Posterior fossa abnormalities seen on magnetic resonance brain imaging in a cohort of newborn infants

Cranial Ultrasound Is an Important Tool in the Recognition of Life-Threatening Infratentorial Hemorrhage in Newborns

Timely detection of severe infratentorial hemorrhage in neonates is crucial, especially in case of life-threatening brain stem compression and/or acute obstructive hydrocephalus, which need lifesaving neurosurgical intervention. Although the detection of infratentorial hemorrhage by ultrasound scanning is often considered as difficult, the use of additional acoustic windows and recognition of characteristic ultrasound features facilitate early diagnosis. In this case series, we report on newborns with severe, symptomatic infratentorial hemorrhage detected primarily by cranial ultrasound. We demonstrate the characteristic ultrasound features present in all cases and discuss how ultrasound diagnosis contributed to early diagnosis and treatment.

Neonatal Cerebellar Hemorrhage and Facial Nerve Palsy: An Unusual Association

Cerebellar hemorrhage is rare in term newborns and is most often seen after traumatic birth. Lifelong sequelae include motor and cognitive impairment. We report the uncommon case of a late preterm infant born by spontaneous delivery who showed right peripheral facial palsy at 24 hours of life. Cranial ultrasound showed lateral ventricles dilatation and a diffuse hyperechoic round lesion in the right cerebellar hemisphere. The computed tomography scan confirmed a hemorrhagic lesion in the right cerebellar hemisphere and in the vermis with midline shift and intraventricular bleeding. Ommaya reservoir was inserted and used for a few days. The facial palsy gradually recovered to a complete remission after 6 weeks. Follow-up examinations at 12 and 18 months evidenced infant's delayed motor function, hyperreflexia, tremors, and speech delay.

Neurodevelopmental Consequences of Preterm Isolated Cerebellar Hemorrhage: A Systematic Review

CONTEXT

The effect of neonatal cerebellar hemorrhage on neurodevelopmental outcome (NDO) in the absence of supratentorial injury is still largely unknown.

OBJECTIVE

To evaluate the influence of isolated neonatal cerebellar hemorrhage on cognitive, motor, language, and behavioral NDOs and assess the effect of location and size on outcome.

DATA SOURCES

Embase, Medline, and Scopus were searched from inception to September 30, 2017.

STUDY SELECTION

Studies in which a diagnosis of isolated cerebellar hemorrhage was reported in preterm infants (<32 weeks' gestation) with a standardized NDO at ≥12 months of age were included.

DATA EXTRACTION

Patient characteristics, location, and size of bleeding and NDO (defined as severe [yes or no] on the basis of given cutoff points) in 4 domains were extracted.

RESULTS

Of the 1519 studies identified, 8 were included in final analyses. Of infants with isolated cerebellar hemorrhage, 128 were described (cumulative incidence: 2.3%). The incidence of severe delay in cognition, motor, language, and behavioral development was 38%, 39%, 41%, and 38%, respectively. The overall incidence of severe neurodevelopmental delay in ≥1 domain ranged from 43% to 75% and was most seen in infants with vermis involvement (87%-93%) and with large bleeds (46%-82%).

LIMITATIONS

Different neurodevelopmental scales lead to data heterogeneity, and reporting of data on a group level limited possibilities for an outcome description on an individual level.

CONCLUSIONS

Of infants with isolated cerebellar hemorrhage, 43% to 75% were severely delayed in cognition, motor, language, and/or behavioral development, with the highest incidence with vermis involvement and with large bleeds.

Clinical impact of term-equivalent magnetic resonance imaging in extremely low-birth-weight infants at a regional NICU

OBJECTIVE

To evaluate the clinical impact of routine term-equivalent magnetic resonance imaging (TE-MRI) for extremely low-birth-weight infants at a regional neonatal intensive care unit.

STUDY DESIGN

This is a single-center retrospective study evaluating preterm survivors who underwent TE-MRI. MRI abnormalities were compared between infants with and without cranial ultrasonography (CUS) abnormalities. Cost analysis comparing imaging modalities was also performed.

