El papel de la rivastigmina en la demencia de origen vascular / The definition of its role in vascular dementia

Vascular dementia represents the second most common type of dementia. The classification of vascular dementia broadly follows three clinico-pathological processes: multi-infarct dementia, single strategic infarct dementia and subcortical dementia. Currently, no established standard treatment for vascular cognitive impairment exists. Reductions in acetylcholine and acetyltransferase activity are common to both Alzheimer's disease and vascular cognitive impairment raising the possibility that cholinesterase inhibitors may also be beneficial for the latter. This review has been conducted to assess the efficacy of rivastigmine in the treatment of people with vascular cognitive impairment. From existing trial data there is some evidence of benefit of rivastigmine in vascular cognitive impairment. However, this conclusion is based on studies which had small numbers of patients, which sought to compare rivastigmine to treatments other than placebo or which used data extrapolated post hoc from large studies involving patients with Alzheimer's disease and vascular risk factors of unclear significance. From these perspectives, one can conclude that large placebocontrolled, double blind and adequately randomised trials are needed before firm conclusions can and should be drawn. The methodology of such trials should acknowledge the biological and clinical features unique to vascular cognitive impairment and its subtypes

La demencia vascular representa el segundo tipo más frecuente de demencia. La clasificación de la demencia vascular sigue tres procesos clínico-patológicos generales: demencia multiinfarto, demencia por infarto único ubicado en una zona estratégica y demencia subcortical. Actualmente no existen tratamientos estandarizados establecidos para los trastornos cognitivos de causa vascular. La disminución de la actividad de la acetilcolinesterasa es una estrategia habitualmente utilizada tanto para el tratamiento de los pacientes que presentan enfermedad de Alzheimer como para aquellos con trastornos cognitivos de causa vascular. En consecuencia, es posible que los inhibidores de la colinesterasa sean una opción conveniente. La presente revisión se llevó a cabo con el propósito de evaluar la eficacia de la rivastigmina para el tratamiento de los individuos que presentan trastornos cognitivos de origen vascular. De acuerdo con los datos provenientes de diferentes estudios, la rivastigmina sería útil para tratar pacientes con deterioro cognitivo de origen vascular. No obstante, esta conclusión se efectuó sobre la base de estudios en los cuales se incluyó un número reducido de pacientes, se buscó comparar la rivastigmina con agentes diferentes del placebo o se extrapolaron datos a partir de estudios de gran magnitud efectuados con pacientes que presentaban enfermedad de Alzheimer y factores de riesgo vasculares de relevancia poco clara. Desde ese punto de vista, se puede concluir que es necesario realizar estudios de gran tamaño, controlados con placebo a doble ciego y adecuadamente aleatorizados antes de poder alcanzar conclusiones sólidas. La metodología empleada en dichos estudios debería responder a las características biológicas y clínicas particulares del deterioro cognitivo vascular y sus subtipos

Vitamin B12 and folate depletion in cognition: a review.

In cross-sectional studies, low levels of folate and B12 have been shown to be associated with cognitive decline and dementia Evidence for the putative role of folate, vitamin B12 in neurocognitive and other neurological functions comes from reported cases of severe vitamin deficiencies, particularly pernicious anemia, and homozygous defects in genes that encode for enzymes of one-carbon metabolism. The neurological alterations seen in these cases allow for a biological role of vitamins in neurophysiology. Results are quite controversial and there is an open debate in literature, considering that the potential and differential role of folate and B12 vitamin in memory acquisition and cognitive development is not completely understood or accepted. What is not clear is the fact that vitamin B12 and folate deficiency deteriorate a pre-existing not overt pathological situation or can be dangerous even in normal subjects. Even more intriguing is the interaction between B12 and folate, and their role in developing hyperhomocysteinemia. The approach to the rehabilitation of the deficiency with adequate vitamin supplementation is very confusing. Some authors suggest it, even in chronic situations, others deny any possible role. Starting from these quite confusing perspectives, the aim of this review is to report and categorize the data obtained from the literature. Despite the plausible biochemical mechanism, further studies, based on clinical, neuropsychological, laboratory and (lastly) pathological features will be necessary to better understand this fascinating biochemical riddle.