Spectrum of brain malformations in fetuses with mild tubulinopathy

OBJECTIVE

To report on a large cohort of fetuses with mild forms of tubulinopathy and to define prenatal ultrasound and magnetic resonance imaging (MRI) features that can facilitate prenatal diagnosis.

METHODS

This was a retrospective multicenter study of fetuses diagnosed between January 2007 and February 2022 with a mild tubulinopathy (without lissencephaly or microlissencephaly). We collected and reviewed brain imaging and genetic data, and defined major criteria as findings observed in ≥ 70% of the patients and minor criteria as those observed in ≥ 50% but < 70% of the patients.

RESULTS

Our cohort included 34 fetuses. The mean gestational age at ultrasound screening, when suspicion of a central nervous system anomaly was first raised, was 24.2 (range, 17-33) weeks. Callosal anomalies (n = 19 (56%)) and abnormal ventricles (n = 18 (53%)) were the main reasons for referral. The mean gestational age at neurosonography was 28.3 (range, 23-34) weeks and that at MRI was 30.2 (range, 24-35) weeks. Major ultrasound criteria were midline distortion, ventricular asymmetry, dysmorphic and/or dilated frontal horn(s) and abnormal sulcation. Minor ultrasound criteria were distortion of the cavum septi pellucidi, abnormal corpus callosum, absent or asymmetric olfactory sulci, ventriculomegaly and basal ganglia dysmorphism. Major MRI criteria were midline distortion, distortion of the cavum septi pellucidi, ventricular asymmetry, dilatation (generally unilateral) and/or distortion, dysmorphic and/or dilated frontal horn(s) and abnormal sulcation (mainly dysgyria). Minor MRI criteria were absent or asymmetric olfactory sulci, abnormal bulge of the pons, anteroposterior diameter of the pons ≤ 5th centile and brainstem asymmetry. A mutation was found in TUBB3 (44.1% of cases), TUBB (23.5%), TUBB2B (14.7%) or TUBA1A (17.6%). The mutation was inherited from a parent in 18/34 cases. The pregnancy was terminated in 23/34 cases.

CONCLUSIONS

Prenatal diagnosis of mild forms of tubulinopathy is possible but challenging. We have defined, in this large series of fetuses, major and minor criteria that can help identify this entity in utero. Most findings can be visualized on ultrasound. This evaluation is also important for prenatal counseling. Once a prenatal diagnosis of mild tubulinopathy is suspected, the family members should be referred for exome sequencing and MRI. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis of rhombencephalosynapsis: neuroimaging features and severity of vermian anomaly

OBJECTIVES

To describe the prenatal neuroimaging spectrum of rhombencephalosynapsis (RES) and criteria for its classification according to the severity of vermian anomaly.

METHODS

In this multicenter retrospective study of fetuses with RES between 2002 and 2020, the medical records and brain ultrasound and magnetic resonance images were evaluated comprehensively to determine the severity of the vermian anomaly and the presence of associated brain findings. RES was classified, according to the pattern of vermian agenesis and the extent of the fusion of the hemispheres, as complete RES (complete absence of the vermis) or partial RES (further classified according to the part of the vermis that was missing and, consequently, the region of hemispheric fusion, as anterior, posterior, severe or mixed RES). Findings were compared between cases with complete and those with partial RES.

RESULTS

Included in the study were 62 fetuses with a gestational age ranging between 12 and 37 weeks. Most had complete absence of the vermis (complete RES, 77.4% of cases), a 'round-shaped' cerebellum on axial views (72.6%) and a transverse cerebellar diameter (TCD) < 3^rd centile (87.1%). Among the 22.6% of cases with partial RES, 6.5% were classified as severe partial, 6.5% as partial anterior, 8.1% as partial mixed and 1.6% as partial posterior. Half of these cases presented with normal or nearly normal cerebellar morphology and 28.5% had a TCD within the normal limits. Infratentorially, the fourth ventricle was abnormal in 88.7% of cases overall, and anomalies of the midbrain and pons were frequent (93.5% and 77.4%, respectively). Ventriculomegaly was observed in 80.6% of all cases, being more severe in cases with complete RES than in those with partial RES, with high rates of parenchymal and septal disruption.

CONCLUSIONS

This study provides prenatal neuroimaging criteria for the diagnosis and classification of RES, and identification of related features, using ultrasound and magnetic resonance imaging. According to our findings, a diagnosis of RES should be considered in fetuses with a small TCD (severe cerebellar hypoplasia) and/or a round-shaped cerebellum on axial views, during the second or third trimester, especially when associated with ventriculomegaly. Partial RES is more common than previously thought, but presents an extreme diagnostic challenge, especially in cases with normal or nearly-normal cerebellar morphobiometric features. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Multiple Brain Developmental Venous Anomalies as a Marker for Constitutional Mismatch Repair Deficiency Syndrome

BACKGROUND AND PURPOSE

Biallelic constitutional mutations in DNA mismatch repair genes cause a distinct syndrome, constitutional mismatch repair deficiency syndrome (CMMRD), characterized by cancers from multiple organs, most commonly brain tumors, during childhood. Surveillance protocols include total and brain MR imaging among other modalities to enable early detection of tumors. Brain surveillance scans revealed prominent brain developmental venous anomalies (DVAs) in some patients. DVAs are benign vascular anomalies, and their incidence in the general population is 2.6%-6.4%. Most developmental venous anomalies are asymptomatic and are found incidentally. Our purpose was to assess the prevalence of DVAs in CMMRD patients and describe their phenotype.

