Person: Fong, Tamara
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Fong
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Tamara
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Fong, Tamara
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Publication Hippocampal Hyperperfusion in Alzheimer's Disease(Elsevier BV, 2008-10-01) Alsop, David; Casement, Melynda; de Bazelaire, Cedric; Fong, Tamara; Press, DanielMany of the regions with the earliest atrophy in Alzheimer’s Disease (AD) do not show prominent deficits on functional imaging studies of flow or metabolism. This paradox may provide unique insights into the pathophysiology of AD. We sought to examine the relationship between function and atrophy in AD using MRI blood flow and anatomic imaging. 22 subjects diagnosed with AD, mean Mini Mental State Exam (MMSE) score 22.2, and 16 healthy elderly controls were imaged with a volumetric arterial spin labeling blood flow MRI technique and an anatomical imaging method using the identical spatial resolution, image orientation, and spatial encoding strategy. Cerebral blood flow(CBF) and gray matter (GM) maps derived from the imaging were transformed to a standard anatomical space. GM and CBF maps were tested for significant differences between groups. Additionally, images were tested for regions with significant mismatch of the CBF and GM differences between groups. CBF was significantly lower in the bilateral precuneus, parietal association cortex and the left inferior temporal lobe but was non-significantly increased in the hippocampus and other medial temporal structures. After correction for GM loss, CBF was significantly elevated in the hippocampus and other medial temporal structures. The hippocampus and other regions affected early in AD are characterized by elevated atrophy-corrected perfusion per cc of tissue. This suggests compensatory or pathological elevation of neural activity, inflammation, or elevated production of vasodilators.Publication Association Between Hospital Readmission and Acute and Sustained Delays in Functional Recovery During 18 Months After Elective Surgery: The Successful Aging after Elective Surgery Study(Wiley, 2017-01) Pisani, Margaret A.; Albuquerque, Asha; Marcantonio, Edward; Jones, Richard N.; Gou, Ray Yun; Fong, Tamara; Schmitt, Eva M.; Tommet, Douglas; Isaza Aizpurua, Ilean I.; Alsop, David; Inouye, Sharon; Travison, ThomasObjectives: To examine the effect of hospital readmission on functional recovery after elective surgery in older adults. Design: Prospective cohort of individuals aged 70 and older undergoing elective surgery, enrolled from June 2010 to August 2013. Setting: Two academic medical centers. Participants: Community-dwelling older adults (N = 566; mean age ± standard deviation 77 ± 5) undergoing major elective surgery and expected to be admitted for at least 3 days. Measurements: Readmission was assessed in multiple interviews with participants and family members over 18 months and validated against medical record review. Physical function was assessed according to ability to perform instrumental activities of daily living (IADLs) and activities of daily living (ADL), Medical Outcomes Study 12-item Short-Form Survey Physical Component Summary score, and a standardized functional composite. Results: Two hundred fifty-five (45%) participants experienced 503 readmissions. Readmissions were associated with delays in functional recovery in all measures of physical function. Having two or more readmissions over 18 months was associated with persistent and significantly greater risk of IADL dependence (relative risk (RR) = 1.8, 95% confidence interval (CI) = 1.5-2.3) and ADL dependence (RR = 3.3, 95% CI = 1.7-6.4). Degree of functional impairment increased progressively with number of readmissions. Readmissions within 2 months resulted in delayed functional recovery to baseline by 18 months, and readmissions between 12 and 18 months after surgery resulted in loss of functional recovery previously achieved. Conclusion: Readmission after elective surgery may contribute to delays in functional recovery and persistent functional deficits in older adults.Publication Alzheimer's-Related Cortical Atrophy Is Associated With Postoperative Delirium Severity in Persons Without Dementia(Elsevier BV, 2017-11) Racine, Annie M.; Fong, Tamara; Travison, Thomas; Jones, Richard N.; Gou, Yun; Vasunilashorn, Sarinnapha; Marcantonio, Edward; Alsop, David; Inouye, Sharon; Dickerson, BradfordPatients with dementia due to Alzheimer’s disease (AD) have increased risk of developing delirium. This study investigated the relationship between a magnetic resonance imaging (MRI)-derived biomarker associated with preclinical AD and postoperative delirium. Participants were older adults (≥70 years) without dementia who underwent preoperative MRI and elective surgery. Delirium incidence and severity were evaluated daily during hospitalization. Cortical thickness was averaged across a published set of a priori brain regions to derive a measure known as the “AD signature.” Logistic and linear regression was used, respectively, to test whether the AD signature was associated with delirium incidence in the entire sample (N=145) or with the severity of delirium among those who developed delirium (N=32). Thinner cortex in the AD signature did not predict incidence of delirium (odds ratio=1.15, p=.38), but was associated with greater delirium severity among those who developed delirium (b=−1.2, p=.014). These results suggest that thinner cortices, perhaps reflecting underlying neurodegeneration due to preclinical AD, may serve as a vulnerability factor that increases severity once delirium