RESULTS

TE-MRI use increased from 17% in 2006 to 76% in 2010. MRI detected new findings in nearly half of infants, whether or not they had known ultrasound abnormalities. MRI detected more cerebellar (18% vs 6%, P=0.04) and moderate white matter injury (12% vs 7%, P<0.001), and altered simulated neurological prognosis across developmental domains. The cost of TE-MRI was $1600, which was comparable to serial CUSs.

CONCLUSION

TE-MRI detects new abnormalities and impacts developmental prognosis in the extremely low birth weight, which supports its use despite the added financial cost.

Cranial ultrasonography of the immature cerebellum: Role and limitations

Cranial ultrasonography (CUS) is a reliable and non-invasive tool to detect frequently occurring brain abnormalities and to monitor brain development and maturation in high risk neonates. Standard CUS views are obtained through the anterior fontanel. However, evaluation of the posterior fossa is often suboptimal with this approach. Cerebellar injury occurs frequently in preterm infants and has important prognostic consequences. Early detection is therefore important. This review focuses on techniques that optimize the performance of CUS when studying the preterm cerebellum, including the use of the mastoid fontanel and the adaptation of focus points and scan frequencies. For illustration, CUS images of the normal posterior fossa anatomy as well as examples of abnormalities that may be encountered in preterm infants are included. We also discuss the limitations of CUS and the role of magnetic resonance imaging.

Preterm birth and cerebellar neuropathology

Improved survival rates in premature infants and more sensitive neuroimaging techniques have expanded the scope of recognized neurodevelopmental disabilities in this vulnerable population and have implicated a role for cerebellar pathology in their origin. Although supratentorial pathologies are well studied, cerebellar pathology has been under-recognized in premature infants. The purpose of this review is to provide a concise description of established acquired cerebellar pathologies in premature infants including cerebellar atrophy/hypoplasia, hemorrhage, and infarction. The cerebellum develops over an extended period during which time cerebellar injury tends to occur with the potential to derail the cerebellum from its expected growth trajectory and perturb the establishment of cerebellar neural circuitry. The occurrence of cerebellar injury in this vulnerable period may have life-long implications that extend beyond the immediate damage sustained by the cerebellum, all of which needs to be considered as we research the causes and effects of neurodevelopmental disabilities in these patients.

Brain Injury and Development in Preterm Infants Exposed to Fentanyl

BACKGROUND

Fentanyl is commonly used in preterm infants. Relatively little is known regarding the neurodevelopmental outcomes of preterm infants exposed to fentanyl.

OBJECTIVE

To investigate the association between cumulative fentanyl dose and brain injury and diameters in a cohort of preterm infants.

METHODS

Data on demographics, perinatal course, and neonatal course, including total fentanyl exposure prior to term equivalent age, were retrospectively evaluated for 103 infants born at ≤30 weeks gestational age (mean gestational age 26.9 ± 1.8 weeks) who underwent magnetic resonance imaging at term equivalent age. Magnetic resonance images were evaluated for brain injury and regional brain diameters. Developmental testing was conducted at term equivalent and 2 years of age.

RESULTS

Seventy-eight infants (76%) received fentanyl (median cumulative dose 3 µg/kg, interquartile range 1-441 µg/kg). Cumulative fentanyl dose in the first week of life correlated with the incidence of cerebellar hemorrhage after correction for covariates (odds ratio 2.1, 95% confidence interval 1.1-4.1). Cumulative fentanyl dose before term equivalent age correlated with reductions in transverse cerebellar diameter after correction for covariates, including the presence of cerebellar hemorrhage (r = 0.461, P = 0.002). No correlation was detected between cumulative fentanyl dose and development at 2 years of age.

CONCLUSIONS

Higher cumulative fentanyl dose in preterm infants correlated with a higher incidence of cerebellar injury and lower cerebellar diameter at term equivalent age. Our findings must be taken with caution, but emphasize the need for future prospective trials examining the risks and benefits of commonly used analgesic agents in preterm infants.

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

Objectives

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard.

Methods

In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated.

Results

Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS.

Conclusions

PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates.

Key Points

• Posterior fossa abnormalities are a frequent finding in high-risk term infants.

• Adding mastoid fontanelle views improves ultrasound detection of clinically relevant abnormalities.

