Alzheimer Disease: Weiner M

Studholme C, Cardenas V, Song E, Ezekiel F, Maudsley A, Weiner M. · Department of Radiology, University of California San Francisco, VAMC 114Q, Bldg. 9, Room 200 4150, Clement Street, San Francisco, CA 94121, USA. · IEEE Trans Med Imaging. · Pubmed #14719691 links to  free full text

Abstract: This paper examines an alternative approach to separating magnetic resonance imaging (MRI) intensity inhomogeneity from underlying tissue-intensity structure using a direct template-based paradigm. This permits the explicit spatial modeling of subtle intensity variations present in normal anatomy which may confound common retrospective correction techniques using criteria derived from a global intensity model. A fine-scale entropy driven spatial normalisation procedure is employed to map intensity distorted MR images to a tissue reference template. This allows a direct estimation of the relative bias field between template and subject MR images, from the ratio of their low-pass filtered intensity values. A tissue template for an aging individual is constructed and used to correct distortion in a set of data acquired as part of a study on dementia. A careful validation based on manual segmentation and correction of nine datasets with a range of anatomies and distortion levels is carried out. This reveals a consistent improvement in the removal of global intensity variation in terms of the agreement with a global manual bias estimate, and in the reduction in the coefficient of intensity variation in manually delineated regions of white matter.

Baskin F, Rosenberg RN, Fang X, Hynan LS, Moore CB, Weiner M, Vega GL. · Department of Neurology, University of Texas Southwestern Medical Center at Dallas, TX 75390-9036, USA. · Neurology. · Pubmed #12821755 No free full text.

Abstract: Platelets, like neurons, contain 120- to 130- and 110-kd amyloid precursor proteins (APPs). Their ratio is reduced in AD, further reductions correlating with reduced Mini-Mental Status Examination scores [r(11) = 0.69, p < 0.05]. As statins alter APP processing, platelet APPs were analyzed in patients with AD given anticholesterol drugs for 6 weeks. APP ratios increased [t(37) = -3.888, p = 0.0004], proportionally with reduced cholesterol [r(36) = -0.45, p = 0.005]. Longer trials may reveal slowed cognitive loss, validating this index.

Aisen PS, Egelko S, Andrews H, Diaz-Arrastia R, Weiner M, DeCarli C, Jagust W, Miller JW, Green R, Bell K, Sano M. · Department of Neurology, Georgetown University Medical Center, Washington, DC 20007, USA. · Am J Geriatr Psychiatry. · Pubmed #12611755 No free full text.

Abstract: OBJECTIVE: Authors determined the impact of high-dose vitamin supplements on plasma homocysteine levels in patients with Alzheimer disease (AD). METHODS: Authors used an open-label trial of folic acid, vitamin B(12), and vitamin B(6), in combination for 8 weeks, with measurement of plasma homocysteine levels in the fasting state and after methionine-loading. A total of 69 subjects with AD were enrolled, including 33 who were taking standard multivitamin supplements; 66 were available at 8-week follow-up. RESULTS: The high-dose vitamin regimen was associated with a significant reduction in fasting and post-methionine-loading homocysteine. Reductions were greater in the subgroup not using multivitamins, but were also significant in the multivitamin users. CONCLUSION: High-dose vitamin supplementation reduces homocysteine levels in patients with AD. The effect of supplementation on rate of cognitive decline will be assessed later in a randomized, double-blind study.

Jack CR, Lowe VJ, Weigand SD, Wiste HJ, Senjem ML, Knopman DS, Shiung MM, Gunter JL, Boeve BF, Kemp BJ, Weiner M, Petersen RC, Anonymous00039. · Clifford R. Jack, Mayo Clinic, Diagnostic Radiology, 200 First Street SW, Rochester, MN 55905, USA. · Brain. · Pubmed #19339253 links to  free full text

