Clinicopathological concordance in dementia diagnostics.

OBJECTIVE: Accurate distinction between dementia subtypes is important for patient care and pharmacological treatment. Continuing systematic comparisons of clinical and neuropathological dementia diagnoses may provide a basis for further improvement of the diagnostic procedure. The purpose of this study was to investigate concordance between clinical dementia diagnosis and neuropathological findings in the specialized dementia care.
METHODS: Inclusion required 1) a clinical dementia disorder diagnosed at a hospital-based memory clinic and 2) a neuropathological examination within the Department of Pathology at the University Hospital in Lund, Sweden, during the years 1996-2006. A total of 176 consecutive patients fulfilled the criteria and were thus included. Clinical dementia diagnoses were obtained from the medical records and compared with the neuropathological findings.
RESULTS: The clinical and pathological dementia diagnoses were in full accordance in 86 (49%) of the patients (kappa 0.37). In an additional 24 (14%) cases, the clinical diagnosis corresponded with some but not all pathological components judged to contribute to the dementia disorder. Of the patients with clinical Alzheimer disease, 84% (46/55) had a significant Alzheimer component with or without other significant pathology at neuropathological examination. The corresponding figure for vascular dementia (VaD) was 59% (24/41), for frontotemporal dementia 74% (20/27), for combined Alzheimer and VaD 25% (4/16), and for dementia with Lewy bodies 67% (6/9).
CONCLUSIONS: This study shows that clinical dementia diagnoses do not always correspond with neuropathological changes. It stresses the importance of neuropathological examination in research and in daily clinical practice.