• Hypoxic-ischemic injury and small posterior fossa haemorrhages are better detected with MRI.

• Cranial ultrasound examination should include mastoid fontanelle views in high-risk term neonates.

The management of birth-related posterior fossa hematomas in neonates

BACKGROUND

Symptomatic posterior fossa hematoma in the term newborn is rare.

OBJECTIVE

To report on the management and outcome of posterior fossa subdural hematoma (PFSDH) in neonates.

METHODS

A retrospective analysis of the department database and clinical notes of neonates admitted since 1985 with a PFSDH was performed together with a literature review of similar case series.

RESULTS

Sixteen patients were included. The median gestational age was 40 weeks with a high proportion of primiparous mothers (n = 9) and forceps delivery (n = 9). Nine neonates had symptoms of brainstem dysfunction within the first 24 hours of life, whereas the other 7 had a delayed presentation (median 4 days) with signs of raised intracranial pressure due to hydrocephalus. Each patient had a cranial ultrasound followed by computed tomography scan that showed the PFSDH. Eleven neonates required surgical evacuation of the PFSDH, whereas hydrocephalus was managed by transient external ventricular drainage in 2 further patients. Eventually, 2 neonates required a permanent ventriculoperitoneal shunt. Five neonates had no operative intervention. With a mean follow-up of 7.8 years, 2 patients had mild developmental delay and 1 had severe developmental delay. The 13 other patients had a normal development.

CONCLUSION

In neonates with a PFSDH, surgery can be safely performed in those who have clinical and radiological signs of brainstem compression or hydrocephalus. A small number of neonates require a ventriculoperitoneal shunt in the long term. Initial aggressive resuscitation should be performed even in cases of initial severe brainstem dysfunction because of the good long-term neurological outcome.

Imaging the premature brain: ultrasound or MRI?

Neuroimaging of preterm infants has become part of routine clinical care, but the question is often raised on how often cranial ultrasound should be done and whether every high risk preterm infant should at least have one MRI during the neonatal period. An increasing number of centres perform an MRI either at discharge or around term equivalent age, and a few centres have access to a magnet in or adjacent to the neonatal intensive care unit and are doing sequential MRIs. In this review, we try to discuss when best to perform these two neuroimaging techniques and the additional information each technique may provide.

Magnetic resonance imaging of the brain at term equivalent age in extremely premature neonates: to scan or not to scan?

In the last decade, the role of magnetic resonance imaging (MRI) in neonatal care for prematurely born infants has rapidly expanded and evolved. Recent investigations addressed many of the practical issues pertaining to image acquisition and interpretation, enabling high-quality MR images to be obtained without sedating medications in preterm infants at any institution. Expanded application has demonstrated that MRI provides superior ability to assess cerebral development and identify and define cerebral injury in comparison to other imaging modalities. Term equivalent MRI results have been shown to correlate with neurodevelopmental outcomes, providing improved predictive ability over other neuroimaging, clinical or physical examination measures. Regular utilisation of MRI in this population is fundamental to gaining the knowledge and expertise necessary for rational, accurate application. Ongoing experiences will continue to shape the nature and type of information available to clinicians and families using MRI, further refining its role as a routine element of neonatal care.

Ultrasound detection of posterior fossa abnormalities in full-term neonates

Routine cranial ultrasonography, using the anterior fontanelle as acoustic window enables visualization of the supratentorial brain structures in neonates and young infants. The mastoid fontanelle enables a better view of the infratentorial structures, especially cerebellar hemorrhage in preterm infants. Reports on the usefulness and reliability of cranial ultrasonography using the mastoid fontanelle approach for the detection of posterior fossa abnormalities, focusing only on full-term neonates are limited. This article describes the technique of mastoid fontanelle ultrasonography in full-term neonates and the features of posterior fossa abnormalities that may be encountered in various neonatal disorders and conditions, combined with subsequent MRI in the same patients. Cranial ultrasound through the mastoid fontanelle plays a pivotal role in the early detection of posterior fossa pathology and selection of neonates with an indication for MRI.

