Radiomic- and dosiomic-based clustering development for radio-induced neurotoxicity in pediatric medulloblastoma.

BACKGROUND: Texture analysis extracts many quantitative image features, offering a valuable, cost-effective, and non-invasive approach for individual medicine. Furthermore, multimodal machine learning could have a large impact for precision medicine, as texture biomarkers can underlie tissue microstructure. This study aims to investigate imaging-based biomarkers of radio-induced neurotoxicity in pediatric patients with metastatic medulloblastoma, using radiomic and dosiomic analysis. METHODS: This single-center study retrospectively enrolled children diagnosed with metastatic medulloblastoma (MB) and treated with hyperfractionated craniospinal irradiation (CSI). Histological confirmation of medulloblastoma and baseline follow-up magnetic resonance imaging (MRI) were mandatory. Treatment involved helical tomotherapy (HT) delivering a dose of 39 Gray (Gy) to brain and spinal axis and a posterior fossa boost up to 60 Gy. Clinical outcomes, such as local and distant brain control and neurotoxicity, were recorded. Radiomic and dosiomic features were extracted from tumor regions on T1, T2, FLAIR (fluid-attenuated inversion recovery) MRI-maps, and radiotherapy dose distribution. Different machine learning feature selection and reduction approaches were performed for supervised and unsupervised clustering. RESULTS: Forty-eight metastatic medulloblastoma patients (29 males and 19 females) with a mean age of 12 ± 6 years were enrolled. For each patient, 332 features were extracted. Greater level of abstraction of input data by combining selection of most performing features and dimensionality reduction returns the best performance. The resulting one-component radiomic signature yielded an accuracy of 0.73 with sensitivity, specificity, and precision of 0.83, 0.64, and 0.68, respectively. CONCLUSIONS: Machine learning radiomic-dosiomic approach effectively stratified pediatric medulloblastoma patients who experienced radio-induced neurotoxicity. Strategy needs further validation in external dataset for its potential clinical use in ab initio management paradigms of medulloblastoma.

Severe A(H1N1)pdm09 influenza acute encephalopathy outbreak in children in Tuscany, Italy, December 2023 to January 2024.

A severe outbreak of influenza A(H1N1pdm09) infection in seven children (median age: 52 months) occurred between December 2023 and January 2024 in Tuscany, Italy. Clinical presentation ranged from milder encephalopathy to acute necrotizing encephalopathy (ANE) with coma and multiorgan failure; one child died. This report raises awareness for clinicians to identify and treat early acute encephalopathy caused by H1N1 influenza and serves as a reminder of severe presentations of influenza in young children and the importance of vaccination.

BIANCA-MS: An optimized tool for automated multiple sclerosis lesion segmentation.

In this work we present BIANCA-MS, a novel tool for brain white matter lesion segmentation in multiple sclerosis (MS), able to generalize across both the wide spectrum of MRI acquisition protocols and the heterogeneity of manually labeled data. BIANCA-MS is based on the original version of BIANCA and implements two innovative elements: a harmonized setting, tested under different MRI protocols, which avoids the need to further tune algorithm parameters to each dataset; and a cleaning step developed to improve consistency in automated and manual segmentations, thus reducing unwanted variability in output segmentations and validation data. BIANCA-MS was tested on three datasets, acquired with different MRI protocols. First, we compared BIANCA-MS to other widely used tools. Second, we tested how BIANCA-MS performs in separate datasets. Finally, we evaluated BIANCA-MS performance on a pooled dataset where all MRI data were merged. We calculated the overlap using the DICE spatial similarity index (SI) as well as the number of false positive/negative clusters (nFPC/nFNC) in comparison to the manual masks processed with the cleaning step. BIANCA-MS clearly outperformed other available tools in both high- and low-resolution images and provided comparable performance across different scanning protocols, sets of modalities and image resolutions. BIANCA-MS performance on the pooled dataset (SI: 0.72 ± 0.25, nFPC: 13 ± 11, nFNC: 4 ± 8) were comparable to those achieved on each individual dataset (median across datasets SI: 0.72 ± 0.28, nFPC: 14 ± 11, nFNC: 4 ± 8). Our findings suggest that BIANCA-MS is a robust and accurate approach for automated MS lesion segmentation.

