INS NYC 2024 Program

Poster	Poster Session 04 Program Schedule 02/15/2024 12:00 pm - 01:15 pm Room: Shubert Complex (Posters 1-60) Poster Session 04: Neuroimaging \| Neurostimulation/Neuromodulation \| Teleneuropsychology/Technology Final Abstract #39 Apathy is Associated with Widespread Decreases in White Matter Quantitative Anisotropy in Cognitively Normal Older Adults at Risk for Alzheimer’s Disease Joshua Gertler, University of Florida, Gainesville, United States Lauren Kenney, University of Florida, Gainesville, United States Adrianna Ratajska, University of Florida, Gainesville, United States Francesca Lopez, University of Florida, Gainesville, United States Katie Rodriguez, University of Florida, Gainesville, United States Rachel Schade, University of Florida, Gainesville, United States Alyssa Ray, University of Florida, Gainesville, United States Jarred Tanner, University of Florida, Gainesville, United States Adam Woods, University of Florida, Gainesville, United States Dawn Bowers, University of Florida, Gainesville, United States Category: Aging Keyword 1: apathy Keyword 2: neuroimaging: structural connectivity Keyword 3: aging (normal) Objective: Apathy is a common neuropsychiatric syndrome observed in a variety of neurodegenerative disorders ranging from mild cognitive impairment to various dementias (Alzheimer’s [AD], vascular, FTD, Parkinson). Apathy is also associated with normal aging and may relate to vascular comorbidities. Across all, it is distinct from depression and characterized by loss of motivation resulting in decreased goal directed behaviors, cognitions, and emotional responsivity. The presumed mechanism relates to disruption of the brain’s motivational circuitry. The goal of this study was to examine the association between apathy and white matter integrity using correlational tractography in cognitively normal older adults with cognitive complaints and a first-degree relative with AD. We hypothesized that decreased integrity of fronto-striatal and fronto-temporal white matter would relate to increased apathy. Participants and Methods: Participants included 84 older adults from the University of Florida (Mean age=71, SD=4.5) who had a first-degree family member with AD. All were cognitively normal (based on the Neuropsychological battery from the NACC, v3) with subjective cognitive complaints (Cognitive Complaints Index>17) and minimal depressive symptoms (Beck Depression Inventory-II <14). All completed the Starkstein Apathy Scale. T1 and multi-shell DW images were acquired using the ADNI-3 advanced protocol from a Siemens 3-T scanner. Data were processed using the DSI Studio default connectometry pipeline which employs Q-Space Diffeomorphic Reconstruction. Briefly, this creates a Spin Distribution Function for each voxel which provides better resolution of crossing fibers for improved registration to MNI space and analysis. Scans were labeled low quality outliers if the DWI slice correlation was greater than 3 SD from the mean. The association between Apathy and Quantitative Anisotropy (QA; sensitive to axonal loss), controlling for age and sex, was assessed by non-parametric correlational tractography. The whole brain was seeded and linearly contiguous voxels with QA ranks correlated with apathy were identified. Whole-brain seeding was conducted in 4000 permutations and 4 iterations of pruning based on False Discovery Rate thresholds. A voxel-wise threshold of p<0.001, length (i.e., linear cluster) threshold of 20, and an overall FDR of p<0.05 was used. Default statistics in “HCP842 Tractography” regional clusters were extracted. Results: Four participants were labeled low quality outliers and removed from the analysis. Increased apathy was associated with decreased QA in the right anterior cingulum (tracts=261, mean length=44, peak-T=3.63), right fronto-occipital fasciculus (tracts=58, mean length=44, peak-T=3.33), right superior longitudinal fasciculus (tracts=11, mean length=41, peak-T=3.55), left cerebellum (tracts=68, mean length=44, peak-T=3.54), corpus callosum splenium (tracts=471, mean length=43, peak-T=3.42), and bilateral cortico-spinal tract (L: tracts=529, mean length=46, peak-T=3.93; R: tracts=512, mean length=46, peak-T=4.09) connecting the midbrain to the caudate tail. Conclusions: We observed widespread white matter abnormalities associated with apathy spanning beyond motivational circuits, but which are unreliably reported across healthy and neurodegenerative populations in prior studies. Widespread QA associations in tracts unreliably reported across analyses of fractional anisotropy may be explained by QA’s improved sensitivity for axonal loss. Alternatively, our larger sample size may have increased power to detect multiple independent pathways among sub-groups. Future studies should look for biomarkers in those at risk for AD and examine data-driven sub-groups.

