherwise indicated by a standardized evaluation

Pearls on Outcomes of Preterm Infants

 More frequent and significant disabilities are associated with decreasing GA and BW  Cognitive deficits > motor deficits  Disabilities or delays may be subtle or appear latently  Deficits in cognitive, verbal, perceptual, motor and visuo-motor measures may not manifest until school age

Pearls on Outcomes of Preterm Infants

 Up to 50% of infants born <25 wks may be found without disability at follow up over the 1 st 3 yrs  Nearly all infants with normal findings on neurodevelopmental examination at the infant’s expected due date continue to develop normally  If no developmental delays during infancy, risk of MR or CP is low

Ophthalmologic Issues

 Ophthalmologic problems of premature infants    ROP, strabismus, myopia – common Higher incidence of visual impairment – 45-60% Poor visual function may directly affect the development of motor and cognitive skills  Require specialized ophthalmologic testing and routine follow-up by pediatric ophthalmologist

ROP Screening

 AAP recommendation for ROP screening  Indications   GA <30 wks or BW <1500g Selected infants with BW 1500 – 2000g, GA >30 wks with severe cardiorespiratory instability  Examinations usually begin at 4-6wks postnatal age or at 31 32 wks postmenstrual age   Continue every 2 wks Once ROP is noted at any stage, examinations become more frequent  Can be discontinued once the retinal vessels have reached the perimeter of Zone 3 – retina is “mature”

Outpatient Monitoring for Infants at Risk for ROP

 Confirm that retinal maturation is complete  If mature, arrange for ophthalmologic ff up at 6-9 months to monitor for amblyopia, strabismus and or refractive errors  If immature, ophthalmologic ff-up per previous guidelines  All PT <32 wks, should undergo ophthalmologic screening at 6-9 months chronologoic age,  Whether or not they were screened for ROP, developed ROP or received tx for ROP  All PT should have formal visual acuity screening, at least once during preschool years  If visual difficulties are seen, refer to appropriate resources

Hearing Loss in Premature Infants

 Overall incidence of severe congenital hearing loss: 1-3/1000 live births  Hearing loss in premature infants: 2-4/100 infants born <32 wks

Risk Factors for Hearing Loss

(Joint Committee on Infant Hearing) 1.

2.

3.

4.

5.

6.

Parental or caregiver concern re: hearing, speech, language or developmental delay Family history of permanent childhood hearing loss Stigmata associated with a syndrome known to cause hearing loss or eustachian tube dysfunction Postnatal infection associated with SNHL – bacterial meningitis Congenital infections – CMV, HSV, rubella, syphilis, HIV, toxoplasmosis Syndromes associated with progressive hearing loss – NF, osteopetrosis, Usher syndrome

Risk Factors for Hearing Loss

(Joint Committee on Infant Hearing) 7.

8.

9.

10.

11.

Neonatal indicators – hyperbilirubinemia requiring exchange (TB >20, needs BAER at 2months), PPHN associated with mechanical ventilation or ECMO Nuerodegenerative disorders – Hunter syndrome, Friedrich ataxia, Charcot-Marie Tooth Head trauma Recurrent or persistent OM with effusion for at least 3 months Prolonged use of potentially ototoxic drugs

Screening Tests

 Universal hearing screening recommended for all newborns  1.

Methodologies for physiologic screening for hearing in newborns Auditory brainstem response (ABR) 2.

Evoked otoacoustic emission (EOAE)

Follow-up Testing and Medical Evaluation

1.

Infants who refer in both ears  wks diagnostic ABR within 2 2.

Unilateral abnormal results  months ff-up testing within 3  Ff-up testing: full diagnostic frequency ABR to measure threshold, evaluation of middle ear function, observation of behavioral response to sound, parental report of emerging communication and auditory behaviors

Follow-up Testing and Medical Evaluation

3.

Any infants at risk for progressive or delayed hearing loss  close audiologic monitoring at least q6 months for the first 3 years) 4.

Hearing assessment at 1 year in all infants born at < 32 wks (even if hearing screen is passed) 5.

