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Douglas Galasko

Publications and source records attributed to Douglas Galasko.

At least 19 recordsLinked to original sources
PubMed2007

Disparate letter and semantic category fluency deficits in autopsy-confirmed frontotemporal dementia and Alzheimer's disease.

Patients with autopsy-confirmed frontotemporal dementia (FTD; n = 16) and Alzheimer's disease (AD; n = 32) were compared on first-letter and semantic category fluency tasks. Despite being matched on age, education, and dementia severity, FTD patients performed worse overall and showed similar impairment in letter and semantic category fluency, whereas AD patients showed greater impairment in semantic category than letter fluency. A measure of the disparity between letter and semantic category fluency (the semantic index) was effective in differentiating FTD from AD patients, and this disparity increased with increasing severity of dementia. These unique patterns of letter and semantic category fluency deficits may be indicative of differences in the relative contribution of frontal-lobe-mediated retrieval deficits and temporal-lobe-mediated semantic deficits in FTD and AD.

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PubMed2006

Characterization of tau pathologies in gray and white matter of Guam parkinsonism-dementia complex.

Guam parkinsonism-dementia complex (PDC) is a neurodegenerative tauopathy in ethnic Chamorro residents of the Mariana Islands that manifests clinically with parkinsonism as well as dementia and is characterized neuropathologically by prominent cortical neuron loss in association with extensive telencephalic neurofibrillary tau pathology. To further characterize cortical gray and white matter tau, alpha-synuclein and lipid peroxidation pathologies in Guam PDC, we examined the brains of 17 Chamorro PDC and control subjects using biochemical and immunohistological techniques. We observed insoluble tau pathology in both gray and white matter of PDC and Guam control cases, with frontal and temporal lobes being most severely affected. Using phosphorylation dependent anti-tau antibodies, abundant tau inclusions were detected by immunohistochemistry in both neuronal and glial cells of the neocortex, while less alpha-synuclein pathology was observed in more limited brain regions. Further, in sharp contrast to Alzheimer's disease (AD), levels of the lipid peroxidation product 8, 12-iso-iPF(2alpha)-VI isoprostane were not elevated in Guam PDC brains relative to controls. Thus, although the tau pathologies of Guam PDC share similarities with AD, the composite Guam PDC neuropathology profile of tau, alpha-synuclein and 8, 12-iso-iPF(2alpha)-VI isoprostane reported here more closely resembles that seen in other tauopathies including frontotemporal dementias (FTDs), which may imply that Guam PDC and FTD tauopathies share underlying mechanisms of neurodegeneration.

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PubMed2006

Cognitive profiles of individual patients with Parkinson's disease and dementia: comparison with dementia with lewy bodies and Alzheimer's disease.

We describe the pattern of cognitive profiles within a community-based sample of patients with Parkinson's disease (PD) and dementia (PDD) using cluster analyses, and compare the results with data from patients with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Fifty patients with PDD and 39 with AD from Stavanger, Norway, and 62 patients with DLB from San Diego, CA, USA were diagnosed by either standardized clinical procedures or criteria (all PDD and all AD cases) or necropsy (all DLB cases). Four subgroups were identified: two subgroups with a subcortical cognitive profile (one with mild and one with moderate dementia severity), one subgroup with global impairment and severe dementia, and one subgroup with a cortical cognitive profile and moderate dementia. Of the patients with PDD and with DLB, 56% and 55%, respectively, had a subcortical cognitive profile, compared with only 33% of the AD patients. Conversely, 30% of the patients with PDD and 26% of those with DLB had a cortical cognitive profile, compared with 67% of the patients with AD. These findings suggest that in some patients with PDD, frontosubcortical changes are the main contributing factor to dementia, whereas in other patients, cortical and hippocampal changes are more important.

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PubMed2006

Effect of statins on Alzheimer's disease biomarkers in cerebrospinal fluid.

BACKGROUND: Treatment with HMG-CoA reductase inhibitors ("statins") has been variably associated with a reduced risk of Alzheimer's disease (AD) in epidemiologic studies and reduced amyloid-beta (Abeta) deposition in animal models of AD. Putative neuroprotective effects of statins may vary in relation to their ability to penetrate into the central nervous system (CNS). METHODS: We measured levels of cerebrospinal fluid (CSF) AD biomarkers following 14 weeks of treatment with simvastatin (a CNS permeant statin; n=10) at 40 mg/day or pravastatin (a CNS impermeant statin; n=13) at 80 mg/day in hypercholesterolemic subjects without dementia. RESULTS: Simvastatin, but not pravastatin, reduced CSF levels of phospho-tau-181 (p-tau181) in all subjects. There were no differences in CSF levels of total tau, Abeta42, Abeta40, soluble amyloid beta protein precursor (sAbetaPP) alpha or beta, or F2-isoprostanes. CONCLUSIONS: Statins may modulate the phosphorylation of tau in humans and this effect may depend on the CNS availability of the statin. These results suggest another mechanism by which statins may act to reduce the risk of AD.

