Birgitte Bo Andersen

Awareness of Deficits in Mild Cognitive Impairment and Alzheimer’s Disease: Do MCI Patients Have Impaired Insight?

In this study we investigated impaired awareness of cognitive deficits in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Very few studies have addressed this topic, and methodological inconsistencies make the comparison of previous studies difficult. From a prospective research program 36 consecutive patients with mild AD (MMSE above 19), 30 with amnesic MCI and 33 matched controls were examined. Using three methods for awareness assessment we found no significant differences in the level of awareness between MCI and AD. Both groups had impaired awareness and significant heterogeneity in the clinical presentation of awareness. The results demonstrate that subjective memory problems should not be a mandatory prerequisite in suspected dementia or MCI, which makes reports from informants together with thorough clinical interview and observation central when assessing suspected dementia disorders.

Aging of the human cerebellum: A stereological study

Cerebella from 19 normal Caucasian males, ages 19–84 years, were studied using stereological methods. Cerebellum was divided into four different regions: the anterior and posterior lobe, the vermis, and the flocculonodular lobe. Total volume of the cerebellar cortex and white matter, cerebellar surface area, total Purkinje and granule cell number, and the distribution of the volumes of the Purkinje cells and their nuclei were estimated in all four regions. The global white matter was reduced by 26% with age; the mean volume of the Purkinje cell body was decreased by 33% with no decrease in the volume of the Purkinje cell nuclei. A tendency towards a 16% total cerebellar volume loss was seen without a concomitant neuron loss. No global Purkinje or granule cell loss was detected with age, total Purkinje cell number being 28 × 106 (coefficient of variation, CV = 0.16) and total granule cell number 109 × 109 (CV = 0.17). However, a significant change was observed with age in the anterior lobe, where a selective 40% loss of both Purkinje and granule cells was found. Furthermore, a 30% loss of volume, mostly due to a cortical volume loss, was recorded in the anterior lobe, which is predominantly involved in motor control. J. Comp. Neurol. 466:356–365, 2003.

Validity of Dementia Diagnoses in the Danish Hospital Registers

Background:The validity of dementia diagnoses in the Danish nationwide hospital registers was evaluated to determine the value of these registers in epidemiological research about dementia. Methods: Two hundred patients were randomly selected from 4,682 patients registered for the first time with a dementia diagnosis in the last 6 months of 2003. The patients’ medical journals were reviewed to evaluate if they fulfilled ICD-10 and/or DSM-IV criteria for dementia and specific dementia subtypes. The patients who were still alive in 2006 were invited to an interview. Results: One hundred and ninety-seven journals were available for review and 51 patients were interviewed. A registered diagnosis of dementia was found to be correct in 169 (85.8%) cases. Regarding dementia subtypes, the degree of agreement between the registers and the results of the validating process was low with a kappa of 0.36 (95% CI 0.24–0.48). Conclusion: The validity of dementia syndrome in the Danish hospital registers was high and allows for epidemiological studies about dementia. Alzheimer’s disease, although underregistered, also had a good validity once the diagnosis was registered. In general, other ICD-10 dementia subtypes in the registers had a low validity and are less suitable for epidemiological research.

Corticobasal and ataxia syndromes widen the spectrum of C9ORF72 hexanucleotide expansion disease

Recently, a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 was reported as the cause of chromosome 9p21‐linked frontotemporal dementia‐amyotrophic lateral sclerosis (FTD‐ALS). We here report the prevalence of the expansion in a hospital‐based cohort and associated clinical features indicating a wider clinical spectrum of C9ORF72 disease than previously described. We studied 280 patients previously screened for mutations in genes involved in early onset autosomal dominant inherited dementia disorders. A repeat‐primed polymerase chain reaction amplification assay was used to identify pathogenic GGGGCC expansions. As a potential modifier, confirmed cases were further investigated for abnormal CAG expansions in ATXN2. A pathogenic GGGGCC expansion was identified in a total of 14 probands. Three of these presented with atypical clinical features and were previously diagnosed with clinical olivopontocerebellar degeneration (OPCD), atypical Parkinsonian syndrome (APS) and a corticobasal syndrome (CBS). Further, the pathogenic expansion was identified in six FTD patients, four patients with FTD‐ALS and one ALS patient. All confirmed cases had normal ATXN2 repeat sizes. Our study widens the clinical spectrum of C9ORF72related disease and confirms the hexanucleotide expansion as a prevalent cause of FTD‐ALS disorders. There was no indication of a modifying effect of the ATXN2 gene.

Reduction of Purkinje cell volume in cerebellum of alcoholics

It is generally believed that chronic alcohol consumption results in cerebellar atrophy and Purkinje cell loss, especially in the anterior vermal region. A post-mortem stereological design was applied to cerebella from 10 chronic male alcoholics (mean age 45.5 years) with a minimum of 10 years of severe addiction and 10 male controls (mean age 42.5 years). All alcoholics had pathoanatomical evidence of alcohol abuse but no clinical signs of Wernickes encephalopathy. Cerebellum was divided into five different areas: the anterior and posterior lobe, the anterior and posterior vermis, and the flocculonodular lobe. The total cortex and white matter volume, the cerebellar surface area, the total Purkinje and granule cell number and density, and the mean volume of Purkinje cells and their cell nuclei were measured in all five regions using stereological methods. The volume of the granular layer was increased by 13% with an increase in layer thickness by 17% possibly due to oedema. Globally, the mean volume of the Purkinje cell perikaryon was decreased by 24% with a decrease in the volume of Purkinje cell nuclei by 16%. The increase of the granular layer and the decrease of Purkinje cell size resulted in a 21% global reduction of Purkinje cell density without a concomitant loss of neurons. No significant regional or global cortical and white matter atrophy was found in cerebella from alcoholics compared to controls.