MATERIALS AND METHODS

A retrospective descriptive analysis of brain MR imaging studies from 10 patients from 3 families with CMMRD was performed. Analysis included the number of developmental venous anomalies, location, draining vessels, and associated vascular anomalies (ie, cavernomas), with clinical correlation of symptoms and tumors.

RESULTS

All 10 patients had ≥2 developmental venous anomalies, and 2 had, in addition, non-therapy-induced cavernomas. There was no clinically symptomatic intracranial bleeding from developmental venous anomalies. Six patients had malignant brain tumors. The location of brain tumors was not adjacent to the developmental venous anomalies. No new developmental venous anomalies developed during follow-up.

CONCLUSIONS

The occurrence of multiple developmental venous anomalies in all our patients with CMMRD suggests that developmental venous anomalies may be a characteristic of this syndrome that has not been previously described. If confirmed, this quantifiable feature can be added to the current scoring system and could result in early implementation of genetic testing and surveillance protocols, which can be life-saving for these patients.

T1-weighted MR imaging of bone marrow pattern in children with adolescent idiopathic scoliosis: a preliminary study

PURPOSE

Distinct normal physiological patterns of fat conversion in vertebrae were described both for children and adults. Our aim was to evaluate the T1-weighted bone marrow pattern of the vertebral bodies in various sites along the scoliotic spine of children with adolescent idiopathic scoliosis (AIS).

METHODS

We retrospectively evaluated spine MRI studies of children with AIS. Scoliosis radiographs were assessed for type of curvature according to the Lenke classification. A paediatric neuroradiologist assessed the T1-weighted signal of vertebral bodies in comparison with the adjacent disc and distinct patterns of fatty conversion within the apical and stable vertebral bodies. Statistical assessment was performed.

RESULTS

MRI study of the spines of 75 children with AIS were assessed, 59 (79%) of whom were female, with an age range of nine to 19 years. The relative overall T1-weighted signal intensity of the vertebral body bone marrow relative to the intervertebral disc was hyperintense in 76% and isointense in 24%. Fatty conversion grade of the stable vertebra was higher than the apex vertebra (p = 0.0001). A significant tendency to have more advanced fat conversion patterns in the apex vertebra up to age 13.5 years old compared with adolescents above that (p = 0.015) was seen.

CONCLUSION

This preliminary study suggests a different pattern of bone marrow conversion in AIS from the normal physiologic pattern described in the literature. Whether these changes are secondary to the biomechanics of the curved spine or may suggest that bone marrow maturation rate and content have a role in the pathogenesis of AIS remains to be further researched.

LEVEL OF EVIDENCE

Level III (Diagnostic Study).

Spinal and Paraspinal Plexiform Neurofibromas in Patients with Neurofibromatosis Type 1: A Novel Scoring System for Radiological-Clinical Correlation

BACKGROUND AND PURPOSE

Neurofibromatosis type 1 is a common tumor predisposition syndrome. The aim of this study was to characterize the radiologic presentation of patients with neurofibromatosis type 1 with widespread spinal disease and to correlate it to clinical presentation and outcome.

MATERIALS AND METHODS

We conducted a historical cohort study of adult patients with neurofibromatosis type 1 with spinal involvement. Longitudinal clinical evaluation included pain and neurologic deficits. Radiologically, spinal involvement was classified according to a novel classification system, and a radiologic risk score was calculated.

RESULTS

Two hundred fifty-seven adult patients with neurofibromatosis type 1 are followed in our center. Thirty-four of these patients qualified for inclusion in this study. Three independent factors were found to be associated with increased risk for neurologic deficit: 1) bilateral tumors at the same level in the cervical region that approximated each other, 2) paraspinal tumors at the lumbar region, and 3) intradural lesions. On the basis of these factors, we calculated a combined risk score for neurologic deficits for each patient. We found a clear correlation between patient status and the calculated radiologic risk score. Patients with neurologic deficits were found to have a higher risk score (9 ± 8.3) than patients without neurologic deficits (2.5 ± 2.9, P < .05). Patients who progressed during the follow-up period had significantly higher scores at presentation than patients with stable conditions (9.9 ± 8.73 versus 3.9 ± 5.3, respectively; P < .05).

CONCLUSIONS

In this series, neurologic deficit is correlated with tumor burden and subtype. We found no direct correlation with tumor burden and pain. Our novel radiologic classification scoring system may be used to predict increased risk for neurologic morbidity.

Prediction of microcephaly at birth using three reference ranges for fetal head circumference: can we improve prenatal diagnosis?

OBJECTIVE

To evaluate the prediction of microcephaly at birth (micB) using established and two new reference ranges for fetal head circumference (HC) and to assess whether integrating additional parameters can improve prediction.

