Dysexecutive syndrome in amnesic mild cognitive impairment: a multicenter study.

BACKGROUND: Executive functions (EF) in Alzheimer's disease (AD), classically related to the prefrontal cortex, have been forgotten in mild stages, given more importance to temporal lobe associated disorders, such as memory. The study of disexecutive syndrome (DS) has been relegated to advanced stages of the disease. Our goal is to demonstrate that EF are already present in amnesic mild cognitive impairment (aMCI). Furthermore, we are interested in knowing whether poor scores in EF tests are related to the progression to AD or another kind of dementia. METHODS: We studied patients with aMCI (n = 81) and healthy controls (n = 142) from neurological departments of several centers of Basque Country with a cross-sectional design. Patients underwent a complete neuropsychological evaluation, neuroimaging testing APOE genotype and 3 year of prospective follow-up. RESULTS: In the first visit, patients with aMCI showed more alterations in tests that evaluate EF such as Stroop, trail-making and categorical verbal fluency. More alterations were also found in NPI scale (P <0.05). Stroop and Trail-Making test were not associated with the future development of AD, but fluency (p = 0.01) and apathy (p = 0.031) did. No patient developed a different kind of dementia different from AD. CONCLUSIONS: DS is a broad concept not confined to frontal lobes, and can be found in early stages of aMCI. DS impacts negatively on patient autonomy and may have prognostic value.

[A study using positron emission tomography of a case of vascular dementia due to left thalamic haematoma, an example of the diaschisis phenomenon]. / Estudio con tomografia por emision de positrones de un caso de demencia vascular por hematoma talamico izquierdo, ejemplo del fenomeno de diasquisis.

INTRODUCTION: Thalamic vascular lesions as strategic strokes can cause amnesia, executive dysfunctions or dysphasia and behavioral or psychological symptoms causing vascular dementia. CASE REPORT: A 58 years-old woman with hypertension and dyslipemia, who after a left thalamic hemorrhage with good radiological evolution, presents a severe amnesic syndrome as well as other subtle changes in orientation and in language, difficulties in managing money and depressive symptoms requiring anxiolytic and antidepressive treatment. All this joined to limitations in the normal course of her work. Followed by neurology service, a positron emission tomography with 18F-2-fluoro-2-deoxy-D-glucose integrated with computed tomography was performed, which showed a hypometabolism in left thalamic area and also in ipsilateral inferior frontal region, explained by the diaschisis phenomenon. CONCLUSIONS: Diaschisis phenomenon is a neuroimaging and pathophysiological finding whereby thalamic or basal ganglia strokes cause hypoperfusion/hypometabolism in the ipsilateral or contralateral cortex and could explain cortical distal symptoms. This case report demonstrates the presence of thalamocortical connections, which helps to understand the circuitry of memory and help to explain the association of other cortical symptoms as dysphasia or executive dysfunction.

TITLE: Estudio con tomografia por emision de positrones de un caso de demencia vascular por hematoma talamico izquierdo, ejemplo del fenomeno de diasquisis.Introduccion. Las lesiones vasculares talamicas que se comportan como ictus estrategicos pueden causar amnesia, disfunciones ejecutivas o disfasia, asi como sintomas comportamentales o psicologicos, y causar una demencia vascular. Caso clinico. Mujer de 58 años, hipertensa y dislipidemica, que, tras una hemorragia talamica izquierda que evoluciono radiologicamente de manera favorable, presento un sindrome amnesico grave y otras alteraciones sutiles en la orientacion y el lenguaje, dificultades en el manejo del dinero y sintomas depresivos que precisaron tratamiento ansiolitico y antidepresivo, todo lo cual fue causa de limitaciones para el normal desempeño de su trabajo. Seguida en la consulta de neurologia, se le practico una tomografia por emision de positrones/tomografia axial computarizada con 18F-2-fluoro-2-desoxi-D-glucosa, donde se aprecio un hipometabolismo en el talamo izquierdo y, ademas, en la region frontal inferior ipsilateral, que se explicaria mediante el fenomeno de diasquisis. Conclusiones. El fenomeno de diasquisis es un hallazgo de neuroimagen y fisiopatologico por el cual los ictus talamicos o de los ganglios basales causan hipoperfusion/hipometabolismo en la corteza ipsilateral o contralateral, y que puede explicar sintomas a distancia corticales. El presente caso evidencia la presencia de conexiones talamocorticales, lo cual ayuda a comprender los circuitos de la memoria y a explicar la asociacion en el de otros sintomas corticales, como la disfasia o las alteraciones ejecutivas.

Progression from amnesic mild cognitive impairment to Alzheimer's disease: ESR1 and ESR2 polymorphisms and APOE gene.

BACKGROUND: Many genes have been studied to determine how they might be involved in Alzheimer's disease (AD). Estrogens have a protective effect in the central nervous system. The mechanisms of action of estrogens are mediated by two estrogen receptors (ERs), ERα and ERß. Thus, these genes could also play a role in the progression of amnesic mild cognitive impairment (MCIa) to AD. The aim of this study was to examine the role of ER single nucleotide polymorphisms (SNPs) as a risk factor for MCIa, as well as the interaction with apolipoprotein E (APOE) ε4 in the progression to AD. METHODS: 79 MCIa patients and 138 healthy controls were analyzed. SNPs were genotyped via restriction fragment length polymorphisms and real-time PCR, RT-PCR or RT-PCR (TaqMan) assays. RESULTS: There is a lack of association between MCIa patients who converted to AD and ER SNPs. APOE ε4 allele is an independent risk factor of MCIa (OR=1.86; 95% CI=1.02-3.38, p=0.042) with a high prevalence in converted subjects. APOE ε4 is able to predict the progression from MCIa patients to AD (OR=2.55; 95% CI=1.20-5.42, p=0.015). CONCLUSIONS: The presence of the APOE ε4 allele, and not the alleles of ER SNPs, is a risk factor for MCIa. Furthermore, APOE genotype seems to predict the conversion from MCIa to AD.