Juan Ignacio Rojas

Acute ischemic stroke and transient ischemic attack in the very old – risk factor profile and stroke subtype between patients older than 80 years and patients aged less than 80 years

Old age groups have different risk profile and stroke features compared to younger groups. Our aim was to examine the risk factor profile and stroke subtype in patients older than 80 years with ischemic stroke. Data of 535 patients with ischemic stroke or transient ischemic attack (TIA) were prospectively recorded. Cardiovascular risk factors and stroke subtype in individuals aged 80 years or older were compared with patients under 80. Of 535 patients a total of 179 were over 80 years (33.5%). The mean age was 84.4 ± 4.4 years (61.8%; 111 women). The most common risk factors included hypertension (82.7%) and hyperlipidemia (40.2%). Lacunar stroke was the most frequent subtype of stroke (41.7%). When the groups were compared, we observed the following risk factors more frequently in the group older than 80: female patients (P = <0.001), hypertension (OR = 1.62), atrial fibrillation (OR = 2.64); whereas diabetes (OR = 0.54), hyperlipidemia (OR = 0.57), smoking (OR = 0.17) and obesity (OR = 0.58) were more frequent in the group younger than 80. In the old group we found a high incidence of ischemic stroke in women. We also found a higher frequency of hypertension and atrial fibrillation. The available and future epidemiological data will provide a better knowledge about the effect of typical risk factors in old people.

A systematic review of the epidemiology of multiple sclerosis in South America.

Hundreds of publications dealing with the prevalence of multiple sclerosis (MS) throughout the world exist, but little data have been published from South America. Epidemiological studies of MS vary according to environmental, racial and genetic factors; a better understanding of MS in South America would help us to elucidate the disease pattern in this population. The aim of this study is to review the evidence relevant to MS epidemiology in South America. We performed a systematic review of articles of MS epidemiology in South America, with special emphasis on those providing information on the incidence and prevalence of MS (population‐based studies). Six papers provided information on MS epidemiology. One paper used the capture‐recapture methodology, while the remainder employed traditional methods to collect the data. Population‐based studies showed an MS prevalence rate ranging from 1.48 to 17 per 100 000 inhabitants. Available data suggest that the prevalence of MS is lower in South America than in developed countries. The reason for this observation is unknown. Some investigators suggest that certain environmental factors like sun exposure and vitamin D supplementation or the called ‘hygiene hypothesis’ may protect this population. Future studies will contribute to elucidate the etiology of that difference.

Prevalence of multiple sclerosis in Buenos Aires, Argentina using the capture‐recapture method

Background:  Scarce data exist about multiple sclerosis (MS) prevalence in South America. The objective of the study is to determine the prevalence of MS in a high populated area from Argentina (Greater Buenos Aires Metropolitan area) using the capture‐recapture methodology.

Previous adult attention-deficit and hyperactivity disorder symptoms and risk of dementia with Lewy bodies: a case–control study

Introduction:  Previous reports have shown that in Dementia with Lewy body (DLB) and attention‐deficit and hyperactivity disorder (ADHD) a hypodopaminergic and noradrenergic substrate seems to play a central role in developing the diseases. We investigated the hypothesis that attention deficit may precede DLB expressed as adult ADHD symptoms long before the clinical onset of dementia.

HLA‐DRB1 and multiple sclerosis in Argentina

Background:  The association of multiple sclerosis (MS) with HLA DR subtypes, and particularly human leukocyte antigen (HLA)‐DRB1*15 has been a consistent finding across nearly all Caucasian MS populations. In South America, scarce data exist about this issue. As the complete characterization of the HLA association range around the world is important to understand the role of this locus in MS susceptibility, we analyzed the frequency of HLA‐DRB1* allelic groups in an MS population in Argentina.

Brain atrophy in radiologically isolated syndromes.

The aim of this study was to compare brain atrophy in radiologically isolated syndrome (RIS), in clinically isolated syndrome (CIS), and in individuals with subjective complaints (ISC).

Incidence of multiple sclerosis in Buenos Aires: a 16-year health maintenance organization-based study

Objective:  The present study was undertaken to determine the incidence of MS in a health maintenance organization from Buenos Aires, the largest populated area in Argentina.

Cardiovascular risk factors and frontotemporal dementia: a case–control study

Cardiovascular risk factors (CRF) were widely described as related to dementia. There are very few studies regarding this association in FTD. The objective of the study was to compare the frequency of CRF in our population with FTD and controls. 100 consecutive subjects with FTD diagnosis according to Lund-Manchester clinical criteria and 200 controls matched by age and sex were included between January 2003 to February 2007 at the Cognitive and Behavior Unit of Hospital Italiano de Buenos Aires. Clinical evaluation, laboratory tests, brain images (CT/MRI), neuropsychological and neuropsychiatric assessment were performed. Multiple regression analysis was performed to analyze the association in CRF between FTD patients vs. controls. The mean age in FTD was 69.7 ± 0.9 vs. 70.1 ± 0.8 in controls (p 0.12). No difference in gender was observed between cases and controls. No differences were identified between patients and controls regarding hypertension (HTA) (65% vs. 67,3% p 0.44); dyslipidemia (57% vs. 54.7% p 0.74); obesity (39% vs. 27.6% p 0.14) and hypothyroidism (26% vs. 17.1% p 0.1). A significant difference was observed for Diabetes Mellitus (39% vs. 22.6% p 0.001). In our population, Diabetes Mellitus was associated as an independent risk factor for FTD. To our knowledge this is the first report in which CRF were evaluated prospectively in FTD patients. More studies are needed to confirm this finding in larger populations.

Incidence and prevalence of Parkinson’s disease in Buenos Aires City, Argentina

Background and purpose:  Epidemiologic studies of incidence and prevalence in Parkinson’s Disease (PD) show highly variable results. Despite the large number of studies performed worldwide during the last decades, little is known about its prevalence in South America and no incidence studies have been performed. The goal of this study is to assess the incidence and prevalence of PD in a health maintenance organization from Buenos Aires City, the capital city of Argentina.

CD24 as a genetic modifier of disease progression in multiple sclerosis in Argentinean patients

INTRODUCTION Previous reports have shown that CD24 gene polymorphisms have an important role in the risk of development and progression of multiple sclerosis (MS). OBJECTIVE To investigate the association between P226 polymorphisms (T/C), P1056 (A/G), P1527 (TG/del) and P1626 (A/G) of the CD24 gene and MS, comparing allele and genotype frequencies of patients versus controls. MATERIALS AND METHODS We analyzed DNA samples from 102 MS patients and from 205 unrelated healthy individuals. DNA was extracted from peripheral blood and polymorphic regions were amplified by nested PCR. Genotyping was performed by restriction fragments length polymorphisms. Time from disease onset to reach EDSS 6 and time to conversion to secondary progressive phase (SP) were used as variables of survival as well as percentage of patients that reached those endpoints. We used the log Rank test for data comparison (significant p≤0.05). RESULTS We found no differences between cases and controls in frequency of polymorphisms at the CD24 gene. 44.6% of patients with the AA genotype (P1626) reached an EDSS 6 vs 16% of patients with other genotypes (p<0.001, HR 3.2, 95% CI 1.4 to 7.4). 45.8% of patients with the AA genotype reached SPMS vs 16.7% without this genotype (p<0.001, HR 3.4, 95% CI 1.5 to 7.8). CONCLUSIONS This study showed a strong association between the presence of AA genotype in the 1626 polymorphism of the CD24 gene and the risk of disease progression in MS patients.