Design and Methods
Case study of 1 elderly man with trisomy 21 and Alzheimer disease who had been followed up prospectively over a 5-year period. The patient was a resident in a supervised community unit and died with end-stage dementia. The MRI changes were correlated with the results of clinical psychopathological analysis and neuropathological brain tissue findings. To our knowledge, this is the first case in which clinical, MRI, and neuropathological data were available in a case involving an elderly patient with Down syndrome and Alzheimer disease.

Results
The MRI findings correlated with the clinical deterioration and neuropathological features of Alzheimer disease. Marked changes in temporal and hippocampal regions were found.

Conclusion
Magnetic resonance imaging is potentially a valuable tool in the diagnosis of Alzheimer disease in adults with Down syndrome, particularly in individuals for whom standard intellectual assessments are not possible.