Abstract: The purpose of this study was to use serial imaging to gain insight into the sequence of pathologic events in Alzheimer's disease, and the clinical features associated with this sequence. We measured change in amyloid deposition over time using serial (11)C Pittsburgh compound B (PIB) positron emission tomography and progression of neurodegeneration using serial structural magnetic resonance imaging. We studied 21 healthy cognitively normal subjects, 32 with amnestic mild cognitive impairment and 8 with Alzheimer's disease. Subjects were drawn from two sources--ongoing longitudinal registries at Mayo Clinic, and the Alzheimer's disease Neuroimaging Initiative (ADNI). All subjects underwent clinical assessments, MRI and PIB studies at two time points, approximately one year apart. PIB retention was quantified in global cortical to cerebellar ratio units and brain atrophy in units of cm(3) by measuring ventricular expansion. The annual change in global PIB retention did not differ by clinical group (P = 0.90), and although small (median 0.042 ratio units/year overall) was greater than zero among all subjects (P < 0.001). Ventricular expansion rates differed by clinical group (P < 0.001) and increased in the following order: cognitively normal (1.3 cm(3)/year) < amnestic mild cognitive impairment (2.5 cm(3)/year) < Alzheimer's disease (7.7 cm(3)/year). Among all subjects there was no correlation between PIB change and concurrent change on CDR-SB (r = -0.01, P = 0.97) but some evidence of a weak correlation with MMSE (r =-0.22, P = 0.09). In contrast, greater rates of ventricular expansion were clearly correlated with worsening concurrent change on CDR-SB (r = 0.42, P < 0.01) and MMSE (r =-0.52, P < 0.01). Our data are consistent with a model of typical late onset Alzheimer's disease that has two main features: (i) dissociation between the rate of amyloid deposition and the rate of neurodegeneration late in life, with amyloid deposition proceeding at a constant slow rate while neurodegeneration accelerates and (ii) clinical symptoms are coupled to neurodegeneration not amyloid deposition. Significant plaque deposition occurs prior to clinical decline. The presence of brain amyloidosis alone is not sufficient to produce cognitive decline, rather, the neurodegenerative component of Alzheimer's disease pathology is the direct substrate of cognitive impairment and the rate of cognitive decline is driven by the rate of neurodegeneration. Neurodegeneration (atrophy on MRI) both precedes and parallels cognitive decline. This model implies a complimentary role for MRI and PIB imaging in Alzheimer's disease, with each reflecting one of the major pathologies, amyloid dysmetabolism and neurodegeneration.

Young K, Du AT, Kramer J, Rosen H, Miller B, Weiner M, Schuff N. · Department of Radiology, University of California-San Francisco, and VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA. · Hum Brain Mapp. · Pubmed #18677745 No free full text.

Abstract: The goal of this project was to utilize an information theoretic formalism for medical image analysis initially proposed in [Young et al. (2005): Phys Rev Lett 94:098701-1] to detect and quantify subtle global and regional differences in spatial patterns in patients suffering from Alzheimer's disease (AD) and frontotemporal dementia (FTD) by estimating the structural complexity of anatomical brain MRI. The sensitivity and specificity of the results are compared with those of a recent analysis, currently considered state of the art for MR studies of neurodegeneration. The previous study used regional estimates of cortical thinning and/or volume loss to differentiate between normal aging, AD, and FTD. The analysis illustrates that the structural complexity estimation method, a general multivariate approach to the study of variation in brain structure which does not depend on highly specialized volumetric and thickness estimates, is capable of providing sensitive and interpretable diagnostic information.

Weiner M, Fields J, Hynan L, Cullum CM. · Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9129, USA. · Clin Neuropsychol. · Pubmed #18609317 links to  free full text

Abstract: The rate of functional change in persons with mild Alzheimer's disease (AD) was compared to that of cognitively normal elderly control subjects. A comparison of annualized rates of change on the Test of Everyday Functional Abilities (TEFA) was carried out, along with a brief measure of instrumental activities of daily living skills, in persons with mild AD (Mini-Mental State Exam score >20) and cognitively normal elderly controls. Persons with AD (N = 30) showed an 8.5 % (3.5 point) annualized decline in TEFA scores over an average of 1.2 years; there was no decline in a group of elderly normal controls (N = 20) over an average of 1.5 years. Persons with mild AD showed functional changes over the course of a year on a direct measure of instrumental activities of daily living; a comparable group of normally aging persons did not.

