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Eric G Tangalos

Publications and source records attributed to Eric G Tangalos.

15 recordsLinked to original sources
PubMed2006

Longitudinal 1H MRS changes in mild cognitive impairment and Alzheimer's disease.

Magnetic resonance (MR)-based volume measurements of atrophy are potential markers of disease progression in patients with amnestic mild cognitive impairment (MCI) and Alzheimer's disease (AD). Longitudinal changes in (1)H MR spectroscopy ((1)H MRS) metabolite markers have not been characterized in MCI subjects. Our objective was to determine the longitudinal (1)H MRS metabolite changes in patients with MCI, and AD, and to compare (1)H MRS metabolite ratios and ventricular volumes in tracking clinical disease progression in AD. The neuronal integrity marker N-acetylaspartate/creatine ratio declined in MCI and AD patients compared to cognitively normal elderly. The change in (1)H MRS metabolite ratios correlated with clinical progression about as strongly as the rate of ventricular expansion, suggesting that (1)H MRS metabolite ratios may be useful markers for the progression of AD. Choline/creatine ratio declined in stable MCI, compared to converter MCI patients and cognitively normal elderly, which may be related to a compensatory mechanism in MCI patients who did not to progress to AD.

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PubMed2006

Neuropathologic features of amnestic mild cognitive impairment.

BACKGROUND: The neuropathologic substrate of amnestic mild cognitive impairment (aMCI) is not known. OBJECTIVE: To determine the neuropathologic features of patients who died while their clinical classification was aMCI. DESIGN: Cohort study. SETTING: Community based. PARTICIPANTS: Sixty-six individuals, including 15 who had memory impairment beyond that allowed for aging but who were not demented, were studied along with 28 clinically healthy individuals and 23 patients with probable Alzheimer disease (AD) for comparison. MAIN OUTCOME MEASURES: Standard neuropathologic techniques and classification according to Khachaturian, Consortium to Establish a Registry for Alzheimer Disease, and National Institute on Aging-Reagan criteria were used to analyze autopsy tissue from 15 individuals who died while their clinical diagnosis was aMCI. For comparison, autopsy data on age-matched groups of clinically healthy individuals and patients with probable AD were analyzed. RESULTS: Most patients with aMCI did not meet the neuropathologic criteria for AD, but their pathologic findings suggest a transitional state of evolving AD. All the patients with aMCI had pathologic findings involving medial temporal lobe structures, likely accounting for their memory impairment. In addition, there were many concomitant pathologic abnormalities, including argyrophilic grain disease, hippocampal sclerosis, and vascular lesions. CONCLUSIONS: The neuropathologic features of aMCI matched the clinical features and seemed to be intermediate between the neurofibrillary changes of aging and the pathologic features of very early AD.

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PubMed2006

Neuropathologic outcome of mild cognitive impairment following progression to clinical dementia.

BACKGROUND: The pathologic outcome of patients diagnosed with mild cognitive impairment (MCI) following progression to dementia is poorly understood. OBJECTIVE: To determine the pathologic substrates of dementia in cases with prior diagnosis of amnestic MCI. DESIGN AND SETTING: Community-based cohort. PATIENTS: Thirty-four subjects followed up prospectively as part of a community-based study who were diagnosed with amnestic MCI, progressed to clinical dementia, and underwent subsequent postmortem brain analysis. MAIN OUTCOME MEASURES: Neuropathologic analyses resulted in assignment of a primary pathologic diagnosis and included staging of Alzheimer pathologic abnormalities and identification of contributing vascular disease, Lewy bodies, and argyrophilic grains. RESULTS: Although the majority of subjects progressed both clinically and pathologically to Alzheimer disease (AD), 10 (29%) of them developed non-AD primary pathologic abnormalities. All of the cases were found to have sufficient pathologic abnormalities in mesial temporal lobe structures to account for their amnestic symptoms regardless of the cause. Most subjects were found to have secondary contributing pathologic abnormalities in addition to primary pathologic diagnoses. No significant differences between subjects with and without neuropathologically proven AD were detected in demographic variables, apolipoprotein E genotype, or cognitive test measures at onset of MCI, onset of dementia, or last clinical evaluation. CONCLUSIONS: The neuropathologic outcome of amnestic MCI following progression to dementia is heterogeneous, and it includes AD at a high frequency. Complex neuropathologic findings including 2 or more distinct pathologic entities contributing to dementia may be common in community-based cohorts. Neither demographic variables nor cognitive measures had predictive value in determining which patients diagnosed with MCI will develop the neuropathologic features of AD.

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PubMed2004

De novo genesis of neuropsychiatric symptoms in mild cognitive impairment (MCI).

