Magnetic resonance T1w/T2w ratio and voxel-based morphometry in multiple system atrophy.

Diagnosis of multiple system atrophy (MSA) may be improved by using multimodal imaging approaches. We investigated the use of T1-weighted/T2-weighted (T1w/T2w) images ratio combined with voxel-based morphometry to evaluate brain tissue integrity in MSA compared to Parkinson's disease (PD) and healthy controls (HC). Twenty-six patients with MSA, 43 patients with PD and 56 HC were enrolled. Whole brain voxel-based and local regional analyses were performed to evaluate gray and white matter (GM and WM) tissue integrity and mean regional values were used for patients classification using logistic regression. Increased mean regional values of T1w/T2w in bilateral putamen were detected in MSA-P compared to PD and HC. The combined use of regional GM and T1w/T2w values in the right and left putamen showed the highest accuracy in discriminating MSA-P from PD and good accuracy in discriminating MSA from PD and HC. A good accuracy was also found in discriminating MSA from PD and HC by either combining regional GM and T1w/T2w values in the cerebellum or regional WM and T1w/T2w in the cerebellum and brainstem. The T1w/T2w image ratio alone or combined with validated MRI parameters can be further considered as a potential candidate biomarker for differential diagnosis of MSA.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids.

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

Incidence and survival of peritoneal malignant mesothelioma between 1989 and 2015: A population-based study.

BACKGROUND: Peritoneal malignant mesothelioma is a rare disease for which few population-based studies are available. The aim of this study was to describe the evolution of the incidence and survival of peritoneal malignant mesothelioma in France between 1989 and 2015, using data derived from the French network of cancer registries. METHODS: Age world-standardized incidence rates and overall survival were calculated using data from 16 French cancer registries. Log-linear Poisson regression analysis was used to estimate the average annual percentage change in incidence rates. Overall survival was performed using age-adjusted Cox proportional hazards model. RESULTS: In French men, the incidence has increased quietly over the reporting period from 0.07 to 0.10 with a maximum of 0.16 per 100,000 persons-years in 2001-2003. For women, the increase in incidence has been lower than for men over the period 1989-2015, ranging from 0.04 to 0.11. A better prognosis was associated with a diagnosis made after 2000 (HR = 1.76; p = 0.013), the epithelioid histological type (p = 0.003), and the fact of being a woman, which has a 5-year risk of death half that of men (HR = 0.55; p = 0.001), regardless of age, diagnosis period or histology. CONCLUSION: Our results are similar to those currently available for other countries. In France, peritoneal mesothelioma remains a rare and fatal cancer with a small increase in the incidence rate since 1989 and a median survival of 1 year; it seemed to develop equally in women and men over this period of time.

New Insights on Diagnostic Reproducibility of Biphasic Mesotheliomas: A Multi-Institutional Evaluation by the International Mesothelioma Panel From the MESOPATH Reference Center.