Cerebellar haemorrhage in the extremely preterm infant

AIM

The aim of this study was to investigate the incidence, risk factors and developmental outcomes of cerebellar haemorrhage in the extremely preterm infant.

METHODS

Over a 4-year period from January 2004, all patients with cerebellar haemorrhage born at 24-27 weeks gestation or with a birthweight < 1000 g were identified from database review. All patients had cranial ultrasound scans including views from the mastoid fontanelle. To verify the incidence, a review of all reports over the 4-year period and a review of all cranial imaging over a 2-year period were carried out.

RESULTS

From the data analysed on 339 neonates, five cases of cerebellar haemorrhage were identified, four on ultrasound scan (1.2%) and one on magnetic resonance imaging (1.5% total). Two cases were associated with grade III peri-intraventricular haemorrhage. The cases had diverse maternal, antenatal and post-natal risk factors. The two with associated peri-intraventricular haemorrhage have developmental delay. The cases with isolated cerebellar haemorrhage had good neurodevelopmental outcomes.

CONCLUSIONS

A low incidence of cerebellar haemorrhage identified from the mastoid fontanelle was demonstrated. The neurodevelopmental outcome was better than that described in previous reports.

Myth: cerebral palsy cannot be predicted by neonatal brain imaging

There is controversy in the literature about the value of brain imaging in neonates regarding the prediction of cerebral palsy (CP). The aim of this review was to unravel the myth that CP cannot be predicted by neuroimaging in neonates. Major intracranial lesions in the preterm infant should be recognized with sequential cranial ultrasound and will predict those with non-ambulatory CP. Magnetic resonance imaging (MRI) at term-equivalent age will refine the prediction by assessment of myelination of the posterior limb of the internal capsule. Prediction of motor outcome in preterm infants with subtle white matter injury remains difficult, even with conventional MRI. MRI is a better tool to predict outcome in the term infant with hypoxic-ischaemic encephalopathy or neonatal stroke. The use of diffusion-weighted imaging as an additional sequence adds to the predictive value for motor outcome. Sequential and dedicated neuroimaging should enable us to predict motor outcome in high risk newborns infants.

Cerebellar hemorrhage in extremely low birth weight siblings: is there a familial disposition?

Cerebellar hemorrhage is an underrecognized complication in the preterm neonate. It is multifactorial including combined maternal, intrapartum, and early postnatal factors. We present the case of 2 preterm brothers, 24 + 1 and 24 + 3 weeks of gestation, who both died because of cerebellar hemorrhage. We sought familial pathogenic factors predisposing to cerebellar hemorrhage. Cerebral imaging performed by ultrasonography through the anterior fontanel was normal and showed no signs of bleeding or brain edema. Postmortem neuropathologic findings confirmed cerebellar hemorrhagic lesions in both infants. Cerebellar vessels showed no signs of morphologic disorders or malformations. There might be a hint to a familial disposition. Neonatal cranial ultrasound protocols should include brainstem and posterior fossa examination with specific scans through the mastoid fontanel.

Unusual case of 'trapped fourth ventricle' in a child with posthemorrhagic hydrocephalus--lessons learnt

In most of the children with posthemorrhagic hydrocephalus (PHH), multidisciplinary follow-up is performed, with the focus on consequences of prematurity, cerebral palsy (CP) and hydrocephalus. A large fourth ventricle is common in these children but imaging performed in order to document ventricles and tissue damage is not oriented to exclude coexisting rare pathologies. We report a 3-year-old child with spastic CP, secondary to prematurity and PHH. A ventriculoperitoneal shunt was inserted at the age of 2 months. On follow-up imaging the child demonstrated well-drained supratentorial ventricles with a persistent large fourth ventricle. Because of a neurological change in spasticity and new-onset torticollis, a repeat MRI was performed, suggesting a cystic, nonenhancing lesion of the fourth ventricle. The surgical exploration revealed a large dermoid of the fourth ventricle. We analyze the differential diagnosis of a clinically significant large fourth ventricle in a shunted child with PHH and CP. This includes conditions without pressure in the posterior fossa such as tissue loss due to cerebellar atrophy, or pathologies causing a true increase in pressure of the fourth ventricle (isolated fourth ventricle, cystic lesions and neoplasms of the fourth ventricle). Neurologically compromised children pose additional challenges in reaching a definitive diagnosis and hence require a careful regular assessment of their clinical status with additional well-timed imaging with appropriate protocols to allow appropriate treatment when indicated and to avoid morbidity due to delayed diagnosis. We present a rare coexistence of a dermoid tumor within the fourth ventricle in a CP child with PHH and express the dilemmas associated with its management.

