Longitudinal analysis of regional brain changes in anti-NMDAR encephalitis: a case report.

BACKGROUND: Anti-NMDA receptor encephalitis is an immune-mediated disorder characterized by antibodies against the GluN1 subunit of the NMDA receptor that is increasingly recognized as a treatable cause of childhood epileptic encephalopathy. In adults, the disorder has been associated with reversible changes in brain volume over the course of treatment and recovery, but in children, little is known about its time course and associated imaging manifestations. CASE PRESENTATION: A previously healthy 20-month-old boy presented with first-time unprovoked seizures, dysautonomia, and dyskinesia. Paraneoplastic workup was negative, but CSF was positive for anti-NMDAR antibodies. The patient's clinical condition waxed and waned over a 14-month course of treatment with first- and second-line immunotherapies (including steroids, IVIG, rituximab, and cyclophosphamide). Serial brain MRIs scans obtained at 5 time points spanning this same period showed no abnormal signal or enhancement but were remarkable for cycles of reversible regional cortical volume loss. All scans included identical 1-mm resolution 3D T1-weighted sequences obtained on the same 3 T scanner. Using a novel longitudinal processing stream in FreeSurfer6 (Reuter M, et. al, Neuroimage 61:1402-18, 2012) we quantified the rate of change in cortical volume at each vertex (% volume change per month) between consecutive scans and correlated these changes with the time course of the patient's treatment and clinical response. We found regionally specific changes in cortical volume (up to 7% per month) that preferentially affected the frontal and occipital lobes and paralleled the patient's clinical course, with clinical decline associated with volume loss and clinical improvement associated with volume gain. CONCLUSIONS: Our results suggest that reversible cortical volume loss in anti-NMDA encephalitis has a regional specificity that mirrors many of the clinical symptoms associated with the disorder and tracks the dynamics of disease severity over time. This case illustrates how quantitative morphometric techniques can be applied to clinical imaging data to reveal patterns of brain change that may provide insight into disease pathophysiology. More widespread application of this approach might reveal regional and temporal patterns specific to different types of autoimmune encephalitis, providing a tool for diagnosis and a surrogate marker for monitoring treatment response.

Definitions and classification of malformations of cortical development: practical guidelines.

Malformations of cortical development are a group of rare disorders commonly manifesting with developmental delay, cerebral palsy or seizures. The neurological outcome is extremely variable depending on the type, extent and severity of the malformation and the involved genetic pathways of brain development. Neuroimaging plays an essential role in the diagnosis of these malformations, but several issues regarding malformations of cortical development definitions and classification remain unclear. The purpose of this consensus statement is to provide standardized malformations of cortical development terminology and classification for neuroradiological pattern interpretation. A committee of international experts in paediatric neuroradiology prepared systematic literature reviews and formulated neuroimaging recommendations in collaboration with geneticists, paediatric neurologists and pathologists during consensus meetings in the context of the European Network Neuro-MIG initiative on Brain Malformations (https://www.neuro-mig.org/). Malformations of cortical development neuroimaging features and practical recommendations are provided to aid both expert and non-expert radiologists and neurologists who may encounter patients with malformations of cortical development in their practice, with the aim of improving malformations of cortical development diagnosis and imaging interpretation worldwide.

Differences in neuropsychological and behavioral parameters and brain structure in patients with familial adenomatous polyposis: a sibling-paired study.

BACKGROUND: Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary colon cancer syndrome caused by mutations in adenomatous polyposis coli (APC) with both colonic and extra-colonic manifestations. Case reports have noted an association with FAP and intellectual disability and animal studies have shown that APC is implicated in neural development and function, but no studies have investigated neuropsychological, behavioral, or structural brain characteristics of patients with FAP. METHODS: We undertook a pilot, sibling-pair study comparing three patients with FAP to their sex-matched siblings without FAP. Each sibling pair underwent neuropsychological testing by a blinded examiner, high resolution brain MRI scans, and the mother of each pair rated her children's adaptive life skills and behavioral and emotional characteristics. Given the small number of study participants in this pilot study, quantitative comparisons of results were made by subtracting the score of the non-FAP sibling from the FAP patient on the various neuropsychological tests and parent rating questionnaires to calculate a difference, which was then divided by the standard deviation for each individual test to determine the difference, corrected for the standard deviation. Diffusion numbers in multiple regions of the brain as assessed by MRI were calculated for each study participant. RESULTS: We found similarity between siblings in all three pairs on a wide range of neuropsychological measures (general intelligence, executive function, and basic academic skills) as tested by the psychologist as well as in descriptions of adaptive life skills as rated by mothers. However, mothers' ratings of behavioral and emotional characteristics of two of the three pairs showed differences between the siblings, specifically that the patients with FAP were found to have more behavioral and emotional problems compared to their siblings. No differences in brain structure were identified by MRI. CONCLUSION: We report the first study exploring neuropsychological, behavioral, emotional, and structural brain characteristics of patients with FAP and found subjective differences as assessed by maternal perception in behavioral and emotional characteristics in patients with FAP compared to their siblings. Larger studies are needed to elucidate the relationship, if any, between FAP and brain function.

