Elevated mean diffusivity in the left hemisphere superior longitudinal fasciculus in autism spectrum disorders increases with more profound language impairment.

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.

Magnetoencephalography for pediatric epilepsy: how we do it.

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.

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.

Intracranial internal carotid artery angioplasty: technique with clinical and radiographic results and follow-up.

OBJECTIVE: Our objective is to describe the use of percutaneous transluminal angioplasty in eight patients with symptomatic high-grade atherosclerotic intracranial internal carotid artery stenoses. We describe our technique for performing the procedure and clinical and radiographic follow-up for an average of 53 months to determine the long-term results. CONCLUSION: Percutaneous transluminal angioplasty was shown to be an efficacious treatment for symptomatic intracranial internal carotid artery atherosclerotic disease in our group of patients.