Neuropsychological performance and disease burden in individuals at risk of developing Huntington disease.

INTRODUCTION: Huntington disease (HD) is a hereditary neurodegenerative disorder. Thanks to predictive diagnosis, incipient clinical characteristics have been described in the prodromal phase. OBJECTIVE: To compare performance in cognitive tasks of carriers (HDC) and non-carriers (non-HDC) of the huntingtin gene and to analyse the variability in performance as a function of disease burden and proximity to the manifest stage (age of symptom onset). METHOD: A sample of 146 participants in a predictive diagnosis of HD programme were divided into the HDC (41.1%) and non-HDC groups (58.9%). Mathematical formulae were used to calculate disease burden and proximity to the manifest stage in the HDC group; these parameters were correlated with neuropsychological performance. RESULTS: Significant differences were observed between groups in performance on the Mini-Mental State Examination (MMSE), Stroop-B, Symbol-Digit Modalities Test (SDMT), and phonological fluency. In the HDC group, correlations were observed between disease burden and performance on the MMSE, Stroop-B, and SDMT. The group of patients close to the manifest stage scored lowest on the MMSE, Stroop-B, Stroop-C, SDMT, and semantic verbal fluency. According to the multivariate analysis of covariance, the MMSE effect shows statistically significant differences in disease burden and proximity to onset of symptoms. CONCLUSIONS: Members of the HDC group close to the manifest phase performed more poorly on tests assessing information processing speed and attention. Prefrontal cognitive dysfunction appears early, several years before the motor diagnosis of HD.

Psychological discomfort in carriers and non-carriers of the Huntington disease mutation and its relationship with disease burden.

INTRODUCTION: Huntington's disease (HD) is a neurodegenerative and hereditary disorder. Due to the predictive diagnosis, incipient clinical characteristics have been described in the prodromal phase. Several studies have reported an increase in psychiatric symptoms in carriers of the HD gene without motor symptoms. OBJECTIVE: To identify psychological distress in carriers of the mutation that causes HD, without motor symptoms, utilizing the Symptom Checklist 90 (SCL-90), and to correlate with the burden and proximity of the disease. METHOD: A sample of 175 participants in a HD Predictive Diagnostic Program (PDP-HD) was divided into HEP carriers (39.4%) and NPEH non-carriers (61.6%) of the HD-causing mutation. By means of mathematical formulas, the disease burden and proximity to the manifest stage in the PEH group were obtained and it was correlated with the results of the SCL-90-R. RESULTS: Comparing the results obtained in the SCL-90-R of the PEH and NPEH, the difference is observed in the positive somatic male index, where the PEH obtains higher average scores. The correlations between disease burden and psychological distress occur in the domains; obsessions and compulsions, interpersonal sensitivity, hostility, global severity index and positive somatic distress index. A low correlation is observed between the burden of disease and the scores obtained in psychological discomfort. CONCLUSIONS: In general, we found that the PEH group obtained a higher score in the dimensions evaluated with the SCL-90-R, showing a relationship with the burden and differences due to the proximity of the disease. Higher scores on the SCL-90-R dimensions in carriers of the HD gene may suggest an early finding of psychological symptoms in the disease.

Neuropsychological performance and disease burden in individuals at risk of developing Huntington disease. / Ejecución neuropsicológica y carga de enfermedad en sujetos en riesgo de desarrollar enfermedad de Huntington.