Continous somatosensory evoked potentials and brain injury in neonatal hypoxic-ischaemic encephalopathy treated with hypothermia.

AIM: To explore whether continuous somatosensory evoked potentials (SEPs) monitoring and video electroencephalograms (VEEG) accurately predict lesions observed on brain magnetic resonance imaging (MRI) in neonates with hypoxic-ischaemic encephalopathy (HIE) receiving therapeutic hypothermia. METHOD: This prospective study included 31 neonates (16 males, 15 females; mean [SD] gestational age 39 weeks [1.67]) who received therapeutic hypothermia for HIE. Therapeutic hypothermia was provided for 72 hours, with a target temperature of 33.0°C to 34.0°C and this was followed by a rewarming rate of approximately 0.5°C per hour, up to 36.5°C. SEPs and VEEG were evaluated simultaneously and continuously for 1 hour under normothermic conditions. MRI was carried out at a mean (SD) age of 6 (2) days. RESULTS: Our results showed a statistically significant correlation between continuous SEP and MRI scores (r=0.37, p=0.03), but not between the VEEG and MRI scores (r=0.30, p=0.09). Receiver operating characteristic analysis confirmed that continuous SEPs were highly specific and sensitive at predicting MRI abnormalities, whereas the VEEG had high specificity but low sensitivity. INTERPRETATION: Continuous monitoring of SEPs could provide early and important prognostic information in neonates with HIE. WHAT THIS PAPER ADDS: Early continuous somatosensory evoked potential (SEP) monitoring is correlated with hypoxic-ischaemic encephalopathy (HIE) lesions. Video electroencephalograms (VEEGs) are associated with lesions diagnosed after magnetic resonance imaging. Both showed high specificity, but VEEGs did not show high sensitivity. Continuously monitoring SEPs provides important information about HIE.

Chiari 1 malformation and exome sequencing in 51 trios: the emerging role of rare missense variants in chromatin-remodeling genes.

Type 1 Chiari malformation (C1M) is characterized by cerebellar tonsillar herniation of 3-5 mm or more, the frequency of which is presumably much higher than one in 1000 births, as previously believed. Its etiology remains undefined, although a genetic basis is strongly supported by C1M presence in numerous genetic syndromes associated with different genes. Whole-exome sequencing (WES) in 51 between isolated and syndromic pediatric cases and their relatives was performed after confirmation of the defect by brain magnetic resonance image (MRI). Moreover, in all the cases showing an inherited candidate variant, brain MRI was performed in both parents and not only in the carrier one to investigate whether the defect segregated with the variant. More than half of the variants were Missense and belonged to the same chromatin-remodeling genes whose protein truncation variants are associated with severe neurodevelopmental syndromes. In the remaining cases, variants have been detected in genes with a role in cranial bone sutures, microcephaly, neural tube defects, and RASopathy. This study shows that the frequency of C1M is widely underestimated, in fact many of the variants, in particular those in the chromatin-remodeling genes, were inherited from a parent with C1M, either asymptomatic or with mild symptoms. In addition, C1M is a Mendelian trait, in most cases inherited as dominant. Finally, we demonstrate that modifications of the genes that regulate chromatin architecture can cause localized anatomical alterations, with symptoms of varying degrees.

Gray matter atrophy cannot be fully explained by white matter damage in patients with MS.

