Deborah M. Zarnow

High prevalence of temporomandibular joint arthritis at disease onset in children with juvenile idiopathic arthritis, as detected by magnetic resonance imaging but not by ultrasound.

OBJECTIVE To determine the prevalence of temporomandibular joint (TMJ) disease in a cohort of children with new-onset juvenile idiopathic arthritis (JIA), and to compare magnetic resonance imaging (MRI) with ultrasound (US) for the detection of acute and chronic changes of TMJ arthritis. METHODS Between January 2005 and April 2007, children with newly diagnosed JIA were prospectively evaluated for TMJ arthritis. Prior to imaging, jaw pain and disability were assessed with questionnaires and physical examination. The TMJs of all patients were imaged with MRI and US within 8 weeks of diagnosis. RESULTS Of the 32 patients enrolled, 78% were female, and the median age was 8.6 years (range 1.5-17.2 years). Acute TMJ arthritis was diagnosed in 75% of the children by MRI and in none by US; chronic arthritis was diagnosed in 69% by MRI and in 28% by US. Findings of both acute and chronic TMJ disease were detected by MRI in 53% of the patients. Of those with acute TMJ arthritis, 71% were asymptomatic, and 63% had normal findings on jaw examination. Fifty-six percent of patients with acute disease had an improved maximal incisal opening after corticosteroid injection. Among these responders, 56% had been asymptomatic and had normal jaw examination findings. CONCLUSION TMJ arthritis was present in the majority of patients with new-onset JIA. Findings on MRI along with responses to treatment among asymptomatic patients with normal jaw examination findings suggest that a history review and physical examination are not sufficient to screen for TMJ disease. Our results also suggest that MRI and US findings are not well correlated, and that MRI is preferable for the detection of TMJ disease in new-onset JIA.

MEG detection of delayed auditory evoked responses in autism spectrum disorders: towards an imaging biomarker for autism

Motivated by auditory and speech deficits in autism spectrum disorders (ASD), the frequency dependence of superior temporal gyrus (STG) 50 msec (M50) and 100 msec (M100) neuromagnetic auditory evoked field responses in children with ASD and typically developing controls were evaluated. Whole‐cortex magnetoencephalography (MEG) was obtained from 17 typically developing children and 25 children with ASD. Subjects were presented tones with frequencies of 200, 300, 500, and 1,000 Hz, and left and right STG M50 and M100 STG activity was examined. No M50 latency or amplitude Group differences were observed. In the right hemisphere, a Group×Frequency ANOVA on M100 latency produced a main effect for Group (P=0.01), with an average M100 latency delay of 11 msec in children with ASD. In addition, only in the control group was the expected association of earlier M100 latencies in older than younger children observed. Group latency differences remained significant when hierarchical regression analyses partialed out M100 variance associated with age, IQ, and language ability (all P‐values <0.05). Examining the right‐hemisphere 500 Hz condition (where the largest latency differences were observed), a sensitivity of 75%, a specificity of 81%, and a positive predictive value (PPV) of 86% was obtained at a threshold of 116 msec. The M100 latency delay indicates disruption of encoding simple sensory information. Given similar findings in language impaired and nonlanguage impaired ASD subjects, a right‐hemisphere M100 latency delay appears to be an electrophysiological endophenotype for autism.

Elevated Mean Diffusivity in the Left Hemisphere Superior Longitudinal Fasciculus in Autism Spectrum Disorders Increases with More Profound Language Impairment

The cause of autism continues to be uncertain and conventional imaging is not helpful. These investigators used DTI to study the language-related white matter tracts in a subset of patients with autism and language impairments. Eighteen patients were compared with 25 controls and showed abnormal DTI parameters in the superior longitudinal fasciculus, particularly in its temporal portion and on the left side. Thus, the white matter subserving language in these patients was abnormal. BACKGROUND AND PURPOSE: Language impairments are observed in a subset of individuals with ASD. To examine microstructural brain white matter features associated with language ability in ASD, we measured the DTI parameters of language-related white matter tracts (SLF) as well as non-language-related white matter tracts (CST) in children with ASD/+LI and ASD/−LI) and in TD. MATERIALS AND METHODS: Eighteen children with ASD/−LI (age range, 6.7–17.5 years), 17 with ASD/+LI (age range, 6.8–14.8 years), and 25 TD (age range, 6.5–18 years) were evaluated with DTI and tractography. Primary DTI parameters considered for analysis were MD and FA. RESULTS: There was a main effect of diagnostic group on age-corrected MD (P < .05) with ASD/+LI significantly elevated compared with TD. This was most pronounced for left hemisphere SLF fiber tracts and for the temporal portion of the SLF. There was significant negative correlation between left hemisphere SLF MD values and the clinical assessment of language ability. There was no main effect of diagnostic group or diagnostic group X hemisphere interaction for FA. Although there was a main effect of diagnostic group on values of MD in the CST, this did not survive hemispheric subanalysis. CONCLUSIONS: Abnormal DTI parameters (specifically significantly elevated MD values in ASD) of the SLF appear to be associated with language impairment in ASD. These elevations are particularly pronounced in the left cerebral hemisphere, in the temporal portion of the SLF, and in children with clinical language impairment.