METHODS

Microcephaly in utero was defined as a fetal HC 3SD below the mean for gestational age according to Jeanty et al.'s reference range. The records of cases with fetal microcephaly (Fmic) were evaluated for medical history, imaging findings, biometry and postnatal examination/autopsy findings. Microcephaly was confirmed at birth (micB) by an occipitofrontal circumference (OFC) or a brain weight at autopsy 2SD below the mean for gestational age. The new INTERGROWTH-21(st) Project and a recent Israeli reference for fetal growth were applied for evaluation of the Fmic positive predictive value (PPV) for diagnosis of micB cases. Optimal HC cut-offs were determined for each of the new references with the aim of detecting all micB cases whilst minimizing the number of false positives found to have a normal HC at birth. We also assessed the difference between the Z-scores of the prenatal HC and the corresponding OFC at birth, the frequency of small-for-gestational age (SGA), decreased HC/abdominal circumference (AC) and HC/femur length (FL) ratios, the prevalence of associated malformations and family history.

RESULTS

Forty-two fetuses were diagnosed as having Fmic according to the Jeanty reference, but micB was confirmed in only 24 (PPV, 57.1%). The optimal INTERGROWTH and Israeli reference HC cut-offs for micB diagnosis were mean - 3SD and mean - 2.3SD, resulting in a statistically non-significant improvement in PPV to 61.5% and 66.7%, respectively. The presence of a family history of microcephaly, SGA, associated malformations and application of stricter HC cut-offs resulted in a higher PPV of micB, although not statistically significant and with a concurrent increase in the number of false-negative results. The deviation of the HC from the mean, by all references, was significantly larger compared with the actual deviation of the OFC at birth, with mean differences between the corresponding Z-scores of -1.15, -1.95 and -0.74 for the Jeanty, INTERGROWTH and Israeli references, respectively.

CONCLUSIONS

The evaluated reference ranges all result in considerable over-diagnosis of fetal microcephaly. The use of the two new HC reference ranges did not significantly improve micB prediction compared with that of Jeanty et al., whilst use of additional characteristics and stricter HC cut-offs could improve the PPV with an increase in false negatives. The postnatal OFC deviates significantly less from the mean compared with the prenatal HC, and we propose that adjustment for this would enable better prediction of the actual OFC deviation at birth. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Application of a novel prenatal vertical cranial biometric measurement can improve accuracy of microcephaly diagnosis in utero

OBJECTIVE

To construct a reference range for a new vertical measurement of the fetal head and to assess whether its combination with fetal head circumference (HC) can prevent the misdiagnosis of microcephaly in fetuses with an acrocephalic-like head deformation.

METHODS

A new vertical cranial biometric measurement was defined: the foramen magnum-to-cranium distance (FCD), measured between the foramen magnum and the upper inner cranial border along the posterior wall of the brainstem. The measurement was performed in a precise mid-sagittal plane using a three-dimensional multiplanar display of a sagittally acquired sonographic volume of the fetal head. The normal reference range was developed by measuring 396 healthy fetuses of low-risk singleton pregnancies between 15 and 40 gestational weeks. This reference was applied to 25 fetuses with microcephaly diagnosed prenatally (Fmic) based on HC ≥ 3 SD below the mean for gestational age. We determined an optimal FCD cut-off for combination with HC to detect all cases found with microcephaly at birth (micB), while excluding the fetuses with normal head circumference at birth (NHCB), who were described postnatally as having an acrocephalic-like cranial deformation.

RESULTS

In the healthy singleton fetuses, FCD increased with gestational age, with a quadratic equation providing an optimal fit to the data (adjusted R(2) = 0.934). The measurement could be assessed in 95.2% of cases. Of the 25 cases diagnosed with Fmic prenatally, on the basis of HC alone, 14 were micB and 11 were NHCB. We observed FCD below the mean - 2SD for gestational age in all 14 micB cases, but in only four of the 11 NHCB cases (P < 0.003). An acrocephalic-like cranial deformation was described at birth in five of the seven NHCB cases with normal FCD. The mean ± SD FCD Z-score of the micB cases was significantly lower (P < 0.001) than that of the false-positive ones: -3.85 ± 0.96 SD and -1.59 ± 1.45 SD, respectively. Based on HC measurement alone, the positive predictive value (PPV) was 56%. Combination of the HC and FCD criteria raised the PPV to 78%, decreasing the number of false positives from 11 to four, without missing any of the 14 micB cases.

CONCLUSIONS

Fetal vertical cranial biometric assessment in the mid-sagittal plane is feasible and correlates well with gestational age. In our series, a vertical cranial deformation was a frequent cause of a false Fmic diagnosis made on the basis of HC alone. Combination of the new vertical cranial biometric measurement with HC measurement can exclude these cases and thus improve diagnostic accuracy for Fmic. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Tumor burden evaluation in NF1 patients with plexiform neurofibromas in daily clinical practice

BACKGROUND

Existing volumetric measurements of plexiform neurofibromas (PNs) are time consuming and error prone, as they require delineation of PN boundaries, a procedure that is not practical in the typical clinical setting. The aim of this study is to assess the Plexiform Neurofibroma Instant Segmentation Tool (PNist), a novel semi-automated segmentation program that we developed for PN delineation in a clinical context. PNist was designed to greatly simplify volumetric assessment of PNs through use of an intuitive user interface while providing objectively consistent results with minimal interobserver and intraobserver variabilities in reasonable time.

MATERIALS AND METHODS

PNs were measured in 30 magnetic resonance imaging (MRI) scans from 12 patients with neurofibromatosis 1. Volumetric measurements were performed using PNist and compared to a standard semi-automated volumetric method (Analyze 9.0).