Adult↗
PubMed2005

Lack of beta-methylamino-l-alanine in brain from controls, AD, or Chamorros with PDC.

High levels of beta-methylamino-l-alanine (BMAA), a putative neurotoxin, have been reported in brain samples from Chamorros and patients with Alzheimer disease (AD) from western Canada. The authors assayed free BMAA in the brains of five control subjects and five patients with AD from the US Pacific Northwest as well as Chamorros with and without Parkinson-dementia complex. In contrast to others, they detected no free BMAA in any of these samples.

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PubMed2005

Vitamin E and donepezil for the treatment of mild cognitive impairment.

BACKGROUND: Mild cognitive impairment is a transitional state between the cognitive changes of normal aging and early Alzheimer's disease. METHODS: In a double-blind study, we evaluated subjects with the amnestic subtype of mild cognitive impairment. Subjects were randomly assigned to receive 2000 IU of vitamin E daily, 10 mg of donepezil daily, or placebo for three years. The primary outcome was clinically possible or probable Alzheimer's disease; secondary outcomes were cognition and function. RESULTS: A total of 769 subjects were enrolled, and possible or probable Alzheimer's disease developed in 212. The overall rate of progression from mild cognitive impairment to Alzheimer's disease was 16 percent per year. As compared with the placebo group, there were no significant differences in the probability of progression to Alzheimer's disease in the vitamin E group (hazard ratio, 1.02; 95 percent confidence interval, 0.74 to 1.41; P=0.91) or the donepezil group (hazard ratio, 0.80; 95 percent confidence interval, 0.57 to 1.13; P=0.42) during the three years of treatment. Prespecified analyses of the treatment effects at 6-month intervals showed that as compared with the placebo group, the donepezil group had a reduced likelihood of progression to Alzheimer's disease during the first 12 months of the study (P=0.04), a finding supported by the secondary outcome measures. Among carriers of one or more apolipoprotein E epsilon4 alleles, the benefit of donepezil was evident throughout the three-year follow-up. There were no significant differences in the rate of progression to Alzheimer's disease between the vitamin E and placebo groups at any point, either among all patients or among apolipoprotein E epsilon4 carriers. CONCLUSIONS: Vitamin E had no benefit in patients with mild cognitive impairment. Although donepezil therapy was associated with a lower rate of progression to Alzheimer's disease during the first 12 months of treatment, the rate of progression to Alzheimer's disease after three years was not lower among patients treated with donepezil than among those given placebo.

Alzheimer Disease↗
PubMed2005

Biomarkers for Alzheimer's disease--clinical needs and application.

Biomarkers for Alzheimer's disease have many diagnostic and therapeutic uses. They can be used to facilitate diagnosis, particularly early diagnosis and possibly presymptomatic diagnosis. In evaluating treatment aimed at modifying the course of AD, biomarkers can help to assess whether the drug is hitting a target or influencing disease mechanisms in the brain, and can help with dose-finding. In definitive clinical trails, biomarkers can be used as surrogate outcome measures. Progress has been made in investigating candidate biomarkers in cerebrospinal fluid and plasma. At present, cerebrospinal fluid levels of amyloid-beta, tau and phospho-tau come closest to meeting criteria proposed for useful biomarkers for diagnosis. Other biomarkers can provide insight into processes such as inflammation and oxidative damage. Unbiased and broad-based searches for novel biomarkers using proteomics have much potential. As efforts to diagnose and treat AD move towards earlier intervention and even towards prevention, biomarkers will gain significance as tools to aid research and ultimately clinical practice.

Alzheimer Disease↗
PubMed2004

A comparison of episodic memory deficits in neuropathologically-confirmed Dementia with Lewy bodies and Alzheimer's disease.

Little is known about possible differences in the memory deficits that occur in Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). We compared 24 autopsy-confirmed DLB and 24 age-, education-, and MMSE-matched autopsy-confirmed AD patients on the California Verbal Learning Test (CVLT) and the Wechsler Memory Scale-Revised Logical Memory subtest. The DLB and AD groups were similarly impaired on CVLT Total Learning (Trials 15) and Long Delayed Free Recall, but the DLB group demonstrated relative improvement in Savings scores and on recognition testing compared to the AD group. Likewise, the patient groups were equally impaired on Logical Memory immediate and delayed recall, but the DLB group's Saving scores were significantly better than those of the AD patients. These results indicate that while both DLB and AD patients exhibit significant memory impairment, the ability to consolidate information may be less severely impaired in DLB patients than in AD patients.