BACKGROUND: Source-based morphometry (SBM) was recently used for non-random "patterns" of gray matter (GM) atrophy or white matter (WM) microstructural damage. OBJECTIVE: To assess whether and to what extent such patterns may be inter-related in MS. METHODS: SBM was applied to images of GM concentration and fractional anisotropy (FA) in MS patients (n = 41, median EDSS = 1) and normal controls (NC, n = 28). The same procedure was repeated on an independent and similar data set (39 MS patients and 13 NC). RESULTS: We found in MS patterns of GM atrophy and reduced FA (p < 0.05, corrected). Deep GM atrophy was mostly (70%) explained by lesion load in projection tracts and lower FA in posterior corona radiata and thalamic radiation. By contrast, sensorimotor and posterior cortex atrophy was less (50%) dependent from WM damage. All patterns correlated with EDSS (r from -0.33 to -0.56, p < 0.03) while the only cognition-related correlation was between posterior GM atrophy pattern and processing speed (r = 0.45, p = 0.014). Reliability analysis showed similar results. CONCLUSION: In relatively early MS, we found a close link between deep GM atrophy pattern and WM damage while sensorimotor and posterior cortex patterns were partially independent from WM damage and perhaps related to primary mechanisms. Patterns were clinically relevant.

Agenesis of internal carotid artery associated with isolated growth hormone deficiency: a case report and literature review.

BACKGROUND: Agenesis of the internal carotid artery (ICA) is a rare congenital abnormality, sporadically reported to be associated with a combined congenital hypopituitarism. Nevertheless, only a few cases have been extensively described, and none of these have been characterized by an isolated growth hormone (GH) deficiency. CASE PRESENTATION: Here, we describe a 17-year old boy referred to our hospital for fatigue, decreased muscle strength and severe headache reported after the cessation of rhGH treatment for a GH deficiency diagnosed at the age of 2 years and 3 months. Magnetic resonance imaging (MRI) showed an adenohypophyseal hypoplasia with a lack of posterior pituitary hyperintensity, whereas MRI angiography indicated the absence of a normal flow void in the left ICA. Endocrinological tests confirmed the GH deficiency (GH peak after growth-hormone-releasing hormone (GHRH) + arginine: 2.42 ng/mL) with a very low IGF-I value (31 ng/mL) and normal function of other pituitary axes. CONCLUSION: To the best of our knowledge this is the first confirmed case of an isolated GH deficiency in a patient with ICA agenesis. The presence of an isolated pituitary deficit is unlike to be considered only as an effect of hemodynamic mechanism, suggesting a role for genetic factor(s) as a common cause of these two rare birth defects. Further studies could clarify this issue and the underlying mechanisms to better understand the etiopathogenetic characteristics of this disorder.

Basal Ganglia Dysmorphism in Patients With Aicardi Syndrome.

OBJECTIVE: Aiming to detect associations between neuroradiologic and EEG evaluations and long-term clinical outcome in order to detect possible prognostic factors, a detailed clinical and neuroimaging characterization of 67 cases of Aicardi syndrome (AIC), collected through a multicenter collaboration, was performed. METHODS: Only patients who satisfied Sutton diagnostic criteria were included. Clinical outcome was assessed using gross motor function, manual ability, and eating and drinking ability classification systems. Brain imaging studies and statistical analysis were reviewed. RESULTS: Patients presented early-onset epilepsy, which evolved into drug-resistant seizures. AIC has a variable clinical course, leading to permanent disability in most cases; nevertheless, some cases presented residual motor abilities. Chorioretinal lacunae were present in 86.56% of our patients. Statistical analysis revealed correlations between MRI, EEG at onset, and clinical outcome. On brain imaging, 100% of the patients displayed corpus callosum malformations, 98% cortical dysplasia and nodular heterotopias, and 96.36% intracranial cysts (with similar rates of 2b and 2d). As well as demonstrating that posterior fossa abnormalities (found in 63.63% of cases) should also be considered a common feature in AIC, our study highlighted the presence (in 76.36%) of basal ganglia dysmorphisms (never previously reported). CONCLUSION: The AIC neuroradiologic phenotype consists of a complex brain malformation whose presence should be considered central to the diagnosis. Basal ganglia dysmorphisms are frequently associated. Our work underlines the importance of MRI and EEG, both for correct diagnosis and as a factor for predicting long-term outcome. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with AIC, specific MRI abnormalities and EEG at onset are associated with clinical outcomes.