INTRODUCTION: The 2015 WHO classification of tumors categorized malignant mesothelioma into epithelioid, biphasic (BMM), and sarcomatoid (SMM) for prognostic relevance and treatment decisions. The survival of BMM is suspected to correlate with the amount of the sarcomatoid component. The criteria for a sarcomatoid component and the interobserver variability between pathologists for identifying this component are not well described. In ambiguous cases, a "transitional" (TMM) subtype has been proposed but was not accepted as a specific subtype in the 2015 WHO classification. The aims of this study were to evaluate the interobserver agreement in the diagnosis of BMM, to determine the nature and the significance of TMM subtype, and to relate the percentage of sarcomatoid component with survival. The value of staining for BRCA-1-associated protein (BAP1) and CDKN2A(p16) fluorescence in situ hybridization (FISH) were also assessed with respect to each of the tumoral components. METHODS: The study was conducted by the International Mesothelioma Panel supported by the French National Cancer Institute, the network of rare cancer (EURACAN) and in collaboration with the International Association for the Study of Lung Cancer (IASLC). The patient cases include a random group of 42 surgical biopsy samples diagnosed as BMM with evaluation of SMM component by the French Panel of MESOPATH experts was selected from the total series of 971 BMM cases collected from 1998 to 2016. Fourteen international pathologists with expertise in mesothelioma reviewed digitally scanned slides (hematoxylin and eosin - stained and pan-cytokeratin) without knowledge of prior diagnosis or outcome. Cases with at least 7 of 14 pathologists recognizing TMM features were selected as a TMM group. Demographic, clinical, histopathologic, treatment, and follow-up data were retrieved from the MESOBANK database. BAP1 (clone C-4) loss and CDKN2A(p16) homozygous deletion (HD) were assessed by immunohistochemistry (IHC) and FISH, respectively. Kappa statistics were applied for interobserver agreement and multivariate analysis with Cox regression adjusted for age and gender was performed for survival analysis. RESULTS: The 14 panelists recorded a total of 544 diagnoses. The interobserver correlation was moderate (weighted Kappa = 0.45). Of the cases originally classified as BMM by MESOPATH, the reviewers agreed in 71% of cases (385 of 544 opinions), with cases classified as pure epithelioid in 17% (93 of 544), and pure sarcomatoid in 12% (66 of 544 opinions). Diagnosis of BMM was made on morphology or IHC alone in 23% of the cases and with additional assessment of IHC in 77% (402 of 544). The median overall survival (OS) of the 42 BMM cases was 8 months. The OS for BMM was significantly different from SMM and epithelioid malignant mesothelioma (p < 0.0001). In BMM, a sarcomatoid component of less than 80% correlated with a better survival (p = 0.02). There was a significant difference in survival between BMM with TMM showing a median survival at 6 months compared to 12 months for those without TMM (p < 0.0001). BAP1 loss was observed in 50% (21 of 42) of the total cases and in both components in 26%. We also compared the TMM group to that of more aggressive patterns of epithelioid subtypes of mesothelioma (solid and pleomorphic of our large MESOPATH cohort). The curve of transitional type was persistently close to the OS curve of the sarcomatoid component. The group of sarcomatoid, transitional, and pleomorphic mesothelioma were very close to each other. We then considered the contribution of BAP1 immunostaining and loss of CDKN2A(p16) by FISH. BAP1 loss was observed in 50% (21 of 41) of the total cases and in both component in 27% of the cases (11 of 41). There was no significant difference in BAP1 loss between the TMM and non-TMM groups. HD CDKN2A(p16) was detected in 74% of the total cases with no significant difference between the TMM and non-TMM groups. In multivariate analysis, TMM morphology was an indicator of poor prognosis with a hazard ratio = 3.2; 95% confidence interval: 1.6 - 8.0; and p = 0.003 even when compared to the presence of HD CDKN2A(p16) on sarcomatoid component (hazard ratio = 4.5; 95% confidence interval: 1.2 - 16.3, p = 0.02). CONCLUSIONS: The interobserver concordance among the international mesothelioma and French mesothelioma panel suggests clinical utility for an updated definition of biphasic mesothelioma that allows better stratification of patients into risk groups for treatment decisions, systemic anticancer therapy, or selection for surgery or palliation. We also have shown the usefulness of FISH detection of CDKN2A(p16) HD compared to BAP1 loss on the spindle cell component for the separation in ambiguous cases between benign florid stromal reaction from true sarcomatoid component of biphasic mesothelioma. Taken together our results further validate the concept of transitional pattern as a poor prognostic indicator.

Tratamiento quirúrgico de aneurismas cerebrales en pacientes en la 8va y 9na década de vida / Surgical treatment of cerebral aneurysms in patients in the 8th and 9th years of life

La hemorragia subarcnoidea por sangrado de aneurismas sigue siendo una enfermedad con una elevada mortalidad y morbilidad. Los avances en microcirugía y en terapia endovascular, no han logrado abatir los altos porcentajes de mala evolución. Por su parte, el tratamiento de los aneurismas no rotos se vuelve cada vez más rutinario, dados los buenos resultados. Un capítulo aparte es el tratamiento o no de aneurismas cerebrales con o sin hemorragia subaracnoidea en pacientes añosos (mayores de 70 años). Hay publicaciones al respecto. Los autores hacen una revisión retrospectiva de 179 pacientes mayores de 70 años portadores de aneurismas cerebrales, con o sin sangrado subaracnoideo. Todos fueron sometidos a cirugía. Se analizan los resultados, los que muestran que la morbimortalidad en este grupo etario no difiere sustancialmente de los que se dan en menores de 70 años.

