Sérgio Murilo Georgeto

Genetic polymorphisms associated with the development and clinical course of multiple sclerosis (Review)

Multiple sclerosis (MS) is an autoimmune disease characterized by areas of inflammation, demyelination and axonal damage. The etiology of MS is multifactorial with an interaction between genetic, environmental and geographical factors. The objective of this study was to review the physiopathology and the genetic polymorphisms associated with the development and clinical course of MS. Studies carried out in populations worldwide showed that polymorphisms in the genes of the major histocompatibility complex (MHC) class II and class III have been associated with susceptibility, resistance and clinical forms of MS. Considerable attention has been focused on studies evaluating disease-modifying effects in MS that identified seven genes of probable importance such as the HLA class II, ApoE, IL-1ra, IL-1β, TNF-α, TNF-β and CCR5 genes. However, the results described in the literature about genetic biomarkers in MS are not consistent in the worldwide population. The detection of a single nucleotide polymorphism involved in the etiology and physiopathology of MS is very difficult and, it is likely that, several genetic polymorphisms are involved, each with a small contribution to the susceptibility or resistance to MS. Taken together the results show the need for continued research in genetically heterogeneous populations to identify new biomarkers associated with MS that could be used as prognostic markers or as therapeutic targets to modulate the autoimmune response in MS patients. This information may contribute to a better understanding of the physiopathology and treatment of MS, with the possibility of developing different therapeutic strategies according to the genetic profile of each individual.

Brainstem cavernomas: a surgical challenge

OBJECTIVE The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review. METHODS From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications. RESULTS The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively. CONCLUSIONS Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

Nearly one-half of Brazilian patients with multiple sclerosis using natalizumab are DNA-JC virus positive

OBJECTIVE Natalizumab is a new and efficient treatment for multiple sclerosis (MS). The risk of developing progressive multifocal leukoencephalopathy (PML) during the use of this drug has created the need for better comprehension of JC virus (JCV) infection. The objective of the present study was to assess the prevalence of JCV-DNA in Brazilian patients using natalizumab. METHOD Qualitative detection of the JCV in the serum was performed with real-time polymerase chain reaction (PCR). RESULTS In a group of 168 patients with MS who were undergoing treatment with natalizumab, JCV-DNA was detectable in 86 (51.2%) patients. DISCUSSION Data on JCV-DNA in Brazil add to the worldwide assessment of the prevalence of the JCV in MS patients requiring treatment with natalizumab.

T1 GRE e T1 IR GRE na identificação das estruturas anatômicas da face lateral do cérebro

Objective To compare brain structures using volumetric magnetic resonance imaging with isotropic resolution, in T1-weighted gradient-echo (GRE) acquisition, with and without inversion recovery (IR). Materials and methods From 30 individuals, we evaluated 120 blocks of images of the left and right cerebral hemispheres being acquired by T1 GRE and by T1 IR GRE. On the basis of the Naidich et al. method for localization of anatomical landmarks, 27 anatomical structures were divided into two categories: identifiable and inconclusive. Those two categories were used in the analyses of repeatability (intraobserver agreement) and reproducibility (interobserver agreement). McNemars test was used in order to compare the T1 GRE and T1 IR GRE techniques. Results There was good agreement in the intraobserver and interobserver analyses (mean kappa > 0.60). McNemars test showed that the frequency of identifiable anatomical landmarks was slightly higher when the T1 IR GRE technique was employed than when the T1 GRE technique was employed. The difference between the two techniques was statistically significant. Conclusion In the identification of anatomical landmarks, the T1 IR GRE technique appears to perform slightly better than does the T1 GRE technique.