Neuropathology correlates of cognitive assessments.

BACKGROUND: Alzheimer's disease and other dementias are the fourth largest contributors to neurological disability and the second largest contributor to deaths from neurological disease. Described in the 1980s as 'the silent epidemic' these disorders principally, though not exclusively, affect persons 80 years or older, and in developed countries, this 'old old' population continues to grow. Definitive diagnosis of the underlying cause of the neurodegenerative disease relies on neuropathological evaluation.` AIMS: Herein, we review the sampling methods, analysis and interpretation of both pathological and immunocytochemical techniques in the diagnostic assessment of neurodegenerative disease.
FINDINGS: Neurodegenerative disorders are characterised by accumulation of pathologically altered protein in the human brain, and in some cases, in the peripheral tissues. Whilst it is suggested that a comprehensive review of the patient's clinical history, cognition and behaviour, together with a full clinical examination and radiological analysis, should lead to a high degree of confidence in the clinical diagnosis, the view persists that underlying pathology can only be predicted on clinical grounds especially in Alzheimer's disease, vascular brain injury and diffuse Lewy body disease with only limited accuracy.
CONCLUSIONS: Neuropathological assessment of well characterised clinical cases provides accurate data on the prevalence of neurodegenerative diseases. This will aid future biomarker, neuroimaging studies and clinical trials focussed on population based cohorts.