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PubMed2004

Galantamine maintains ability to perform activities of daily living in patients with Alzheimer's disease.

OBJECTIVES: To examine the effect of galantamine on activities of daily living (ADLs) with respect to baseline dementia severity, correlation with cognitive and global function, specific ADLs affected, and maintenance of ADL independence. DESIGN: Secondary analysis of a 5-month randomized, placebo-controlled trial. SETTING: Multiple U.S. clinical centers. PARTICIPANTS: Six hundred fifty-nine patients with mild to moderate Alzheimer's disease (AD) who completed 5 months of treatment. INTERVENTION: Galantamine at a maintenance dose of 16 or 24 mg/d. MEASUREMENTS: The AD Cooperative Study ADL Inventory (ADCS/ADL). RESULTS: Galantamine resulted in more improvement in ADCS/ADL scores than placebo regardless of baseline dementia severity, with the greatest differences occurring in patients with more severe disease. Changes in ADCS/ADL scores correlated significantly with change scores on the cognitive subscale of the AD Assessment Scale (r=-0.24). Galantamine treatment resulted in maintenance or improvement of basic and instrumental ADLs, and change from baseline to Month 5 in scores for each individual ADL item favored galantamine over placebo in three of six basic ADLs and six of 17 instrumental ADLs. CONCLUSION: Galantamine has a favorable effect on ADL performance in patients with AD, detectable after 5 months of treatment, regardless of dementia severity. The ADCS/ADL appears to better measure distinct abilities that may be relevant not only in clinical trials but also in individual patients than do cognitive assessments.

Activities of Daily Living↗
PubMed2003

Amyotrophic lateral sclerosis and parkinsonism-dementia complex of Guam: changing incidence rates during the past 60 years.

In the 1950s, the incidence of amyotrophic lateral sclerosis (ALS, or Lytico) and parkinsonism-dementia complex (PDC, or Bodig) on the island of Guam was much higher than anywhere else in the world. From the late 1960s to the early 1980s, the incidence of both disorders has decreased. The objective of the present study was to ascertain whether the decreasing incidence continued until the end of the century (1999). The average annual incidence of ALS and PDC was calculated for each 5-year period from 1940 to 1999, utilizing registration records of all ALS and PDC cases on Guam during that period. The results of this study confirmed that the incidence of ALS declined steadily during the past 40 years. The incidence of PDC also declined until the late 1980s but, unlike ALS, showed a slight increase from 1980 to 1999. The rapid decrease in incidence is not likely to be due to genetic factors. Instead, it is most likely to be the results of radical socioeconomic, ethnographic, and ecologic changes brought about by the rapid westernization of Guam.

Adult↗
PubMed2003

Cerebrospinal fluid tau and beta-amyloid: how well do these biomarkers reflect autopsy-confirmed dementia diagnoses?

BACKGROUND: Tau and beta-amyloid (Abeta) are proposed diagnostic biomarkers for Alzheimer disease (AD). Previous studies report their relationship to clinical diagnoses of AD and other dementias. To understand their value as predictors of disease-specific pathology, levels determined during life must be correlated with definitive diagnoses in mixed dementia groups and cognitively normal subjects. OBJECTIVES: To correlate antemortem cerebrospinal fluid (CSF) tau and Abeta levels with definitive dementia diagnosis in a diverse group of patients; to calculate statistics for CSF tau and Abeta. DESIGN: Prospective study. SETTING: Ten clinics experienced in the diagnosis of neurodegenerative dementias. Patients One hundred six patients with dementia and 4 cognitively normal subjects with a definitive diagnosis, and 69 clinically diagnosed cognitively normal subjects. MAIN OUTCOME MEASURES: Correlation of CSF tau and Abeta with final diagnosis. RESULTS: Mean tau level was 612 pg/mL for the 74 patients with AD, 272 pg/mL for 10 patients with frontal dementia, 282 pg/mL for 3 patients with dementia with Lewy bodies, and 140 pg/mL for 73 cognitively normal control subjects. Tau was less than 334 pg/mL for 20 patients with AD. Abeta42 was reduced in patients with AD (61 fmol/mL) compared with patients with frontal dementia (133 fmol/mL) and control subjects (109 fmol/mL), but not compared with patients with dementia with Lewy bodies (14 fmol/mL) or prion disease (60 fmol/mL). CONCLUSIONS: Elevated CSF tau levels are associated with AD pathology and can help discriminate AD from other dementing disorders. However, some patients with AD have a level less than the mean +/- 2 SDs of the cognitively normal cohort.

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PubMed2003

Tropicamide effects on pupil size and pupillary light reflexes in Alzheimer's and Parkinson's disease.

