Year: 2013
Type: article
Study design: Observational Study
Abstract: The structural deterioration of brain tissue in older adults is thought to be responsible for the majority of age-related cognitive decline, and it has been suggested that disruption of widespread cortical networks due to a loss of axonal integrity may play an important role.However, the relationship between cortical network disruption and cognitive deterioration remains unclear.The research examining correlations between structural change and functional decline has focused heavily on working memory, processing speed, and executive processes while other aspects of cognition, such as language functioning, have received less attention.The current study aimed to determine whether age-related changes in the superior longitudinal fasciculus (SLF), a connection between temporoparietal and frontal language regions, are responsible for the deterioration in language functioning associated with age.Subjects included 112 righthanded volunteers (ages 19-76).For each subject, the SLF of the left hemisphere was reconstructed from diffusion tensor images (DTI).Mean fractional anisotropy (FA) values were extracted from parietal (SLFp) and temporal (SLFt) bundles.Language functioning was measured using the Peabody Picture Vocabulary Test (PPVT), Boston Naming Test (BNT), Controlled Oral Word Association Test (COWAT), and Semantic Fluency Test (SFT).Regression analyses assessed the relationship between age, sex, and FA from SLFt and SLFp.Males and females showed a different pattern of decline in FA across adulthood.For all subjects, greater SLFt FA was significantly associated with better COWAT performance and age predicted BNT performance.For males, greater SLFt FA was significantly associated with increased COWAT performance, and there was a positive relationship between both age and SLFp FA with BNT scores.In females, greater SLFp FA was related to lower COWAT performance.Taken together, the results suggest that white matter integrity of the SLF follows aiii different pattern of decline in adulthood for males and females, and this decline differentially affects language functioning.iv v approach to science, both of which have helped me to become a better researcher.I want to thank Dr. Steven Howe for his invaluable statistical contributions, but more importantly, for his sense of humor and for many laughs over the past six years.Thank you to Dr. Paula Shear for her critical involvement in guiding my professional growth and for always having answers to my questions, both personal and professional.I would also like to acknowledge the National Institutes of Health for providing the necessary financial support for this research (R01 NS048281; PI: Szaflarski).Special thanks to my family.To my parents, Michael and Patricia, and my siblings Laura and Danny for their love and encouragement.I will always be grateful to my grandfather for showing me by example the importance of asking questions and continuing to learn, even at the age of ninety-seven.To my son, Kiran, you have only been around five short months, but your many naps were integral to the completion of this project.This work is dedicated to my husband, Deepak, for whom my mere expression of thanks does not suffice.
Author: Kiely M. Madhavan
Institution: University of Cincinnati
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2278527318