Kuczynski B, Reed B, Mungas D, Weiner M, Chui HC, Jagust W. · Helen Wills Neuroscience Institute and the Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA. · Arch Neurol. · Pubmed #18474742 links to  free full text

Abstract: BACKGROUND: Alzheimer disease and cerebrovascular disease affect elderly persons through alterations in brain structure and metabolism that produce cognitive decline. Understanding how each disease contributes to dementia is essential from both a pathophysiologic and diagnostic perspective. OBJECTIVE: To elucidate how baseline cognitive function (episodic memory and executive function) and brain anatomy (white matter hyperintensities and hippocampal volume) are associated with baseline (positron emission tomography-1 [PET1]) and longitudinal (PET2) glucose metabolism in 38 subjects older than 55 years ranging from normal cognition, cognitive impairment without dementia, and dementia. DESIGN: Cross-sectional regression analyses across subjects. SETTING: Multicenter, university-based study of subcortical vascular dementia. MAIN OUTCOME MEASURES: Regional cerebral glucose metabolism was the primary outcome, with the major hypotheses that memory and hippocampal volume are related to temporoparietal hypometabolism while executive function and white matter hyperintensities correlate with frontal lobe hypometabolism. RESULTS: Low baseline hippocampal volume predicted longitudinal development (PET2) of medial temporal hypometabolism. Lower memory was associated with parietal and cingulate hypometabolism at PET1, which increased at the 2-year-follow-up (PET2). Executive function was associated with frontal and temporoparietal hypometabolism at PET1 but only with frontal hypometabolism at follow-up. White matter hyperintensities predicted hypometabolism over time in the frontoparietal regions, predicting a rate of metabolic change (PET1 - PET2/time). CONCLUSIONS: Low baseline episodic memory and hippocampal volume predict the metabolic alterations associated with Alzheimer disease, whereas elevated baseline white matter hyperintensities predict a different pattern of metabolic decline that is plausibly associated with cerebrovascular disease.

Iordanova B, Rosenbaum D, Norman D, Weiner M, Studholme C. · Department of Radiology, Magnetic Resonance Unit, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA. · AJNR Am J Neuroradiol. · Pubmed #16971629 links to  free full text

Abstract: BACKGROUND AND PURPOSE: Brain volumetry is widely used for evaluating tissue degeneration; however, the parcellation methods are rarely validated and use arbitrary planes to mark boundaries of brain regions. The goal of this study was to develop, validate, and apply an MR imaging tracing method for the parcellation of 3 major gyri of the frontal lobe, which uses only local landmarks intrinsic to the structures of interest, without the need for global reorientation or the use of dividing planes or lines. METHODS: Studies were performed on 25 subjects--healthy controls and subjects diagnosed with Lewy body dementia and Alzheimer disease--with significant variation in the underlying gyral anatomy and state of atrophy. The protocol was evaluated by using multiple observers tracing scans of subjects diagnosed with neurodegenerative disease and those aging normally, and the results were compared by spatial overlap agreement. To confirm the results, observers marked the same locations in different brains. We illustrated the variabilities of the key boundaries that pose the greatest challenge to defining consistent parcellations across subjects. RESULTS: The resulting gyral volumes were evaluated, and their consistency across raters was used as an additional assessment of the validity of our marking method. The agreement on a scale of 0-1 was found to be 0.83 spatial and 0.90 volumetric for the same rater and 0.85 spatial and 0.90 volumetric for 2 different raters. The results revealed that the protocol remained consistent across different neurodegenerative conditions. CONCLUSION: Our method provides a simple and reliable way for the volumetric evaluation of frontal lobe neurodegeneration and can be used as a resource for larger comparative studies as well as a validation procedure of automated algorithms.

Duarte A, Hayasaka S, Du A, Schuff N, Jahng GH, Kramer J, Miller B, Weiner M. · Center for Imaging of Neurodegenerative Diseases, San Francisco VA Medical Center, CA, USA. · Neurosci Lett. · Pubmed #16904823 links to  free full text

Abstract: In Alzheimer's disease (AD), atrophy negatively impacts cognition while in healthy adults, inverse relationships between brain volume and cognition may occur. We investigated correlations between gray matter volume and cognition in elderly controls, AD and mild cognitive impairment (MCI) patients with memory and executive deficits. AD demonstrated substantial loss in temporal, parietal and frontal regions while MCI exhibited moderate volume loss in temporal and frontal regions. In controls, memory and executive function were negatively correlated with frontal regions, while in AD, memory was positively correlated with temporal and frontal gyri, and executive function with frontal regions. The combination of the two patterns may explain the lack of correlations in MCI. Developmental versus pathological contributions to these relationships are discussed.