Diagnostic tests for Alzheimer's disease (AD) involving tropicamide blockade of cholinergic oculomotor functions were examined in AD patients (n=15), Parkinson's disease (PD) patients (n=15), and non-clinical control (NC) participants (n=15). Pupillographic methods were used to measure pupil diameter and pupillary light reflexes after double-blind ocular administration of dilute tropicamide (0.01%) in one eye and saline in the other eye. Changes in pupil size were measured in bright background light and near-darkness. Tropicamide increased pupil diameter to a similar extent in all three groups in light and darkness. Tropicamide also reduced the amplitude and latency of the pupillary light reflex to a similar extent for all three groups. Tropicamide pupillary response tests, therefore, were not sensitive or specific diagnostic tests for AD. Peak constriction amplitude of the pupillary light reflex was significantly reduced in both eyes in AD and PD groups relative to non-clinical controls, but AD and PD groups did not differ significantly. The pupillary light reflex test, therefore, was sensitive to AD, but lacked adequate specificity. Finally, peak constriction amplitude correlated significantly with dementia severity and donepezil treatment may have partially normalized pupillary light reflex abnormalities in AD patients. The pupillary light reflex test, therefore, may index central cholinergic dysfunction associated with disease progression and improvement in cholinergic function associated with pharmacologic treatment response in AD.

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PubMed2002

Age at onset is associated with disease severity in Lewy body variant and Alzheimer's disease.

This study investigated the influence of age at onset on cognitive performance, neuropathological and neurochemical features in autopsy-confirmed sporadic Lewy body variant (LBV) and in Alzheimer's disease (AD). We compared 28 early-onset (< or = 70 years) LBV subjects with 28 matched late-onset (> 70 years) subjects. Similarly, we examined the same features in 89 early onset AD and 89 matched late onset AD patients. Patients with early onset LBV and early onset AD declined more rapidly, had more neuritic plaques, and greater neocortical cholinergic loss compared to late onset LBV and late onset AD subjects. Taken together, these results suggest that for both LBV and AD, earlier age at onset may predict a more aggressive disease course.

Age of Onset↗
PubMed2002

Effect of extrapyramidal signs and Lewy bodies on survival in patients with Alzheimer disease.

BACKGROUND: Patients with Alzheimer disease (AD) who have psychiatric and parkinsonian symptoms experience faster cognitive deterioration and shorter survival vs those without such disease features. Extrapyramidal signs (EPSs) in particular have been associated with the presence of Lewy bodies (LBs) on autopsy and with poorer survival in patients with AD. Lewy bodies found at autopsy are not always correlated with EPSs during late life. OBJECTIVE: To determine whether the association between LBs and age at death is modified by the presence of EPSs, hallucinations, or delusions. DESIGN: An autopsy series of patients with clinically diagnosed AD. SETTINGS: Three AD clinics (San Diego and Sacramento, Calif, and Portland, Ore). PATIENTS: Data on 379 patients with a clinical diagnosis of AD who were initially assessed between May 1, 1984, and August 1, 1996, and who were autopsied between January 1, 1990, and April 1, 1998, were pooled from 3 AD centers. MAIN OUTCOME MEASURES: Presence of LBs on autopsy and differences in age at death in those with EPSs, LBs, or both. RESULTS: Individuals with EPSs at initial assessment were more than 3 times as likely to have LBs at autopsy than were those without EPSs. Age at death was younger in those with LBs and EPSs than in those with LBs only and those without EPSs or LBs. CONCLUSIONS: The presence of EPSs in patients with AD indicates worse prognosis and may be related to underlying LBs. The presence of EPSs is a strong predictor of LBs.

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PubMed2002

Decline in verbal memory during preclinical Alzheimer's disease: examination of the effect of APOE genotype.

A subtle decline in episodic memory often occurs prior to the emergence of the full dementia syndrome in nondemented older adults who develop Alzheimer's disease (AD). The APOE-epsilon4 genotype may engender a more virulent form of AD that hastens this decline. To examine this possibility, we compared the rate of decline in episodic memory during the preclinical phase of AD in individuals with or without at least one APOE epsilon4 allele. Nondemented normal control (NC; n = 84) participants, nondemented older adults who subsequently developed dementia within 1 or 2 years (i.e., preclinical AD; n = 20), and patients with mild AD (n = 53) were examined with 2 commonly employed tests of episodic memory, the Logical Memory subtest of the Wechsler Memory Scale-Revised and the California Verbal Learning Test. Results revealed a precipitous decline in verbal memory abilities 1 to 2 years prior to the onset of the dementia syndrome, but there was little effect of APOE genotype on the rate of this memory decline. The presence of an APOE-epsilon4 allele, however, did have a differential effect on the sensitivity of the 2 types of memory tests for tracking progression and made an independent contribution to the prediction of conversion to AD.

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