RESUMO
Studies on prodromal stage in spinocerebellar ataxias (SCAs) have become high priority approaches in view of their usefulness to detect biomarkers that herald the onset of permanent ataxia and assess the efficacy of future therapeutical trials [1]. The most comprehensive evaluation of prodromal SCA2 comes from the large and homogeneous population of Cuban preclinical carriers, which derives from a 13 years presymptomatic diagnostic program and the nationwide molecular epidemiological survey (AU)
Assuntos
Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Ataxina-2/genética , Equilíbrio Postural , Sintomas Prodrômicos , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/fisiopatologia , Marcha , Expansão das Repetições de TrinucleotídeosRESUMO
The spinocerebellar ataxia type 2 has a prevalence of 43 per 100,000 inhabitants in Holguín province,which is the highest one reported worldwide. It is due to an intergenerational CAG repeat expansion contained in the first exonof diseasecausinggene, and it is characterized by a high variability in its clinical and electrophysiological presentation, evenintrafamiliarly. Objective. Factors identification, which explains this variability, could lead to the findings of therapeuticalways that may retard the disease onset. Patients and methods. We have done this research in order to contribute to thisphenotypic variability knowledge of the different structures and functions of the nervous system. Results. By means of molecularand electrophysiological studies we have found two groups well differentiated in a 52patientsample. The first one wascharacterized by CAG repeat expansions above 41 units and by the total blockade of the afferent conduction that is, basicelectrophysiological alteration with axonal damage predominance. The second one was characterized by CAG repeat expansionslower or equal to 41 units and showed a high variability in its electrophysiological behavior with myelinic damage predominance.We realized of the existence of statistical significance correlations between the electrophysiological, clinical and molecularvariables considered. Conclusions. These findings suggest that for by CAG repeat expansions lower or equal to 41 unitsshould be affecting other genetics and/or environmental factors that explain the variability found in this group which arenot significant for clinical and electrophysiological presentation in individuals with CAG repeat expansions...(AU)
Assuntos
Humanos , Ataxias Espinocerebelares/diagnóstico , Eletrofisiologia , DisartriaRESUMO
Introducción: la ataxia espinocerebelosa tipo 2 tiene la mayor prevalencia del mundo en la provincia de Holguín (Cuba). Es causada por la expansión de una secuencia de CAG contenida en el gen SCA2, y se caracteriza por una gran variabilidad en su expresión clínica y electrofisiológica, aun intrafamiliarmente. La identificación de factores que expliquen esta variabilidad podría conducir al descubrimiento de vías terapéuticas que retarden el comienzo de la enfermedad. Objetivo: con el propósito de contribuir al conocimiento de dicha variabilidad fenotípica hemos desarrollado esta investigación. Pacientes y métodos: primero determinamos el número exacto de repeticiones de CAG en una muestra de 52 pacientes SCA2, y luego practicamos estudios electrofisiológicos (estudios de conducción nerviosa periférica y sensitiva, PESS de nervio mediano y tibial posterior así como reflejo H). Resultados: Se identificaron dos grupos bien diferenciados entre sí. El primero incluyó a los pacientes con expansiones mayores de 41 unidades de CAG, y se caracterizó por el bloqueo total de la conducción aferente y el predominio de una lesión tipo axonal. El segundo grupo incluyó a enfermos con expansiones iguales o menores a 41 unidades de CAG, y mostró una gran variabilidad en su comportamiento electrofisiológico además de una lesión predominantemente mielínica. También demostramos la existencia de correlaciones estadísticamente significativas entre las variables electrofisiológicas y las clínicas y moleculares consideradas. Conclusiones: estos hallazgos sugieren que para expansiones menores o iguales a 41 unidades de CAG deben estar influyendo otros factores genéticos o ambientales que provoquen la variabilidad observada y que no son significativos para las manifestaciones clínicas y electrofisiológicas en individuos con expansiones mayores de 41 unidades de CAG(AU)
Introduction: the spinocerebellar ataxia type 2 has a prevalence of 43 per 100,000 inhabitants in Holguín province, which is the highest one reported worldwide. It is due to an intergenerational CAG repeat expansion contained in the first exon of disease causing gene, and it is characterized by a high variability in its clinical and electrophysiological presentation, even intrafamiliarly. Objetive: factors identification, which explains this variability, could lead to the findings of therapeutical ways that may retard the disease onset. Patients and Methods: we have done this research in order to contribute to this phenotypic variability knowledge of the different structures and functions of the nervous system. Results: by means of molecular and electrophysiological studies we have found two groups well differentiated in a 52-patient sample. The first one was characterized by CAG repeat expansions above 41 units and by the total blockade of the afferent conduction that is, basic electrophysiological alteration with axonal damage predominance. The second one was characterized by CAG repeat expansions lower or equal to 41 units and showed a high variability in it s electrophysiological behavior with myelinic damage predominance. We realized of the existence of statistical significance correlations between the electrophysiological, clinical and molecular variables considered. Conclusions: these findings suggest that for by CAG repeat expansions lower or equal to 41 units should be affecting other genetics and/or environmental factors that explain the variability found in this group which are not significant for clinical and electrophysiological presentation in individuals with CAG repeat expansions above 41 units(AU)
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Ataxias Espinocerebelares/fisiopatologia , Expansão das Repetições de Trinucleotídeos/genéticaRESUMO
A patient with type 2 spinocerebellar ataxia has difficulty in carrying out alternate movements such aspronation and supination. Objectives. To evaluate the function of an automatized system for measuring disorders of alternatemovements. Patients and methods. We studied the measurement of diadochokinesia in two groups of healthy patients, a first group (64persons) to determine the normal intervals and a second group to validate the test (52 persons). We also studied 100 patients forvalidation of the system. A further 53 patients were evaluated before and after rehabilitation. Results. Analysis of the basic measurementsfor diagnosis of diadochokinesia showed that the higher the cutoff point, the greater the sensitivity of the test, whereas the oppositeoccurred with the specificity. Thus, regarding a higher cutoff, there is a five times greater probability of a positive results in the patientsthan in healthy persons. However, the probability of a normal result is six times higher in healthy than in affected persons. The resultsof variant analysis done on patients before and after rehabilitation suggest that the presence of quantitative changes in the second studywas due to the positive effect of neurorehabilitation...(AU)