Vascular cognitive disorders and depression after first-ever stroke: the Fogarty-Mexico Stroke Cohort.

BACKGROUND AND PURPOSE: Stroke is the major cause of vascular behavior and cognitive disorders worldwide. In developing countries, there is a dearth of information regarding the public health magnitude of stroke. The aim of the Fogarty-Mexico cohort was to assess the prevalence of vascular behavioral and cognitive disorders, ranging from mild vascular cognitive impairment (VCI) to vascular dementia (VaD), in a cohort of acute first-ever symptomatic stroke patients in Mexico. METHODS: A total of 165 consecutive, first-ever stroke patients admitted to the National Institute of Neurology and Neurosurgery in Mexico City, were included in the cohort. Patients were eligible if they had an ischemic stroke, primary intracerebral hemorrhage, or cerebral venous thrombosis (CVT). Stroke diagnosis required the presence of an acute focal deficit lasting more than 24 h, confirmed by a corresponding lesion on CT/MRI. Stroke severity was established with the NIH Stroke Scale. The pre-stroke functional status was determined by the IQCODE. Three months after the occurrence of stroke, 110 survivor patients returned for follow-up and were able to undergo functional outcome (modified Rankin scale, Barthel index), along with neurological, psychiatric, neuropsychological, laboratory, and imaging assessments. We compared depression, demographic, and clinical and imaging features between patients with and without dementia, and between patients with VCI and those with intact cognition. RESULTS: Of the 110 patients (62% men, mean age 56 ± 17.8, education 7.7 ± 5.2 years) 93 (84%) had ischemic strokes, 14 (13%) intracerebral hemorrhage, and 3 (3%) CVT. The main risk factors were hypertension (50%), smoking (40%), hypercholesterolemia (29%), hyperhomocysteinemia (24%), and diabetes (22%). Clinical and neuropsychological evaluations demonstrated post-stroke depression in 56%, VCI in 41%, and VaD in 12%; 17% of the latter had pre-stroke functional impairment (IQCODE >3.5). Cognitive deficits included executive function in 69%, verbal memory in 49%, language in 38%, perception in 36%, and attention in 38%. Executive dysfunction occurred in 36% of non-demented subjects, 65% of them with mild-moderate deficits in daily living activities. Female gender (p ≤ 0.054), older age (mean age 65.6 years vs. 49.3, p < 0.001), diabetes (p ≤ 0.004), illiteracy and lower education (p ≤ 0.001), and PSD (p = 0.03) were significantly higher in VCI-VaD compared with cognitively intact post-stroke subjects. We could not demonstrate an association with lesion site and distribution of the cognitive deficits. CONCLUSIONS: The Fogarty-Mexico cohort recruited relatively young acute stroke patients, compared with other Mexican stroke cohorts. PSD and VCI occurred frequently but prevalence of VaD (12%) was lower than expected. A high prevalence of treatable stroke risk factors suggests that preventive interventions are advisable.

Uptake of genetic testing and long-term tumor surveillance in von Hippel-Lindau disease.

BACKGROUND: von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome caused by germline mutations in the VHL gene. Patients have significant morbidity and mortality secondary to vascular tumors. Disease management is centered on tumor surveillance that allows early detection and treatment. Presymptomatic genetic testing is therefore recommended, including in at-risk children. METHODS: We tested 17 families (n = 109 individuals) for VHL mutations including 43 children under the age of 18. Personalized genetic counseling was provided pre and post-test and the individuals undergoing presymptomatic testing filled out questionnaires gathering socio-demographic, psychological and psychiatric data. Mutation analysis was performed by direct sequencing of the VHL gene. Mutation-carriers were screened for VHL disease-related tumors and were offered follow-up annual examinations. RESULTS: Mutations were identified in 36 patients, 17 of whom were asymptomatic. In the initial screening, we identified at least one tumor in five of 17 previously asymptomatic individuals. At the end of five years, only 38.9% of the mutation-carriers continued participating in our tumor surveillance program. During this time, 14 mutation carriers developed a total of 32 new tumors, three of whom died of complications. Gender, education, income, marital status and religiosity were not found to be associated with adherence to the surveillance protocol. Follow-up adherence was also independent of pre-test depression, severity of disease, or number of affected family members. The only statistically significant predictor of adherence was being symptomatic at the time of testing (OR = 5; 95% CI 1.2 - 20.3; p = 0.02). Pre-test anxiety was more commonly observed in patients that discontinued follow-up (64.7% vs. 35.3%; p = 0.01). CONCLUSIONS: The high initial uptake rate of genetic testing for VHL disease, including in minors, allowed the discontinuation of unnecessary screening procedures in non mutation-carriers. However, mutation-carriers showed poor adherence to long-term tumor surveillance. Therefore, many of them did not obtain the full benefit of early detection and treatment, which is central to the reduction of morbidity and mortality in VHL disease. Studies designed to improve adherence to vigilance protocols will be necessary to improve treatment and quality of life in patients with hereditary cancer syndromes.