The clinical presentation of preterm cerebellar haemorrhage

The objective of this study was to evaluate clinical symptoms and findings on cranial ultrasound (CUS) in preterm infants with cerebellar haemorrhage through retrospective analysis of all preterm infants with a postnatal CUS or MRI diagnosis of cerebellar haemorrhage admitted in a tertiary care centre between January 2002 and June 2009. Fifteen infants were identified; median gestational age was 25 2/7 weeks and median birth weight 730 g. We discerned six types of haemorrhage: subarachnoid (n = 3), folial (n = 1), lobar (n = 9, of which 4 bilateral), giant lobar (n = 1, including vermis) and contusional (n = 1). Especially in infants with lobar cerebellar haemorrhage, CUS showed preceding or concurrent lateral ventricle dilatation, mostly without intraventricular haemorrhage (IVH). Thirteen infants suffered from notable, otherwise unexplained motor agitation in the days preceding the diagnosis. In conclusion, motor agitation may be a presenting symptom of cerebellar haemorrhage in preterm infants. Unexplained ventriculomegaly can be a first sign of cerebellar haemorrhage and should instigate sonographic exploration of the cerebellum.

Cerebellum of the premature infant: rapidly developing, vulnerable, clinically important

Brain abnormality in surviving premature infants is associated with an enormous amount of neurodevelopmental disability, manifested principally by cognitive, behavioral, attentional, and socialization deficits, most commonly with only relatively modest motor deficits. The most recognized contributing neuropathology is cerebral white matter injury. The thesis of this review is that acquired cerebellar abnormality is a relatively less recognized but likely important cause of neurodevelopmental disability in small premature infants. The cerebellar disease may be primarily destructive (eg, hemorrhage, infarction) or primarily underdevelopment. The latter appears to be especially common and relates to a particular vulnerability of the cerebellum of the small premature infant. Central to this vulnerability are the extraordinarily rapid and complex developmental events occurring in the cerebellum. The disturbance of development can be caused either by direct adverse effects on the cerebellum, especially the distinctive transient external granular layer, or by indirect remote trans-synaptic effects. This review describes the fascinating details of cerebellar development, with an emphasis on events in the premature period, the major types of cerebellar abnormality acquired during the premature period, their likely mechanisms of occurrence, and new insights into the relation of cerebellar disease in early life to subsequent cognitive/behavioral/attentional/socialization deficits.

Cerebellar injury in term infants: clinical characteristics, magnetic resonance imaging findings, and outcome

Although cerebellar injury in the premature infant is an increasingly recognized form of neonatal brain injury, its structural and functional outcomes remain poorly defined in the term infant. The objective of this cross-sectional study was to characterize the clinical and magnetic resonance imaging features and neurodevelopmental outcome in children, born at term, with cerebellar injury. Over a 5-year period, 20 infants were identified with ischemic (n = 3) or hemorrhagic (n = 17) cerebellar injury. Lesions were small (<1 cm) in 12 cases, and large in 8 cases. Prenatal and intrapartum factors frequently documented in term infants with cerebellar injury included primiparity (55%), advanced maternal age (30%), group B streptococcus-positive mothers (35%), abnormal fetal heart rate (35%), instrumented delivery (30%), and cesarean section (25%). At follow-up of 18 cases (median age, 32 months), 39% had neurologic abnormalities. Gross motor delays, expressive language deficits, and externalizing behavioral problems were the most common (44%). Cognitive deficits were present in one third of cases. Larger cerebellar lesions were associated with significantly lower cognitive, gross motor, expressive language, and social-behavioral scores. Cerebellar injury in the term infant is associated with a broad spectrum of neurodevelopmental disabilities, particularly in infants with large cerebellar lesions.