Relevance of cognitive deterioration in early relapsing-remitting MS: a 3-year follow-up study.

OBJECTIVE: To assess longitudinally cognitive functioning in relapsing-remitting multiple sclerosis (RRMS) patients and its relationship with clinical and MRI variables. METHODS: Early RRMS patients and matched healthy controls were assessed in parallel in three testing sessions over 3 years, using the Rao's Brief Repeatable Battery of Neuropsychological Tests. Patients also underwent an MRI analysis of T2-weighted lesion volume (T2LV), number of gadolinium-enhanced lesions and whole brain atrophy. Forty-nine RRMS patients (mean age 36.9 ± 8.9 years; mean disease duration 2.9 ± 1.7 years, mean Expanded Disability Status Scale, 1.7 ± 0.7) and 56 healthy controls were recruited. RESULTS: At baseline, cognitive impairment was detected in 15 patients (30.6%). After 3 years, cognitive functioning worsened in the 29.3% of patients, whereas Expanded Disability Status Scale progression was observed in only three patients. The most sensitive test to detect cognitive deterioration over time was the Symbol Digit Modalities Test (SDMT). Only the presence of moderate cognitive impairment at baseline predicted further cognitive deterioration (p = 0.03). Among MRI variables, T2LV showed a weak to moderate relationship with some cognitive tasks. CONCLUSIONS: Over a 3-year period cognitive deterioration can be expected in approximately one-third of MS patients with relatively short disease duration. The SDMT is particularly suitable for longitudinal assessment of MS-related cognitive changes.

Familial hemophagocytic lymphohistiocytosis: clinical and neuroradiological findings and review of the literature.

BACKGROUND: Familial hemophagocytic lymphohistiocytosis (FHL) is a rare multisystem congenital disorder characterized by uncontrolled proliferation and infiltration of activated lymphocytes and histiocytes, secreting high amounts of inflammatory cytokines; this may affect multiple organs including liver, spleen, lymph nodes, bone marrow, and central nervous system (CNS; Janka, Eur J Pediatr 166:95-109, 1). OBJECTIVE: The objective of this study is to describe the characteristics of the encephalopathy and to correlate the neuroradiological findings with the clinical symptoms and the treatment response in a child with FHL type 3 studied by total body computed tomography and by brain magnetic resonance (MR) and MR spectroscopy. RESULTS: VF, a 14-month-old female, developed a full-blown FHL, with facial nerve palsy as the only CNS complication. Brain MR imaging showed several focal areas of pathological signal in the subcortical and periventricular white matter, left thalamus, cerebellum, and brain stem. Proton MR spectroscopy also demonstrated no elevated peak of Cho, no lactate peak, and elevated glutamine/glutamate complex. Moreover, an elevated N-acetyl aspartate (NAA) peak was detected. The follow-up MR study after hematopoietic stem cells transplantation showed a dramatic reduction of the lesions and normalization of the metabolic pattern at spectroscopy. CONCLUSION: Brain lesions and metabolic alterations documented by MR and spectroscopy during active FHL reverted during disease control achieved by therapy.

Changes in grey matter volume and functional connectivity in cluster headache versus migraine.

Cluster headache (CH) shows a more severe clinical picture than migraine (Mig). We tested whether brain changes can explain such difference. Multimodal MRI was acquired in attack-free patients with CH (n = 12), Mig (n = 13) and in normal controls (NC, n = 13). We used FSL for MRI data analysis and nonparametric permutation testing for voxelwise analyses (p < 0.01, corrected). CH showed lower grey matter (GM) volume, compared to Mig and NC, in frontal cortex regions (inferior frontal gyrus and frontal pole [FP], respectively) and, only compared to Mig, in lateral occipital cortex (LOC). Functional connectivity (FC) of CH was higher than Mig and NC within working memory and executive control networks and, only compared to Mig, between cerebellar and auditory language comprehension networks. In the attack-free state, the CH brain seems to be characterized by: (i) GM volume decrease, compared to both Mig and NC, in pain modulation regions (FP) and, only with respect to Mig, in a region of visual processing modulation during pain and working memory (LOC); (ii) increased FC at short range compared to both Mig and NC and at long range only with respect to Mig, in key cognitive networks, likely due to maladaptation towards more severe pain experience.

