ABSTRACT
The basis for cognitive deficits in Parkinson's disease (PD) is unknown. Hippocampal atrophy has been shown in Alzheimer's disease (AD) and PD. N-Acetyl aspartate (NAA)/creatine (Cr) ratio in the posterior cingulate gyrus (PCG) is decreased in AD, but unknown in PD. Volumetric magnetic resonance (MR) imaging (at 1.5 T) determined corrected HC volume and MR spectroscopy (MRS) PCG metabolites in 12 non-demented mild to moderately affected PD patients (six male, six female) and ten controls (five male, five female). Age (PD=60.6 years, control=62.2; P=0.62), education (PD=14.1 years, controls=13.8; P=0.89) and global cognition (Mini-Mental State Exam score: PD=28.7, controls=29.6; P=0.14) did not differ. Only recall (CVLT-II, P=0.046) and NAA/Cr (PD=1.53, controls=1.78; P=0.03) were decreased in PD. Memory correlated with NAA/Cr (r=0.65, P=0.02) in PD. In conclusion, cingulate metabolic changes occur in PD.
Subject(s)
Aspartic Acid/analogs & derivatives , Gyrus Cinguli/metabolism , Parkinson Disease/metabolism , Aged , Aspartic Acid/metabolism , Case-Control Studies , Choline/metabolism , Cognition/physiology , Creatine/metabolism , Female , Gyrus Cinguli/pathology , Humans , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Male , Mental Status Schedule , Middle Aged , Parkinson Disease/pathologyABSTRACT
Neuropsychological CERAD data from 960 patients with Alzheimer's disease and 465 controls were subjected to separate yet identical classification procedures. Consistent with past research, three patient subgroups were reliably identified: Subgroup 1 (LAD; n = 312) was characterized by severe naming impairment yet borderline-normal figure-copying skills; Subgroup 2 (RAD; n = 247) displayed average naming ability but moderately-impaired copying performance; Subgroup 3 (GAD; n = 161) evinced profound anomia and constructional dyspraxia. LAD patients were older and less educated than those of the other subgroups. Control subgroups (n = 2) did not resemble the patient subgroups. Initial patterns of performance remained discernible across time for LAD and GAD, but were less consistent for RAD. Members from patient subgroups were present across disease stage.
Subject(s)
Alzheimer Disease/classification , Neuropsychological Tests/statistics & numerical data , Aged , Aged, 80 and over , Alzheimer Disease/diagnosis , Alzheimer Disease/psychology , Anomia/classification , Anomia/diagnosis , Anomia/psychology , Apraxias/classification , Apraxias/diagnosis , Apraxias/psychology , Female , Humans , Longitudinal Studies , Male , Middle Aged , Psychometrics , Psychomotor Disorders/classification , Psychomotor Disorders/diagnosis , Psychomotor Disorders/psychology , Reference Values , Registries , Reproducibility of Results , United StatesABSTRACT
It has been suggested that the 30-item version of the Boston Naming Test (BNT), in which either the odd or even items from the standard 60-item test are given, is the most psychometrically sound short form. However, no normative data are available for this version. We administered the Odd/Even BNT to 30 community-dwelling elderly individuals (age M = 72.93, range 61-84; education M = 13.73) in order to collect normative data. Odd and even forms were equivalent. The combined mean total correct score was 27.13 (SD = 2.06), a score consistent with that derived by retrospective extraction in the original odd/even test construction study. Each form discriminated normals from age- and education-matched patients with probable Alzheimer's disease, suggesting criterion-related validity.
Subject(s)
Geriatric Assessment , Neuropsychological Tests , Aged , Alzheimer Disease , Cognition Disorders/diagnosis , Female , Humans , Male , Reference Standards , Reproducibility of Results , Retrospective StudiesABSTRACT
Case descriptions of patients with probable Alzheimer's disease (AD) who were reliably classified into three neuropsychological subgroups (global [GAD], right-hemisphere [RAD], and left-hemisphere [LAD]) in an earlier cluster analytic study (Fisher et al., 1996) are presented. Concordance between the neuropsychological patterns and clinical histories of randomly selected and hand-selected cases from within each subgroup was high. Longitudinal analysis revealed stable subgroup-specific neuropsychological progression patterns. Results are discussed in terms of future research avenues worth pursuing, in addition to the conceptual shift in research design necessary to uncover both quantitative and qualitative subgroup-specific ability differences.
Subject(s)
Alzheimer Disease/psychology , Neuropsychological Tests , Aged , Aged, 80 and over , Female , Humans , Male , Research DesignABSTRACT
Neuropsychological data from 134 patients diagnosed with probable Alzheimer's disease (AD) were studied retrospectively to investigate whether subgroups of patients with qualitatively distinct profiles could be identified. Three empirical classification approaches were undertaken in this regard: Q-type factor analysis, hierarchical agglomerative cluster analysis, and iterative partitioning. Three subgroups were consistently identified across the clustering methods. Subgroup 1, the largest of the groups, was marked by moderate to severe anomia and constructional dyspraxia. Individuals in subgroup 2 displayed relatively spared visual-perceptual/constructional functioning but severe anomia. Members of subgroup 3 exhibited intact naming and nonverbal reasoning and moderate difficulty in copying overlapping figures. The three subgroups did not differ with respect to age, age at disease onset, duration of illness, educational level, or Hamilton depression rating. Detailed description of the data analyses are provided as a tutorial outlining subtyping methodology. Results are discussed in terms of the subgroup and the stage model approaches to the conceptualization of AD.