RESULTS

High correlation was detected between PNist and the semi-automated method (R(2) = 0.996), with a mean volume overlap error of 9.54 % and low intraobserver and interobserver variabilities. The segmentation time required for PNist was 60 % of the time required for Analyze 9.0 (360 versus 900 s, respectively). PNist was also reliable when assessing changes in tumor size over time, compared to the existing commercial method.

CONCLUSIONS

Our study suggests that the new PNist method is accurate, intuitive, and less time consuming for PN segmentation compared to existing commercial volumetric methods. The workflow is simple and user-friendly, making it an important clinical tool to be used by radiologists, neurologists and neurosurgeons on a daily basis, helping them deal with the complex task of evaluating PN burden and progression.

Isolated mild white matter signal changes in preterm infants: a regional approach for comparison of cranial ultrasound and MRI findings

OBJECTIVE

To compare echogenicity detected using cranial ultrasound (cUS) and diffuse excessive high signal intensity (DEHSI) detected using magnetic resonance imaging (MRI) by identical region-based scoring criteria in preterm infants. To explore the association between these white matter (WM) signal changes with early neurobehavior.

STUDY DESIGN

Forty-nine pre-selected premature infants with only echogenicity on a first routine cUS1 underwent MRI and a repeated cUS2 at term equivalent age. Echogenicity and DEHSI were graded in various brain areas and diffusivity values were calculated. Neurobehavior was assessed using the Rapid Neonatal Neurobehavioral Assessment Procedure.

RESULT

WM signal changes were significantly higher on cUS1 than cUS2; and higher in MRI than cUS2 in posterior regions. Infants with DEHSI demonstrated reduced tissue integrity. Imaging findings were not correlated with early neurobehavior.

CONCLUSION

Echogenicity and DEHSI likely represent the same phenomenon. Reduction of over-interpretation of WM signal changes may help define criteria for the judicious use of imaging in routine follow-up of premature infants.

Fetal optic nerve sheath measurement as a non-invasive tool for assessment of increased intracranial pressure

OBJECTIVES

To describe the sonographic technique for assessment of the fetal optic nerve sheath and to report on three fetuses with intracranial lesions and enlarged optic nerve sheath diameter (ONSD) compared with normal controls matched for gestational age (GA).

METHODS

In this cross-sectional study ONSD was measured sonographically in three fetuses (aged 23, 24 and 35 gestational weeks) with intracranial findings associated with increased intracranial pressure (ICP; dural thrombosis and intracranial tumors) as well as 42 healthy controls matched for GA ± 1 week (aged 22-25 and 34-36 weeks). For fetal eye assessment, transabdominal and transvaginal routes and high-resolution transducers were used for optimal visualization depending on fetal position. Measurements were made using an axial view at the level of the orbits, with the fetal face positioned towards the transducer. The ONSD was measured 1.5 or 2 mm behind the papilla (depending on GA) in all fetuses. Mean ± 2 SD ONSD of controls were calculated for each GA and compared with data from the three fetuses with intracranial pathology.

RESULTS

In the 42 normal fetuses, ONSD increased from 1.2 mm at 23 weeks to 2.6 mm at 36 weeks. The measurements at 36 weeks correlated well with those observed in newborns. ONSD measurements of the three cases were above mean + 2 SD of values obtained from healthy controls at the same GA and also exceeded values of fetuses that were 1 week older.

CONCLUSIONS

Fetal ONSD measurement is feasible using a technique similar to that used in adults and children. ONSD enlargement was observed in all three fetuses with intracranial lesions and may be an early tool with which to diagnose increased ICP.

Optic nerve sheath diameter on MR imaging: establishment of norms and comparison of pediatric patients with idiopathic intracranial hypertension with healthy controls

BACKGROUND AND PURPOSE

IIH is a disorder associated with increased intracranial pressure with no clinical, laboratory, or radiologic evidence of an intracranial space-occupying lesion. The aim of this study was to establish ONSD standards of healthy pediatric subjects and compare the normal measurements with those of patients with IIH.

MATERIALS AND METHODS

One hundred fifteen MR imaging studies of children 4 months to 17 years of age were blinded and reviewed by a pediatric neuroradiologist. A total of 230 optic nerves were measured. Eighty-six MR imaging examinations were performed in apparently healthy subjects. This control group included subjects who underwent MR imaging for various reasons, and their MR imaging findings were interpreted as normal. Twenty-nine MR imaging examinations were performed in patients with documented IIH. The ONSD was measured 1 cm anterior to the optic foramina on an axial T2 sequence. For statistical analysis, both patients and controls were stratified into 4 age groups (I, 0-3 years; II, 3-6 years; III, 6-12 years; IV, 12-18 years).

RESULTS

The mean ONSD of the control group in all age groups (I, 3.1 mm; II, 3.41 mm; III, 3.55 mm; IV, 3.56 mm) was significantly smaller than the mean ONSD of patients (I, 4.35 mm; II, 4.37 mm; III, 4.25 mm; IV, 4.69 mm). A positive correlation between age and ONSD (r = 0.414, P < .01) was found in the control group.

CONCLUSIONS

According to our study, in pediatric patients with IIH, the ONSD is significantly larger than that in healthy controls regardless of age group and sex. This measurement might prove to be an auxiliary tool in the diagnosis of increased intracranial pressure in pediatric patients.