PCP should monitor all infants for normal hearing and language development and refer any infant with delays for hearing assessment

Referrals

 Once an infant is diagnosed with a true hearing loss, the following referrals should be made: 1.

2.

3.

4.

Complete evaluation by an otolaryngology or otology specialist who has experience with infants Genetic evaluation and counseling (hearing loss with no definite etiology) Pediatric ophthalmology (evaluate for additional sensory loss) Developmental pediatric, neurology, cardiology, and or nephrology as indicated by other clinical findings and known associated problems with syndromes

Habilitation/Management

    Early intervention services to enhance acquisition of developmentally appropriate language skills Amplification systems – hearing aids Cochlear implant: profound, bilateral SNHL, no benefit from hearing aids, no medical conditions that will interfere with procedure, realistic expectations from family “Stimulation” or “mapping” sessions

White Matter Injury

    Periventricular leukomalacia (PVL) – white matter injury in preterm infants Results from insults to the developing brain 23-32 wks Incidence: 5-15% of those born GA<32 wks US: echodensity in periventricular white matter adjacent to lateral ventricles  cystic changes  Outcomes: MR, CP, developmental delay, visual impairments

Intraventricular Hemorrhage

 Occurs in ~35-50% of infants born <35 wks  Grade III IVH associated with 30% risk of CP/MR and 50% risk of developmental disability  Intraparenchymal hemorrhage associated with 70% risk of CP/MR and 90% risk for developmental disability

Care and Assessment of Shunted Neonates

 Closely observe for long-term complications  Over-drainage related problems   collapse of thin cortex, subdural effusion/hematoma, craniosynostosis   Evidenced by sunken fontanel, overlapping sutures MX: positional precautions, upgrade or readjustment of valve settings  Wound breakdown  Shunted infants with myelomeningocele  Arnold-Chiari II malformation  Risk for brainstem dysfunction secondary to compression (retropulsion of head, stridor, drooling, increased tone in extremities)

Neurologic Surveillance

 1.

2.

3.

4.

Perform periodic neurologic examinations Tone (passive resistance) Strength (active resistance) DTR Coordination, station and gait   Use assessments over time to establish prognosis Single encounters provide a mere snapshot of ongoing developmental trajectories

Neurologic Surveillance

   Abnormal tone can be suggestive of CP or Maybe transient  resolve in the 1 st year w/o sequelae May evolve from one form to another (hypotonia  hypertonia)   Multidisciplinary evaluation Extensive evaluations as necessary: MRI, cytogenetic studies, metabolic work-up

Findings of Abnormal Tone

 1.

2.

3.

4.

5.

Hypotonia Exaggerated head lag Excessive ‘slip through’ when held at the shoulders Poor head control Poor truncal tone  exaggerated curve in ventral suspension Persistent hypotonia + decreased DTRs 3.

4.

5.

6.

 1.

2.

Hypertonia Spastic form Dyskinetic form with rigid extension Early rolling over Hypertonia with leg extension Absent weight bearing Persistent/early feeding problems

Neurologic Surveillance

 Assess for persistence or delay of reflexes  Primitive reflexes   Moro, tonic labyrynthe, asymmetric tonic neck Appear and readily elicited in the 1 6-8 months st 3 months  disappear by  Postural reflexes  Complex, self-protective reflexes involving righting, protection and equilibrium movements  Slow to evolve in children with CNS injury

Developmental Surveillance

 Assess neurodevelopmental and behavioral status  Developmental tools – screening tools, not diagnostic tools  Parent questionnaires, history and discussion during clinical encounter  Consult appropriate specialists if results are concerning

AAP Algorithm for Developmental Surveillance and Screening

Pediatrics Vol 118, July 2006    Developmental surveillance incorporated at every well child visit If any concerns  screening tests standardized developmental Regular screening tests: 9, 18 and 30 (24) month visits  Children diagnosed with developmental disorders: children with special health care needs requiring chronic condition management

Developmental Surveillance