Cerebellar hemorrhage in extremely low birth weight infants: incidence, risk factors, and impact on long-term outcomes

Improvements in neuroimaging technology and techniques have contributed to the increased recognition of cerebellar hemorrhage (CBH) in the prererm infant. Studies have indicated that the extremely low birth weight (ELBW) infant (< 1,000 g) is at highest risk for this injury. Associated risk factors include a constellation of antenaral, intrapartum, and neonatal factors, with immaturity, fetal distress, and cardiorespiratory instability in the early neonatal course as significant contributors. The long-term impact of CBH for the ELBW infant is not fully understood, but recent reports suggest that, in addition to motor impairments, deficits in cognitive, language, and social-behavioral function are also apparent. This article reviews the current state of knowledge of cerebellar development, risk factors for injury, and long-term developmental consequences of injury. Implications for nursing practice, education, and research are discussed.

Magnetic resonance imaging of the brain in newborn infants: practical aspects

Magnetic Resonance Imaging is becoming more widely available and increasingly important for imaging the neonatal brain. In newborn infants it poses challenges regarding patient preparation, safety, optimal timing, and sequence optimization. These issues are addressed in this paper and indications for performing neonatal Magnetic Resonance Imaging are presented.

Preterm birth and disruptive cerebellar development: assessment of perinatal risk factors

OBJECTIVE

Abnormal cerebellar development was recently recognized to be related to prematurity. Aim of the present study was to evaluate preterm birth and possible peri- and postnatal risk factors associated with this type of brain injury.

PATIENTS AND METHODS

We report on a series of 35 very low birth weight infants (birth weight 986+/-257g S.D.) born between 24 and 32 weeks of gestation (27.0+/-1.8 weeks of gestation S.D.) sustaining disruption of cerebellar development after preterm birth. Perinatal medical records of study patients were compared to 41 preterm control infants (birth weight 900+/-358g S.D., gestational age 26.3+/-2.1 weeks S.D.) with normal cerebellar development on MRI scan.

RESULTS

A severely compromised postnatal condition with consecutive intubation and catecholamine support was found to be significant risk factor. Additional supratentorial hemorrhagic brain injury followed by posthemorrhagic hydrocephalus, neurosurgical interventions and hemosiderin deposits on the cerebellar surface were significantly related to disruptive cerebellar development. No other differences in perinatal factors were found between the groups.

CONCLUSION

Premature birth between 24 and 32 gestational weeks associated with poor postnatal conditions and complicated supratentorial hemorrhagic brain lesions represents a high-risk situation for disruption of cerebellar development.

Prevalence and evolution of intracranial hemorrhage in asymptomatic term infants

BACKGROUND AND PURPOSE

Subdural hemorrhage (SDH) is often associated with infants experiencing nonaccidental injury (NAI). A study of the appearance and natural evolution of these birth-related hemorrhages, particularly SDH, is important in the forensic evaluation of NAI. The purpose of this study was to determine the normal incidence, size, distribution, and natural history of SDH in asymptomatic term neonates as detected by sonography (US) and MR imaging within 72 hours of birth.

MATERIALS AND METHODS

Birth history, delivery method, duration of each stage of labor, pharmaceutic augmentation, and complications during delivery as well as postnatal physical examination were recorded. Brain MR imaging and US were performed on 101 asymptomatic term infants at 3-7 days, 2 weeks, 1 month, and 3 months. Clinical follow-up at 24 months was recorded.

RESULTS

Forty-six neonates had SDH by MR imaging within 72 hours of delivery. SDH was seen in both vaginal and cesarean deliveries. All neonates were asymptomatic, with normal findings on physical examination. All 46 had supratentorial SDH seen in the posterior cranium. Twenty (43%) also had infratentorial SDH. US detected 11 of the 20 (55%) infratentorial SDHs and no supratentorial SDH. Most SDHs present at birth were <or=3 mm and had resolved by 1 month, and all resolved by 3 months on MR imaging. Most children with SDHs had normal findings on developmental examinations at 24 months.

CONCLUSION

SDH in asymptomatic term neonates after delivery is limited in size and location.

Does cerebellar injury in premature infants contribute to the high prevalence of long-term cognitive, learning, and behavioral disability in survivors?