Can syndromic macrocephaly be diagnosed in utero?

OBJECTIVES

To compare the outcomes of fetuses with apparently isolated macrocephaly and those with associated findings, and to compare prenatal findings with postnatal diagnoses in children with syndromic macrocephaly.

METHODS

We reviewed the files of all patients referred for suspected fetal macrocephaly, during a 10-year period from 2000, to a large prenatal diagnosis unit with expertise in fetal neurology counseling. Macrocephaly was defined as head circumference (HC) > 2 SDs of the norm. Patients with confirmed HC > 2 SD were identified and contacted, and their development was evaluated.

RESULTS

Adequate data for analysis were available for 98 patients, in 82 of whom the fetal macrocephaly was considered isolated (Group A), and in 16 of whom associated fetal anomalies were identified (Group B). Macrocephaly was diagnosed earlier in Group B patients (28.4 vs. 32.3 weeks, P = 0.069), and the HC in Group B patients was larger (Z-score 2.95 vs. 2.3, P < 0.001). From Group A there were 81 liveborn; one of whom was diagnosed as having infantile autism. From Group B, there were nine liveborn. The associated central nervous system findings, as demonstrated by ultrasound and magnetic resonance imaging, included mild ventriculomegaly, malformations of cortical development, callosal abnormalities, overdeveloped sulcation, large cavum septi pellucidi, large subarachnoid spaces, mega cisterna magna, periventricular pseudocyst, open operculum and vermian dysgenesis. Syndromic diagnosis was made in utero in five fetuses and after birth in three. In eight patients, associated malformations were confirmed after birth but a specific diagnosis was not reached.

CONCLUSIONS

When fetal macrocephaly is associated with other brain or systemic anomalies, syndromic macrocephaly can be diagnosed in utero. Fetuses with syndromic macrocephaly have a significantly larger HC, usually > 2.5 SD above the mean. Isolated macrocephaly, particularly when the HC is < 2.5 SD above the norm, may be clinically benign.

Regression of subependymal giant cell astrocytomas with RAD001 (Everolimus) in tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder caused by inactivating mutations in the TSC1 or TSC2 genes and characterized by slow-growing tumors in multiple organs. Of the affected individuals, 10% display subependymal giant cell astrocytomas (SEGAs), which can lead to substantial neurological morbidity. The TSC1/TSC2 protein complex is a negative regulator of the mTOR pathway. Hence, mutations in these genes in preclinical models are associated with increased mTOR pathway activation and heightened sensitivity to mTOR inhibitors. We hereby report our experience with RAD001 (Everolimus) therapy, a novel mTOR inhibitor, in inducing a dramatic regression of SEGAs.

METHODS

A patient with TSC and SEGAs was treated with 10 mg/day oral RAD001. MRIs and neuro-ophthalmological exams were performed before and at regular intervals following the initiation of therapy.

RESULTS

The lesions exhibited significant regression in several tumor locations and stabilization in others, accompanied with an improvement of his visual status. Treatment was well tolerated for 11 months but was than discontinued due to hypertension and elevated CPK, without evidence for rhabdomyolysis. Yet, during 9 months following the interruption of therapy, SEGAs remained unchanged.

CONCLUSIONS

Oral RAD001 demonstrated preliminary encouraging results as treatment of astrocytomas associated with TSC. These preliminary results were recently supported by the Novartis announcement of the phase II study of RAD001 for SEGAs, which was not published yet. According to their statement, 75% of the patients showed reduction of SEGAs' volume following treatment with RAD001. Based on these results, RAD001 may be an alternative to surgery in selected patients with TSC and SEGAs.

Thick fetal corpus callosum: an ominous sign?

OBJECTIVE

Anomalies of the corpus callosum are frequently diagnosed during pregnancy, but a thick corpus callosum is a rare finding and its significance is not clear. We aimed to assess the significance of thick fetal corpus callosum by reviewing our experience of such cases.

METHODS

The records of all fetuses with anomalies of the corpus callosum referred to the prenatal diagnosis units of two university hospitals from 2000 to 2007 were reviewed. Nine fetuses with a thick corpus callosum were identified.

RESULTS

In all cases there were associated abnormalities: macrocephaly, ventriculomegaly, vermian agenesis, abnormal sulcation or encephalocele. Four pregnancies were terminated and in each of these cases the autopsy confirmed dysmorphic features and additional brain abnormalities. Five infants were delivered; two died shortly after birth, one suffers from mental retardation, one had neonatal convulsions and one is developing normally.

CONCLUSIONS

A thick fetal corpus callosum is usually associated with other brain anomalies and is part of a neurogenetic syndrome in most cases.

Recurrent meningitis and cerebrospinal fluid leak-two sides of the same vestibulocochlear defect: report of three cases

Cochlear dysplasia is a rare congenital anomaly. However, early detection of this anomaly can prevent serious consequences. We describe three cases of cochlear dysplasia that presented with recurrent meningitis and cerebro-spinal fluid (CSF) leak in children in which early diagnosis prevented further complications.

Prenatal diagnosis of malformations of cortical development by dedicated neurosonography

OBJECTIVE

Malformations of cortical development (MCD) are rarely diagnosed in utero. We describe and compare the ultrasonographic and pathology findings in a cohort of fetuses with MCD.