Poster

02/15/2024
12:00 pm - 01:15 pm
Room: Shubert Complex (Posters 1-60)

Poster Session 04: Neuroimaging | Neurostimulation/Neuromodulation | Teleneuropsychology/Technology

Final Abstract #39

Apathy is Associated with Widespread Decreases in White Matter Quantitative Anisotropy in Cognitively Normal Older Adults at Risk for Alzheimer’s Disease

Joshua Gertler, University of Florida, Gainesville, United States
Lauren Kenney, University of Florida, Gainesville, United States
Adrianna Ratajska, University of Florida, Gainesville, United States
Francesca Lopez, University of Florida, Gainesville, United States
Katie Rodriguez, University of Florida, Gainesville, United States
Rachel Schade, University of Florida, Gainesville, United States
Alyssa Ray, University of Florida, Gainesville, United States
Jarred Tanner, University of Florida, Gainesville, United States
Adam Woods, University of Florida, Gainesville, United States
Dawn Bowers, University of Florida, Gainesville, United States

Category: Aging

Keyword 1: apathy
Keyword 2: neuroimaging: structural connectivity
Keyword 3: aging (normal)

Objective:

Apathy is a common neuropsychiatric syndrome observed in a variety of neurodegenerative disorders ranging from mild cognitive impairment to various dementias (Alzheimer’s [AD], vascular, FTD, Parkinson). Apathy is also associated with normal aging and may relate to vascular comorbidities. Across all, it is distinct from depression and characterized by loss of motivation resulting in decreased goal directed behaviors, cognitions, and emotional responsivity. The presumed mechanism relates to disruption of the brain’s motivational circuitry. The goal of this study was to examine the association between apathy and white matter integrity using correlational tractography in cognitively normal older adults with cognitive complaints and a first-degree relative with AD. We hypothesized that decreased integrity of fronto-striatal and fronto-temporal white matter would relate to increased apathy.

Participants and Methods:

Participants included 84 older adults from the University of Florida (Mean age=71, SD=4.5) who had a first-degree family member with AD. All were cognitively normal (based on the Neuropsychological battery from the NACC, v3) with subjective cognitive complaints (Cognitive Complaints Index>17) and minimal depressive symptoms (Beck Depression Inventory-II <14). All completed the Starkstein Apathy Scale. T1 and multi-shell DW images were acquired using the ADNI-3 advanced protocol from a Siemens 3-T scanner. Data were processed using the DSI Studio default connectometry pipeline which employs Q-Space Diffeomorphic Reconstruction. Briefly, this creates a Spin Distribution Function for each voxel which provides better resolution of crossing fibers for improved registration to MNI space and analysis. Scans were labeled low quality outliers if the DWI slice correlation was greater than 3 SD from the mean. The association between Apathy and Quantitative Anisotropy (QA; sensitive to axonal loss), controlling for age and sex, was assessed by non-parametric correlational tractography. The whole brain was seeded and linearly contiguous voxels with QA ranks correlated with apathy were identified. Whole-brain seeding was conducted in 4000 permutations and 4 iterations of pruning based on False Discovery Rate thresholds. A voxel-wise threshold of p<0.001, length (i.e., linear cluster) threshold of 20, and an overall FDR of p<0.05 was used. Default statistics in “HCP842 Tractography” regional clusters were extracted.

Results:

Four participants were labeled low quality outliers and removed from the analysis. Increased apathy was associated with decreased QA in the right anterior cingulum (tracts=261, mean length=44, peak-T=3.63), right fronto-occipital fasciculus (tracts=58, mean length=44, peak-T=3.33), right superior longitudinal fasciculus (tracts=11, mean length=41, peak-T=3.55), left cerebellum (tracts=68, mean length=44, peak-T=3.54), corpus callosum splenium (tracts=471, mean length=43, peak-T=3.42), and bilateral cortico-spinal tract (L: tracts=529, mean length=46, peak-T=3.93; R: tracts=512, mean length=46, peak-T=4.09) connecting the midbrain to the caudate tail.

Conclusions:

We observed widespread white matter abnormalities associated with apathy spanning beyond motivational circuits, but which are unreliably reported across healthy and neurodegenerative populations in prior studies. Widespread QA associations in tracts unreliably reported across analyses of fractional anisotropy may be explained by QA’s improved sensitivity for axonal loss. Alternatively, our larger sample size may have increased power to detect multiple independent pathways among sub-groups. Future studies should look for biomarkers in those at risk for AD and examine data-driven sub-groups.