Caries Prevalence in Older Persons with and without Dementia

OBJECTIVES: To examine the prevalence of coronal and root caries in a memory clinic–based population of elderly patients with and without a diagnosis of dementia and to examine the influence of age, sex, social relations, social position, and functional ability.

A stereological study of substantia nigra in young and old rhesus monkeys

The number of pigmented and non-pigmented neurons in the substantia nigra (SN) of 10 old and six young female Macaca mulatta monkeys and in three old alpha male monkeys were estimated using new stereological cell counting methods. No systematic right-left differences were noted, nor were old animals different from young ones with respect to SN volume (68.9 mm3 vs. 62.8 mm3) or absolute number of nerve cells (320,000 vs. 312,000). However, the total number of pigmented neurons was about eight times higher in old animals compared with young ones (166,000 vs. 21,400) while the total number of non-pigmented SN neurons was less than half in old animals compared with young ones (139,000 vs. 285,000). These differences create difficulties in generalizing experimental results from the rhesus animal model to man. It seems unlikely that a simple correlation can be made between pigmented and tyrosine hydroxylase (TH) positive neurons in SN in monkeys. Instead of estimating the total number of pigmented and non-pigmented cells, only SN neurons positive for TH using immunohistochemical techniques might be used an indicator of the total number of dopaminergic neurons in SN in monkeys.

Moderate-to-High Intensity Physical Exercise in Patients with Alzheimer's Disease: A Randomized Controlled Trial

BACKGROUNDnStudies of physical exercise in patients with Alzheimers disease (AD) are few and results have been inconsistent.nnnOBJECTIVEnTo assess the effects of a moderate-to-high intensity aerobic exercise program in patients with mild AD.nnnMETHODSnIn a randomized controlled trial, we recruited 200 patients with mild AD to a supervised exercise group (60-min sessions three times a week for 16 weeks) or to a control group. Primary outcome was changed from baseline in cognitive performance estimated by Symbol Digit Modalities Test (SDMT) in the intention-to-treat (ITT) group. Secondary outcomes included changes in quality of life, ability to perform activities of daily living, and in neuropsychiatric and depressive symptoms.nnnRESULTSnThe ITT analysis showed no significant differences between intervention and control groups in change from baseline of SDMT, other cognitive tests, quality of life, or activities of daily living. The change from baseline in Neuropsychiatric Inventory differed significantly in favor of the intervention group (mean: -3.5, 95% confidence interval (CI) -5.8 to -1.3, pu200a=u200a0.002). In subjects who adhered to the protocol, we found a significant effect on change from baseline in SDMT as compared with the control group (mean: 4.2, 95% CI 0.5 to 7.9, pu200a=u200a0.028), suggesting a dose-response relationship between exercise and cognition.nnnCONCLUSIONSnThis is the first randomized controlled trial with supervised moderate-to-high intensity exercise in patients with mild AD. Exercise reduced neuropsychiatric symptoms in patients with mild AD, with possible additional benefits of preserved cognition in a subgroup of patients exercising with high attendance and intensity.

Stereological quantification of the cerebellum in patients with Alzheimer's disease

Nonquantitative studies indicate that the cerebellum is neuropathologically affected in Alzheimers disease; however, no quantitative studies on the subject have yet been conducted. Ten cerebella from elderly female subjects with severe Alzheimers disease and 10 age- and gender-matched controls were examined. The cerebellum was divided into 5 regions and the Purkinje and granule cell number and density, cortical volume, molecular and granular layer volume and thickness, white matter volume, surface area, and the Purkinje cell gradient were stereologically estimated. There was no significant difference between the groups in Purkinje or granule cell number or density, and no overall difference in Purkinje cell gradient. However, there was a significant 12.7% reduction in total cerebellar volume in the Alzheimers group and significant localized differences between the groups regarding other parameters. The relative lack of neuropathological changes in the cerebellum of severely demented Alzheimers patients suggests that neuronal cell bodies on a global scale apparently still are intact.

Measuring Morphological and Cellular Changes in Alzheimers Dementia: A Review Emphasizing Stereology

From a clinical as well as a neuropathological point of view Alzheimers disease (AD) has been the focus of intense research for more than three decades. Most studies to identify morphometric correlates with the declining cognitive function in normal aging and AD have employed semi-quantitative methods to assess neuropathological markers such as neurofibrillary tangles, senile plaques, neuronal, or glial cell densities, and neuron sizes. To this end, many cell counting methods have employed two-dimensional designs in single sections, yielding estimates of cell numbers either as neuron densities (number of cell profiles per area) or estimates of the size distribution of neuron profiles in columns vertical to the cortical surface. This approach gives rise to difficulties in interpretation because of the three-dimensional size, shape, and orientation of the counted cells, and the effect of shrinkage artifacts. Modern stereological techniques offer a more rigorous approach for quantifying neuropathological changes associated with aging and degenerative disease. However the stereological studies also suffer from the limitations of high biological variability in AD-type neuropathology, and the relative scarcity of autopsied brains from well-studied non-demented comparison subjects. As a result, the clinicopathological associations between neuropathology and indices of cognitive performance in aging and AD are not yet firmly established. The requirement for the proper description of morphologic neuropathology of AD is clear: any macroscopic or microscopic abnormalities, are subtle and must consequently be demonstrated reproducibly in well-controlled studies. In this review we try to evaluate which, if any, of the contemporary claims for morphometric brain abnormalities in AD can be said to be well established, with special emphasis placed on human stereological post-mortal studies.