ABSTRACT
INTRODUCTION: Essential tremor (ET) is the most frequent movement disorder in adults. Its pathophysiology is not clearly understood, however there is growing evidence showing common etiologic factors with other neurodegenerative disorders such as Alzheimer's and Parkinson's diseases (AD, PD). Recently, a rare p.R47H substitution (rs75932628) in the TREM2 protein (triggering receptor expressed on myeloid cells 2; OMIM: *605086) has been proposed as a risk factor for AD, PD and amyotrophic lateral sclerosis (ALS). The objective of the study was to determine whether TREM2 p.R47H allele is also a risk factor for developing ET. METHODS: This was a cross-sectional multicenter international study. An initial case-control cohort from Spain (n = 456 ET, n = 2715 controls) was genotyped. In a replication phase, a case-control series (n = 897 ET, n = 1449 controls) from different populations (Italy, Germany, North-America and Taiwan) was studied. Owed to the rarity of the variant, published results on p.R47H allele frequency from 14777 healthy controls from European, North American or Chinese descent were additionally considered. The main outcome measure was p.R47H (rs75932628) allelic frequency. RESULTS: There was a significant association between TREM2 p.R47H variant and ET in the Spanish cohort (odds ratio [OR], 5.97; 95% CI, 1.203-29.626; p = 0.042), but it was not replicated in other populations. CONCLUSIONS: These results argue in favor of population-specific differences in the allelic distribution and suggest that p.R47H (rs75932628) variant may contribute to the susceptibility of ET in Spanish population. However, taking into account the very low frequency of p.R47H, further confirmatory analyses of larger ET series are needed.
Subject(s)
Arginine/genetics , Essential Tremor/genetics , Histidine/genetics , Membrane Glycoproteins/genetics , Receptors, Immunologic/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , DNA Mutational Analysis , Essential Tremor/etiology , Female , Genetic Predisposition to Disease , Genotype , Germany , Humans , International Cooperation , Italy , Male , Middle Aged , North America , Risk Factors , Spain , Taiwan , Young AdultABSTRACT
To investigate the association between APOE-epsilon4 allele and memory phenotype in the preclinical stage of Alzheimer's disease (AD). We compared an extensive preclinical memory profile at the baseline evaluation of 2 AD genotype groups: APOE-epsilon4 allele carriers and patients with APOE-epsilon3 homozygosity. Baseline memory performance was carried out at least 2 years (interval of 27.7 +/- 4 months) before AD diagnosis was established, and analysis included different modalities of working memory (visuoperceptive, visuospatial, digit span and processing speed), of declarative memory (recent, verbal learning, prospective and semantic) and of nondeclarative memory (procedural, incidental and priming). We found no significant differences: memory performance was similar in both genotype groups. The presence of the APOE-epsilon4 allele does not seem to be sufficient to cause a distinctive preclinical memory phenotype in AD patients.
Subject(s)
Alzheimer Disease/genetics , Alzheimer Disease/physiopathology , Apolipoproteins E/genetics , Memory/physiology , Aged , Aged, 80 and over , Alleles , Analysis of Variance , Apolipoprotein E3 , Apolipoprotein E4 , Chi-Square Distribution , Female , Homozygote , Humans , Male , Mental Processes/physiology , Middle Aged , Polymorphism, Genetic , Verbal Learning/physiology , Visual Perception/genetics , Visual Perception/physiologyABSTRACT
Patients with dementia of Alzheimer's type (DAT) show severe impairment in recognizing famous people. The aim of the current study was to investigate if this well-known memory impairment of famous faces is already present in the preclinical phase of DAT and if the famous faces test can help to differentiate patients with mild cognitive impairment (MCI) who progress to dementia and those who do not. We compared baseline performance in a task of famous face identification in a sample of 116 patients with subjective memory complaints classified in three groups: 17 participants with no evidence of cognitive impairment; 26 patients with MCI who had not developed dementia, and 27 patients with MCI who had developed probable DAT 2 years later. The remaining patients were excluded because they abandoned or did not meet the applied restrictive criteria for DAT, MCI or control. MCI patients who were diagnosed 2 years later with DAT performed significantly worse in the preclinical phase than MCI and control participants (p < 0.004). Patients with MCI but not DAT obtained intermediate results between control subjects and MCI patients who develop Alzheimer's disease. A neuropsychological task of semantic knowledge of famous people may be useful in the early diagnosis of Alzheimer's disease.
Subject(s)
Alzheimer Disease/psychology , Cognition Disorders/psychology , Memory , Activities of Daily Living , Aged , Aged, 80 and over , Alzheimer Disease/diagnosis , Cognition Disorders/diagnosis , Diagnosis, Differential , Disease Progression , Famous Persons , Female , Follow-Up Studies , Humans , Infarction, Middle Cerebral Artery/diagnosis , Infarction, Middle Cerebral Artery/psychology , Male , Middle Aged , Neuropsychological Tests , Predictive Value of Tests , Risk FactorsABSTRACT
La Estimulación Magnética Transcraneal repetitiva (EMTr) consiste en la aplicación de trenes de estimulación sobre zonas corticales concretas. En los últimos años se ha probado como tratamiento en pacientes psiquiátricos, fundamentalmente en los trastornos afectivos, aunque también se ha probado en pacientes con esquizofrenia y con trastorno obsesivo-compulsivo. En la presente revisión hemos recogido los principales trabajos científicos que han estudiado la efectividad de la aplicación de la EMTr como tratamiento en los diferentes trastornos psiquiátricos. (AU)