BACKGROUND: There is inadequate information regarding the neuropsychiatric aspect of Mild Cognitive Impairment (MCI). OBJECTIVE: To determine the neuropsychiatric profile of MCI, and compare this with normal controls and patients with mild Alzheimer's Disease (AD). DESIGN: Cross-sectional assessment of psychiatric symptoms in subjects that are enrolled in Mayo Clinic's longitudinal study of normal aging, MCI and dementia. METHODS AND PARTICIPANTS: The Neuropsychiatric Inventory (NPI) was administered to normal control subjects, MCI subjects and patients with early AD. Individual NPI domain scores and total NPI scores were compared among the three groups after controlling for age, educational status, Dementia Rating Scale (DRS) and Mini-Mental State Examination (MMSE) scores. Statistical analysis was performed by utilizing ANOVA, chi2 and Fisher's exact test. RESULTS: Data were analyzed on 514 normal controls, 54 MCI subjects, and 87 subjects with mild AD (CDR of 0.5 or 1); females consisted of 60.3%, 53.7% and 57.5%; and, the average ages (SD) were 77.8 (1.95), 79 (4.6), 80.5 (14.6) respectively. ANOVA pair-wise comparison revealed that both MMSE and DRS differences among the three groups were significantly different at (p = 0.05). The total NPI scores were significantly different (p =0.0001, F = 107.93) among the three groups using ANOVA. Pair-wise comparison of individual behavioral domain of NPI showed statistically significant differences between MCI and normals; and MCI and AD (p = 0.001). Group differences on NPI remained after controlling for age and education at p = 0.0375 and p = 0.0050 respectively. CONCLUSION: The neuropsychiatric pattern is reminiscent of the clinical, neuroimaging and neuropsychological profile of MCI. It gives further credence to the view that MCI is indeed the gray zone, with overlap on both ends of the pole.

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PubMed2004

Patient satisfaction with point-of-care international normalized ratio testing and counseling in a community internal medicine practice.

Point-of-care international normalized ratio (POC INR) testing is increasingly used to monitor anticoagulant therapy. This study assessed patient satisfaction with registered nurse--managed POC INR testing in a primary care internal medicine practice. One hundred eighty-seven of the first 216 (87%) patients using the program responded to the survey. The respondents were surveyed for satisfaction after they had experienced the nurse-managed POC INR system at the Mayo Clinic, Rochester, Minnesota, for one month. Eighty-eight percent of patients indicated that they were very satisfied or satisfied with the POC INR system. The authors conclude that nurse-managed POC INR testing is quick, convenient, less painful, and more satisfying for patients compared with traditional venipuncture and telephone follow-up.

Anticoagulants↗
PubMed2003

Comparison of the short test of mental status and the mini-mental state examination in mild cognitive impairment.

BACKGROUND: The Mini-Mental State Examination (MMSE) is the most widely used brief screening measure of cognition, but it is not sensitive in detecting mild memory or other cognitive impairments. The Short Test of Mental Status (STMS) was specifically developed for use in dementia assessment and was intended to be more sensitive to problems of learning and mental agility that may be seen in mild cognitive impairment (MCI). OBJECTIVE: To compare the STMS and MMSE for detecting or predicting MCI. DESIGN: Comparison of STMS and MMSE scores at baseline among 4 groups of patients: 788 patients with stable normal cognition, 75 patients with normal cognition at baseline but who developed incident MCI or Alzheimer disease during follow-up, 129 patients with prevalent MCI at baseline, and 235 patients with prevalent mild Alzheimer disease. All patients and control subjects for this study were evaluated through the Mayo Alzheimer's Disease Patient Registry or the Mayo Clinic Alzheimer's Disease Research Center, Rochester, Minn, using a standardized diagnostic approach. RESULTS: The STMS was slightly more sensitive than the MMSE in discriminating between patients with stable normal cognition and patients with prevalent MCI. The STMS was superior to the MMSE in detecting deficits in cognition in individuals who had normal cognition at baseline but later developed incident MCI or Alzheimer disease. CONCLUSIONS: Compared with the MMSE, the STMS was better able to document MCI and was more sensitive in detecting deficits in cognition in individuals who had normal cognition at baseline but later developed incident MCI or Alzheimer disease.

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PubMed2003

Proton MR spectroscopy in mild cognitive impairment and Alzheimer disease: comparison of 1.5 and 3 T.

