title: Cognitive change and neuroimaging following immunoablative therapy and hematopoietic stem cell transplantation in multiple sclerosis: A pilot study.
abstract: BACKGROUND
  Individuals with MS undergoing immunoablative therapy and hematopoietic stem cell transplantation (HSCT) show substantial decrease in brain volume over 2.4 months, presumably from chemotoxic effects, although other mechanisms have also been postulated.
  
  
  OBJECTIVE
  We examined whether volume loss was accompanied by a concomitant decrease in cognition. White and gray matter volumes, and the effect of stem cell dosage were considered.
  
  
  METHODS
  Seven individuals with rapidly progressing MS and poor prognosis underwent high dose immunosuppression and autologous HSCT. Neuropsychological testing and MRI scans were performed at baseline, 2 and 24 months post-procedure.
  
  
  RESULTS
  Cognitive impairment was noted at all times in most participants. Median decline of 1.39% in total brain volume was noted 2 months post-HSCT. By 24 months a further decline of 1.65% was noted. At 2 months significant decline was observed for areas of executive functioning. At 24 months almost no significant declines were noted. No significant correlations were found between cognitive decline and change in imaging variables or stem cell dosage.
  
  
  CONCLUSIONS
  Cognition changed in the early period following treatment but with little apparent relationship to volume changes. With temporal distance from the HSCT procedure, cognition returned to baseline levels. With the caution of a very small sample, preliminary results suggest that immunoablation and HSCT may have no lasting deleterious effects on cognition.
authors: Neuropsychology Service, The Ottawa Hospital, Ottawa, Canada; The Ottawa Hospital Research Institute, Ottawa, Canada; University of Ottawa, Faculty of Medicine, Ottawa, Canada; University of Ottawa, School of Psychology, Ottawa, Canada. Electronic address: lwalker@ottawahospital.on.ca.
authors: L A S
authors: LA
authors: Walker
authors: The Ottawa Hospital Research Institute, Ottawa, Canada; University of Ottawa, School of Psychology, Ottawa, Canada. Electronic address: jberard@toh.on.ca.
authors: J A
authors: JA
authors: Berard
authors: The Ottawa Hospital Research Institute, Ottawa, Canada; University of Ottawa, Faculty of Medicine, Ottawa, Canada. Electronic address: hatkins@ohri.ca.
authors: H L
authors: HL
authors: Atkins
authors: The Ottawa Hospital Research Institute, Ottawa, Canada. Electronic address: mbowman@toh.on.ca.
authors: M
authors: M
authors: Bowman
authors: Montreal Neurological Institute and Hospital, Montreal, Canada. Electronic address: hyunwoo.lee@mail.mcgill.ca.
authors: H
authors: H
authors: Lee
authors: The Ottawa Hospital Research Institute, Ottawa, Canada; University of Ottawa, Faculty of Medicine, Ottawa, Canada. Electronic address: mfreedman@toh.on.ca.
authors: M S
authors: MS
authors: Freedman
keywords: Cognition; Immunoablation; Information processing speed; MRI; Multiple sclerosis; Stem cell