Parkinson's disease

Ecology

Biology

Cohort

Progressive supranuclear palsy

Sign (mathematics)

Radiology

Physics

Parkinsonism

Psychology

Mathematics

Optics

Glory

Hummingbird

Atrophy

Central nervous system

Midbrain

Internal medicine

Mathematical analysis

Medicine

Morning

Audiology

Disease

Pathology

Parkinsonism & Related Disorders

IntroductionThe hummingbird sign and the morning glory flower sign, reflecting midbrain pathology on MRI, have previously been shown to separate patients with progressive supranuclear palsy (PSP) from those with Parkinson's disease (PD) and multiple system atrophy (MSA). The aim of the present study was to determine the diagnostic accuracy and reproducibility of visual assessment of midbrain atrophy patterns in a large cohort of patients with neurodegenerative parkinsonism.MethodsRetrospective analysis of midbrain atrophy patterns on T1-weighted MRI in a large cohort of patients with neurodegenerative parkinsonism and healthy controls who underwent MR imaging during their diagnostic work-up.Results481 patients with neurodegenerative parkinsonism and 79 healthy controls were included in the present study. The presence of the hummingbird sign had a specificity of 99.5% and a positive predictive value of 96.1% for a diagnosis of PSP while sensitivity was suboptimal with 51.6%. Similarly, the presence of the morning glory flower sign yielded a specificity of 97.7% for a diagnosis of PSP, but sensitivity was only 36.8%. Sensitivity of both signs was 35.3% in early, clinically unclassifiable parkinsonism. Visual assessment of these midbrain alterations showed excellent inter-rater agreement.ConclusionMidbrain atrophy patterns are useful in the differential diagnosis of neurodegenerative parkinsonism but both the hummingbird sign and more so the morning glory flower sign suffer from low sensitivity, especially in early disease stages.

The diagnostic accuracy of the hummingbird and morning glory sign in patients with neurodegenerative parkinsonism