Novel KIF7 missense substitutions in two patients presenting with multiple malformations and features of acrocallosal syndrome.

We present two children who both had two missense mutations in the Kinesin Family Member 7 (KIF7) gene. A seven year old female with severe developmental delays, failure to thrive and growth retardation, infantile spasms, a cardiac vascular ring and right-sided aortic arch, imperforate anus, hydronephrosis with a right renal cyst, syndactyly and abnormal white matter was a compound heterozygote for c.3365C > G, predicting p.(Ser1122Trp) that was maternally inherited and c.2482G > A, predicting p.(Val828Met) that was paternally inherited. An eight year old female with severe developmental delays, epilepsy, left postaxial polydactyly of the hand and abnormalities of brain development including hydrocephalus, pachygyria and absence of the body and splenium of the corpus callous was a compound heterozygote for c.461G > A, predicting p.(Arg154Gln) and c.2959 G > A, predicting p.(Glu987Lys) that was maternally inherited and her father was unavailable for testing. The presentations in these children include features of acrocallosal syndrome, such as hypoplasia of the corpus callosum, enlarged ventricles, facial dysmorphism with a prominent forehead and broad halluces in the first child, but included atypical findings for individuals previously reported to have truncating mutations in KIF7, including imperforate anus, infantile spasms and severe growth retardation. We conclude that these phenotypes may result from the KIF7 sequence variants and abnormal hedgehog signaling, but that the full spectrum of KIF7-associated features remains to be determined.

De novo ANKRD11 and KDM1A gene mutations in a male with features of KBG syndrome and Kabuki syndrome.

KBG syndrome is a rare, autosomal dominant disorder caused by mutations or deletions leading to haploinsufficiency for the Ankrin Repeating Domain-Containing protein 11 (ANKRD11) at chromosome 16q24.3. Kabuki syndrome is caused by mutations or deletions of lysine (K)-specific methyltransferase 2D (KMT2D) and lysine-specific methylase 6A (KDM6A). We report on a male with developmental delays, cleft palate, craniofacial dysmorphism, hypotonia, and central nervous system anomalies including diminished white matter with thinning of the corpus callosum. Exome sequencing revealed a de novo mutation in ANKRD11, c.2606_2608delAGA, predicting p.Lys869del and an additional, de novo mutation, c.2353T>C, predicting p.Tyr785His in KDM1A, a gene not previously associated with a human phenotype. We describe this child as the first report of a deleterious sequence variant in KDM1A and hypothesize that his phenotype resulted from the combined effect of both mutations.

Posterior fossa in primary microcephaly: relationships between forebrain and mid-hindbrain size in 110 patients.

Microcephalies vary widely in clinical severity and in morphology. The purpose of this study is to determine the frequency of disproportion between the size of the cerebrum and the size of midbrain and hindbrain structures in infants and children with microcephaly, as analysis of such disproportions might aid understanding of these disorders and facilitate testing for specific genetic causes. The relative sizes of the forebrain, each component of the brain stem, and vermis and hemispheres of the cerebellum were analyzed visually on magnetic resonance (MR) images of 110 microcephalic patients. A disproportionally large cerebellum, compared with the cerebrum, was found in 50 cases (45.5%), a proportional cerebellum in 49 cases (44.5%), and a disproportionally small cerebellum in 11 cases (10%). Proportional cerebella were most common in mild (86%) and moderate (55%) microcephaly patients, whereas disproportionately large cerebella were most common in severe (57%) and moderate (32%) microcephaly. Disproportionately small cerebella were seen only in moderate (13%) and severe (9%) microcephaly. As genes are expressed at different times in cerebral and cerebellar development, it is postulated that analysis of relative cerebellar and brain stem size may be useful in the initial analysis of microcephaly by MR images both to categorize and to help determine likely genetic causes.

Developmental progress and creatine restoration upon long-term creatine supplementation of a patient with arginine:glycine amidinotransferase deficiency.

BACKGROUND: Arginine:glycineamidinotransferase (AGAT/GATM) deficiency has been described in 9 patients across 4 families. Here we describe the clinical outcome and response to creatine supplementation in a patient of the second family affected with AGAT deficiency-a 9-year-old girl. PATIENT AND METHODS: Delayed motor milestones were noticed from 4 months of age and at 14 months moderate hypotonia, developmental delay and failure to thrive. Laboratory studies revealed low plasma creatine as well as extremely low levels of guanidinoacetic acid in urine and plasma. Proton magnetic resonance spectroscopy (MRS) of the brain showed absence of creatine. DNA sequence analysis revealed a homozygous mutation (c.484+1G>T) in the AGAT/GATM gene. AGAT activity was not detectable in lymphoblasts and RNA analysis revealed a truncated mRNA (r.289_484del196) that is degraded via Nonsense Mediated Decay. At 16 months, Bayley's Infant Development Scale (BIDS) showed functioning at 43% of chronologic age. Oral creatine supplementation (up to 800 mg/kg/day) was begun. RESULTS: At age 9 years she demonstrated advanced academic performance. Partial recovery of cerebral creatine levels was demonstrated on MRS at 25 months of age. Brain MRS at 40 months of age revealed a creatine/NAA ratio of about 80% of that in age-matched controls. CONCLUSIONS: 8 years post initiation of oral creatine supplementation, patient demonstrates superior nonverbal and academic abilities, with average verbal skills. We emphasize that early diagnosis combined with early treatment onset of AGAT deficiency may lead to improvement of developmental outcome.

Disorders of Neuronal Migration/Organization Convey the Highest Risk of Neonatal Onset Epilepsy Compared With Other Congenital Brain Malformations.

BACKGROUND: Although seizures in neonates are common and often due to acute brain injury, 10-15% are unprovoked from congenital brain malformations. A better understanding of the risk of neonatal-onset epilepsy by the type of brain malformation is essential for counseling and monitoring. METHODS: In this retrospective cohort study, we evaluated 132 neonates with congenital brain malformations and their risk of neonatal-onset epilepsy. Malformations were classified into one of five categories based on imaging patterns on prenatal or postnatal imaging. Infants were monitored with continuous video EEG (cEEG) for encephalopathy and paroxysmal events in addition to abnormal neuroimaging. RESULTS: Seventy-four of 132 (56%) neonates underwent EEG monitoring, and 18 of 132 (14%) were diagnosed with neonatal-onset epilepsy. The highest prevalence of epilepsy was in neonates with disorders of neuronal migration/organization (9/34, 26%; 95% confidence interval [CI] = 13-44%), followed by disorders of early prosencephalic development (6/38, 16%; 95% CI = 6-31%), complex total brain malformations (2/16, 13%; 95% CI = 2-38%), and disorders of midbrain/hindbrain malformations (1/30, 3%; 95% CI = 0-17%). Of neonates with epilepsy, 5 of 18 (28%) had only electrographic seizures, 13 of 18 (72%) required treatment with two or more antiseizure medicines (ASMs), and 7 of 18 (39%) died within the neonatal period. CONCLUSION: Our results demonstrate that disorders of neuronal migration/organization represent the highest-risk group for early-onset epilepsy. Seizures are frequently electrographic only, require treatment with multiple ASMs, and portend a high mortality rate. These results support American Clinical Neurophysiology Society recommendations for EEG monitoring during the neonatal period for infants with congenital brain malformations.

Pulmonary, gonadal, and central nervous system status after bone marrow transplantation for sickle cell disease.

We conducted a prospective, multicenter investigation of human-leukocyte antigen (HLA) identical sibling bone marrow transplantation (BMT) in children with severe sickle cell disease (SCD) between 1991 and 2000. To determine if children were protected from complications of SCD after successful BMT, we extended our initial study of BMT for SCD to conduct assessments of the central nervous system (CNS) and of pulmonary function 2 or more years after transplantation. In addition, the impact on gonadal function was studied. After BMT, patients with stroke who had stable engraftment of donor cells experienced no subsequent stroke events after BMT, and brain magnetic resonance imaging (MRI) exams demonstrated stable or improved appearance. However, 2 patients with graft rejection had a second stroke after BMT. After transplantation, most patients also had unchanged or improved pulmonary function. Among the 11 patients who had restrictive lung changes at baseline, 5 were improved and 6 had persistent restrictive disease after BMT. Of the 2 patients who had obstructive changes at baseline, 1 improved and 1 had worsened obstructive disease after BMT. There was, however, significant gonadal toxicity after BMT, particularly among female recipients. In summary, individuals who had stable donor engraftment did not experience sickle-related complications after BMT, and were protected from progressive CNS and pulmonary disease.

Registration-based approach for reconstruction of high-resolution in utero fetal MR brain images.

RATIONALE AND OBJECTIVES: This paper describes a novel approach to forming high-resolution MR images of the human fetal brain. It addresses the key problem of fetal motion by proposing a registration-refined compounding of multiple sets of orthogonal fast two-dimensional MRI slices, which are currently acquired for clinical studies, into a single high-resolution MRI volume. MATERIALS AND METHODS: A robust multiresolution slice alignment is applied iteratively to the data to correct motion of the fetus that occurs between two-dimensional acquisitions. This is combined with an intensity correction step and a super-resolution reconstruction step, to form a single high isotropic resolution volume of the fetal brain. RESULTS: Experimental validation on synthetic image data with known motion types and underlying anatomy, together with retrospective application to sets of clinical acquisitions, are included. CONCLUSION: Results indicate that this method promises a unique route to acquiring high-resolution MRI of the fetal brain in vivo allowing comparable quality to that of neonatal MRI. Such data provide a highly valuable window into the process of normal and abnormal brain development, which is directly applicable in a clinical setting.

Etiological heterogeneity of familial periventricular heterotopia and hydrocephalus.

Periventricular heterotopia (PH) represents a neuronal migration disorder that results in gray matter nodules along the lateral ventricles beneath an otherwise normal appearing cortex. While prior reports have shown that mutations in the filamin A (FLNA) gene can cause X-linked dominant PH, an increasing number of studies suggest the existence of additional PH syndromes. Further classification of these cortical malformation syndromes associated with PH allows for determination of the causal genes. Here we report three familial cases of PH with hydrocephalus. One pedigree has a known FLNA mutation with hydrocephalus occurring in the setting of valproic acid exposure. Another pedigree demonstrated possible linkage to the Xq28 locus including FLNA, although uncharacteristically a male was affected and sequencing of the FLNA gene in this individual revealed no mutation. However, in the third family with an autosomal mode of inheritance, microsatellite analysis ruled out linkage with the FLNA gene. Routine karyotyping and fluorescent in situ hybridization using BAC probes localized to FLNA also showed no evidence of genomic rearrangement. Western blot analysis of one of the affected individuals demonstrated normal expression of the FLNA protein. Lastly, sequencing of greater than 95% of the FLNA gene in an affected member failed to demonstrate a mutation. In conclusion, these findings demonstrate the etiological heterogeneity of PH with hydrocephalus. Furthermore, there likely exists an autosomal PH gene, distinct from the previously described X-linked and autosomal recessive forms. Affected individuals have severe developmental delay and may have radiographic findings of hydrocephalus.

Maldevelopment of the cerebral cortex in the surgically induced model of myelomeningocele: implications for fetal neurosurgery.

PURPOSE: The purpose of this study is to describe the malformations of cortical development detected in a model of cerebrospinal fluid (CSF) leakage and the influence of surgical closure technique on developmental outcome. METHODS: Using a surgically induced model of myelomeningocele (MMC) in sheep, we studied the effects of different repair methods upon the development of hydrocephalus, the presence of the Arnold-Chiari II (AC-II) hindbrain malformation, and cerebral cortex developmental anomalies using gross and histologic (hematoxylin and eosin and Nissl staining) study techniques. RESULTS: A malformed cerebral cortex, including 2 anomalous cortical folding patterns, and lower brain weights were observed in the untreated animals. Hydrocephalus and AC-II malformations were also found in this group. These malformations were mostly prevented with prenatal 2-layer closure. CONCLUSIONS: Cerebral cortical malformations and hydrocephalus, in addition to the AC-II hindbrain malformation, are disorders caused by fetal CSF leakage. These malformations were prevented with the technique of MMC closure currently used in humans. Both observations magnify the importance of the second hit associated with chronic CSF leakage, in addition to the primary defect causing the MMC, in the development of the malformation complex.

Non-iterative relative bias correction for 3D reconstruction of in utero fetal brain MR imaging.

The slice intersection motion correction (SIMC) method is a powerful tool to compensate for motion that occurs during in utero acquisition of the multislice magnetic resonance (MR) images of the human fetal brain. The SIMC method makes use of the slice intersection intensity profiles of orthogonally planned slice pairs to simultaneously correct for the relative motion occurring between all the acquired slices. This approach is based on the assumption that the bias field is consistent between slices. However, for some clinical studies where there is a strong bias field combined with significant fetal motion relative to the coils, this assumption is broken and the resulting motion estimate and the reconstruction to a 3D volume can both contain errors. In this work, we propose a method to correct for the relative differences in bias field between all slice pairs. For this, we define the energy function as the mean square difference of the intersection profiles, that is then minimized with respect to the bias field parameters of the slices. A non iterative method which considers the relative bias between each slice simultaneously is used to efficiently remove inconsistencies. The method, when tested on synthetic simulations and actual clinical imaging studies where bias was an issue, brought a significant improvement to the final reconstructed image.

A system for measuring regional surface folding of the neonatal brain from MRI.

This paper describes a novel approach to in-vivo measurement of brain surface folding in clinically acquired neonatal MR image data, which allows evaluation of surface curvature within subregions of the cortex. This paper addresses two aspects of this problem. Firstly: normalization of folding measures to provide area-independent evaluation of surface folding over arbitrary subregions of the cortex. Secondly: automated parcellation of the cortex at a particular developmental stage, based on an approximate spatial normalization of previously developed anatomical boundaries. The method was applied to seven premature infants (age 28-37 weeks) from which gray matter and gray-white matter interface surfaces were extracted. Experimental results show that previous folding measures are sensitive to the size of the surface of analysis, and that the area independent measures proposed here provide significant improvements. Such a system provides a tool to allow the study of structural development in the neonatal brain within specific functional subregions, which may be critical in identifying later neurological impairment.

Symptomatic epidural lipomatosis of the spinal cord in a child: MR demonstration of spinal cord injury.

We report a case of symptomatic epidural lipomatosis in an 8-year-old girl with Cushing's syndrome secondary to longstanding high-dose steroid therapy for Crohn's disease. MR imaging of the spine revealed massive diffuse epidural fat compressing the entire spinal cord with T2 prolongation in the central gray matter of the cord suggesting ischemic myelopathy. This finding has not been previously demonstrated on imaging. A proposed mechanism underlying these findings is discussed.

Changes in globus pallidus with (pre)term kernicterus.

OBJECTIVE: We report serial magnetic resonance (MR) and sonographic behavior of globus pallidus in 5 preterm and 3 term infants with kernicterus and describe the clinical context in very low birth weight preterm infants. On the basis of this information, we suggest means of diagnosis and prevention. METHODS: Charts and MR and ultrasound images of 5 preterm infants and 3 term infants with suspected bilirubin-associated brain damage were reviewed. Included were preterm infants with severe hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150, the diagnosis was confirmed during the neonatal period. The others were picked up as outpatients and scanned at 12 or 22 months' corrected age. Three instances of term kernicterus were included for comparison of serial MRI in the neonatal period and early infancy: they were caused by glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration plus fructose 1-6 biphosphatase deficiency. RESULTS: Five preterm infants of 25 to 29 weeks' gestational age presented with total serum bilirubin (TSB) levels below exchange transfusion thresholds commonly advised. Mixed acidosis was present in 3 infants around the TSB peak. The bilirubin/albumin molar ratio was >0.5 in all, in the absence of displacing drugs. All failed to pass bedside hearing screen tests and had severe hearing loss on auditory brain response testing. Symmetrical homogeneous hyperechogenicity of globus pallidus was the alerting feature in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in this child. The other infants presented with severe developmental delay as a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was normal on T1- but hyperintense on T2-weighted MR images at 12 or 22 months' corrected age. Subthalamic involvement was documented in coronal fluid attenuated inversion recovery MRI in 2 infants. The term infants with classical clinical presentation in the neonatal period had MR behavior similar to the preterms, but pallidal injury was not recognized with targeted sonographic examination. Their neonatal MR images demonstrated pallidal T1 hyperintensity and mild T2 hyperintensity. CONCLUSION: Acidotic very low birth weight preterm infants with low serum albumin levels develop MR-confirmed pallidal injury and hearing loss facing "accepted" TSB levels. Serial MRI documents a shift from acute mainly T1 hypersignal to permanent T2 hypersignal in globus pallidus within the late neonatal period. Subthalamic and not thalamic involvement helps to differentiate from ischemic or metabolic disorder. As newborns, these infants are rigid and have severe apnea, before developing hypertonic quadriplegia in infancy.