Presymptomatic diagnosis in Huntington's disease: the Mexican experience.

Huntington's disease (HD) is an autosomal dominant progressive, disabling neurodegenerative disorder, for which there is no effective treatment. Predictive testing (PT) for this illness began in 1986 and by 1993 it became more precise after cloning of the gene and the discovery of a CAG repeat expansion as the underlying cause. The objective of this paper is to illustrate the implementation and results of a PT program in a group of at-risk Mexican individuals with 12 years of follow-up. Our PT program conforms to the guidelines proposed by the International Huntington Association and the HD Working group of the World Federation of Neurology. Seventy-five individuals requested the testing, four of them did not fulfill the inclusion criteria, and five abandoned the program voluntarily before receiving the test results. Therefore, 66 results were delivered to 41 noncarriers and 25 mutation carriers. We did not have any catastrophic event, but 4 individuals with normal results and 11 mutation carriers were depressed. Even if this is a small sample, it is the first report of PT in a Latin-American population in which we have been faced with the same problems referred to in larger series.

Current concepts of mild cognitive impairment and their applicability to persons at-risk for familial Alzheimer's disease.

The definition of mild cognitive impairment (MCI) as a precursor for Alzheimer's disease (AD) represented an important step forward in diagnosing the illness in its earliest stage. However, diagnoses based principally on cognitive performance have limitations in that there is variability between centers in which tests are employed and in how they are interpreted. Advances in our understanding of imaging and biochemical changes occurring early in the illness have improved our ability to diagnose AD in this early phase and diagnostic criteria for AD have been proposed recently based on such biomarkers. Persons inheriting autosomal dominant mutations causing familial AD (FAD) are essentially certain to develop the disease. In our studies of preclinical persons at-risk for inheriting FAD, we applied MCI diagnostic criteria to carriers of FAD mutations to ascertain the extent to which they identified persons in the earliest stages of the clinical illness. Our results indicate the relative prevalence of MCI subtypes varies considerably depending on the tests used to measure cognition. Furthermore, we found that cognitive complaints in such persons were less predictive of mutation status than were informants' reports of cognitive loss. The study of FAD provides an opportunity to test various criteria for early AD and these observations should be taken into consideration in future iterations of such diagnostic criteria.

Performance on MMSE sub-items and education level in presenilin-1 mutation carriers without dementia.

BACKGROUND: Spanish-language screening tests that are sensitive to the early cognitive changes of Alzheimer's disease (AD) are needed. Persons known to be at 50% risk for young-onset AD due to presenilin-1 (PSEN1) mutations provide the opportunity to assess which measures on the Mini-mental State Examination (MMSE) are most sensitive to these early changes. METHODS: We performed genetic and Spanish-language cognitive testing on 50 Mexican persons without dementia at risk for inheriting PSEN1 mutations. We then compared the performance on sub-items of the MMSE between PSEN1 mutation carriers (MCs) and non-carriers (NCs) using t-tests and Fisher's exact tests. Exploratory multiple logistic regression analyses were also performed. RESULTS: Twenty-nine persons were MCs and 21 NCs. NCs tended to achieve higher levels of education (p = 0.039) than did MCs. MCs tended to perform more poorly when spelling "MUNDO" backwards and on Orientation, particularly regarding the date. In multiple regression analyses the ability of backwards spelling to predict PSEN1 mutation status was reduced when education was included as an independent variable. CONCLUSION: Subjects in the earliest stage of PSEN1-related AD showed deficits on orientation to date and in divided attention when spelling backwards. It is unclear if educational level should be considered an associated feature or a con-founding variable in this population although it should be taken into account when considering performance on the MMSE task of divided attention. The relative lack of deficits on delayed recall of three words probably represents the insensitivity of this measure in early AD. This study supports the utility of autosomal dominant AD as a model of the more common sporadic form of the disorder.