Subarachnoid haemorrhage due to bleeding of cerebral aneurysms remains a disease with high mortality and morbidity. Advances in microsurgery and endovascular therapy have failed to reduce the high percentages of poor outcome. The treatment of unruptured aneurysms, on the other hand, becomes more and more routinary, given the good results. A separate chapter is the treatment or not of cerebral aneurysms with or without subarachnoid hemorrhage in elderly patients (older than 70 years). There are several publications about it. The authors make a retrospective review of 179 patients older than 70 years with cerebral aneurysms, with or without subarachnoid bleeding.All were submitted to surgery. We analyze the results, which show that morbidity and mortality in this age group do not differ substantially from those occurring under 70 years of age.

Greater brain response to emotional expressions of their own children in mothers of preterm infants: an fMRI study.

OBJECTIVE: The birth of a preterm infant and Neonatal Intensive Care Unit hospitalization constitute a potentially traumatic experience for mothers. Although behavioral studies investigated the parenting stress in preterm mothers, no study focused on the underlying neural mechanisms. We examined the effect of preterm births in mothers, by comparing brain activation in mothers of preterm and full-term infants. STUDY DESIGN: We used functional magnetic resonance imaging to measure the cerebral response of 10 first-time mothers of preterm infants (gestational age <32 weeks and/or birth weight <1500) and 11 mothers of full-term infants, viewing happy-, neutral- and distress-face images of their own infant, along with a matched unknown infant. RESULTS: While viewing own infant's face preterm mothers showed increased activation in emotional processing area (i.e., inferior frontal gyrus) and social cognition (i.e., supramarginal gyrus) and affiliative behavior (i.e., insula). CONCLUSION: Differential brain activation patterns in mothers appears to be a function of the atypical parenthood transition related to prematurity.

Management of giant cell arteritis: Recommendations of the French Study Group for Large Vessel Vasculitis (GEFA).

PURPOSE: Management of giant cell arteritis (GCA, Horton's disease) involves many uncertainties. This work was undertaken to establish French recommendations for GCA management. METHODS: Recommendations were developed by a multidisciplinary panel of 33 physicians, members of the French Study Group for Large Vessel Vasculitis (Groupe d'étude français des artérites des gros vaisseaux [GEFA]). The topics to be addressed, selected from proposals by group members, were assigned to subgroups to summarize the available literature and draft recommendations. Following an iterative consensus-seeking process that yielded consensus recommendations, the degree of agreement among panel members was evaluated with a 5-point Likert scale. A recommendation was approved when ≥ 80% of the voters agreed or strongly agreed. RESULTS: The 15 retained topics resulted in 31 consensus recommendations focusing on GCA nomenclature and classification, the role of temporal artery biopsy and medical imaging in the diagnosis, indications and search modalities for involvement of the aorta and its branches, the glucocorticoid regimen to prescribe, treatment of complicated GCA, indications for use of immunosuppressants or targeted biologic therapies, adjunctive treatment measures, and management of relapse and recurrence. CONCLUSIONS: The recommendations, which will be updated regularly, are intended to guide and harmonize the standards of GCA management.

Mastication induces long-term increases in blood perfusion of the trigeminal principal nucleus.

Understanding mechanisms for vessel tone regulation within the trigeminal nuclei is of great interest because some headache syndromes are due to dysregulation of such mechanisms. Previous experiments on animal models suggest that mastication may alter neuron metabolism and blood supply in these nuclei. To investigate this hypothesis in humans, arterial spin-labeling magnetic resonance imaging (MRI) was used to measure blood perfusion within the principal trigeminal nucleus (Vp) and in the dorsolateral-midbrain (DM, including the mesencephalic trigeminal nucleus) in healthy volunteers, before and immediately after a mastication exercise consisting of chewing a gum on one side of the mouth for 1 h at 1 bite/s. The side preference for masticating was evaluated with a chewing test and the volume of the masseter muscle was measured on T1-weighted MRI scans. The results demonstrated that the mastication exercise caused a perfusion increase within the Vp, but not in the DM. This change was correlated to the preference score for the side where the exercise took place. Moreover, the basal Vp perfusion was correlated to the masseter volume. These results indicate that the local vascular tone of the trigeminal nuclei can be constitutively altered by the chewing practice and by strong or sustained chewing.

Brain anatomical substrates of mirror movements in Kallmann syndrome.