OBJECTIVE

Although cerebellar hemorrhagic injury is increasingly diagnosed in infants who survive premature birth, its long-term neurodevelopmental impact is poorly defined. We sought to delineate the potential role of cerebellar hemorrhagic injury in the long-term disabilities of survivors of prematurity.

DESIGN

We compared neurodevelopmental outcome in 3 groups of premature infants (N = 86; 35 isolated cerebellar hemorrhagic injury, 35 age-matched controls, 16 cerebellar hemorrhagic injury plus supratentorial parenchymal injury). Subjects underwent formal neurologic examinations and a battery of standardized developmental, functional, and behavioral evaluations (mean age: 32.1 +/- 11.1 months). Autism-screening questionnaires were completed.

RESULTS

Neurologic abnormalities were present in 66% of the isolated cerebellar hemorrhagic injury cases compared with 5% of the infants in the control group. Infants with isolated cerebellar hemorrhagic injury versus controls had significantly lower mean scores on all tested measures, including severe motor disabilities (48% vs 0%), expressive language (42% vs 0%), delayed receptive language (37% vs 0%), and cognitive deficits (40% vs 0%). Isolated cerebellar hemorrhagic injury was significantly associated with severe functional limitations in day-to-day activities. Significant differences were noted between cases of cerebellar hemorrhagic injury versus controls on autism screeners (37% vs 0%) and internalizing behavioral problems (34% vs 9%). Global developmental, functional, and social-behavioral deficits were more common and profound in preterm infants with injury to the vermis. Preterm infants with cerebellar hemorrhagic injury and supratentorial parenchymal injury were not at overall greater risk for neurodevelopmental disabilities, although neuromotor impairment was more severe.

CONCLUSIONS

Cerebellar hemorrhagic injury in preterm infants is associated with a high prevalence of long-term pervasive neurodevelopment disabilities and may play an important and underrecognized role in the cognitive, learning, and behavioral dysfunction known to affect survivors.

Reduction in cerebellar volumes in preterm infants: relationship to white matter injury and neurodevelopment at two years of age

A substantial number of prematurely born infants will experience later neurodevelopmental challenges. Abnormal development of the cerebellum may be related to some of the impairments exhibited by preterm children. To test the hypothesis that cerebellar development is structurally impaired in preterm infants and associated with adverse outcomes, we studied 83 preterm infants and 13 term controls using volumetric magnetic resonance imaging techniques to obtain cerebellar volumes (CV) at term corrected and subsequent neurodevelopmental assessment at 2 y of age. The preterm group had smaller mean CV at term compared with the term control infants [mean (SD) CV, 22.0 (5.0) versus 23.5 (5.0) cc; mean difference (95% confidence interval), 1.5 (-1.5, 4.4)] although this did not reach statistical significance. Within the preterm group, there was evidence of a reduction in CV related to the presence of white matter injury (WMI) after adjusting for intracranial volume (ICV) [WMI grade 1 versus grade 2: mean (SD) CV, 23.6 (5.0) versus 21.6 (4.5); p = 0.01; WMI grade 1 versus grade 3 and 4: 23.6 (5.0) versus 20.8 (5.6); p = 0.07]. Within the preterm infants, there was no apparent relationship between CV at term and gestational age at birth after adjusting for ICV. At 2 y of age, CV showed a weak correlation with cognitive and motor development, although this was principally mediated by WMI. In conclusion, we found no evidence for a primary impairment in cerebellar development in relation to prematurity, although there was evidence for a secondary effect of cerebral WMI on cerebellar development independent of immaturity.

Magnetic resonance imaging in preterm infants

MR imaging of the premature infant poses a number of challenges with regard to safety, sequence optimization and recognition of the normal appearances of the developing brain. In this paper we discuss these challenges, and review the common intracerebral abnormalities associated with premature birth. Although the outcome for very-low-birth-weight babies has improved over the last decade, there remains a significant risk of subsequent development of neurological disability. The relationship between MRI abnormalities and long-term outcome is considered.