Mintzer J, Greenspan A, Caers I, Van Hove I, Kushner S, Weiner M, Gharabawi G, Schneider LS. · Department of Psychiatry and Behavioral Sciences, VA Medical Center, Medical University of South Carolina, Charleston, 29406, USA. · Am J Geriatr Psychiatry. · Pubmed #16505133 No free full text.

Abstract: OBJECTIVE: The objective of this study was to evaluate efficacy and safety of low-dose risperidone for treating psychosis of Alzheimer disease (AD). METHOD: The authors conducted a randomized, eight-week, double-blind, placebo-controlled, multicenter trial involving nursing home residents diagnosed with AD and psychosis. Four hundred seventy-three patients were randomly assigned to placebo (N = 238) or 1.0 to 1.5 mg risperidone per day (N = 235). Coprimary efficacy end points were: changes in scores on the Behavioral pathology in Alzheimer's Disease (BEHAVE-AD) Psychosis subscale and Clinical Global Impression of Change (CGI-C). Protocol-specified subgroup analyses were performed by demographics and dementia severity. RESULTS: Efficacy analysis included 416 patients. Both groups improved significantly on the BEHAVE-AD Psychosis subscale and CGI-C with no significant difference between groups. In the subgroups analyses, a statistically significant treatment by Mini-Mental Status Examination (MMSE) interaction on the CGI-C (F([2,381]) = 3.90, p = 0.021) was observed with patients with more severe dementia (MMSE <10) showing significant differences at end point favoring risperidone treatment (chi(2) ([1]) = 5.11, p = 0.024). Mean risperidone dose was 1.03 +/- 0.24 mg per day. All-cause discontinuation rates were 25% for both risperidone and placebo. Treatment-emergent adverse events occurred in 74% risperidone versus 64% placebo patients, with somnolence occurring significantly more frequently with risperidone (16.2% versus 4.6%). Nine (3.8%) risperidone- and six (2.5%) placebo patients died during or within 30 days after treatment. CONCLUSION: This trial did not confirm earlier findings in this population.

Vega GL, Weiner M, Kölsch H, von Bergmann K, Heun R, Lutjohan D, Nguyen A, Moore C. · Department of Clinical Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9052, USA. · Curr Alzheimer Res. · Pubmed #15975088 No free full text.

Abstract: To examine the effect of gender and polymorphisms of CYP46 and apo E on plasma levels of 24S-hydroxycholesterol in Alzheimer's disease (AD) patients and to determine whether these factors contribute to the variability in responses to statin treatment. Fifty-three AD patients had measurement of plasma levels of 24S-hydroxycholesterol, plasma and lipoprotein cholesterol and genotyping of CYP46 and apo E. Thirty-nine of the subjects subsequently participated in a statin trial for 6 weeks, and had a repetition of the baseline measurements. Baseline levels of 24S-hydroxycholesterol were higher in women than in men. There was a positive and significant correlation of plasma oxysterol levels with levels of total plasma cholesterol (women: r = .72, P < .0001; men: r = .47, P = .02) and non-HDL cholesterol (women: r = .68, P < .0001; men: r = 0.51, P = .01) (and LDL cholesterol) but not HDL cholesterol levels. There was no association of CYP46 or apo E polymorphisms with plasma levels of 24S-hydroxycholesterol. AD subjects treated with statins had a similar percent reduction in lathosterol, 24S-hydroxycholesterol, total cholesterol and non-HDL (and LDL) cholesterol regardless of gender and polymorphisms of CYP46. Subjects with the 4/4 polymorphism had less reduction in the ratios of 24S-hydroxycholesterol-LDL cholesterol. Women with AD had higher levels of plasma 24S-hydroxycholesterol levels than men. Women also showed a very strong correlation of plasma levels of 24S-hydroxycholesterol-to-total and non-HDL cholesterol. This may suggest that the oxysterol may be an important marker of AD risk instead of total cholesterol, as suggested by others. Polymorphisms of CYP46 or apo E do not explain levels of oxysterol or non-HDL cholesterol or the responsiveness to statin treatment in this study.

