The GBS scale in multi-infarct dementia and senile dementia of Alzheimer type

[Impact of vascular pathology on survival times of 173 dementia patients--Hachinski's ischemic score as a predictive tool for clinical purposes]

Alzheimer's disease and vascular dementia still may be looked upon as distinct nosologic entities, representing the two main etiologic categories of senile dementia. However, rather recent findings suggest a comorbidity of neurodegenerative and ischemic pathology in a majority of dementia cases in later life. The effect of the vascular pathology on the survival time was studied in 173 dementia outpatients. For 147 patients with complete datasets, we were able to gain information concerning their survival time. As an indicator of cerebrovascular morbidity the 18-point ischemic scale of Hachinski (HIS) was correlated with the survival time. Thus, we did not use the HIS for its original purpose to differentiate between degenerative and vascular dementia, but to roughly evaluate the cerebrovascular impact in a continuum model. Using the Cox model we calculated mortality risks for every point on the HIS. We found a Cox hazard ratio of 1.038 for each supplementary point on the HIS, which equals a 3.8% higher relative mortality risk. The result misses significance (p=0.092), but indicates a clear tendency towards a shortening of survival time by vascular comorbidity. Future prospective studies should integrate brain imaging to further corroborate our findings.

Vascular dementia: dead or alive?

The term 'Vascular Dementia' remains popular as a diagnostic entity, since it encompasses a variety of vascular pathologies. This is in stark contrast to many clinical classificatory systems that weight their definitions strongly towards stroke alone. A diagnosis of vascular dementia is complicated by compounding factors that reduce both the validity and specificity of diagnostic systems. This review highlights some of the problems faced in epidemiological, clinical, neuropathological and radiological studies attempting to define a clear-cut syndrome of dementia associated with cerebrovascular disease. The role of non-stroke ischaemia is also discussed. It is concluded that the term vascular dementia may have outlived its usefulness as a valid concept; alternative approaches are suggested.

Patterns of neuropsychological impairment in mild dementia: a comparison between Alzheimer's disease and multi-infarct dementia

The objective was to investigate the clinical and psychometric differences between patients with dementia of Alzheimer type (DAT) and patients with multi-infarct dementia (MID), matched for age, sex, education, and severity. Sixteen patients with DAT, 16 patients with MID, and 30 healthy individuals, were drawn from a longitudinal study on aging and dementia. Subjects with medical or previous mental disorders were excluded. DAT and controls with focal brain abnormalities on magnetic resonance imaging (MRI) were excluded. Diagnosis of dementia was carried out according to DSM-III-R criteria. Dementia severity was staged using the Clinical Dementia Rating (CDR) scale, and only patients with a score of 0.5-1 on CDR were studied. The main outcome measures were quantitative clinical scales of the assessment of global mental status, depression and anxiety, as well as a wide battery of neuropsychological tests for the evaluation of executive/conceptual functions and memory, as well as attention verbal ability, and visuospatial skill functions. The performance of demented patients compared to normal controls was affected on all measurements except for depression and anxiety. DAT patients showed compared to MID patients a greater extent of impairment on tasks assessing verbal comprehension and memory while MID patients were more significantly impaired on measures of frontal lobe functioning. Clinically matched DAT and MID patients show a differential pattern of neuropsychological impairment when studied in an early stage of dementia and with a mild degree of severity. Such patterns might be of value for the development of clinical diagnostic criteria.