title: Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy.
abstract: OBJECTIVE
  Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes.
  
  
  METHODS
  With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated.
  
  
  RESULTS
  In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases.
  
  
  CONCLUSIONS
  It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases.
authors.affiliation: Department of Diagnostic Radiology, Tokyo Metropolitan Medical Center of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan. ksak666@yahoo.co.jp.
authors.forename: Keita
authors.identifier: http://orcid.org/0000-0002-8849-7335
authors.initials: K
authors.lastname: Sakurai
authors.affiliation: Department of Diagnostic Radiology, Tokyo Metropolitan Medical Center of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.
authors.forename: Aya M
authors.initials: AM
authors.lastname: Tokumaru
authors.affiliation: Department of Diagnostic Radiology, Tokyo Metropolitan Medical Center of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Shimoji
authors.affiliation: Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Murayama
authors.affiliation: Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
authors.forename: Kazutomi
authors.initials: K
authors.lastname: Kanemaru
authors.affiliation: Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Morimoto
authors.affiliation: Department of Neurology, National Hospital Organization Higashi Nagoya National Hospital, Nagoya, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Aiba
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Motoo
authors.initials: M
authors.lastname: Nakagawa
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ozawa
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Shimohira
authors.affiliation: Department of Neurology and Neuroscience, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Matsukawa
authors.affiliation: Choju Medical Institute, Fukushimura Hospital, Toyohashi, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hashizume
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D001284:Atrophy; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008636:Mesencephalon / Q000000981:diagnostic imaging* / Q000473:pathology*; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging* / Q000473:pathology*
keywords: Atypical case; Atypical subtype; Magnetic resonance imaging (MRI); Progressive supranuclear palsy (PSP); Voxel-based morphometry (VBM)