Reversal of Hindbrain Herniation after Maternal-fetal Surgery for Myelomeningocele Subsequently Impacts on Brain Stem Function

The aim of our study was to delineate whether the reversal of hindbrain herniation (HH) following fetal myelomeningocele (fMMC) closure subsequently reduces the incidence and severity of HH-associated brainstem dysfunction (BSD). Prior to the NIH-sponsored Management of Myelomeningocele Study (MOMS) trial, 54 children underwent fMMC closure at our institution. Forty-eight (89%) families participated in a structured survey focusing on HH-associated BSD (e.g., apnea, neurogenic dysphagia [ND], gastro-esophageal reflux disease [GERD], neuro-ophthalmologic disturbances [NOD]). Median age at follow-up was 72 months (range: 46-98). Fifty-percent required shunting. HH-related symptoms were completely absent in 15 (63%) non-shunted and 10 (42%) shunted children (P=0.15). No HH-related death occurred and none developed severe persistent cyanotic apnea. ND was reported in 2 (8%) non-shunted and 9 (38%) shunted infants (P=0.03). Mild GERD (medically managed) developed in 2 (8%) without and 6 (25%) with shunt placement (P=0.24). NOD was found in 6 (25%) and 13 (54%) of non-shunted and shunted children, respectively (P=0.07). The majority of fMMC children developed no or only mild BSD at follow-up. Our data support the hypothesis that neurodevelopmental deficits associated with MMC are at least partially acquired and that reversal of HH following fMMC surgery may help to reduce the incidence and severity of BSD.

Preschool neurodevelopmental outcome of children following fetal myelomeningocele closure.

OBJECTIVE We sought to investigate the preschool neurodevelopmental outcomes of children following fetal myelomeningocele (fMMC) surgery. STUDY DESIGN Prior to the Management of Myelomeningocele Study trial, 54 children underwent fMMC closure at our institution. Thirty (56%) returned at 5 years of age for standardized neurocognitive examination. Scores were grouped as high-average, average, mildly delayed, and severely delayed by SD intervals. RESULTS Mean verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full intelligence quotient (FIQ) scores were within normal population range. High-average or average scores for VIQ, PIQ, FIQ, and processing speed were found in 93%, 90%, 90%, and 60%, respectively. Mean FIQ and processing speed of nonshunted children were significantly higher than for those who required shunt placement (P=.02 and P=.01, respectively). Mean VIQ and PIQ tended to be higher in nonshunted fMMC children (P=.05). CONCLUSION The majority of fMMC children in this highly selective population had average preschool neurodevelopmental scores. fMMC children who did not require shunt placement were more likely to have better scores.

Developmental correlation of diffusion anisotropy with auditory-evoked response

White matter diffusion anisotropy in the acoustic radiations of the auditory pathway was characterized as a function of development in children and adolescents. Auditory-evoked neuromagnetic fields were also recorded from the same individuals, and the latency of the left and right superior temporal gyrus auditory response of approximately 100 ms was also obtained. White matter diffusion anisotropy increased with age. There was a commensurate shortening of the auditory-evoked response latency with increased age as well as with increased white matter diffusion anisotropy. The significant negative correlation between structural integrity of white matter pathways and electrophysiological function (response timing) of distal cortex supports a biophysical model of developmental changes in white matter myelination, conduction velocity, and cortical response timing.

Abnormal brain development and maturation on magnetic resonance imaging in survivors of severe congenital diaphragmatic hernia

PURPOSE The aim of the study was to evaluate the incidence of abnormal brain maturation in survivors of severe congenital diaphragmatic hernia (CDH). MATERIAL AND METHODS Between July 2004 and December 2009, 50 CDH survivors underwent detailed brain magnetic resonance (MR) imaging before discharge. Magnetic resonance images were analyzed to evaluate the presence of structural brain abnormalities and to calculate overall brain maturation using the total maturation score (TMS). RESULTS Thirty-two children (64%) underwent MR imaging between 39 and 43 weeks of gestation, allowing for evaluation of the TMS. Eighteen (36%) underwent MR imaging between 44 and 69 weeks of gestation, allowing for structural analysis of brain maturity only. The mean TMS was 14.1 ± 1.2 and significantly lower than reported age-matched normative data in infants without CDH (15.3 ± 1.0, P = .02). The TMS in 4 patients (12.5%) corresponded to a delay of 1 month in structural brain development. Eight infants (25%) demonstrated a 2-week delay. Periventricular leukomalacia was detected in 9 (18%), incomplete development of the opercula in 7 (14%), various degrees of intracranial hemorrhage in 24 (48%), and prominent extraaxial fluid spaces in 20 (40%) cases. CONCLUSIONS Brain maturation in infants with severe CDH appears to be delayed. Long-term neurodevelopmental follow-up is needed to determine the significance of a lower-than-expected TMS and the presence of structural brain abnormalities on functional outcomes in this population.

