BACKGROUND: Progressive supranuclear palsy (PSP) is a syndrome characterized by progressive parkinsonism with early falls due to postural instability, typically vertical gaze supranuclear ophthalmoplegia, pseudobulbar dysfunction, neck dystonia and upper trunk rigidity as well as mild cognitive dysfunction. Progressive supranuclear palsy must be differentiated from Parkinson\'s disease taking into account several so-called red flags.
METHODS: We report a case series hallmarked by gait abnormalities, falls and bradykinesia in which Parkinson\'s disease was the initial diagnosis.
RESULTS: Due to a torpid clinical course, magnetic resonance imaging (MRI) was performed demonstrating midbrain atrophy, highly suggestive of progressive supranuclear palsy.
CONCLUSIONS: The neuroradiological exams (magnetic resonance imaging, single photon emission computer tomography, and positron emission tomography) can be useful for diagnosis of PSP. Treatment with levodopa should be considered, especially in patients with a more parkinsonian phenotype.

OBJECTIVE: To describe and illustrate the key findings on structural magnetic resonance imaging (MRI) in the most common dementias of neurodegenerative origin: Alzheimer\'s disease, vascular dementia, dementia with Lewy bodies, variants of frontotemporal dementia, progressive supranuclear palsy, variants of multiple system atrophy, Parkinson dementia, and corticobasal degeneration.
CONCLUSIONS: Today the role of MRI is no longer limited to ruling out underlying causes of cognitive deterioration. MRI can show patterns of atrophy with a predictive value for certain dementias which, although not specific or unique to each disease, can help to confirm diagnostic suspicion or to identify certain processes. For this reason, it is important for radiologists to know the characteristic findings of the most common dementias.