Biomedical subjects

Robert J Ivnik

Publications and source records attributed to Robert J Ivnik.

32 records · Page 2Linked to original sources

PubMed2004

Confrontation naming does not add incremental diagnostic utility in MCI and Alzheimer's disease.

As the incidence of dementia increases, there is a growing need to determine the diagnostic utility of specific neuropsychological tests in the early diagnosis of Alzheimer's disease (AD). In this study, the relative utility of Boston Naming Test (BNT) in the diagnosis of AD was examined and compared to the diagnostic utility of other neuropsychological measures commonly used in the evaluation of AD. Individuals with AD (n = 306), Mild Cognitive Impairment (MCI; n = 67), and cognitively normal subjects (n = 409) with at least 2 annual evaluations were included. Logistic regression analysis suggested that initial BNT impairment is associated with increased risk of subsequent AD diagnosis. However, this risk is significantly less than that imparted by measures of delayed recall impairments. A multivariate Cox proportional hazards regression analysis suggested that BNT impairment imparted no additional risk for subsequent AD diagnosis after delayed recall impairments were included in the model. Although BNT impairment occurred in all severity groups, it was ubiquitous only in moderate to severe dementia. Collectively these results suggest that although BNT impairments become more common as AD progresses, they are neither necessary for the diagnosis of AD nor particularly useful in identifying early AD.

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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

Cognitive asymmetries associated with apolipoprotein E genotype in patients with Alzheimer's disease.

The relationship between apolipoprotein E (apoE) genotype and cognitive performance was examined in 200 patients with probable Alzheimer's disease (AD). Differences between composite measures of verbal and nonverbal functioning were used to define asymmetric patterns of cognition. Patients who were homozygous for apoE epsilon4 demonstrated relatively worse nonverbal as compared to verbal cognitive ability. In contrast, participants who were heterozygous for apoE epsilon4 or who possessed no epsilon4 allele demonstrated relatively equivalent verbal and nonverbal cognitive abilities. Although age and dementia severity also contributed to these patterns, apoE genotype appears to have a significant unique contribution to cognitive performance in these individuals. The epsilon4 allele may thus be associated with a specific neurocognitive phenotype among patients with AD, with the overall pattern of cognitive asymmetry dependent upon epsilon4 dose.

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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

Dementia with Lewy bodies may present as dementia and REM sleep behavior disorder without parkinsonism or hallucinations.

Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance that commonly occurs in Dementia with Lewy bodies (DLB). Retrospective examination of DLB course has shown that RBD and cognitive decline may precede the onset of parkinsonism and visual hallucinations. Therefore, some patients with DLB may initially present with dementia and RBD, but would not meet current formal criteria for probable DLB at that time. The purpose of this study is to determine whether patients with dementia and RBD, who do not have parkinsonism or visual hallucinations, have cognitive profiles that can be distinguished from autopsy-confirmed definite AD, but not from clinically probable DLB. If so, this would support the hypothesis that the presence of RBD and dementia, as the only presenting symptoms, reflects the early manifestation of DLB. Results show that early dementia in probable DLB and dementia with RBD are neuropsychologically indistinguishable. Both groups differ from definite AD of a similar early stage with significantly worse visual perceptual organization, sequencing and letter fluency but significantly better confrontation naming and verbal memory. In addition, follow-up data from a subset of patients with dementia and RBD reveal the subsequent development of parkinsonism or hallucinations 1 to 6 years later. Results indicate that the presentation of dementia and RBD is suggestive of underlying Lewy body disease and not Alzheimer's disease. This provides further evidence in support of including RBD as one of the core diagnostic features of DLB.

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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

Diagnostic utility of letter fluency, category fluency, and fluency difference scores in Alzheimer's disease.

Word generation tasks, specifically letter fluency and category fluency, are a standard part of most test protocols used by clinical neuropsychologists to measure aspects of language and executive retrieval functions. Given the reliance on these measures as clinical tools, it is important to understand the diagnostic implications of patients' performances. In Alzheimer's disease (AD), category fluency has generally been found to be disproportionately impaired, whereas letter fluency is usually more mildly impaired. It has been proposed that this performance pattern occurs because access to temporal-lobe semantic stores is necessary for category fluency but not letter fluency. In this study, the diagnostic utility of category fluency, letter fluency, and difference scores (letter fluency minus category fluency) in AD were examined. Forty AD patients and 221 normal control subjects took category fluency and letter fluency tests. Traditional t-test comparisons revealed that the groups differed significantly on the two test tasks and in terms of mean difference scores. However, using sensitivity and specificity to calculate predictive values, only category fluency and letter fluency (but not difference scores) were useful in predicting AD in individuals. Furthermore, category fluency was superior to letter fluency in this regard. Likelihood ratio tables are provided for use in calculating the odds of AD for specific category fluency and letter fluency scores generated by individual patients.