Inner ear abnormalities in four patients with dRTA and SNHL: clinical and genetic heterogeneity.

A significant number of patients affected by autosomal recessive primary distal renal tubular acidosis (dRTA) manifest sensorineural hearing loss (SNHL). Mutations in ATP6V1B1 are associated with early onset SNHL, whereas ATP6V0A4 mutations have been described in dRTA and late-onset SNHL. Enlarged vestibular aqueduct (EVA) was described in patients with recessive dRTA and SNHL, and recently, this abnormality has been associated with mutations in the ATP6V1B1 gene. In our study, we evaluated the presence of inner-ear abnormalities in four patients affected by dRTA and SNHL, characterized by molecular analysis. Two patients affected by severe dRTA with early onset SNHL showed the same mutation in the ATP6V1B1 gene and bilateral EVA with a different degree of severity. The other two presented similar clinical manifestations of dRTA and different mutations in the ATP6V0A4 gene: one patient, showing EVA, developed an early SNHL, whereas in the other one, the SNHL appeared in the second decade of life and the vestibular aqueduct was normal. Our study confirms the association of EVA and mutations in the ATP6V1B1 gene and demonstrates that mutations in the ATP6V0A4 gene can also be associated with EVA probably only when the SNHL has an early onset. The pathophysiology of SNHL and EVA are still to be defined.

Sine causa tetraparesis: A pilot study on its possible relationship with interferon signature analysis and Aicardi Goutières syndrome related genes analysis.

Tetraparesis is usually due to cerebral palsy (CP), inborn errors of metabolism, neurogenetic disorders and spinal cord lesions. However, literature data reported that about 10% of children with tetraparesis show a negative/non-specific neuroradiological findings without a specific etiological cause. Aicardi Goutières Syndrome (AGS) is a genetic encephalopathy that may cause tetraparesis. Interferon signature is a reliable biomarker for AGS and could be performed in sine-causa tetraparesis. The aim of the study was to examine the type I interferon signature and AGS related-genes in children with sine causa tetraparesis, to look for misdiagnosed AGS. A secondary aim was to determine which aspects of the patient history, clinical picture and brain imaging best characterize tetraparesis due to an interferonopathy.Seven out of 78 patients affected by tetraparesis, characterized by unremarkable pre-peri-postnatal history and normal/non-specific brain magnetic resonance imaging (MRI) were selected and underwent anamnestic data collection, clinical examination, brain imaging review, peripheral blood interferon signature and AGS-related genes analysis.At our evaluation time (mean age of 11.9 years), all the 7 patients showed spastic-dystonic tetraparesis. At clinical onset brain MRI was normal in 4 and with non-specific abnormalities in 3; at follow-up 3 patients presented with new white-matter lesions, associated with brain calcification in 1 case. Interferon signature was elevated in one subject who presented also a mutation of the IFIH1 gene.AGS should be considered in sine-causa tetraparesis. Core features of interferonopathy-related tetraparesis are: onset during first year of life, psychomotor regression with tetraparesis evolution, brain white-matter lesions with late calcifications. A positive interferon signature may be a helpful marker to select patients with spastic tetraparesis who should undergo genetic analysis for AGS.

Pronounced Structural and Functional Damage in Early Adult Pediatric-Onset Multiple Sclerosis with No or Minimal Clinical Disability.