Among male patients affected by Kallmann syndrome, a genetically determined disease due to defective neural migration leading to hypogonadropic hypogonadism and hypo/anosmia, about 40% present the peculiar phenomenon of mirror movements, i.e. involuntary movements mirroring contralateral voluntary hand movements. Several pathogenic hypotheses have been proposed, but the ultimate neurological mechanisms are still elusive. The aim of the present study was to investigate brain anatomical substrates of mirror movements in Kallmann syndrome by means of a panel of quantitative MRI analyses. Forty-nine male Kallmann syndrome patients underwent brain MRI. The study protocol included 3D-T1-weighted gradient echo, fluid attenuated inversion recovery and diffusion tensor imaging. Voxel-based morphometry, sulcation, curvature and cortical thickness analyses and tract based spatial statistics were performed using SPM8, Freesurfer and FSL. All patients underwent a complete physical and neurological examination including the evaluation of mirror movements (according to the Woods and Teuber criteria). Kallmann syndrome patients presenting with mirror movements (16/49, 32%) displayed the following brain changes: 1) increased gray matter density in the depth of the left precentral sulcus behind the middle frontal gyrus; 2) decreased cortical thickness in the precentral gyrus bilaterally, in the depth of right precentral sulcus and in the posterior portion of the right superior frontal gyrus; and 3) decreased fractional anisotropy in the left hemisphere involving the temporal lobe and peritrigonal white matter. No differences were shown by cortical curvature and sulcation analyses. The composite array of brain changes observed in Kallmann syndrome patients with mirror movements likely represents the anatomical-structural underpinnings leading to the peculiar derangement of the complex circuitry committed to unilateral hand voluntary movements.

Degeneration and plasticity of the optic pathway in Alström syndrome.

BACKGROUND AND PURPOSE: Alström syndrome is a rare inherited ciliopathy in which early progressive cone-rod dystrophy leads to childhood blindness. We investigated functional and structural changes of the optic pathway in Alström syndrome by using MR imaging to provide insight into the underlying pathogenic mechanisms. MATERIALS AND METHODS: Eleven patients with genetically proved Alström syndrome (mean age, 23 years; range, 6-45 years; 5 females) and 19 age- and sex-matched controls underwent brain MR imaging. The study protocol included conventional sequences, resting-state functional MR imaging, and diffusion tensor imaging. RESULTS: In patients with Alström syndrome, the evaluation of the occipital regions showed the following: 1) diffuse white matter volume decrease while gray matter volume decrease spared the occipital poles (voxel-based morphometry), 2) diffuse fractional anisotropy decrease and radial diffusivity increase while mean and axial diffusivities were normal (tract-based spatial statistics), and 3) reduced connectivity in the medial visual network strikingly sparing the occipital poles (independent component analysis). After we placed seeds in both occipital poles, the seed-based analysis revealed significantly increased connectivity in patients with Alström syndrome toward the left frontal operculum, inferior and middle frontal gyri, and the medial portion of both thalami (left seed) and toward the anterior portion of the left insula (right and left seeds). CONCLUSIONS: The protean occipital brain changes in patients with Alström syndrome likely reflect the coexistence of diffuse primary myelin derangement, anterograde trans-synaptic degeneration, and complex cortical reorganization affecting the anterior and posterior visual cortex to different degrees.

Two cases of aggressive nontumoral folliculotropic mycosis fungoides with visceral involvement.

Mycosis fungoides (MF) is the most common type of primary cutaneous T-cell lymphoma (CTCL), and folliculotropic MF (FMF) is one clinical variant of classic MF. MF generally has a good prognosis with an indolent clinical course, but for FMF greater therapeutic resistance is suggested. Visceral involvement is very rare in these two clinical forms. We report two exceptional cases of FMF with pulmonary and hepatic involvement. Five years after their initial diagnoses, patient 1 presented with a pulmonary localization of his FMF, and patient 2 with liver involvement, without lymph node or T-cell clones in the blood. These two patients had FMF corresponding to stage T2N0M1B0. These two cases highlight the aggressiveness of this rare variant of MF. They suggest that the T lymphocytes found in the folliculotropic form of CTCL could be characterized by greater visceral tropism. They raise the question of the molecular and functional characteristics of these T lymphocytes, and the possibility of a common target in the hair follicles and certain organs. Studies have shown that chemokine receptors are likely to be involved in the skin tropism that characterizes CTCL. These two cases show the aggressiveness of FMF and point to the interest in comparing the molecular characteristics of T lymphocytes in the folliculotropic and nonfolliculotropic forms of CTCL.

