title: Neuropathological findings of PSP in the elderly without clinical PSP: possible incidental PSP?
abstract: OBJECTIVE
  We aimed to describe cases with incidental neuropathological findings of progressive supranuclear palsy (PSP) from the Banner Sun Health Research Institute Brain and Body Donation Program.
  
  
  METHODS
  We performed a retrospective review of 277 subjects with longitudinal motor and neuropsychological assessments who came to autopsy. The mean Gallyas-positive PSP features grading for subjects with possible incidental neuropathological PSP was compared to those of subjects with clinically manifest disease.
  
  
  RESULTS
  There were 5 cases with histopathological findings suggestive of PSP, but no parkinsonism, dementia or movement disorder during life. Cognitive evaluation revealed 4 of the 5 cases to be cognitively normal; one case had amnestic mild cognitive impairment (MCI) in her last year of life. The mean age at death of the 5 cases was 88.9 years (range 80-94). All 5 individuals had histopathologic microscopic findings suggestive of PSP. Mean Gallyas-positive PSP features grading was significantly lower in subjects with possible incidental neuropathological PSP than subjects with clinical PSP, particularly in the subthalamic nucleus.
  
  
  CONCLUSIONS
  We present 5 patients with histopathological findings suggestive of PSP, without clinical PSP, dementia or parkinsonism during life. These incidental neuropathological PSP findings may represent the early or pre-symptomatic stage of PSP. The mean Gallyas-positive PSP features grading was significantly lower in possible incidental PSP than in clinical PSP, thus suggesting that a threshold of pathological burden needs to be reached within the typically affected areas in PSP before clinical signs and symptoms appear.
authors.affiliation: Department of Neurology, Mayo Clinic, 13400 E. Shea Blvd., Scottsdale, AZ 85259, USA. evidente.virgilio@mayo.edu
authors.forename: Virgilio Gerald H
authors.initials: VG
authors.lastname: Evidente
authors.forename: Charles H
authors.initials: CH
authors.lastname: Adler
authors.forename: Marwan N
authors.initials: MN
authors.lastname: Sabbagh
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Connor
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Hentz
authors.forename: John N
authors.initials: JN
authors.lastname: Caviness
authors.forename: Lucia I
authors.initials: LI
authors.lastname: Sue
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Beach
mesh_terms: D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D016631:Lewy Bodies / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D016501:Neurites / Q000473:pathology; D009474:Neurons / Q000473:pathology; D012189:Retrospective Studies; D013494:Supranuclear Palsy, Progressive / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology*