Use of Thalamus L-Sign to Differentiate Periventricular Leukomalacia From Neurometabolic Disorders.

PURPOSE: To assess the diagnostic value of the thalamus L-sign on magnetic resonance imaging (MRI) in distinguishing between periventricular leukomalacia and neurometabolic disorders in pediatric patients. METHODS: In this retrospective study, clinical and imaging information was collected from 50 children with periventricular leukomalacia and 52 children with neurometabolic disorders. MRI was used to evaluate the L-sign of the thalamus (ie, injury to the posterolateral thalamus) and the lobar distribution of signal intensity changes. Age, sex, gestational age, and level of Gross Motor Function Classification System (only for periventricular leukomalacia) constituted the clinical parameters. Statistical evaluation of group differences for imaging and clinical variables were conducted using univariable statistical methods. The intra- and inter-observer agreement was evaluated using Cohen's kappa. Univariable or multivariable logistic regression was employed for selection of variables, determining independent predictors, and modeling. RESULTS: The thalamus L-sign was observed in 70% (35/50) of patients in the periventricular leukomalacia group, but in none of the patients with neurometabolic disorder (P < .001). The gestational age between groups varied significantly (P < .001). Involvement of frontal, parietal, and occipital lobes differed significantly between groups (P < .001). In the logistic regression, the best model included negative thalamus L-sign and gestational age, yielding an area under the curve, accuracy, sensitivity, specificity, and precision values of 0.995, 96.1%, 96%, 96.2%, and 96%, respectively. Both the lack of thalamus L-sign and gestational age were independent predictors (P < .001). CONCLUSIONS: The thalamus L-sign and gestational age may be useful in distinguishing between periventricular leukomalacia and neurometabolic disorders.

Malignant brain tumors in patients with glutaric aciduria type I.

Three young patients with glutaric aciduria type I (age 6-23 years) of different ethnic origins, treated for their metabolic disease since early childhood, presented with malignant central nervous system tumors. We recommend continuing clinical follow-up, including monitoring of neurological manifestations and neuroradiological findings, in all patients with glutaric aciduria type I beyond early childhood, especially if adherence to diet is poor or the treatment was not started neonatally.

Genotype-phenotype correlation in 18 Egyptian patients with glutaric acidemia type I.

Glutaric acidemia I (GAI) is an autosomal recessive metabolic disease caused by a deficiency of glutaryl-CoA dehydrogenase enzyme (GCDH). Patients with GAI are characterized by macrocephaly, acute encephalitis-like crises, dystonia and frontotemporal atrophy. In this study, we investigated 18 Egyptian patients that were diagnosed with GAI based on their clinical, neuroradiological, and biochemical profiles. Of the 18 patients, 16 had developmental delay and/or regression, dystonia was prominent in 75% of the cases, and three patients died. Molecular genetics analysis identified 14 different mutations in the GCDH gene in the 18 patients, of the 14 mutations, nine were missense, three were in the 3'-Untranslated Region (3'-UTR), one was nonsense, and one was a silent mutation. Four novel mutations were identified (c.148 T > A; p.Trp50Arg, c.158C > A; p.Pro53Gln, c.1284C > G; p.Ile428Met, and c.1189G > T; p.Glu397*) that were all absent in 300 normal chromosomes. The 3'-UTR mutation (c.*165A > G; rs8012), was the most frequent mutation observed (0.5; 18/36), followed by the most common mutation among Caucasian patients (p.Arg402Trp; rs121434369) with allele frequency of 0.36 (13/36), and the 3'-UTR mutation (c.*288G > T; rs9384, 0.22; 8/16). The p.Arg257Gln mutation was found with allele frequency of ~0.17 (6/36). The marked homozygosity observed in our patients is probably due to the high level of consanguinity that is observed in 100% of the cases. We used nine in silico prediction tools to predict the pathogenicity (SIFT, PhD-SNP, SNAP, Meta-SNP, PolyPhen2, and Align GVGD) and protein stability (I-Mutant2.0, Mupro, and istable) of the nine missense mutants. The mutant p.Arg402Trp was predicted to be most deleterious by all the six pathogenicity prediction tools and destabilizing by all the three-stability prediction tools, and highly conserved by the ConSurf server. Using the clinical, biochemical, family history of the 18 patients, and the in silico analysis of the missense mutations, our study showed a mix of conclusive and inconclusive genotype-phenotype correlations among our patient's cohort and suggests the usefulness of using various sophisticated computational analysis to be utilized for future variant classifications in the genetic clinics.

The Down syndrome brain in the presence and absence of fibrillar ß-amyloidosis.

People with Down syndrome (DS) have a neurodevelopmentally distinct brain and invariably developed amyloid neuropathology by age 50. This cross-sectional study aimed to provide a detailed account of DS brain morphology and the changes occuring with amyloid neuropathology. Forty-six adults with DS underwent structural and amyloid imaging-the latter using Pittsburgh compound B (PIB) to stratify the cohort into PIB-positive (n = 19) and PIB-negative (n = 27). Age-matched controls (n = 30) underwent structural imaging. Group differences in deep gray matter volumetry and cortical thickness were studied. PIB-negative people with DS have neurodevelopmentally atypical brain, characterized by disproportionately thicker frontal and occipitoparietal cortex and thinner motor cortex and temporal pole with larger putamina and smaller hippocampi than controls. In the presence of amyloid neuropathology, the DS brains demonstrated a strikingly similar pattern of posterior dominant cortical thinning and subcortical atrophy in the hippocampus, thalamus, and striatum, to that observed in non-DS Alzheimer's disease. Care must be taken to avoid underestimating amyloid-associated morphologic changes in DS due to disproportionate size of some subcortical structures and thickness of the cortex.

Central tegmentum tract hyperintensities in pediatric neurological patients: Incidence or coincidence.

AIM: The central tegmental tract hyperintensities (CTTH) have been found in many different pediatric neurological conditions. There is only scarce data about the value of this radiological phenomenon. In this study we aimed to show the neurological conditions associated with this radiological finding. MATERIALS AND METHODS: We performed a retrospective analysis of all pediatric brain MRI's between 2013 and 2015. After finding those patients with CTTH, we evaluated them in the pediatric neurology clinic. RESULTS: There were 41 out of 1464 brain MRI's with CTTH with 2.8% prevalence. Thirty four patients (23 male, age range 3months-98months) were available for evaluation. CTTH were present in mainly younger age group. There were many different neurological conditions associated with CTTH. These included brain tumors, epilepsy, developmental delay, metabolic disorders and genetic syndromes. CONCLUSION: CTTH is found in many different pediatric neurological conditions. Further neuropathological and prospective MRI and clinical studies are needed to better understand this interesting radiological finding.

Novel assessment of global metabolism by 18F-FDG-PET for localizing affected lobe in temporal lobe epilepsy.

The aim of this study was to develop a novel method of global quantitative analysis for use in the diagnosis and treatment evaluation of temporal lobe epilepsy (TLE). We studied 16 patients diagnosed with TLE who underwent fluorine-18 fluorodeoxyglucose-PET (F-FDG-PET) and MRI at the Hospital of the University of Pennsylvania. To quantify temporal lobe hypometabolism, we averaged the mean standardized uptake value across regions of interest (ROIs) encompassing each lobe in its entirety and calculated the metabolic ratios and lateralization indices for each patient on the basis of global measurements. For comparison, we carried out a traditional 'punch biopsy' ROI analysis by averaging the mean standardized uptake value within 1 cm diameter ROIs across select slices. Both techniques were performed twice by the same rater to test intraobserver variability. An expert observer carried out visual analyses of both F-FDG-PET and MRI for reference. The global quantitative analysis identified a seizure focus lateralization in agreement with clinical evaluations for 91% of patients on both trials, with intraclass correlation coefficients of 0.97 and 0.92 for metabolic ratios and lateralization indices, respectively. The punch biopsy analysis was in agreement for 91 and 82% of patients on respective trials, with intraclass correlation coefficients of 0.90 and 0.75. Expert visual analyses carried out on F-FDG-PET and MRI were in agreement for 64 and 9% of patients, respectively. The global quantitative analysis proved to be the most accurate and reliable of the methods tested. This technique has the potential to improve metabolic analysis in TLE and other neuropsychiatric disorders.

[Clinical investigation and genetic analysis of a Chinese family with glutaric acidemia type I].

OBJECTIVE: To review the clinical features of a families affected with glutaric acidemia type I (GA-1) and screen potential mutations in glutaryl-CoA dehydrogenase (GCDH) gene. METHODS: Clinical data of the patients and their family members was analyzed. Genomic DNA was extracted from peripheral blood samples. The 11 exons and flanking sequences of the GCDH gene were amplified with PCR and subjected to direct DNA sequencing. RESULTS: Two patients have manifested macrocephaly. Imaging analysis revealed arachnoid cyst and subdural effusion. The elder sister had encephalopathy crisis. The younger sister had significantly raised glutaric acid, whilst the elder sister was normal during the non-acute phase. Genetic analysis has revealed a homozygous c.1244-2A> C mutation of the GCDH gene in both patients. CONCLUSION: The clinical features and mutation of the GCDH gene have been delineated in a Chinese family affected with GA-1. The c.1244-2A> C mutation may be particularly common in the Chinese population.

[Di George syndrome: not always a pediatric diagnosis]. / Sindrome di Di George: una diagnosi non sempre pediatrica.

We describe a delayed diagnosis of Di George syndrome, in a 51 yr-old woman, with past medical history of epilepsy, mental retardation, chronic psychosis, nephrocalcinosis. She presented facial dysmorphism, multiple encephalic calcifications, hypocalcemia and lymphopenia. A microdeletion of 22q 11.2 was detected by fluorescence in situ hybridization (FISH), confirming the clinical suspicion .

Pituitary adenomas can appear as hypermetabolic lesions in (18) F-FDG PET imaging.

OBJECTIVE: The 2-deoxy-2-[(18) F] fluoro-D-glucose positron emission tomography (FDG-PET) scan is commonly used in detection and staging of many malignant neoplasms. However, several benign or non-neoplastic conditions avidly accumulate (18) F-FDG, causing ambiguity in interpretation of results. It is unknown whether pituitary adenomas uptake (18) F-FDG and appear positive in PET imaging. Here, we present 2 cases of benign pituitary adenoma with elevated metabolic activity in (18) F-FDG PET scan. METHODS: Medical, neurologic, and psychiatric histories; physical examination findings; laboratory work up results; and pathologic and imaging studies were documented. RESULTS: The (18) F-FDG-PET images revealed foci of marked FDG uptake in pituitary adenomas of 2 patients. CONCLUSION: Pituitary micro- and macro-adenomas may present as hypermetabolic foci on (18) F-FDG PET scan.

Brain lactic alkalosis in Aicardi-Goutières syndrome.

Aicardi-Goutières syndrome is a rare progressive encephalopathy characterized by acquired microcephaly, basal ganglia calcification, and chronic CSF lymphocytosis, raised levels of interferon alpha in CSF and plasma and chill-blain type lesions. A possible mechanism of injury is cytokine related microangiopathy. We report brain imaging and proton (1H) and phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) findings during the first year after birth in two patients. In patient 1 the evolution of brain metabolite ratios and intracellular pH obtained from serial 1H (long TE) and 31P MRS studies are described; in patient 2 a single 1H (short TE) MRS study is described. Imaging findings included basal ganglia calcifications, cerebral atrophy, and leukodystrophy. The MRS results demonstrated that Aicardi-Goutières syndrome is associated with reduced NAA/Cr, reflecting decreased neuronal/axonal density or viability, increased myo-inositol/Cr, reflecting gliosis or osmotic stress and a persisting brain lactic alkalosis. A brain lactic alkalosis has also been observed in those infants surviving perinatal hypoxia-ischaemia but with a poor neurodevelopmental outcome. A possible mechanism leading to brain alkalosis is up-regulation of the Na+/H+ transporter by focal areas of ischaemia related to the microangiopathy or by pro-inflammatory cytokines. Such brain alkalosis may be detrimental to cell survival and may increase glycolytic rate in astrocytes leading to an increased production of lactate.

Extratemporal hypometabolism on FDG PET in temporal lobe epilepsy as a predictor of seizure outcome after temporal lobectomy.

