RESUMO
En el mundo hay unos 47 millones de personas que padecen demencia, y cada año se registran cerca de 10 millones de nuevos casos. La demencia es una de las principales causas de discapacidad y dependencia entre las personas mayores de 65 años. La demencia vascular constituye la segunda causa de demencia en adultos mayores y en ocasiones su diagnóstico es poco asertivo por la variedad y similitud de síntomas entre las diferentes enfermedades que originan demencia vascular, incluyendo CADASIL (acrónimo inglés de Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy); particularmente el déficit cognitivo es de los síntomas más complejos de diagnóstico, teniendo en cuenta que su manifestación clínica depende de la magnitud y localización de la lesión. La enfermedad de CADASIL, aunque se constituye como una infrecuente causa de demencia vascular de naturaleza hereditaria a nivel mundial, representa una patología de gran importancia en el ámbito nacional, dado que en familias colombianas se ha reportado mutaciones que conllevan a dicha patología. Por lo tanto, su diagnóstico y tratamiento constituyen un reto para el personal clínico, sabiendo que la identificación temprana y precisa es la mejor estrategia para evitar la progresión precoz de la enfermedad y el mejoramiento de la calidad de vida del paciente. De acuerdo con lo anterior, se realizó una revisión de la diferenciación clínica del déficit cognitivo del CADASIL con respecto a las demás demencias vasculares, con el fin de generar una herramienta que apoye la diferenciación clínica de dicha patología.
In the world, there are approximately 47 million people who have dementia, and every year they register near 10 million new cases. The dementia is one of the principal reasons for disability and dependence between people older than 65 years old. Vascular dementia constitutes the second reason of dementia in the elders, and sometimes the diagnosis is slightly assertive because of the variety and similarity of symptoms between the different diseases that originate vascular dementia, including CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy). Particularly, the cognitive deficit is one of the most complex symptoms of diagnosis, bearing in mind that its clinical manifestation depends on the magnitude and location of the injury. CADASIL disease, though it constituted as an infrequent reason of vascular dementia of hereditary nature worldwide, represents a pathology of great importance in the national area, because, in Colombian families, there have been reported mutations that carry to the above-mentioned pathology. Therefore, its diagnosis and treatment constitute a challenge for the clinical personnel, knowing that the early and precise identification is the best strategy to avoid the rapid progression of the disease and the improvement of the quality of life of the patient. In agreement with the previous information, there was made a review of the clinical differentiation of the cognitive deficit of CADASIL regarding other vascular dementias, to generate a tool that supports the clinical differentiation of the pathology mentioned above.
Assuntos
Humanos , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , CADASIL/diagnóstico , CADASIL/fisiopatologia , Demência Vascular/diagnóstico , Demência Vascular/fisiopatologiaRESUMO
OBJECTIVE: To perform linkage analysis between the Short Tandem Repeats (STR) microsatellite markers D19S923, D19S929, D19S22, which are in strong genetic linkage to Notch3 gene in order to contrast the hypothesis that the vascular hereditary dementia phenotype described in a multigenerational extended pedigree from Colombia correspond to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy). Even we know that using techniques as the Single Strand Conformational Polymorphisms (SSCP) could determine mutations in Notch3, the rationality of this approach is that intronic variations could not be defined and that we are interested in determine if some forms of the clinical presentation and its phenotypic variability make part of CADASIL. INTRODUCTION: The CADASIL phenotype is caused by mutations in the Notch3 gene. Clinical features of CADASIL are: 1. Recurrent cerebra-vascular episodes; 2. Migraine history; 3. History of transitory ischemic attack and, 4. Behavior changes and dementia. MATERIAL AND METHODS: By using SIMLINK we showed that the extended genealogy had the enough power to detect significant LOD (logarithm of oods) score values when Notch3 was considered the disorder cause. Linkage analysis was carried out by using parametric and non parametrical methods. The Elston-Stewart general method was used as the parametrical analysis and the sib pair method as the non-parametrical one. We perform simulations changing the affection status codification by including as affected or not including those individuals with migraine. Furthermore, in order to detect the stability of the results, we changed the penetrance values, the genetic frequencies on both, the marker loci and the affection locus. RESULTS: The maximum pair-wise LOD score was 2.04 which was detected at the marker D19S23 with q= 0.11cM. This distance correspond exactly with the Notch3 location. That is 100 times more probable that there is linkage that there is not. In other words this probability could be explained as if the phenotype correspond to CADASIL than to other vascular dementia. The non parametric results were compatibles with the parametric ones. When the migraine symptom was considered as a part of the affected status, the LOD score values showed not linkage. CONCLUSIONS: The results of the linkage analysis to these STR microsatellite markers suggest that the vascular hereditary dementia phenotype described in this family correspond to CADASIL caused by a polymorphism on the Notch3 gene. On the contrary, these same results suggest that the migraine phenotype is not a part of the progressive dementia.