White matter integrity assessment in spinocerebellar ataxia type 2 (SCA2) patients.

AIM: To assess the burden of white matter (WM) damage in the cerebrum and cerebellum of spinocerebellar ataxia type 2 (SCA2) patients in an attempt to identify key regions affected by the neurodegenerative processes using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Nine SCA2 patients and 16 age-matched healthy controls were examined twice (SCA2 patients 3.6 ± 0.7 years and controls 3.3 ± 1.0 years apart) on the same 1.5 T scanner by acquiring T1-weighted and diffusion-weighted (b-value = 1,000 s/mm2) images. Using tract-based spatial statistics, DTI analysis on fractional anisotropy (FA), mean diffusivity (MD), axial (AD)/radial (RD) diffusivity was performed. RESULTS: At baseline magnetic resonance imaging (MRI), FA was significantly decreased in SCA2 patients in the corticospinal tracts, inferior and superior cerebellar peduncles, middle cerebellar peduncles, cerebral peduncles, right superior and posterior corona radiata. RD was only significantly increased in SCA2 patients in the middle cerebellar peduncles. No significant AD and MD changes were observed. Tract-based spatial statistics (TBSS) analysis between SCA2 patients at baseline and at follow-up showed no significant changes in any of the DTI metrics. CONCLUSIONS: DTI is a sensitive tool for following the progression of WM neurodegeneration and severity assessment in patients with SCA2. These findings add to a better understanding of the neurological underpinnings of the symptoms experienced by SCA2 patients.

Main inherited neurodegenerative cerebellar ataxias, how to recognize them using magnetic resonance imaging?

Ataxia is a neurodegenerative disease resulting from brainstem, cerebellar, and/or spinocerebellar tracts impairments. Symptoms onset could vary widely from childhood to late-adulthood. Autosomal cerebellar ataxias are considered as one of the most complex group in neurogenetics. In addition to their genetic heterogeneity, there is an important phenotypic variability in the expression of cerebellar impairment, complicating the genetic mutation research. A pattern recognition approach using brain MRI measures of atrophy, hyperintensities and iron-induced hypointensity of the dentate nuclei, could be therefore helpful in guiding genetic research. This review will discuss a pattern recognition approach that, associated with the age at disease onset, and clinical manifestations, may help neuroradiologists differentiate the most frequent profiles of ataxia.

Gray Matter-White Matter De-Differentiation on Brain Computed Tomography Predicts Brain Death Occurrence.

BACKGROUND: Previous studies have shown that a loss of distinction between gray matter (GM) and white matter (WM) on unenhanced CT scans was predictive of poor outcome after cardiac arrest. The aim of this study was to identify a marker/predictor of imminent brain death. METHODS: In this retrospective study, 15 brain-dead patients after anoxia and cardiac arrest were included. Patients were paired (1:1) with normal control subjects. Only patients' unenhanced CT scans performed before brain death and during the 24 hours after initial signs were analyzed. WM and GM densities were measured in predefined regions of interest (basal ganglia level, centrum semi-ovale level, high convexity level, brainstem level). At each level, GM and WM density and GM/WM ratio for brain-dead patients and normal control subjects were compared using the Wilcoxon signed-rank test. RESULTS: At each level, a lower GM/WM ratio and decreased GM and WM densities were observed in brain-dead patients' CT scans when compared with normal control subject CT scans. A cut-off value of 1.21 at the basal ganglia level was identified, below which brain death systematically occurred. CONCLUSIONS: GM/WM dedifferentiation on unenhanced CT scan is measurable before the occurrence of brain death, highlighting its importance in brain death prediction. The mechanism of GM/WM differentiation loss could be explained by the lack of oxygen caused by ischemia initially affecting the mitochondrial system.

OFSEP, a nationwide cohort of people with multiple sclerosis: Consensus minimal MRI protocol.