BACKGROUND AND PURPOSE: Theoretically, proton ((1)H) MR spectroscopy at a higher field strength has the advantages of higher signal-to-noise ratio and improved spectral resolution. We therefore compared the ability of single-voxel (1)H MR spectroscopy at 1.5 and 3 T to diagnostically discriminate among cognitively normal elderly subjects, patients with mild cognitive impairment (MCI), and patients with Alzheimer disease (AD). METHODS: At both 1.5 and 3 T, we studied 41 cognitively normal elderly subjects, 20 patients with MCI, and 20 patients with AD. In each subject, (1)H MR spectroscopy was performed at TEs of 30 and 135 ms and from voxels placed over the posterior cingulate gyri. RESULTS: Average line widths and interexamination variability of metabolite ratios were higher at 3 T than at 1.5 T. Consistent quantification of glutamine (Gln) + glutamate/creatine (Cr) and Gln/Cr peak ratios occurred at 3 T but not at 1.5 T. Choline (Cho)/Cr (at TE = 135 ms) and myo-inositol (MI)/Cr were higher and N-acetylaspartate (NAA)/Cr (at TE = 135 ms) and NAA/MI were lower in patients with MCI than in cognitively normal subjects only at 1.5 T. MI/Cr and Cho/Cr were higher and NAA/Cr and NAA/MI were lower in patients with AD than in cognitively normal subjects at both 1.5 and 3 T. Differentiation of patients with AD from cognitively normal subjects by using the NAA/MI data was similar at both field strengths (P >.05). CONCLUSION: With currently available technology, the diagnostic performance of (1)H MR spectroscopy in patients with MCI and those with AD was not better at 3 T than at 1.5 T.

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PubMed2002

1H magnetic resonance spectroscopy, cognitive function, and apolipoprotein E genotype in normal aging, mild cognitive impairment and Alzheimer's disease.

The aim of this study was to examine the associations of apolipoprotein E (APOE) genotype, metabolic changes in the posterior cingulate detected by 1H magnetic resonance spectroscopy (MRS), and neuropsychologic measures of memory and cognition both in normally aging elderly, and in patients with mild cognitive impairment (MCI) and AD. We studied 67 controls, 18 MCI and 33 AD patients. We used the Dementia Rating Scale total score (DRSTOT) as a measure of general cognitive function and the total learning from the Auditory Verbal Learning Test (AVTOT) as a measure of memory performance. No differences were noted on 1H-MRS metabolite ratios or cognitive measures across APOE genotype within control and patient groups. In controls, age was a significant predictor of both cognitive test scores, and NAA/Cr was a univariate associate of DRSTOT. All 3 1H-MRS metabolite ratios, N-acetylaspartate (NAA)/creatine (Cr), myoinositol (MI)/Cr, and NAA/MI, were univariate associates of AVTOT and DRSTOT scores in the combined MCI and AD group. In stepwise regression analyses in the combined patient group only NAA/MI entered the models. These data suggest NAA/Cr could be a modest predictor of general cognitive function in both healthy elderly and impaired patients, while MI/Cr is a more specific marker for neuropsychologic dysfunction associated with neurodegenerative disease. Among 1H-MRS measurements, the NAA/MI ratio maybe the most efficient predictor of memory and cognitive function in patients with MCI and AD.

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PubMed2002

Comparative diagnostic utility of different MR modalities in mild cognitive impairment and Alzheimer's disease.

This study compares the diagnostic accuracy of magnetic resonance (MR)-based hippocampal volumetry, single voxel (1)H MR spectroscopy ((1)H MRS) and MR diffusion-weighted imaging (DWI) measurements in discriminating patients with amnestic mild cognitive impairment (MCI), Alzheimer's disease (AD) and normally aging elderly. Sixty-one normally aging elderly, 24 MCI and 22 AD patients underwent MR-based hippocampal volumetry, (1)H MRS and DWI. (1)H MRS voxels were placed over both of the posterior cingulate gyri, and N-acetyl aspartate (NAA)/creatine (Cr), myoinositol (MI)/Cr and NAA/MI ratios were obtained. Apparent diffusion coefficient (ADC) maps were derived from DWI, and hippocampal borders were traced to measure hippocampal ADC. At 80% specificity, the most sensitive single measurement to discriminate MCI (79%) and AD (86%) from controls was hippocampal volumes. The most sensitive single measurement to discriminate AD from MCI was posterior cingulate gyrus NAA/Cr (67%). At high specificity (>85-90%), combinations of MR measures had superior diagnostic sensitivity compared with any single MR measurement for the AD vs. control and control vs. MCI comparisons. The MR measures that best discriminate more from less affected individuals along the cognitive continuum from normal to AD vary with disease severity. Selection of imaging measures used for clinical assessment or monitoring efficiency of therapeutic intervention should be tailored to the clinical stage of the disease.

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