Title Structural brain anomalies in healthy adolescents in the NCANDA cohort : relation to neuropsychological test performance , sex , and ethnicity Permalink

StructuralMRI of volunteers deemed Bnormal^ following clinical interview provides a window into normal brain developmental morphology but also reveals unexpected dysmorphology, commonly known as Bincidental findings. ^ Although unanticipated, these anatomical findings raise questions regarding possible treatment that could even ultimately require neurosurgical intervention, which itself carries significant risk but may not be indicated if the anomaly is nonprogressive or of no functional consequence. Neuroradiological readings of 833 structural MRI from the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) cohort found an 11.8 % incidence of brain structural anomalies, represented proportionately across the five collection sites and ethnic groups. Anomalies included 26 mega cisterna magna, 15 subarachnoid cysts, 12 pineal cysts, 12 white matter dysmorphologies, 5 tonsillar ectopias, 5 prominent perivascular spaces, 5 gray matter heterotopias, 4 pituitary masses, 4 excessively large or asymmetrical ventricles, 4 cavum septum pellucidum, 3 developmental venous anomalies, 1 exceptionally large midsagittal vein, and single cases requiring clinical followup: cranio-cervical junction stenosis, parietal cortical mass, and Chiari I malformation. A case of possible demyelinating disorder (e.g., neuromyelitis optica or multiple sclerosis) newly emerged at the 1-year NCANDA followup, requiring clinical referral. Comparing test performance of the 98 anomalous cases with 619 anomaly-free noto-low alcohol consuming adolescents revealed significantly lower scores on speed measures of attention and motor functions; these differences were not attributed to any one anomaly subgroup. Further, we devised an automated approach for quantifying posterior fossa CSF volumes for detection of mega cisterna magna, which represented 26.5 % of clinically identified anomalies. Automated quantification fit a Gaussian distribution with a rightward skew. Using a 3SD cut-off, quantification identified 22 of the 26 clinically-identified cases, indicating that cases with percent of CSF in the posteriorinferior-middle aspect of the posterior fossa ≥3SD merit further review, and support complementing clinical readings with objective quantitative analysis. Discovery of asymptomatic brain structural anomalies, even when no clinical action is indicated, can be disconcerting to the individual and responsible family members, raising a disclosure dilemma: refrain from relating the incidental findings to avoid unnecessary alarm or anxiety; or alternatively, relate the neuroradiological Electronic supplementary material The online version of this article (doi:10.1007/s11682-016-9634-2) contains supplementary material, which is available to authorized users. * Edith V. Sullivan edie@stanford.edu 1 Department of Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Road, Stanford, CA 94305-5723, USA 2 Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA 3 Center for Health Sciences, SRI International, Menlo Park, CA, USA 4 Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA 5 Department of Psychiatry & Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA 6 Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA 7 Departments of Psychiatry and Behavioral Neuroscience, Oregon Health & Sciences University, Portland, OR, USA Brain Imaging and Behavior DOI 10.1007/s11682-016-9634-2 Author's personal copy