Ezekiel F, Chao L, Kornak J, Du AT, Cardenas V, Truran D, Jagust W, Chui H, Miller B, Yaffe K, Schuff N, Weiner M. · Magnetic Resonance Unit, San Francisco Veterans Affairs Medical Center, San Francisco, California 94121, USA. · Alzheimer Dis Assoc Disord. · Pubmed #15592130 links to  free full text

Abstract: The objectives of this study were to (1) compare atrophy rates associated with normal aging and Alzheimer disease (AD) using the semi-automated Boundary Shift Integral (BSI) method and manual tracing of the entorhinal cortex (ERC) and hippocampus and (2) calculate power of BSI vs. ERC and hippocampal volume changes for clinical trials in AD. We quantified whole brain and ventricular BSI atrophy rates and ERC and hippocampal atrophy rates from longitudinal MRI data in 20 AD patients and 22 age-matched healthy controls. All methods revealed significant brain atrophy in controls and AD patients. AD patients had approximately 2.5 times greater whole brain BSI atrophy rates and more than 5 times greater ERC and hippocampal atrophy rates than controls. ERC and hippocampal atrophy rates were higher in both groups than whole brain BSI atrophy rates, but lower than ventricular BSI atrophy rates. Effect size and power calculations suggest that ERC and hippocampal measurements may be more sensitive than ventricular or whole brain BSI for detecting AD progression and the potential effects of disease modifying agents. Logistic regression analysis revealed that combined rates of ERC and ventricular BSI were the best explanatory variables for classifying AD from controls.

DeCarli C, Mungas D, Harvey D, Reed B, Weiner M, Chui H, Jagust W. · Department of Neurology, University of California at San Francisco, USA. · Neurology. · Pubmed #15277612 links to  free full text

Abstract: BACKGROUND: Mild cognitive impairment (MCI) is widely viewed as the transition phase between normal aging and Alzheimer disease (AD). Given that MCI can also result from cerebrovascular disease (CVD), the authors used clinical, MRI, and cognitive measures of AD and CVD to test the hypothesis that CVD increases the likelihood of progression from MCI to dementia within 3 years. OBJECTIVE: To examine the impact of CVD on progression of MCI to dementia. METHODS: Fifty-two consecutive patients with MCI (71% men) including many with symptomatic CVD were longitudinally evaluated for 3.1 +/- 1.3 years. MCI was defined as a Clinical Dementia Rating Scale (CDR) score of 0.5. Dementia was defined as progression to a CDR score of > or =1.0. RESULTS: Forty-four percent of the MCI patients had MRI infarcts, 50% of which were symptomatic. Thirty-three percent of patients progressed to dementia, and 37.8% of these had MRI infarcts. Clinically probable or possible AD was diagnosed in approximately 82% of converters. Of the clinical and MRI measures, only hippocampal volume was associated with increased risk to progression (hazard ratio [HR] = 0.31 [95% CI 0.1 to 0.92], p = 0.03). When neuropsychological measures were included in the analysis, memory (HR = 0.90 [95% CI 0.84 to 0.96], p = 0.002) and executive function (HR = 0.96 [95% CI 0.92 to 1.0], p = 0.045) were associated with increased risk of dementia progression, whereas APOE genotype, cerebrovascular risk factors, clinical stroke, presence or absence of lacunes, and extent of white matter hyperintensities did not predict progression. CONCLUSION: Within a heterogenous group of MCI patients, including many with clinically significant CVD, baseline memory and executive performance significantly predicted likelihood to develop dementia.

Liu W, Miller BL, Kramer JH, Rankin K, Wyss-Coray C, Gearhart R, Phengrasamy L, Weiner M, Rosen HJ. · Department of Neurology, University of California at San Francisco, USA. · Neurology. · Pubmed #15007124 links to  free full text