Adult↗

PubMed2002

Mayo's Older Americans Normative Studies: expanded AVLT Recognition Trial norms for ages 57 to 98.

This paper expands upon previously published Mayo's Older Americans Normative Studies (MOANS) Auditory Verbal Learning Test (AVLT) norms by presenting age and gender specific data for Recognition Trial accuracy (recognition 'hits' corrected for false positive errors) in a total of 836 subjects (the original sample, augmented by an additional 311 subjects). Observations are offered concerning clinical implications of AVLT Recognition Trial performance. Gender differences in recognition memory are discussed.

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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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PubMed1984

Prescription medication dependence and neuropsychologic function.

The abuse of prescription drugs is an insidious complication among patients with chronic pain. This study examines cognitive intellectual functions in patients with chronic pain who are using prescribed analgesics, sedatives and hypnotics. A comprehensive battery of psychologic tests measuring intelligence, learning, memory, sensory-perceptual integrity, motor skills and general adaptive abilities was administered to 47 subjects. The subjects were patients admitted to a chronic pain management program, and they were divided into drug-dependent, drug-abusing and non-drug-abusing groups according to strictly defined criteria. Findings indicated that the prescribed use of these medications for pain over a prolonged time is detrimental to the cognitive function of such patients and complicates their clinical management.

Adult↗

PubMedDate not supplied

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Auditory Verbal Learning Test and the Visual Spatial Learning Test.

Although normative data sets for standardized neuropsychometric instruments frequently feature adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of education may be less closely associated with test performances than is overall intellectual functioning. In this last of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Rey Auditory Verbal Learning Test and the Visual Spatial Learning Test were found to be more strongly related to Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.150 to .395) than to education (rs=.060 to .236) for healthy older examinees between 56 and 99 years of age. Although AVLT-FSIQ correlations were greatest at moderate levels of intelligence, VSLT-FSIQ correlations consistently increased in strength as intelligence increased (cf. Dodrill, 19971999). Based on these results, we present tables of age- and IQ-adjusted percentile equivalents of Mayo age-adjusted AVLT index scores and MOANS age-adjusted AVLT and VSLT scaled scores for ten age ranges and either seven (AVLT) or five (VSLT) IQ ranges.

Acoustic Stimulation↗

PubMedDate not supplied

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Wechsler Memory Scale--Revised.

Normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables. There are reasons to believe, however, that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, "years of formal education" may be less closely related to test performances than is general intellectual functioning. In this third of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted index and scaled scores for the Wechsler Memory Scale-Revised were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.271 to .631) than with education (rs=.089 to .310) for healthy older examinees between 56 and 99 years of age. These associations were strongest for Attention/Concentration and General Memory Index scores and, in general, for individuals with average intelligence (cf. Dodrill, 19971999). Tables of age- and IQ-adjusted percentile equivalents of Mayo age-adjusted WMS-R index scores and MOANS age-adjusted WMS-R subtest scaled scores are presented for eleven age ranges and seven IQ ranges.

Age Factors↗

PubMedDate not supplied

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Trail-Making Test, the Stroop Test, and MAE Controlled Oral Word Association Test.

Although normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of formal education may be less closely related to test performances than is general intellectual functioning. In this second of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Trail-Making Test, the Stroop Color-Word Test, and the MAE Controlled Oral Word Associations Test were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.368 to .495) than with education (rs=.174 to .367) for healthy older examinees between 56 and 99 years of age. For the TMT and the COWAT, but not the Stroop, these associations became stronger as IQ increased (cf. Dodrill, 1997, 1999). Tables of age- and IQ-adjusted percentile equivalents of MOANS age-adjusted TMT, Stroop, and COWAT scores are presented for eleven age ranges and seven IQ ranges.

Age Factors↗

PubMedDate not supplied

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Boston Naming Test, the MAE Token Test, and the Judgment of Line Orientation Test.

Although many extant normative data sets for standardized neuropsychometric instruments feature adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, several theoretical considerations suggest that years of formal education may be less closely related to test performances than is general intellectual functioning. In this first of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores on the Boston Naming Test, the MAE Token Test, and the Judgment of Line Orientation Test were indeed found to be more strongly associated with Mayo Age-adjusted WAIS-R Full Scale IQ scores (rs=.608, .473, and .502, respectively) than with education (rs=.310, .306, and .236, respectively) for healthy older examinees (56-99 years). Consistent with the remarks of Dodrill (19971999), these correlations generally decreased at higher levels of intelligence. The magnitude and pattern of such declines varied across the three tests, however, suggesting that IQ-test score associations must be empirically determined rather than assumed to be linear. Tables of Age- and IQ-Adjusted percentile equivalents of MOANS Age-adjusted BNT, Token Test, and JLO scaled scores are presented for eleven age ranges and seven IQ ranges. The article concludes with a discussion of factors that may underlie observed relations among age, intelligence, and neuropsychometric test performances.

Age Factors↗