INTRODUCTION: Huntington disease (HD) is a hereditary neurodegenerative disorder. Thanks to predictive diagnosis, incipient clinical characteristics have been described in the prodromal phase. OBJECTIVE: To compare performance in cognitive tasks of carriers (HDC) and non-carriers (non-HDC) of the huntingtin gene and to analyse the variability in performance as a function of disease burden and proximity to the manifest stage (age of symptom onset). METHOD: A sample of 146 participants in a predictive diagnosis of HD programme were divided into the HDC (41.1%) and non-HDC groups (58.9%). Mathematical formulae were used to calculate disease burden and proximity to the manifest stage in the HDC group; these parameters were correlated with neuropsychological performance. RESULTS: Significant differences were observed between groups in performance on the Mini-Mental State Examination (MMSE), Stroop-B, Symbol-Digit Modalities Test (SDMT), and phonological fluency. In the HDC group, correlations were observed between disease burden and performance on the MMSE, Stroop-B, and SDMT. The group of patients close to the manifest stage scored lowest on the MMSE, Stroop-B, Stroop-C, SDMT, and semantic verbal fluency. According to the multivariate analysis of covariance, the MMSE effect shows statistically significant differences in disease burden and proximity to onset of symptoms. CONCLUSIONS: Members of the HDC group close to the manifest phase performed more poorly on tests assessing information processing speed and attention. Prefrontal cognitive dysfunction appears early, several years before the motor diagnosis of HD.

Verbal fluency tests: Normative data for the Latin American Spanish speaking adult population.

OBJECTIVE: To generate normative data for the Verbal Fluency Tests across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the Verbal Fluency Test as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models for the letter F explained 8-30% of the variance, 7-32% for letter A, 8-32% for the letter S, and 16-43% for the animal category in Verbal Fluency Test scores. Although t-tests showed significant differences between men and women on the Verbal Fluency Test, they did not have an effect size larger than 0.3. As a result, gender-adjusted norms were not generated. CONCLUSIONS: This is the first normative multicenter study conducted in Latin America aiming to create norms for the Verbal Fluency Test; this study will have important outcomes for the future of neuropsychology in the region.

Semantic verbal fluency in elderly Mexican adults: Reference values.

INTRODUCTION: The semantic verbal fluency test (SVF) is sensitive to detecting cognitive decline. It is fast and easy to use in any cultural context; therefore, it is included in most of the neuropsychological assessment protocols. OBJECTIVE: To estimate normative values for the SVF test (animals), in an elderly population aged 65 years and over. MATERIAL AND METHOD: 1233 subjects who were healthy, cognitively preserved, residents of two areas (rural and urban) of Mexico were assessed. A neurological and neuropsychological exploration battery was applied, including SVF. RESULTS: The age average was 73+6 and schooling was 4.0+3.9 years, with 59% women. The average of the words generated in the SVF test was 14+5, and a correlation of 0.16 of these scores with age, education, and gender was found (p<.001), this allowed the estimation of the percentiles in accordance with these variables. CONCLUSIONS: The most important contribution provided by this study was that the data analysis enabled normative values to be obtained for an elderly Mexican population aged 65 years and over. It was also confirmed, as other neuropsychological assessment studies have done, that the SVF test is influenced by socio-demographic variables, such as age and education, aspects to be considered at the time of obtaining normative values. Finally, it was noted that the average scores obtained were lower than other published reference values, due to the low educational level of our sample.

Recall strategies for the verbal fluency test in patients with multiple sclerosis.

UNLABELLED: Multiple sclerosis (MS) is a neurodegenerative disease characterised by inflammation and demyelination. It generates irreversible myelin changes, which in turn give rise to physical and cognitive disorders. The verbal fluency test (VF) has been shown to be a sensitive tool for detecting cognitive impairment in these patients. OBJECTIVE: To compare quantitative and qualitative aspects of performance on semantic and phonological fluency tests between MS patients and healthy controls by analysing total words produced and strategies used (clusters and switching). METHOD: We evaluated 46 patients with MS and 33 healthy controls using the VF test. RESULTS: The semantic VF task revealed no significant differences between groups; for the phonological task, patients demonstrated reduced word production (F [77]=2.286 P<.001) and poorer use of grouping strategies, resulting in more frequent switching (F [77]=3.808 P<.005). CONCLUSIONS: These results support using qualitative analysis for recall strategies, since the technique provides data about which components of the task are affected by brain damage. Clusters depend on the integrity of semantic memory, while switching has to do with developing effective search strategies, cognitive flexibility, and the ability to modify responses. Frontal lobe damage has been reported in MS, and this is consistent with results from the phonological VF test.