title: Extracting patterns of morphometry distinguishing HIV associated neurodegeneration from mild cognitive impairment via group cardinality constrained classification.
abstract: HIV-Associated Neurocognitive Disorder (HAND) is the most common constellation of cognitive dysfunctions in chronic HIV infected patients age 60 or older in the U.S. Only few published methods assist in distinguishing HAND from other forms of age-associated cognitive decline, such as Mild Cognitive Impairment (MCI). In this report, a data-driven, nonparameteric model to identify morphometric patterns separating HAND from MCI due to non-HIV conditions in this older age group was proposed. This model enhanced the potential for group separation by combining a smaller, longitudinal data set containing HAND samples with a larger, public data set including MCI cases. Using cross-validation, a linear model on healthy controls to harmonize the volumetric scores extracted from MRIs for demographic and acquisition differences between the two independent, disease-specific data sets was trained. Next, patterns distinguishing HAND from MCI via a group sparsity constrained logistic classifier were identified. Unlike existing approaches, our classifier directly solved the underlying minimization problem by decoupling the minimization of the logistic regression function from enforcing the group sparsity constraint. The extracted patterns consisted of eight regions that distinguished HAND from MCI on a significant level while being indifferent to differences in demographics and acquisition between the two sets. Individually selecting regions through conventional morphometric group analysis resulted in a larger number of regions that were less accurate. In conclusion, simultaneously analyzing all brain regions and time points for disease specific patterns contributed to distinguishing with high accuracy HAND-related impairment from cognitive impairment found in the HIV uninfected, MCI cohort. Hum Brain Mapp 37:4523-4538, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, 94305.
authors.forename: Yong
authors.identifier: 0000-0002-0238-0719
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, 94305.|Center for Health Sciences, SRI International, Menlo Park, California, 94025.
authors.forename: Dongjin
authors.initials: D
authors.lastname: Kwon
authors.affiliation: Memory and Aging Center, UCSF, San Francisco, California.
authors.forename: Pardis
authors.initials: P
authors.lastname: Esmaeili-Firidouni
authors.affiliation: Center for Health Sciences, SRI International, Menlo Park, California, 94025.
authors.forename: Adolf
authors.initials: A
authors.lastname: Pfefferbaum
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, 94305.
authors.forename: Edith V
authors.initials: EV
authors.lastname: Sullivan
authors.affiliation: Center for Technology in Learning in the Education Division, SRI International, Menlo Park, California, 94025.
authors.forename: Harold
authors.initials: H
authors.lastname: Javitz
authors.affiliation: Memory and Aging Center, UCSF, San Francisco, California.
authors.forename: Victor
authors.initials: V
authors.lastname: Valcour
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, 94305.|Center for Health Sciences, SRI International, Menlo Park, California, 94025.
authors.forename: Kilian M
authors.initials: KM
authors.lastname: Pohl
mesh_terms: D015526:AIDS Dementia Complex / Q000150:complications / Q000000981:diagnostic imaging*; D000368:Aged; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D009929:Organ Size; D010363:Pattern Recognition, Automated / Q000379:methods
keywords: HIV-associated neurocognitive disorder; MRI; logistic regression; mild cognitive impairment; sparsity