RESUMO
INTRODUCTION: Neurodegenerative diseases, especially frontotemporal lobar degeneration and Alzheimer's disease, often lead to impaired language functions, and so speech analysis can provide objective measures with which to classify the different syndromes. AIM: To study the nature, cognitive correlates and clinical utility of 21 variables related to speech and silence times. SUBJECTS AND METHODS: Derivation of acoustic variables with Praat in three spontaneous speech tasks conducted in 22 subjects, distributed in six diagnostic groups (five with neurodegenerative diseases + control). A descriptive analysis is performed, with ROC and principal component curves, to study how acoustic variables are related to the different neurodegenerative syndromes and what information they can provide. RESULTS: Three groups of variables are identified related, respectively, to: a) total number of silent pauses and total duration of the task; b) variability of the phonic groups; and c) variability of the periods of silence. These components correlate differentially with the different syndromes studied. CONCLUSIONS: Detailed analysis of speech and silence times can provide relevant information for the diagnosis of different neurodegenerative syndromes that are not reflected in traditional neuropsychological assessments. Thus, the total number of silent pauses may be a valuable aid in discriminating patients with lexical access deficits, phonic group parameters seem to reflect motor speech problems, and pause variability is associated with dysexecutive and global impairment.
TITLE: Estudio preliminar de variables temporales del habla continua en pacientes con síndromes neurodegenerativos del espectro degeneración lobar frontotemporal.Introducción. Las enfermedades neurodegenerativas, especialmente la degeneración lobar frontotemporal y la enfermedad de Alzheimer, conllevan a menudo una alteración de las funciones del lenguaje, por lo que el análisis del habla puede proporcionar medidas objetivas para clasificar los diferentes síndromes. Objetivo. Estudiar la naturaleza, correlatos cognitivos y utilidad clínica de 21 variables relacionadas con el tiempo de habla y de silencio. Sujetos y métodos. Derivación de variables acústicas con Praat en tres tareas de habla espontánea en 22 sujetos, distribuidos en seis grupos de diagnóstico (cinco con enfermedades neurodegenerativas + control). Se realiza un análisis descriptivo, con curvas ROC y de componentes principales, para estudiar cómo las variables acústicas se relacionan con los distintos síndromes neurodegenerativos y qué información pueden aportar. Resultados. Se identifican tres grupos de variables relacionadas, respectivamente, con: a) número total de pausas silenciosas y duración total de la tarea; b) variabilidad de los grupos fónicos, y c) variabilidad de los períodos de silencio. Dichas componentes se correlacionan diferencialmente con los distintos síndromes estudiados. Conclusiones. El análisis detallado del tiempo de habla y de silencio puede aportar información relevante para el diagnóstico de diferentes síndromes neurodegenerativos, no reflejado en las evaluaciones de neuropsicología tradicionales. Así, el número total de pausas silenciosas puede tener valor para discriminar los pacientes con déficits de acceso léxico, los parámetros del grupo fónico parecen reflejar los problemas motores del habla, mientras que la variabilidad de las pausas se asocia con el deterioro disejecutivo y global.
Assuntos
Degeneração Lobar Frontotemporal/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Fala/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Estudos Prospectivos , Síndrome , Fatores de TempoRESUMO
BACKGROUND: Peripheral biomarkers that identify individuals at risk of developing Alzheimer's disease (AD) or predicting high amyloid beta (Aß) brain burden would be highly valuable. To facilitate clinical trials of disease-modifying therapies, plasma concentrations of Aß species are good candidates for peripheral AD biomarkers, but studies to date have generated conflicting results. METHODS: The Fundació ACE Healthy Brain Initiative (FACEHBI) study uses a convenience sample of 200 individuals diagnosed with subjective cognitive decline (SCD) at the Fundació ACE (Barcelona, Spain) who underwent amyloid florbetaben(18F) (FBB) positron emission tomography (PET) brain imaging. Baseline plasma samples from FACEHBI subjects (aged 65.9 ± 7.2 years) were analyzed using the ABtest (Araclon Biotech). This test directly determines the free plasma (FP) and total plasma (TP) levels of Aß40 and Aß42 peptides. The association between Aß40 and Aß42 plasma levels and FBB-PET global standardized uptake value ratio (SUVR) was determined using correlations and linear regression-based methods. The effect of the APOE genotype on plasma Aß levels and FBB-PET was also assessed. Finally, various models including different combinations of demographics, genetics, and Aß plasma levels were constructed using logistic regression and area under the receiver operating characteristic curve (AUROC) analyses to evaluate their ability for discriminating which subjects presented brain amyloidosis. RESULTS: FBB-PET global SUVR correlated weakly but significantly with Aß42/40 plasma ratios. For TP42/40, this observation persisted after controlling for age and APOE ε4 allele carrier status (R2 = 0.193, p = 1.01E-09). The ROC curve demonstrated that plasma Aß measurements are not superior to APOE and age in combination in predicting brain amyloidosis. It is noteworthy that using a simple preselection tool (the TP42/40 ratio with an empirical cut-off value of 0.08) optimizes the sensitivity and reduces the number of individuals subjected to Aß FBB-PET scanners to 52.8%. No significant dependency was observed between APOE genotype and plasma Aß measurements (p value for interaction = 0.105). CONCLUSION: Brain and plasma Aß levels are partially correlated in individuals diagnosed with SCD. Aß plasma measurements, particularly the TP42/40 ratio, could generate a new recruitment strategy independent of the APOE genotype that would improve identification of SCD subjects with brain amyloidosis and reduce the rate of screening failures in preclinical AD studies. Independent replication of these findings is warranted.