Abstract: OBJECTIVE: To compare the behavioral features and to investigate the neuroanatomic correlates of behavioral dysfunction in anatomically defined temporal and frontal variants of frontotemporal dementia (tvFTD and fvFTD). METHODS: Volumetric measurements of the frontal, anterior temporal, ventromedial frontal cortical (VMFC), and amygdala regions were made in 51 patients with FTD and 20 normal control subjects, as well as 22 patients with Alzheimer disease (AD) who were used as dementia controls. FTD patients were classified as fvFTD or tvFTD based on the relative degree of frontal and anterior temporal volume loss compared with controls. Behavioral symptoms, cerebral volumes, and the relationship between them were examined across groups. RESULTS: Both variants of FTD showed significant increases in rates of elation, disinhibition, and aberrant motor behavior compared with AD. The fvFTD group also showed more anxiety, apathy, and eating disorders, and tvFTD showed a higher prevalence of sleep disturbances than AD. The only behaviors that differed significantly between fvFTD and tvFTD were apathy, greater in fvFTD, and sleep disorders, more frequent in tvFTD. FvFTD was associated with greater frontal atrophy and tvFTD was associated with more temporal and amygdala atrophy compared with AD, but both groups showed significant atrophy in the VMFC compared with AD, which was not associated with VMFC atrophy. In FTD, the presence of many of the behavioral disorders was associated with decreased volume in right-hemispheric regions. CONCLUSION: FvFTD and tvFTD show many similarities in behavior, which appear to be associated with damage to right frontal and temporal structures.

Studholme C, Cardenas V, Maudsley A, Weiner M. · Department of Radiology, VAMC (114Q), University of California-San Francisco, 4150 Clement Street, San Francisco, CA 94121, USA. · Neuroimage. · Pubmed #12948718 No free full text.

Abstract: Deformation tensor morphometry makes use of the derivatives of spatial transformations between anatomies, to provide highly localized volumetric maps of relative anatomical size. The analysis of such maps, however, has the challenge of describing the data in a way that allows the spatial scale and extent of the local shape properties to match those induced by the disease process being studied. This study examines an approach to the spatial filtering of transformation Jacobian maps created in multisubject studies of brain anatomy, which constrains the filter neighborhood within common structural boundaries present in the spatially normalized image data. The filtering incorporates information derived from the spatial normalization process, using a statistical framework to introduce a measure of uncertainty in local regional intensity correspondence following spatial normalisation. The proposed filtering approach is compared to the use of spatially invariant Gaussian filtering in the analysis of Jacobian determinant maps of brain shape and shape change in Alzheimer's disease and normal aging. Results show significantly improved delineation of fine scale patterns of shape difference (in cross-sectional studies) and shape change (from multiple serial magnetic resonance imaging studies).

Boxer AL, Rankin KP, Miller BL, Schuff N, Weiner M, Gorno-Tempini ML, Rosen HJ. · Memory and Aging Center and the Department of Neurology, University of California at San Francisco, 94143, USA. · Arch Neurol. · Pubmed #12873851 links to  free full text

Abstract: BACKGROUND: Progressive brain atrophy is associated with Alzheimer disease (AD) and other dementias. Regional differences in brain atrophy may reflect clinical features of disease. OBJECTIVE: To identify regions of cerebral atrophy that are associated with AD vs other dementias. SETTING: University hospital dementia clinic. PARTICIPANTS: Eleven patients with AD and 11 with semantic dementia (SD), matched for age, sex, education, and degree of overall cognitive impairment and 15 normal controls. METHODS: Voxel-based morphometry was used to compare patterns of gray matter loss, measured on T1-weighted magnetic resonance images, between patients with AD or SD, a subtype of frontotemporal lobar degeneration, and controls. Statistically significant differences in regional gray matter concentration, after multiple-comparisons correction, between groups of subjects were identified. RESULTS: Patients with AD were more impaired than those with SD on tests of visuospatial function and on simple calculations. Consistent with these neuropsychological deficits, the most significant area of atrophy in the AD group was the left parietal cortex vs controls (z = 5.0; P =.04). Compared with SD, AD was associated with more atrophy in the left parietal lobe (z = 5.6; P =.04) and bilaterally in the posterior cingulate/precuneus (z = 5.1; P =.04). A discriminant function analysis demonstrated that the degree of atrophy of right posterior cingulate, left parietal lobe, right amygdala, and right anterior temporal lobe structures correctly classified 96% of the patients. CONCLUSION: Alzheimer disease is associated with a specific pattern of cortical atrophy compared with SD.

Chapman SB, Zientz J, Weiner M, Rosenberg R, Frawley W, Burns MH. · Center for BrainHealth, University of Texas at Dallas, USA. · Alzheimer Dis Assoc Disord. · Pubmed #12218649 No free full text.