Brain changes in Kallmann syndrome.

BACKGROUND AND PURPOSE: Kallmann syndrome is a rare inherited disorder due to defective intrauterine migration of olfactory axons and gonadotropin-releasing hormone neurons, leading to rhinencephalon hypoplasia and hypogonadotropic hypogonadism. Concomitant brain developmental abnormalities have been described. Our aim was to investigate Kallmann syndrome-related brain changes with conventional and novel quantitative MR imaging analyses. MATERIALS AND METHODS: Forty-five male patients with Kallmann syndrome (mean age, 30.7 years; range, 9-55 years) and 23 age-matched male controls underwent brain MR imaging. The MR imaging study protocol included 3D-T1, FLAIR, and diffusion tensor imaging (32 noncollinear gradient-encoding directions; b-value=800 s/mm2). Voxel-based morphometry, sulcation, curvature, and cortical thickness analyses and tract-based spatial statistics were performed by using Statistical Parametric Mapping 8, FreeSurfer, and the fMRI of the Brain Software Library. RESULTS: Corpus callosum partial agenesis, multiple sclerosis-like white matter abnormalities, and acoustic schwannoma were found in 1 patient each. The total amount of gray and white matter volume and tract-based spatial statistics measures (fractional anisotropy and mean, radial, and axial diffusivity) did not differ between patients with Kallmann syndrome and controls. By specific analyses, patients with Kallmann syndrome presented with symmetric clusters of gray matter volume increase and decrease and white matter volume decrease close to the olfactory sulci; reduced sulcal depth of the olfactory sulci and deeper medial orbital-frontal sulci; lesser curvature of the olfactory sulcus and sharper curvature close to the medial orbital-frontal sulcus; and increased cortical thickness within the olfactory sulcus. CONCLUSIONS: This large MR imaging study on male patients with Kallmann syndrome featured significant morphologic and structural brain changes, likely driven by olfactory bulb hypo-/aplasia, selectively involving the basal forebrain cortex.

Occupational and non-occupational attributable risk of asbestos exposure for malignant pleural mesothelioma.

OBJECTIVES: To estimate the proportion of pleural mesothelioma cases that can be attributed to asbestos exposure in France including non-occupational exposure. METHODS: A population-based case-control study including 437 incident cases and 874 controls was conducted from 1998 to 2002. Occupational and non-occupational asbestos exposure was assessed retrospectively by two expert hygienists. ORs of pleural mesothelioma for asbestos-exposed subjects compared to non-exposed subjects, and population-attributable risk (ARp) of asbestos exposure were estimated using a conditional logistic regression. RESULTS: A clear dose-response relationship was observed between occupational asbestos exposure and pleural mesothelioma (OR=4.0 (99% CI 1.9 to 8.3) for men exposed at less than 0.1 f/mL-year vs. 67.0 (99% CI 25.6 to 175.1) for men exposed at more than 10 f/mL-year). The occupational asbestos ARp was 83.1% (99% CI 74.5% to 91.7%) for men and 41.7% (99% CI 25.3% to 58.0%) for women. A higher risk of pleural mesothelioma was observed in subjects non-occupationally exposed to asbestos compared to those never exposed. The non-occupational asbestos ARp for these subjects was 20.0% (99% CI -33.5% to 73.5%) in men and 38.7% (99% CI 8.4% to 69.0%) in women. When considering all kinds of asbestos exposure, ARp was 87.3% (99% CI 78.9% to 95.7%) for men and 64.8% (99% CI 45.4% to 84.3%) for women. CONCLUSIONS: Our study suggests that the overall ARp in women is largely driven by non-occupational asbestos exposure arguing for the strong impact of such exposure in pleural mesothelioma occurrence. Considering the difficulty in assessing domestic or environmental asbestos exposure, this could explain the observed difference in ARp between men and women.