METHODS

Fetuses with MCD were identified among all fetuses evaluated for suspected brain anomalies at the Fetal Neurology Clinic, and the ultrasonographic findings were compared with the results of the pathology examination.

RESULTS

We suspected the presence of MCD by ultrasonography in 23 fetuses. The mean gestational age at the time of ultrasound diagnosis was 26.2 (range, 18-40) weeks. The ultrasonographic findings leading to the diagnosis of MCD were abnormally overdeveloped gyri and sulci for gestational age (n = 7), delay in sulcation (n = 5), abnormally thin cortex (n = 5) abnormally wide and broad sulci (n = 3), bulging into the lateral ventricle (n = 1), cortical cleft (n = 1), and multiple intraparenchymal echogenic nodules (n = 1). All fetuses had associated central nervous system (CNS) and/or non-CNS anomalies. Pathology examination (performed in 17 fetuses) confirmed MCD in 16.

CONCLUSIONS

Cortical malformations can be diagnosed in utero by ultrasonography based on the presence of specific deviations from the normal pattern of development. The identified cases may represent the more severe forms in the MCD spectrum. The pathology findings do not always conform to the current classification systems of MCD but help in differentiating between possible genetic and acquired etiologies and in some cases provide a definitive syndromic diagnosis.

Diffusion tensor imaging in hydrocephalus: initial experience

PURPOSE AND BACKGROUND

Diffusion tensor imaging (DTI) is an MR imaging-based technique that provides an in vivo tool for visualization of white matter tracts. In this preliminary study, we used this technique to investigate the diffusion characteristics of white matter tracts in patients with hydrocephalus before and after surgery and compared them with age-matched volunteers.

MATERIALS AND METHODS

Seven patients with different types of acute hydrocephalus (defined by acute clinical signs of increased intracranial pressure and imaging evidence of enlarged ventricles) underwent MR imaging including a DTI protocol before and after surgery for shunt placement/revision or ventriculostomy. Eight age-matched healthy subjects served as a control group. The DTI was acquired in a clinical setting that included 6 gradient directions with a b value of 1000 s/mm(2).

RESULTS

Before surgery, in fiber systems lateral to the ventricles (corona radiata), the diffusion parallel to the fibers was increased (+10%) and the diffusion perpendicular to the fibers was decreased (-25%) in all patients, resulting in an overall increase in the fractional diffusion anisotropy (FA, +28%). Following surgery, the FA values approached those of control values in all except 1 patient. In the corpus callosum, the presurgery FA values in patients with hydrocephalus (HCP) were lower than those of control values, and no significant changes were seen following surgery.

CONCLUSIONS

DTI can distinguish the compression characteristics of white matter before and after surgery in patients with HCP. At the acute stage of the disease, DTI characteristics point to white matter compression as a possible cause of the observed changes.

Rotation of the vermis as a cause of enlarged cisterna magna on prenatal imaging

OBJECTIVES

Dandy-Walker complex is a continuum of developmental anomalies of the posterior fossa which includes vermian rotation. However, vermian rotation alone may be benign. The aim of this study was to describe our experience with sagittal-plane prenatal ultrasound in the diagnosis of rotation of the vermis in cases of suspected enlarged cisterna magna on routine antenatal imaging, and to describe the follow-up of these patients.

METHODS

Seven women, who were referred to our ultrasound unit for evaluation of an enlarged fetal cisterna magna and suspected agenesis of the vermis on axial-plane imaging, underwent further multiplanar studies of the posterior fossa and measurements of the vermis.

RESULTS

The mean maternal age was 27 (range, 20-33) years and the mean gestational age at diagnosis was 19.5 (range, 18-31) weeks. The standard axial plane image showed a 'direct communication' between the cisterna magna and the fourth ventricle. In the mid-sagittal plane, the vermis was clearly delineated, with posterosuperior rotation. Vermis size was within normal limits for gestational age in all cases. Findings were confirmed by prenatal magnetic resonance imaging (MRI) in two cases and postnatal MRI and/or sonography in five. During a mean follow-up of 4.5 (range, 1-7.5) years, all children developed normally, with no neurological complications.

CONCLUSION

The finding of an enlarged cisterna magna on standard- (axial-)plane ultrasound should be evaluated further in the sagittal plane to determine whether the cause is rotation of a normal vermis. This may spare patients unnecessary tests, anxiety and, in some cases, pregnancy termination.

Fetal brain imaging: a comparison between magnetic resonance imaging and dedicated neurosonography

OBJECTIVES

To evaluate whether fetal brain magnetic resonance imaging (MRI) adds useful clinical information to that obtained by dedicated fetal neurosonography using a combined transabdominal and transvaginal approach in fetuses with suspected brain anomalies.

METHODS

In the 2-year period between January 2000 and January 2002, 42 fetuses underwent neurosonographic and MRI examinations of the brain. The referral indications were: asymmetric ventriculomegaly (13), ventriculomegaly (7), periventricular cysts (2), suspected midline findings (7), agenesis of the corpus callosum (3), infratentorial pathology (3), cytomegalovirus (CMV) infection (2) and miscellaneous indications (5).

