title: Analysis of the substantia innominata volume in patients with Parkinson's disease with dementia, dementia with lewy bodies, and Alzheimer's disease.
abstract: OBJECTIVE
  The substantia innominata (SI) contains the nucleus basalis of Meynert, which is the major source of cholinergic input to the cerebral cortex. We hypothesized that degeneration of the SI and its relationship to general cognitive performance differs in amyloidopathy and synucleinopathy.
  
  
  METHODS
  We used magnetic resonance imaging (MRI)-based volumetric analysis to evaluate the SI volume in patients with amnestic mild cognitive impairment (aMCI), Alzheimer's disease (AD), Parkinson's disease-mild cognitive impairment (PD-MCI), PD with dementia (PDD), dementia with Lewy bodies (DLB), and healthy elderly controls. The correlation between SI volume and general cognitive performance, measured using the Korean version of the Mini-Mental State Examination (K-MMSE), was examined.
  
  
  RESULTS
  Compared to control subjects, the mean normalized SI volume was significantly decreased in all of the other groups. The normalized SI volume did not differ between the subjects with PDD and DLB, whereas it was significantly smaller in subjects with PDD (p = 0.029) and DLB (p = 0.011) compared with AD. In subjects with PD-related cognitive impairment (PD-MCI, PDD, or DLB), there was a significant positive correlation between the SI volume and K-MMSE score (r = 0.366, p < 0.001), whereas no correlation was seen in subjects with AD-related cognitive impairment (aMCI or AD).
  
  
  CONCLUSIONS
  Our data suggest that the SI loss is greater in synucleinopathy-related dementia (PDD or DLB) than in AD and that the contribution of the SI to cognitive performance is greater in synucleinopathy than in amyloidopathy.
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Soo Jeong
authors.initials: SJ
authors.lastname: Shin
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Sohn
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
keywords: Alzheimer’s disease; Parkinson’s disease-related cognitive dysfunction; The substantia innominata