title: Hippocampal myo-inositol and cognitive ability in adults with Down syndrome: an in vivo proton magnetic resonance spectroscopy study.
abstract: BACKGROUND
  Down syndrome (DS) is the most common genetic cause of mental retardation. However, the biological determinants of this are poorly understood. The serum sodium/myo-inositol cotransporter gene is located on chromosome 21, and myo-inositol affects neuronal survival and function. Nevertheless, few in vivo studies have examined the role of myo-inositol in DS.
  
  
  OBJECTIVE
  To determine if people with DS have significant differences in brain myo-inositol concentration from controls and if, within people with DS, this is related to cognitive ability.
  
  
  METHODS
  A case-control study.
  
  
  METHODS
  Outpatient.
  
  
  METHODS
  The sample was composed of 38 adults with DS without dementia (age range, 18-66 years) and 42 healthy controls (age range, 19-66 years). The DS and control groups did not differ significantly in age, sex, ethnic origin, apolipoprotein E status, or handedness.
  
  
  METHODS
  Hippocampal myo-inositol concentration and cognitive performance, as measured by the Cambridge Cognitive Examination.
  
  
  RESULTS
  Hippocampal myo-inositol concentration was significantly higher in people with DS than in controls (P = .006), and within people with DS, increased myo-inositol concentration was significantly negatively correlated with overall cognitive ability (P = .04).
  
  
  CONCLUSIONS
  Adults with DS have a significantly increased brain concentration of myo-inositol, and this is associated with reduced cognitive ability. Future studies are required to relate myo-inositol concentration in people with DS to brain development and increased risk for developing Alzheimer disease.
authors.affiliation: Section of Brain Maturation, Department of Psychological Medicine, Neuroimaging Research Group, Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, England, UK.
authors.forename: Felix
authors.initials: F
authors.lastname: Beacher
authors.forename: Andy
authors.initials: A
authors.lastname: Simmons
authors.forename: Eileen
authors.initials: E
authors.lastname: Daly
authors.forename: Verinder
authors.initials: V
authors.lastname: Prasher
authors.forename: Claire
authors.initials: C
authors.lastname: Adams
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Margallo-Lana
authors.forename: Robin
authors.initials: R
authors.lastname: Morris
authors.forename: Simon
authors.initials: S
authors.lastname: Lovestone
authors.forename: Kieran
authors.initials: K
authors.lastname: Murphy
authors.forename: Declan G M
authors.initials: DG
authors.lastname: Murphy
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D016022:Case-Control Studies; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006624:Hippocampus / Q000737:chemistry*; D006801:Humans; D007294:Inositol / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000706:statistics & numerical data*; D008297:Male; D011522:Protons; D011581:Psychological Tests / Q000706:statistics & numerical data*
chemical_list: D011522:Protons; D007294:Inositol