Diagnostic approach to cerebellar disease in children

We reviewed the clinical records of 51 extensively investigated pediatric patients with structural abnormalities of the cerebellum as revealed by magnetic resonance imaging (MRI). Ten had hypoplasia of the vermis, 21 had hypoplasia of the vermis and cerebellar hemispheres, 2 had pontocerebellar hypoplasia, and 18 had progressive cerebellar atrophy. A clear diagnosis was reached in 37 (72.5%). Initial characterization of the cerebellar alterations by MRI separated hypoplastic from atrophic cases and confirmed MRI as an essential preliminary means for distinguishing malformations from metabolic-degenerative conditions. However, the diagnostic possibilities are so numerous that it is not feasible to propose a standardized diagnostic protocol for pediatric patients with an altered cerebellum. Subsequent investigations should be suggested by the neuroradiologic and clinical peculiarities of each case.

Cerebellar hemorrhage in the preterm infant: ultrasonographic findings and risk factors

Cerebellar hemorrhage (CBH) in premature infants is increasingly diagnosed secondary to improved neuroimaging techniques and survival of very small preterm infants. Information is limited, however, on the incidence, topography, and risk factors for CBH in the preterm infant.

OBJECTIVES

To define the incidence of CBH in preterm infants diagnosed by neonatal cranial ultrasound (US), describe the sonographic features of CBH, and identify maternal and perinatal risk factors associated with this lesion.

METHODS

A systematic electronic database search identified preterm infants born 1998-2002 with US diagnosis of CBH. For 35 cases of CBH we double-matched (according to gestational age, gender, and year of birth) 70 preterm controls with normal cranial USs and performed detailed medical-record reviews for both patients and controls.

RESULTS

Unilateral CBH was seen in 25 patients (71%), vermian hemorrhage was seen in 7 (20%), and combined bihemispheric and vermian hemorrhage was seen in 3 (9%). Isolated CBH occurred in 8 patients (23%); the remaining infants had associated supratentorial lesions. The incidence of CBH in preterm infants weighing <750 g at birth showed significant increase over the study period. Univariate analyses identified maternal, intrapartum, and early postnatal hemodynamic risk factors; multivariate regressions indicated that emergent caesarian section, patent ductus arteriosus, and lower 5-day minimum pH independently increased the odds of CBH. Neonatal mortality and morbidity were significantly higher among patients with CBH compared with preterm controls.

CONCLUSIONS

CBH is an important complication of extreme preterm birth and has been underrecognized in surviving preterm infants. Predictors of CBH seem to be multifactorial and include combined maternal, intrapartum, and early postnatal factors.

Ultrasound abnormalities preceding cerebral palsy in high-risk preterm infants

OBJECTIVE

To assess sequential high-resolution cranial ultrasound (US) in high-risk preterm infants to predict cerebral palsy (CP).

STUDY DESIGN

Preterm infants were prospectively studied (n=2139), 1636 <or=32 weeks gestational age (GA) (group A) and 503 with a GA of 33 to 36 weeks (group B). US was performed once a week until discharge and at 40 weeks postmenstrual age (PMA), using a 7.5-MHz transducer. Grade III and IV hemorrhage, cystic periventricular leukomalacia (c-PVL), and focal infarction were considered major US abnormalities. A diagnosis of CP was made at a minimum age of 24 months.

RESULTS

Seventy-six (5%) of the 1460 survivors in group A developed CP. US abnormalities were present in 70 of 76 (92%) infants, being major in 58 (83%) and minor in 12 (17%). In 29% of the CP cases with major US abnormalities, cysts were first detected beyond day 28. A further 6 infants without US abnormalities developed CP, and 3 of these infants developed ataxic CP. Twenty-nine (6%) of the 469 survivors in group B developed CP. US abnormalities were present in 28 of 29 (96%) infants, being major in 25 (89%) and minor in 3 (11%). One infant without US abnormalities developed CP. Considering the major US abnormalities, a specificity of 95% and 99% and a sensitivity of 76% and 86% were found for group A and B, respectively. The positive predictive value was 48% in group A and 83% in group B.

CONCLUSION

Seventy-nine percent of our CP cases had major US abnormalities. To detect c-PVL, the most predictive US marker for CP, sequential scans with a 7.5-MHz transducer are required.