Pediatric-onset multiple sclerosis (POMS) may represent a model of vulnerability to damage occurring during a period of active maturation of the human brain. Whereas adaptive mechanisms seem to take place in the POMS brain in the short-medium term, natural history studies have shown that these patients reach irreversible disability, despite slower progression, at a significantly younger age than adult-onset MS (AOMS) patients. We tested for the first time whether significant brain alterations already occurred in POMS patients in their early adulthood and with no or minimal disability (n = 15) in comparison with age- and disability-matched AOMS patients (n = 14) and to normal controls (NC, n = 20). We used a multimodal MRI approach by modeling, using FSL, voxelwise measures of microstructural integrity of white matter tracts and gray matter volumes with those of intra- and internetwork functional connectivity (FC) (analysis of variance, p ≤ 0.01, corrected for multiple comparisons across space). POMS patients showed, when compared with both NC and AOMS patients, altered measures of diffusion tensor imaging (reduced fractional anisotropy and/or increased diffusivities) and higher probability of lesion occurrence in a clinically eloquent region for physical disability such as the posterior corona radiata. In addition, POMS patients showed, compared with the other two groups, reduced long-range FC, assessed from resting functional MRI, between default mode network and secondary visual network, whose interaction subserves important cognitive functions such as spatial attention and visual learning. Overall, this pattern of structural damage and brain connectivity disruption in early adult POMS patients with no or minimal clinical disability might explain their unfavorable clinical outcome in the long term.

Cortical damage in brains of patients with adult-form of myotonic dystrophy type 1 and no or minimal MRI abnormalities.

OBJECTIVE: To evaluate, by using quantitative MRI metrics, subtle cortical changes in brains of patients with the adult form of myotonic dystrophy type I (DM1) who showed no or minimal abnormalities on MRI. BACKGROUND: DM1 is an autosomal dominant multisystem disorder caused by the expansion of CTG repeats in the myotonic dystrophy-protein kinase gene. Mild to severe involvement of the CNS can be part of the clinical features of the disease. Several MRI studies have demonstrated that both focal white matter (WM) lesions and diffuse grey matter atrophy can be found in the brains of DM1 patients. However, whether these two processes are related or may occur independently is not clear. DESIGN/METHODS: Ten genetically-proven DM1 patients who showed no or minimal abnormalities on MRI underwent a new brain MRI examination to obtain computerized measures of total and regional brain volumes normalized to head size and regional measurements of the magnetization transfer ratio (MTr). RESULTS: Normalized brain volumes (NBV) were significantly (p < 0.0001) lower in DM1 subjects than in a group of age- and sex-matched normal controls. Normalized cortical volumes (NCV) also were lower (p = 0.003) in DM1 subjects than in normal controls, whereas normalized WM volumes were not different between the two groups (p = 0.3). In agreement with this, values of MTr in the neocortex (cortical-MTr) were significantly (p = 0.006) lower in DM1 patients than in normal controls and this difference was not found in the WM tissue (p = 0.8). CONCLUSIONS: Neocortical damage seems to be evident in the absence of visible WM lesions suggesting that a neocortical pathology, unrelated to WM lesion formation, occurs in DM1 brains.

Diffuse structural and metabolic brain changes in Fabry disease.

OBJECTIVES: To assess structural and metabolic brain changes in subjects affected by Fabry disease (FD) or carrying the disease mutation. BACKGROUND: FD is an X-linked metabolic disorder due to alpha-galactosidase A deficiency, which leads to storage of glycosphingolipids in many tissues and organs. Previous MR studies have shown structural and metabolic brain abnormalities in FD patients. It is not clear, however, whether tissue damage can be seen in both the brains of hemizygous and heterozygous and whether quantitative MR metrics are useful to monitor disease evolution. DESIGN/METHODS: We studied 4 males and 4 females with FD. Each subject underwent brain proton MRI/MR spectroscopic imaging (MRSI) examinations to obtain measures of total brain volumes, total brain lesion volumes, magnetization transfer ratios (MTr) in WM and central brain levels of N-acetylaspartate (NAA) to creatine (Cr). A second MR examination was performed in five subjects after 2 years. RESULTS: Focal WM lesions were found in 2 males and 1 female. The MTr values were always low in the WM lesions of FD subjects (p < 0.001) and also were low in the normal-appearing WM of 2 affected males. Total brain volumes were never decreased in FD subjects. Brain NAA/Cr values were significantly (p = 0.005) lower in FD subjects than in normal controls and correlated closely with Rankin scale measures (r = -0.79). On follow-up examinations, no significant MR changes were found. However, the small changes in NAA/Cr correlated closely with changes in Rankin scores (r = -0.86). CONCLUSIONS: Subtle structural and metabolic tissue damage can extend beyond WM lesions in FD subjects. Diffuse brain NAA/Cr decrease can be found in FD subjects in relation to the degree of their CNS involvement and its evolution over time.