occurs.Publication Cognitive and Physical Demands of Activities of Daily Living In Older Adults: Validation of Expert Panel Ratings: The SAGES Functional Measures Working Group(2015) Fong, Tamara; Gleason, Lauren J.; Wong, Bonnie; Habtemariam, Daniel; Jones, Richard N.; Schmitt, Eva M.; de Rooij, Sophia E.; Saczynski, Jane S.; Gross, Alden L.; Bean, Jonathan; Brown, Cynthia J.; Fick, Donna M.; Gruber-Baldini, Ann L.; O’Connor, Margaret; Tabloski, Patrica A.; Marcantonio, Edward; Inouye, SharonBackground: Difficulties with performance of functional activities may result from cognitive and/or physical impairments. To date, there has not been a clear delineation of the physical and cognitive demands of activities of daily living. Objectives: To quantify the relative physical and cognitive demands required to complete typical functional activities in older adults. Design: Expert panel survey. Setting: Web-based platform. Participants: Eleven experts from eight academic medical centers and 300 community dwelling elderly adults age 70 and older scheduled for elective non-cardiac surgery from two academic medical centers. Methods: Sum scores of expert ratings were calculated and then validated against objective data collected from a prospective longitudinal study. Main Outcome Measurements Correlation between expert ratings and objective neuropsychological tests (memory, language, complex attention) and physical measures (gait speed and grip strength) for performance-based tasks. Results: Managing money, self-administering medications, using the telephone, and preparing meals were rated as requiring significantly more cognitive demand, while walking and transferring, moderately strenuous activities, and climbing stairs were assessed as more physically demanding. Largely cognitive activities correlated with objective neuropsychological performance (r=0.13–0.23, p<.05) and largely physical activities correlated with physical performance (r=0.15–0.46, p<.05). Conclusions: Quantifying the degree of cognitive and/or physical demand for completing a specific task adds an additional dimension to standard measures of functional assessment. This additional information may significantly influence decisions about rehabilitation, post-acute care needs, treatment plans, and caregiver education.Publication Telephone Interview for Cognitive Status: Creating a crosswalk with the Mini-Mental State Examination(Elsevier BV, 2009) Fong, Tamara; Fearing, Michael A.; Jones, Richard Norman; Shi, Peilin; Marcantonio, Edward; Rudolph, James; Yang, Frances Margaret; Kiely, Dan K.; Inouye, SharonBackground Brief cognitive screening measures are valuable tools for both research and clinical applications. The most widely used instrument, the Mini-Mental State Examination (MMSE), is limited in that it must be administered face-to-face, cannot be used in participants with visual or motor impairments, and is protected by copyright. Screening instruments such as the Telephone Interview for Cognitive Status (TICS) were developed to provide a valid alternative, with comparable cut-point scores to rate global cognitive function. Methods The MMSE, TICS-30, and TICS-40 scores from 746 community-dwelling elders who participated in the Aging, Demographics, and Memory Study (ADAMS) were analyzed with equipercentile equating, a statistical process of determining comparable scores based on percentile equivalents for different forms of an examination. Results Scores from the MMSE and TICS-30 and TICS-40 corresponded well, and clinically relevant cut-point scores were determined. For example, an MMSE score of 23 is equivalent to 17 and 20 on the TICS-30 and TICS-40, respectively. Conclusions These findings indicate that TICS and MMSE scores can be linked directly. Clinically relevant and important MMSE cut points and the respective ADAMS TICS-30 and TICS-40 cut-point scores are included, to identify the degree of cognitive impairment among respondents with any type of cognitive disorder. These results will help in the widespread application of TICS in both research and clinical practice.Publication Aging, brain disease, and reserve: Implications for delirium(2010) Jones, Richard Norman; Fong, Tamara; Metzger, Eran; Tulebaev, Samir; Yang, Frances Margaret; Alsop, David; Marcantonio, Edward; Cupples, L; Gottlieb, Gary; Inouye, SharonCognitive and brain reserve are well studied in the context of age-associated cognitive impairment and dementia. However, there is a paucity of research that examines the role of cognitive or brain reserve in delirium. Indicators (or proxy measures) of cognitive or brain reserve (such as brain size, education, and activities) pose challenges in the context of the long prodromal phase of Alzheimer disease but are diminished in the context of delirium, which is of acute onset. This article provides a review of original articles on cognitive and brain reserve across many conditions affecting the central nervous system, with a focus on delirium. The authors review current definitions of reserve. The authors identify indicators for reserve used in earlier studies and discuss these indicators in the context of delirium. The authors highlight future research directions to move the field ahead. Reserve may be a potentially modifiable characteristic. Studying the role of reserve in delirium can advance prevention strategies for delirium and may advance knowledge of reserve and its role in aging and neuropsychiatric disease generally.Publication Development of a unidimensional composite measure of neuropsychological functioning in older cardiac surgery patients with good measurement precision(Informa UK Limited, 2010) Jones, Richard