Alzheimer’s: Distinct Cognitive Deficits Associated with Regional Brain Atrophy

MedicalResearch.com Interview with:
Lieke Smits drs. L.L. Smits
VU University Medical Center
Department of Neurology – Alzheimer Center
1081 HV Amsterdam, The Netherlands

MedicalResearch.com:  What are the main findings of the study?

Answer: In this study we used two visual ratings scales to estimate atrophy of the medial temporal lobe (MTA) and posterior atrophy (PA) on MRI in patients with Alzheimer’s disease. We assessed associations between MTA and PA with cognitive impairment. We found that MTA was associated with worse performance in memory, language and attention, while PA was associated with worse performance in viuso-spatial functioning and executive functioning.

Further stratification for age at diagnosis revealed that in late onset (>65 years old) MTA was associated with impairment in memory, language, visuo-spatial functioning and attention. In early onset patients (<65 years old), worse performance on visuo-spatial functioning almost reached significance.

MedicalResearch.com: Were any of the findings unexpected?

Answer: Based on dichotomized MRI ratings we found that 27% of patients had no atrophy and 17% had only PA. For a disease where MTA is traditionally regarded as a hallmark, the number of patients without appreciable MTA is quite high. An explanation could be that our cohort was relatively young and in patients with an early onset we found less MTA.

MedicalResearch.com: What should clinicians and patients take away from your report?

Answer: The visual rating scale for MTA has been used over two decades, the rating scale for PA has recently been developed. With those easy to use scales we observed the heterogeneity of atrophy in Alzheimer’s disease. Clinicians should be aware that patients with Alzheimer’s disease can have PA in absence of MTA or show no atrophy at all. Finally, relations between atrophy and cognition are not set in stone, as a substantial proportion of patients had no atrophy, even when there was clear cognitive impairment.

MedicalResearch.com:  What recommendations do you have for future research as a result of this study?

Answer:  Future research should further correlate the PA rating scale with clinical heterogeneity in Alzheimer’s disease. And it would be of interest to validate the scale for other types of dementia, for example Dementia with Lewy bodies. Finally, an important research question is whether pattern of atrophy is a determinant for rate of progression.

Citation:
Regional atrophy is associated with impairment in distinct cognitive domains in Alzheimer’s disease

Smits LL, Tijms BM, Benedictus MR, Koedam EL, Koene T, Reuling IE, Barkhof F, Scheltens P, Pijnenburg YA, Wattjes MP, van der Flier WM.

Alzheimers Dement. 2013 Nov 6. pii: S1552-5260(13)02494-1. doi: 10.1016/j.jalz.2013.06.007. [Epub ahead of print]

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