RESUMEN
Oxidative stress has been implicated in the pathogenesis of multiple sclerosis (MS). Glutathione-S-transferases (GSTs) are detoxification enzymes, evolved to protect cells against reactive oxygen metabolites. Both GSTT1 and GSTM1 genes exhibit a homozygous deletion polymorphism (null genotype) leading to abolished enzyme activity. We studied the impact of the GSTT1 and GSTM1 polymorphisms on MS susceptibility in a case-control study of 47 Greek patients and 165 controls. Correlations between genotype, gender and disability status were also investigated. The incidence of both GSTT1 and GSTM1 genotypes did not differ significantly between controls and patients. A significantly increased frequency of GSTM1 null genotype was found amongst female patients (65.5%) as compared with males (33.3%, P =0.04). The results suggest that GSTT1 and GSTM1 have no major pathogenetic role on the MS occurrence, nor any strong modifying effect on the disability status. The higher incidence of GSTM1 null genotype observed in female patients, suggests a possible role of the GSTM1 detoxification pathway in a gender-dependent manner.
Asunto(s)
Glutatión Transferasa/genética , Esclerosis Múltiple/enzimología , Esclerosis Múltiple/genética , Polimorfismo Genético/genética , Adulto , Anciano , Anciano de 80 o más Años , Sistema Nervioso Central/enzimología , Sistema Nervioso Central/fisiopatología , Análisis Mutacional de ADN , Femenino , Depuradores de Radicales Libres/metabolismo , Marcadores Genéticos/genética , Pruebas Genéticas , Genotipo , Glutatión/metabolismo , Grecia/etnología , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/etnología , Estrés Oxidativo/fisiología , Proyectos Piloto , Caracteres Sexuales , Distribución por SexoRESUMEN
PURPOSE: We evaluated the use of Vestibular Evoked Myogenic Potentials (VEMPs) in the assessment of neural function, following medullary lesions. METHODS: A 54-year-old male presented with symptoms and signs typical of right lateral medullary (Wallenberg) syndrome. He underwent brain MRI and three successive neurophysiological investigations, which included VEMPs, Brainstem Auditory Evoked Responses (BAERs) and the blink reflex. RESULTS: VEMPs amplitude on the left (unaffected) side was 256.8 microv in the first investigation and remained approximately equal to that value in the following two ones. Their amplitude on the right (affected) side was 37.9 microv, 154.2 microv and 235.2 microv correspondingly. At the same time vertigo, diplopia and nystagmus gradually improved. Right blink reflex comprised a normal R1, but delayed R2 ipsilateral and R2 contralateral responses, which remained unaltered during the follow-up period. Brain MRI disclosed a right dorsolateral medullary infarct. CONCLUSIONS: VEMPs amplitude progressively increased, parallel to the improvement of vestibular symptoms. The blink reflex evolved differently, while BAERs were not affected. As the three evoked responses are mediated by separate neural circuits, they provide information on different aspects of brainstem function. Thus, VEMPs seem to be a useful method that complements existing ones in the assessment of brainstem lesions.