RESULTS

Neurosonography and MRI produced similar diagnoses in 29 fetuses: normal examination (10), isolated asymmetric ventriculomegaly (11), isolated ventriculomegaly (3), periventricular cysts (2), agenesis of the corpus callosum (1), pericallosal lipoma (1) and cerebellar hemorrhage (1). The neurosonographic diagnoses were more accurate in seven patients: hemimegalencephaly, pericallosal lipoma, signs of CMV infection, brain anomalies associated with agenesis of the corpus callosum and three fetuses with a normal ultrasound scan in which MRI suggested a parenchymal abnormality. MRI provided a more accurate diagnosis in three patients: a third ventricular dilatation was ruled out, normal ventricles in a fetus with an ultrasonographic finding of asymmetric ventricles, and diagnosis of progression of asymmetric ventriculomegaly. In three patients the identified pathologies were differently interpreted, each examination provided another aspect of the anomaly or a definitive diagnosis was not possible.

CONCLUSIONS

Our study demonstrated that dedicated neurosonography is equal to MRI in the diagnosis of fetal brain anomalies. In most of the cases MRI confirmed the ultrasonographic diagnosis; in a minority of cases each modality provided additional/different information. The major role of MRI was in reassurance of the parents regarding the presence or absence of brain anomalies.

Omental infarction: an unusual cause of acute abdomen in children

Acute abdomen is caused by a wide variety of etiologies, many of which require surgical intervention. Two boys were hospitalized for acute abdominal pain and low-grade fever. Physical examination revealed epigastric and right upper abdominal fullness, and laboratory studies showed elevated erythrocyte sedimentation rates, with normal leukocyte counts and coagulation profiles. Abdominal ultrasound and computerized tomography revealed pseudotumor in both cases. Symptomatic treatment and cefazolin were administered, and pain and fever subsided after 6 to 10 days. Pseudotumor due to omental infarction can present as acute abdomen in children. A high index of suspicion and the use of both ultrasonography and computerized tomography will help avoid unnecessary surgical intervention in such cases.

Progression of terminal syrinx in occult spina bifida after untethering

OBJECT

The association of spinal dysraphism and terminal syringomyelia is a well-known entity, and untethering with or without syrinx drainage is usually the surgery of choice. However, progression of the previously existing syrinx after an untethering procedure is an uncommon course. The objective of this study was to discuss the diagnostic, surgical, and follow-up consequences of such an occurrence.

METHODS

Four children with occult spina bifida associated with terminal syrinx at the time of initial presentation are included in this study. After the primary releasing procedure, all developed enlargement of the syrinx. Two of them were operated on for placement of a syringo-subarachnoid shunt, while the other two were followed up conservatively. One of the shunted patients also had a second releasing procedure.

CONCLUSION

Progression of the pre-existing terminal syrinx after the primary untethering procedure should be kept in mind even in the absence of overt neurological progression.

In utero ultrasound detection of a large fetal sarcoma of the back

A congenital fibrosarcoma, a very rare soft-tissue tumor of infancy, was suspected on prenatal ultrasound at 23 weeks' gestation. On sonography, a large soft tissue growth on the left side of the fetal back, measuring 53 x 65 x 22 mm, was observed. The diagnosis was further validated by magnetic resonance imaging. Delivery by Cesarian section occurred at 31 weeks of gestation, due to fetal distress. The baby underwent an unusual embolization of the tumor-feeding arteries and an operation at the age of 1 month to remove the tumor. The pathological and cytogenetic examinations were consistent with the diagnosis of a fibrosarcoma.

Outlet fenestration for isolated fourth ventricle with and without an internal shunt

Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.

The postnatal management of congenital cystic adenomatoid malformation

BACKGROUND

Routine prenatal ultrasound has increased the frequency of prenatal diagnosis of congenital cystic lung malformation, such as cystic adenomatoid malformation, pulmonary sequestration, congenital lobar emphysema, and bronchogenic cyst.

OBJECTIVES

To evaluate the methods of postnatal diagnosis, the optimal age for operation since surgery is always required, and the optimal extent of lung resection.

METHODS

The clinical courses of 11 patients with congenital lung cysts who underwent surgical lung resection (8 lobectomies and 3 segmentectomies) were reviewed.

RESULTS

The diagnosis was confirmed by computed tomography scan in all. In nine patients the diagnosis was made prenatally. Chest X-ray was normal postnatally in all patients except for two who had recurrent pneumonia. Postoperative follow-up showed excellent recovery in all operated children. One patient who underwent surgery for CCAM following episodes of severe pneumonia died from another cause 5 months later. Postoperative chest CT scan showed no residual disease in eight patients. In two who had undergone limited resection, tomography showed a small segment of residual disease in one and a suspected residual lesion in the other.

CONCLUSION

With prenatal ultrasound the true frequency of congenital cystic lung anomaly appears to be higher than previously reported. Postnatal CT is mandatory to confirm or to rule out the diagnosis. The mere presence of cystic lung malformation is an indication for surgery. Complete removal of the affected lung lobe is recommended. Segmental resection may be inadequate. Early operation is tolerated well by infants and small children and we recommend that surgery be performed in children between 6 and 12 months of age.

Severe scrotal pain in boys with Henoch-Schönlein purpura: incidence and sonography

BACKGROUND

Henoch-Schönlein purpura (HSP) is a systemic vasculitis with multiorgan involvement. The scrotal involvement and its sonographic appearance are less well recognized than that of the kidneys and abdomen, and the reported incidence is varied.

OBJECTIVE

To review the incidence of significant scrotal involvement in boys with HSP and its sonographic characteristics.