Multiple sclerosis (MS) is most generally considered as a severe disease with high physical and mental risks of disability. Since the end of the 1990s, several high cost long-term disease-modifying treatments provided some clinical efficiency. However, patient's follow-up was needed for the detection and the assessment of their side-effects. The "Observatoire français de la sclérose en plaques" (OFSEP) project aims to improve the clinical, biological and imaging systematic longitudinal follow-up of patients. It should increase the quality, efficiency and safety of patients' care, with a unique opportunity of large scale, about 41,000 patients followed in 62 French centers using the European Database for Multiple Sclerosis (EDMUS) software. OFSEP is divided into three working groups (clinical, biological and imaging). The imaging working group defines standards for routine MRI follow-up in the whole cohort and contains three subgroups: acquisition, workflow, and data processing. A common and feasible brain and spinal cord acquisition protocol has been defined by the acquisition group, and accepted by the OFSEP steering and scientific committees. This protocol can be implemented in all French MRI centers. The major MRI manufacturers have agreed to provide the dedicated collection of sequences as an "OFSEP box" with every software upgrade or new MRI machine. The new OFSEP protocol will provide a unique opportunity to study a population-based collection of data from people with MS.

Reliability of longitudinal brain volume loss measurements between 2 sites in patients with multiple sclerosis: comparison of 7 quantification techniques.

BACKGROUND AND PURPOSE: Brain volume loss is currently a MR imaging marker of neurodegeneration in MS. Available quantification algorithms perform either direct (segmentation-based techniques) or indirect (registration-based techniques) measurements. Because there is no reference standard technique, the assessment of their accuracy and reliability remains a difficult goal. Therefore, the purpose of this work was to assess the robustness of 7 different postprocessing algorithms applied to images acquired from different MR imaging systems. MATERIALS AND METHODS: Nine patients with MS were followed longitudinally over 1 year (3 time points) on two 1.5T MR imaging systems. Brain volume change measures were assessed using 7 segmentation algorithms: a segmentation-classification algorithm, FreeSurfer, BBSI, KN-BSI, SIENA, SIENAX, and JI algorithm. RESULTS: Intersite variability showed that segmentation-based techniques and SIENAX provided large and heterogeneous values of brain volume changes. A Bland-Altman analysis showed a mean difference of 1.8%, 0.07%, and 0.79% between the 2 sites, and a wide length agreement interval of 11.66%, 7.92%, and 11.94% for the segmentation-classification algorithm, FreeSurfer, and SIENAX, respectively. In contrast, registration-based algorithms showed better reproducibility, with a low mean difference of 0.45% for BBSI, KN-BSI and JI, and a mean length agreement interval of 1.55%. If SIENA obtained a lower mean difference of 0.12%, its agreement interval of 3.29% was wider. CONCLUSIONS: If brain atrophy estimation remains an open issue, future investigations of the accuracy and reliability of the brain volume quantification algorithms are needed to measure the slow and small brain volume changes occurring in MS.

Diffusion tensor-MRI evidence for extra-axonal neuronal degeneration in caudate and thalamic nuclei of patients with multiple sclerosis.

BACKGROUND AND PURPOSE: MS is an inflammatory demyelinating disease affecting both WM and GM. While WM lesions are easily visualized by conventional MR imaging, the detection of GM alterations remains challenging. This diffusion tensor MR imaging study aimed to detect and characterize diffuse microscopic alterations in 2 deep GM structures, the caudate nucleus and the thalamus, in patients with RR and SP MS. The relationship between diffusivity markers, and atrophy of the caudate and the thalamus, as well as brain lesion load and clinical status of the patients was also explored. MATERIALS AND METHODS: Twenty-three RR and 18 SP patients, along with 27 healthy controls, underwent MR imaging examination including anatomic and DTI acquisitions. Volumes, mean FA, and MD of the caudate and the thalamus, as well as WM lesion volumes, were assessed. RESULTS: FA was significantly (P < .001) increased in the caudate and the thalamus of patients with MS compared with controls, and was higher in SP compared with RR patients. Increased FA was associated with volume decreases of caudate (r = -0.712; P < .001) and thalamus (r = -0.407; P < .01) in patients with MS. WM T2 lesion load was significantly associated with caudate (r = 0.611; P < .001) and thalamic (r = 0.354; P < .05) FA. Caudate FA, and, to a lesser extent, thalamic FA, were associated with functional deficits, as measured by EDSS and MSFC. CONCLUSIONS: Increased FA in the caudate and the thalamus may constitute a sensitive marker of MS pathologic processes, such as loss of dendrites and/or swelling of neuronal cell bodies.