Maturational differences in thalamocortical white matter microstructure and auditory evoked response latencies in autism spectrum disorders

White matter diffusion anisotropy in the acoustic radiations was characterized as a function of development in autistic and typically developing children. Auditory-evoked neuromagnetic fields were also recorded from the same individuals and the latency of the left and right middle latency superior temporal gyrus auditory ~50ms response (M50)(1) was measured. Group differences in structural and functional auditory measures were examined, as were group differences in associations between white matter pathways, M50 latency, and age. Acoustic radiation white matter fractional anisotropy did not differ between groups. Individuals with autism displayed a significant M50 latency delay. Only in typically developing controls, white matter fractional anisotropy increased with age and increased white matter anisotropy was associated with earlier M50 responses. M50 latency, however, decreased with age in both groups. Present findings thus indicate that although there is loss of a relationship between white matter structure and auditory cortex function in autism spectrum disorders, and although there are delayed auditory responses in individuals with autism than compared with age-matched controls, M50 latency nevertheless decreases as a function of age in autism, parallel to the observation in typically developing controls (although with an overall latency delay). To understand auditory latency delays in autism and changes in auditory responses as a function of age in controls and autism, studies examining white matter as well as other factors that influence auditory latency, such as synaptic transmission, are of interest.

Magnetoencephalography for Pediatric Epilepsy: How We Do It

SUMMARY: Magnetoencephalography (MEG) is increasingly being used in the preoperative evaluation of pediatric patients with epilepsy. The ability to noninvasively localize ictal onset zones (IOZ) and their relationships to eloquent functional cortex allows the pediatric epilepsy team to more accurately assess the likelihood of postoperative seizure freedom, while more precisely prognosticating the potential functional deficits that may be expected from resective surgery. Confirmation of clinically suggested multifocality may result in a recommendation against resective surgery because the probability of seizure freedom will be low. Current paradigms for motor and somatosensory testing are robust. Paradigms allowing localization of those regions necessary for competent language function, though promising, are under continuous optimization. MR imaging white matter trajectory data, created from diffusion tensor imaging obtained in the same setting as the localization brain MR imaging, provide ancillary information regarding connectivity of the IOZ to sites of rapid secondary spread and the spatial relationship of the IOZ to functionally important white matter bundles, such as the corticospinal tracts. A collaborative effort between neuroradiology, neurology, neurosurgery, neuropsychology, technology, and physics ensures successful implementation of MEG within a pediatric epilepsy program.

Left Hemisphere Diffusivity of the Arcuate Fasciculus: Influences of Autism Spectrum Disorder and Language Impairment

The authors used DTI measurements of the arcuate fasciculus in 14 children with language impairment, in 16 autistic children with language impairment, 18 autistic children without language impairment, and 25 controls. Although white matter abnormalities appeared similar in language impairment and autism spectrum disorder when examining broad white matter measures, detailed analysis indicated different mechanisms for the white matter microstructural anomalies associated with these disorders. BACKGROUND AND PURPOSE: There has been much discussion whether brain abnormalities associated with specific language impairment and autism with language impairment are shared or are disorder specific. Although white matter tract abnormalities are observed in both specific language impairment and autism spectrum disorders, the similarities and differences in the white matter abnormalities in these 2 disorders have not been fully determined. MATERIALS AND METHODS: Diffusion tensor imaging diffusion parameters of the arcuate fasciculus were measured in 14 children with specific language impairment as well as in 16 children with autism spectrum disorder with language impairment, 18 with autism spectrum disorder without language impairment, and 25 age-matched typically developing control participants. RESULTS: Language impairment and autism spectrum disorder both had (elevating) main effects on mean diffusivity of the left arcuate fasciculus, initially suggesting a shared white matter substrate abnormality. Analysis of axial and radial diffusivity components, however, indicated that autism spectrum disorder and language impairment differentially affect white matter microstructural properties, with a main effect of autism spectrum disorder on axial diffusivity and a main effect of language impairment on radial diffusivity. CONCLUSIONS: Although white matter abnormalities appear similar in language impairment and autism spectrum disorder when examining broad white matter measures, a more detailed analysis indicates different mechanisms for the white matter microstructural anomalies associated with language impairment and autism spectrum disorder.