Overexpression and promoter mutation of the TERT gene in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a very aggressive tumor with no known curative treatment. Better knowledge of the molecular mechanisms of mesothelial carcinogenesis is required to develop new therapeutic strategies. MPM, like all cancer cells, needs to maintain telomere length to prevent senescence. Previous studies suggested that the telomere lengthening mechanism in MPM is based mainly on telomerase activity. For this reason, we focused on the key catalytic enzyme, TERT (telomerase reverse transcriptase), by analyzing its gene expression in MPM and by studying the mechanism underlying its upregulation. We used our large collection of MPM composed of 61 MPM in culture and 71 frozen MPM tumor samples. Evaluation of TERT mRNA expression by quantitative RT-PCR showed overexpression in MPM in culture compared with normal mesothelial cells, and in MPM tumor samples compared with normal pleura. We identified a 'hot spot' of mutations in the TERT gene core promoter in both MPM in culture and in MPM tumor samples with an overall frequency of 15%. Furthermore, data clearly identified mutation in the TERT promoter as a mechanism of TERT mRNA upregulation in MPM. In contrast, gene copy number amplification was not associated with TERT overexpression. Then, we analyzed the clinicopathological, etiological and genetic characteristics of MPM with mutations in the TERT promoter. TERT promoter mutations were more frequent in MPM with sarcomatoid histologic subtype (P<0.01), and they were frequently associated with CDKN2A gene inactivation (P=0.03). In conclusion, a subgroup of MPM presents TERT promoter mutations, which lead to TERT mRNA upregulation. This is the first recurrent gain-of-function oncogenic mutations identified in MPM.

Tratamiento quirúrgico en malformación de chiari I en la edad pediátrica: estudio y resultados en serie de 57 casos / Surgical treatment in chiari I malformation in the pediatric age: study and results in a series of 57 cases

Introducción: Las malformaciones de Chiari constituyen un grupo heterogéneo de patologías que ocasionan la herniación descendente de estructuras de la fosa posterior. La malformación de Chiari tipo I (MCI) se define como la herniación amigdalina de al menos 3 a 5 mm por debajo del nivel del foramen magno. La resonancia magnética ha aumentado el número de casos diagnosticados, inclusive en la edad pediátrica. Este trabajo tiene por objetivo presentar los resultados en cuanto a hallazgos clínicos y evolución postoperatoria en una serie pediátrica y se realiza una revisión del tema. Pacientes y métodos: Se efectuó un análisis retrospectivo de cohorte única de 57 pacientes operados a lo largo de 20 años por el mismo equipo neuroquirúrgico. Se revisaron los registros de uno de los autores (ES) para obtener datos sobre presentación clínica, diagnóstico, tratamiento y evolución postoperatoria, con un seguimiento de al menos 6 meses en cada paciente. Resultados: Se operaron 57 pacientes de entre 3 a 13 años de edad. El 100% de las malformaciones de Chiari I operadas eran sintomáticas. El síntoma más frecuente fue la cefalea (90%). En todos los casos se efectuó descompresión de la fosa posterior con duroplastia. El 100% de los pacientes presentaron mejoría clínica postoperatoria que se mantuvo a los 6 meses de seguimiento. Se registraron 3 casos de pseudomeningocele y un solo caso de fístula externa de LCR (7%). Conclusiones: La descompresión de fosa posterior con duroplastia es una opción quirúrgica muy efectiva y con baja tasa de complicaciones.

Introduction: Chiari malformations constitute a heterogeneous group of disorders characterized by a maldevelopment of the hindbrain and posterior cranial fossa that determines downward herniation of the cerebellar tonsils. Chiari malformation type I is defined as a 3 to 5 mm tonsillar herniation below the level of the foramen magnum. MRI has increased the number of cases diagnosed even in the pediatric age. Hence, the aim of this article is to present our results concerning clinical findings and outcomes on an exclusively pediatric series and to perform a review of the subject.Patients and methods:this is a retrospective, single-cohort study involving 57 patients operated in a 20-year period by the same neurosurgical team. Clinical records of one of the authors (ES) were reviewed in order to obtain data about symptoms, diagnosis, treatment and postoperative outcome at 6-month follow up.Results: 57 patients between 3 and 13 years of age were operated on. All of the patients were symptomatic at the time of diagnosis. The most frequent symptom was headache (90. All of the patients underwent posterior fossa decompression with duroplasty. 100% of the patients experienced sustained clinical improvement even at 6 month-follow up. Three cases of pseudomeningocele and only one case of external CSF leak were observed (7%).Conclusions:according to our findings and international literature, posterior fossa decompression with duroplasty is an effective surgical treatment with a low rate of complications.