Culture-negative neutrocytic ascites: a less severe variant of spontaneous bacterial peritonitis.

The clinical signs and symptoms, the biological data and the prognosis of 38 cirrhotic patients with culture-positive spontaneous bacterial peritonitis and 15 cirrhotic patients with culture-negative neutrocytic ascites were compared. The diagnosis of culture-negative neutrocytic ascites was based on the following criteria: an ascitic fluid polymorphonuclear count greater than 250/mm3, a negative ascitic fluid culture and the absence of previous antibiotic therapy and intraabdominal source of infection. All patients were treated by antibiotic therapy. There were no differences in clinical signs and symptoms and Pugh grading between the two groups of patients. Serum creatinine and prevalence of positive-blood culture were higher in spontaneous bacterial peritonitis. Patients with culture-positive spontaneous bacterial peritonitis had a higher ascitic fluid polymorphonuclear count and a lower ascitic fluid pH. Mortality was higher in patients with culture-positive spontaneous bacterial peritonitis than in patients with culture-negative neutrocytic ascites (relative risk: 2.6, p less than 0.01): cumulative mortality was, respectively, 50% and 20% at 1 months, 61% and 33% at 6 months, 75% and 41% at 1 year. The higher mortality observed in patients with culture-positive spontaneous bacterial peritonitis persisted after hospitalization (relative risk: 3, p less than 0.03). Our results suggest that culture-negative neutrocytic ascites is a less severe variant of spontaneous bacterial peritonitis.

[Prognosis of spontaneous ascitic infection in cirrhotic patients]. / Pronostic de l'infection spontanée d'ascite chez le cirrhotique.

The aim of this retrospective study was to define prognostic factors for cure and survival after spontaneous bacterial peritonitis. In a 4-year period from 1982 to 1986, spontaneous bacterial peritonitis was diagnosed in 38 consecutive hospitalized cirrhotic patients (positive ascites culture and polymorphonuclear cell concentration greater than 250 cells per mm3). Twenty-five patients recovered from their infection (69 p. 100) in a mean time of 9 +/- 7 days. The cumulative survival was 68 p. 100 at one week, 50 p. 100 at one month, and 25 p. 100 at one year. The best independent prognostic factors for lack of cure from peritonitis were a low ascitic pH value (p less than 0.001), an elevated serum creatinine level (p = 0.01) and the presence of hepatocellular carcinoma (p less than 0.05). The best prognostic factors for death were low ascitic pH value (p = 0.001) and gastrointestinal hemorrhage (p = 0.005). A low ascitic pH value was correlated with other signs of severe infection (signs of generalized infection, ongoing infection during the first week after diagnosis), with signs of severe liver disease (encephalopathy, hepatocellular carcinoma) or severe renal dysfunction (high serum creatinine level, low arterial pH value). Because of the late high-death rate associated with spontaneous bacterial peritonitis, liver transplantation should be considered in these patients.

[Association of hepatocellular adenoma and focal nodular hyperplasia of the liver in a woman on oral contraceptives]. / Association d'un adénome hépatocellulaire et d'une hyperplasie nodulaire focale du foie chez une femme sous contraceptifs oraux.

PIP: The case of a 37-year old woman with no previous pathology who developed liver adenoma and focal nodular hyperplasia after taking various oral contraceptive (OC) combined preparations over 15 years is described. The woman was hospitalized after discovery of a mass in the right hypochondrium. Other clinical findings were normal. During laparotomy 2 hepatic tumors were found: a mass 10 cm in diameter in the right lobe found at histological examination to be a focal nodular hyperplasia, and a mass 1 cm in diameter discovered fortuitously in the left lobe and which demonstrated the histological characteristics of a hepatic adenoma. The role of OCs in the development of hepatic adenomas is supported by epidemiological evidence, but the relationship between pills and focal nodular hyperplasia is much less clear. Although they occur in men and children, their development and the appearance of occasionally serious hemorrhagic complications appear to be encouraged by OCs. The complications are probably due to the vascular modifications observed in the tumor during OC use. The association of the 2 types of tumor in 1 patient has apparently been reported only once previously. Various hypotheses may be advanced to explain the occurrence.^ieng