Norman; Rudolph, James; Inouye, Sharon; Yang, Frances Margaret; Fong, Tamara; Milberg, William; Tommet, Douglas; Metzger, Eran; Cupples, L. Adrienne; Marcantonio, EdwardThe objective of this analysis was to develop a measure of neuropsychological performance for cardiac surgery and to assess its psychometric properties. Older patients (n = 210) underwent a neuropsychological battery using nine assessments. The number of factors was identified with variable reduction methods. Factor analysis methods based on item response theory were used to evaluate the measure. Modified parallel analysis supported a single factor, and the battery formed an internally consistent set (coefficient alpha = .82). The developed measure provided a reliable, continuous measure (reliability > .90) across a broad range of performance (–1.5 SDs to +1.0 SDs) with minimal ceiling and floor effects.Publication Delirium: An Independent Predictor of Functional Decline After Cardiac Surgery(Wiley-Blackwell, 2010) Rudolph, James; Inouye, Sharon; Jones, Richard N.; Yang, Frances Margaret; Fong, Tamara; Levkoff, Sue; Marcantonio, EdwardOBJECTIVES: To determine whether patients who developed delirium after cardiac surgery were at risk of functional decline. DESIGN: Prospective cohort study. SETTING: Two academic hospitals and a Veterans Affairs Medical Center. PARTICIPANTS: One hundred ninety patients aged 60 and older undergoing elective or urgent cardiac surgery. MEASUREMENTS: Delirium was assessed daily and was diagnosed according to the Confusion Assessment Method. Before surgery and 1 and 12 months postoperatively, patients were assessed for function using the instrumental activities of daily living (IADL) scale. Functional decline was defined as a decrease in ability to perform one IADL at follow-up. RESULTS: Delirium occurred in 43.1% (n=82) of the patients (mean age 73.7±6.7). Functional decline occurred in 36.3% (n=65/179) at 1 month and in 14.6% (n=26/178) at 12 months. Delirium was associated with greater risk of functional decline at 1 month (relative risk (RR)=1.9, 95% confidence interval (CI)=1.3–2.8) and tended toward greater risk at 12 months (RR=1.9, 95% CI=0.9–3.8). After adjustment for age, cognition, comorbidity, and baseline function, delirium remained significantly associated with functional decline at 1 month (adjusted RR=1.8, 95% CI=1.2–2.6) but not at 12 months (adjusted RR=1.5, 95% CI=0.6–3.3). CONCLUSION: Delirium was independently associated with functional decline at 1 month and had a trend toward association at 12 months. These findings provide justification for intervention trials to evaluate whether delirium prevention or treatment strategies might improve postoperative functional recovery.Publication Association cortex hypoperfusion in mild dementia with Lewy bodies: a potential indicator of cholinergic dysfunction?(Springer Science + Business Media, 2010) Fong, Tamara; Inouye, Sharon; Dai, Weiying; Press, Daniel; Alsop, DavidDementia with Lewy bodies (DLB) is often associated with occipital hypometabolism or hypoperfusion, as well as deficits in cholinergic neurotransmission. In this study, 11 mild DLB, 16 mild AD and 16 age-matched controls underwent arterial spin-labeled perfusion MRI (ASL-pMRI) and neuropsychological testing. Patterns of cerebral blood flow (CBF) and cognitive performance were compared. In addition, combined ASL-pMRI and ChEI drug challenge (pharmacologic MRI) was tested as a probe of cholinergic function in 4 of the DLB participants. Frontal and parieto-occipital hypoperfusion was observed in both DLB and AD but was more pronounced in DLB. Following ChEI treatment, perfusion increased in temporal and parieto-occipital cortex, and cognitive performance improved on a verbal fluency task. If confirmed in a larger study, these results provide further evidence for brain cholinergic dysfunction in DLB pathophysiology, and use of pharmacologic MRI as an in vivo measure of cholinergic function.Publication Identifying Indicators of Important Diagnostic Features of Delirium(Wiley-Blackwell, 2012) Huang, Li-Wen; Inouye, Sharon; Jones, Richard Norman; Fong, Tamara; Rudolph, James; O, Margaret G.; Metzger, Eran; Crane, Paul K.; Marcantonio, EdwardOBJECTIVES: To use an expert consensus process to identify indicators of delirium features to help enhance bedside recognition of delirium. DESIGN: Modified Delphi consensus process to assign existing cognitive and delirium assessment items to delirium features in the Confusion Assessment Method (CAM) diagnostic algorithm. SETTING: Meetings of expert panel. PARTICIPANTS: Panel of seven interdisciplinary clinical experts. MEASUREMENTS: Panelists' assignments of each assessment item to indicate CAM features. RESULTS: From an initial pool of 119 assessment items, the panel assigned 66 items to at least one CAM feature, and many items were assigned to more than one feature. Experts achieved a high level of consensus, with a postmeeting kappa for agreement of 0.98. The study staff compiled the assignment results to create a comprehensive list of CAM feature indicators, consisting of 107 patient interview questions, cognitive tasks, and interviewer observations, with some items assigned to multiple features. A subpanel shortened this list to 28 indicators of important delirium features. CONCLUSION: A systematic, well-described qualitative methodology was used to create a list of indicators for delirium based on the features of the CAM diagnostic algorithm. This indicator list may be useful as a clinical tool for enhancing delirium recognition at the bedside and for aiding in the development of a brief delirium screening instrument.
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