MATERIALS AND METHODS

Thirteen boys (ages 4-11 years) out of 87 boys diagnosed with HSP, over a 15-year period had significant scrotal complaints. Seven underwent sonographic evaluation to define the extent of scrotal involvement and because testicular torsion was being considered.

RESULTS

Scrotal involvement producing significant pain occurred in 15 % of boys with HSP. The majority of boys had the diagnosis of HSP established before developing scrotal complaints. Sonographic findings consistently included an enlarged, rounded epididymis, thickened scrotal skin, and a hydrocele. The testes themselves were usually sonographically normal.

CONCLUSIONS

Scrotal involvement in boys with HSP is not uncommon. The sonographic findings in the scrotum are sufficiently characteristic to allow distinction from torsion in most cases.

MR line-scan diffusion-weighted imaging of term neonates with perinatal brain ischemia

BACKGROUND AND PURPOSE

MR diffusion-weighted imaging provides early demonstration of neonatal brain infarction. The evolution and limitations of diffusion-weighted imaging findings in newborns, however, have not been evaluated. Using line-scan diffusion imaging (LSDI), we investigated perinatal ischemic brain injury.

METHODS

Nineteen term newborns (age, 9 hours to 8 days; mean age, 2.6 days) with perinatal brain ischemia were evaluated using LSDI (1520/62.5/1 [TR/TE/excitations]) (b maximum = 750 s/mm2) and T1- and T2-weighted spin-echo (conventional) MR imaging. Follow-up examinations were performed in seven patients and autopsy in one. Apparent diffusion coefficients (ADCs) were measured in deep gray matter, white matter, the cortex, and focal lesions.

RESULTS

Based on conventional MR imaging or pathologic findings, patients were divided into two groups. Group 1 (n = 12) had symmetric/diffuse injury consistent with global hypoperfusion. Group 2 (n = 7) had focal/multifocal injury suggesting cerebrovascular occlusion. ADCs were abnormal at initial examination in 10 newborns in group 1 and in all newborns in group 2. The results of LSDI were abnormal before conventional MR imaging was performed in three newborns in group 1. ADCs were maximally decreased between days 1 and 3 in deep gray matter, perirolandic white matter, and focal lesions. Delayed decreases in ADCs were observed in subcortical white matter from days 4 through 10 in three patients in group 1.

CONCLUSION

After global hypoperfusion, LSDI showed deep gray matter and perirolandic white matter lesions before conventional MR imaging. LSDI may underestimate the extent of injury, however, possibly because of variations in the compartmentalization of edema, selective vulnerability, and delayed cell death. Differences in LSDI of symmetric/diffuse and focal/multifocal lesions may reflect differences in pathophysiology or timing of the injury. These findings may have implications for acute interventions.

Factors predicting mortality of patients with lung abscess

BACKGROUND

The rates of morbidity and mortality associated with lung abscess are still significant despite the introduction of antibiotic treatments. The aim of this work was to identify the factors that predict a poor outcome for patients with lung abscess.

METHODS

We retrospectively reviewed the records and the roentgenographic files of adult patients with lung abscess who were hospitalized from 1980 to 1996 at the Hadassah University Hospital, in Jerusalem, Israel.

RESULTS

The study population comprised 75 patients, and the mean age was 52 years old (range, 12 to 89 years). The mean (+/- SD) hospitalization duration was 25.7+/-21.5 days (range, 5 to 94 days). Fifteen patients (20%) succumbed to the infection. The patients who died had more predisposing factors (+/-SD), such as pneumonia, neoplasm, and altered consciousness, than those who survived, respectively: 2.73+/-1.4 vs 1.9+/-1.3 (p < 0.03). The patients with anemia on admission (hemoglobin levels of < 10 g/dL) had a higher mortality rate than those with higher hemoglobin levels, respectively: 58.3 vs 12.9% (p = 0.0008). A higher mortality rate was also associated with infection by Pseudomonas aeruginosa (83%), Staphylococcus aureus (50%), and Klebsiella pneumoniae (44%). The patients who died had larger abscess volumes (+/-SD) than those who survived (233+/-99 vs 157+/-33 mL), although it did not reach statistical significance. The diameter of the abscess correlated with the hospitalization time (r = 0.5; p < 0.001).

CONCLUSION

High rates of morbidity and mortality are associated with lung abscess despite appropriate antibiotic therapy and better supportive care. In patients with several predisposing factors, such as a large abscess size and a right-lower-lobe location, the prognosis was worse. The patients infected with S aureus, K pneumoniae, and particularly P aeruginosa had an ominous prognosis. As the prognosis for lung abscess has not improved sufficiently since the introduction of antibiotics, other modalities should be considered for patients with poor prognostic signs.

Lactic acid as a predictor for erythrocyte transfusion in healthy preterm infants with anemia of prematurity

Elevated blood lactate levels that declined to normal after erythrocyte transfusion were observed in 17 of 37 otherwise healthy infants with anemia of prematurity (26.1 +/- 2.1 mg/dl vs 12.3 +/- 0.9 mg/dl; p < 0.001). Posttransfusion heart rate in this group decreased from 155 +/- 1 beats/min to 150 +/- 2 beats/min (p = 0.01). Blood lactate concentration may be a predictor of the need for transfusion in anemia of prematurity.