Neocortical volume decrease in relapsing-remitting multiple sclerosis with mild cognitive impairment.

The aim of the study was to assess neocortical changes and their relevance to cognitive impairment in early relapsing-remitting multiple sclerosis (RRMS). Conventional magnetic resonance was acquired in 41 RRMS patients and 16 demographically matched normal controls (NC). An automated analysis tool was used to obtain measures of cortical brain volumes normalized for head size. Neuropsychological performance of MS patients was assessed through the Rao's Brief Repeatable Battery. We identified 18 cognitively preserved (MS-cp) and 23 cognitively impaired (MS-ci) MS patients. Values of normalized cortical volumes (NCV) in the whole MS sample were lower than those in the NC group (p=0.01). MS-ci patients showed NCV values lower (p=0.02) than did both MS-cp patients and NC. Moreover, we found a positive correlation between NCV values and measures of verbal memory (r=0.51, p=0.02), verbal fluency (r=0.51, p=0.01) and attention/concentration (r=0.65, p<0.001) in MS-ci patients. Furthermore, NCV values were significantly decreased in patients who scored lower on a greater number of tests (r=-0.58, p<0.01) in the MS-ci group. Only MS-ci patients had cortical atrophy significantly correlated with a poorer neuropsychological performance. Grey matter pathology may contribute to the development of cognitive impairment in MS from the earliest stages of the disease.

Early Diagnosis and Monitoring of Neurodegenerative Langerhans Cell Histiocytosis.

BACKGROUND: Neurodegenerative Langerhans Cell Histiocytosis (ND-LCH) is a rare, unpredictable consequence that may devastate the quality of life of patients cured from LCH. We prospectively applied a multidisciplinary diagnostic work-up to early identify and follow-up patients with ND-LCH, with the ultimate goal of better determining the appropriate time for starting therapy. METHODS: We studied 27 children and young adults with either ND-LCH verified by structural magnetic resonance imaging (MRI) (group 1) or specific risk factors for (diabetes insipidus, craniofacial bone lesions), but no evidence of, neurodegenerative MRI changes (group 2). All patients underwent clinical, neurophysiological and MRI studies. RESULTS: Seventeen patients had MRI alterations typical for ND-LCH. Nine showed neurological impairment but only three were symptomatic; 11 had abnormal somatosensory evoked potentials (SEPs), and five had abnormal brainstem auditory evoked potentials (BAEPs). MR spectroscopy (MRS) showed reduced cerebellar NAA/Cr ratio in nine patients. SEPs showed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for predicting ND-LCH of 70.6% (95%CI, 44.0%-89.7%), 100% (69.2%-100%), 100% (73.5%-100%), and 66.7% (38.4%-88.2%), respectively. Repeated investigations in group 1 revealed increasingly abnormal EP parameters, or neurological examination, or both, in nine of fifteen patients while MRI remained unchanged in all but one patient. CONCLUSION: A targeted MRI study should be performed in all patients with risk factors for ND-LCH for early identification of demyelination. The combined use of SEPs and careful neurological evaluation may represent a valuable, low-cost, well-tolerated and easily available methodology to monitor patients from pre-symptomatic to symptomatic stages. We suggest a multidisciplinary protocol including clinical, MRS, and neurophysiological investigations to identify a population target for future therapeutic trials.