Abstract: The purpose of this study was to determine the sensitivity of discourse gist measures to the early cognitive-linguistic changes in Alzheimer disease (AD) and in the preclinical stages. Differences in discourse abilities were examined in 25 cognitively normal adults, 24 adults with mild probable AD, and 20 adults with mild cognitive impairment (MCI) at gist and detail levels of discourse processing. The authors found that gist and detail levels of discourse processing were significantly impaired in persons with AD and MCI as compared with normal control subjects. Gist-level discourse processing abilities showed minimal overlap between cognitively normal control subjects and those with mild AD. Moreover, the majority of the persons with MCI performed in the range of AD on gist measures. These findings indicate that discourse gist measures hold promise as a diagnostic complement to enhance early detection of AD. Further studies are needed to determine how early the discourse gist deficits arise in AD.

Rosen HJ, Kramer JH, Gorno-Tempini ML, Schuff N, Weiner M, Miller BL. · Department of Neurology, Memory and Aging Center, University of California at San Francisco, CA 94143-1207, USA. · Am J Geriatr Psychiatry. · Pubmed #11790639 No free full text.

Abstract: The authors illustrate the spectrum of clinical and imaging patterns in primary progressive aphasia (PPA), a syndrome of slowly progressive speech and language impairment occurring with neurodegenerative disease. Although PPA presents with relatively isolated impairment in language, many patients progress to global cognitive or behavioral dysfunction. The syndrome may be associated with frontotemporal dementia (FTD)- or Alzheimer disease (AD)-type changes. Authors describe the clinical presentation in three cases of PPA and analyze the pattern of cerebral atrophy in each case with voxel-based morphometry. Two patients presented with nonfluent progressive aphasia. Subtle differences in the clinical features were suggestive of FTD in one case and AD in the other. Neuroimaging revealed a predominance of frontal atrophy in the first case and temporo-parietal atrophy in the second. The third case presented with the syndrome of semantic dementia and showed the typical behavioral problems associated with FTD and a pattern of left-greater-than-right temporal atrophy. Different clinical syndromes in PPA are associated with different patterns of atrophy. In the future, combined analysis of imaging and clinical characteristics may allow more accurate etiologic diagnosis.

Reed BR, Eberling JL, Mungas D, Weiner M, Jagust WJ. · Department of Neurology, University of California, Davis, CA, USA. · Arch Neurol. · Pubmed #11255455 links to  free full text

Abstract: BACKGROUND: A proportion of patients with subcortical lacunes will suffer progressive cognitive dysfunction, but the basis for this decline is controversial and little is known about predicting cognitive decline in these patients. Studies of Alzheimer disease have shown that imaging measures of temporal and parietal metabolism and blood flow predict disease course. OBJECTIVE: To determine whether regional cerebral glucose metabolism predicts cognitive decline by testing 2 opposing hypotheses: (1) temporoparietal activity predicts decline (based on the idea that concomitant Alzheimer disease causes decline) vs (2) frontal hypometabolism predicts decline (based on evidence that subcortical frontal circuits are especially vulnerable to small vessel ischemia). DESIGN: Prospective cohort study. SETTING: University outpatient dementia center. PATIENTS: A convenience sample of 26 patients with radiologically defined lacunes and baseline cognitive function ranging from normal to moderately demented. MAIN OUTCOME MEASURES: Regional cerebral metabolism was quantitated in the form of atrophy-corrected positron emission tomographic activity ratios in cortical regions that were defined a priori. Patients were followed up at a mean of 1.8 years, and the dependent variable was rate of change in the Mini-Mental State Examination score. RESULTS: Bilateral and right hemisphere dorsolateral frontal metabolism significantly predicted cognitive decline, with right dorsolateral frontal metabolism explaining 19% of the variance. No other positron emission tomographic region was a significant predictor, nor were demographic variables or baseline Mini-Mental State Examination scores significant predictors. CONCLUSION: Cognitive decline in patients with lacunes may result in part from progressive vascular compromise in subcortical frontal circuits.

Weiner M, Powe NR, Anderson GF. · No affiliation provided · J Am Geriatr Soc. · Pubmed #10522971 No free full text.

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