The impact of MRI combined with visual rating scales on the clinical diagnosis of dementia: a prospective study.

Objectives: Dementia is foremost a clinical diagnosis. However, in diagnosing dementia, it is advocated to perform at least one neuroimaging study. This has two purposes: to rule out potential reversible dementia (PRD), and to help determine the dementia subtype. Our first goal was to establish if MRI combined with visual rating scales changes the clinical diagnosis. The second goal was to demonstrate if MRI contributes to a geriatrician's confidence in the diagnosis.

Methods: The dementia subtype was determined prior to and after MRI. Scoring scales used were: global cortical atrophy (GCA), medial temporal atrophy (MTA), and white matter hyperintensity measured according to the Fazekas scale. The confidence level of the geriatrician was determined using a visual analogue scale.

Results: One hundred and thirty-five patients were included. After MRI, the diagnosis changed in 23.7 % (CI 17.0 %-31.1 %) of patients. Change was due to vascular aetiology in 13.3 % of patients. PRD was found in 2.2 % of all patients. The confidence level in the diagnosis increased significantly after MRI (p = 0.001).

Conclusions: MRI, combined with visual rating scales, has a significant impact on dementia subtype diagnosis and on a geriatrician's confidence in the final diagnosis.

Key Points: • MRI with visual rating scales changes the dementia subtype diagnosis significantly. • MRI is essential in demonstrating vascular disease as a cause of dementia. • All suspected dementia patients should undergo an MRI with visual rating scales. • MRI improves a geriatrician's confidence in the diagnosis of the dementia subtype. • MRI remains essential during the workup of dementia to exclude reversible causes.