We investigated the relationship between the presence of extratemporal hypometabolism on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) and seizure outcome after temporal lobectomy in patients with medically intractable temporal lobe epilepsy (TLE). In 47 patients with intractable unilateral mesial TLE, regional metabolic changes on FDG PET images obtained during the 2 months preceding anterior temporal lobectomy were compared with postoperative seizure outcome. Postoperative seizure outcome was evaluated with a mean follow-up period of 6.1+/-0.6 years (range 5.2-7.2 years). Forty-two (89%) of the 47 patients achieved a good postoperative seizure outcome (Engel class I or II). All patients had hypometabolism in the temporal cortex ipsilateral to the epileptogenic region on FDG PET scans. Fourteen (78%) of the 18 patients with hypometabolism only in the ipsilateral temporal cortex were completely seizure free (Engel class Ia) after surgery. In contrast, five (45%) of the 11 patients with extratemporal cortical hypometabolism confined to the ipsilateral cerebral hemisphere and only four (22%) of the 18 patients with hypometabolism in the contralateral cerebral cortex were completely seizure free after surgery. The postoperative seizure-free rates were significantly different across the three groups of patients with different cortical metabolic patterns ( P<0.005). Furthermore, all of the nine patients with a non-class I outcome (Engel class II-IV) had extratemporal (including contralateral temporal) cortical hypometabolism. Thalamic hypometabolism was noted in 20 (43%) of the 47 patients (ipsilateral in 12, bilateral in 8). Sixteen (59%) of the 27 patients with normal thalamic metabolism were completely seizure free after surgery, while only seven (35%) of the 20 patients with thalamic hypometabolism became completely seizure free ( P<0.05). Multivariate analysis revealed that among variables including clinical, EEG, magnetic resonance imaging, pathological and FDG PET metabolic findings, only cortical metabolic pattern was an independent factor for the prediction of postoperative seizure outcome ( P<0.005). It is concluded that extratemporal cortical hypometabolism outside the seizure focus, in particular hypometabolism in the contralateral cerebral cortex, may be associated with a poorer postoperative seizure outcome in TLE and may represent underlying pathology that is potentially epileptogenic. Thalamic hypometabolism, which was associated, but not independently, with a higher likelihood of postoperative seizures, may be secondary to extratemporal or temporal pathology.

Neurosonographic findings in high risk neonates with hypoglycemia.

In a prospective study, 28 neonates with hypoglycemia underwent a series of neurosonographic follow-ups. Most of the patients completed a total of 12 scans beginning on the first day of admission and finishing at age of 6 months. One patient died of intracranial hemorrhage, 5 cases had severe neurological sequelae and 22 cases developed normally. The main sonographic findings during early the neonatal stage included: (1) diffuse increase of echogenecity; (2) compressed ventricles; (3) increased periventricular echogenecity and (4) hemorrhage. In late neonatal stage, the abnormal findings were (1) increased periventricular echogenecity; (2) ventricular dilatation and (3) increased gyral pattern. Periventricular cystic leukomalacia and brain atrophy were observed on the late follow-up sonography in those cases with neurological sequelae. Hypoglycemia per se may not account for all the damage in the brain. Treatment of the underlying causes should start as soon as possible. However, early sonographic finding may provide critical information for vigorous treatment of hypoglycemia, while the late scans enable early prediction of poor neurological outcome.

[Polyglucosan body disease]. / La maladie des corps polysaccharidiques.

A 78 year-old male presented with a bilateral pyramidal syndrome, urinary incontinence and mild intellectual slowing. He died seven months after onset of the neurological signs from cerebral infarct and heart failure. Neuropathological examination showed predominant involvement of the cerebral white matter including diffuse myelin pallor, astrocytic gliosis and small necrotic foci. Polyglucosan bodies were diffuse in the cerebral cortex, white matter, brainstem, cerebellum and proximal part of the cranial nerves. In these latter, some polyglucosan bodies were found within myelinated axons but the inclusions mostly involved astrocytic processes. This case is characteristic of the polyglucosan body disease. It is compared with the autopsy and biopsy cases previously reported in the literature.