title: Lower Ipsilateral Hippocampal Integrity after Ischemic Stroke in Young Adults: A Long-Term Follow-Up Study.
abstract: OBJECTIVE
  Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first occurrence of structural damage and are preceded by microscopic changes that may already be associated with a worse memory function. We therefore examined the relationship between hippocampal integrity, volume, and memory performance long after first-ever ischemic stroke in young adults.
  
  
  METHODS
  We included all consecutive first-ever ischemic stroke patients, without hippocampal strokes or recurrent stroke/TIA, aged 18-50 years, admitted to our academic hospital between 1980 and 2010. One hundred and forty-six patients underwent T1 MPRAGE, DTI scanning and completed the Rey Auditory Verbal Learning Test and were compared with 84 stroke-free controls. After manual correction of hippocampal automatic segmentation, we calculated mean hippocampal fractional anisotropy (FA) and diffusivity (MD).
  
  
  RESULTS
  On average 10 years after ischemic stroke, lesion volume was associated with lower ipsilateral hippocampal integrity (p<0.05), independent of hippocampal volume. In patients with a normal ipsilateral hippocampal volume (volume is less than or equal to 1.5 SD below the mean volume of controls) significant differences in ipsilateral hippocampal MD were observed (p<0.0001). However, patients with a normal hippocampal volume and high hippocampal MD did not show a worse memory performance compared with patients with a normal volume and low hippocampal MD (p>0.05).
  
  
  CONCLUSIONS
  Patients with average ipsilateral hippocampal volume could already have lower ipsilateral hippocampal integrity, although at present with no attendant worse memory performance compared with patients with high hippocampal integrity. Longitudinal studies are needed to investigate whether a low hippocampal integrity after stroke might lead to exacerbated memory decline with increasing age.
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Pauline
authors.initials: P
authors.lastname: Schaapsmeerders
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Anil M
authors.initials: AM
authors.lastname: Tuladhar
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Noortje A M
authors.initials: NA
authors.lastname: Maaijwee
authors.affiliation: Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Loes C A
authors.initials: LC
authors.lastname: Rutten-Jacobs
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Renate M
authors.initials: RM
authors.lastname: Arntz
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Hennie C
authors.initials: HC
authors.lastname: Schoonderwaldt
authors.affiliation: Department of Neurology, Medisch Spectrum Twente, Enschede, the Netherlands.
authors.forename: Lucille D A
authors.initials: LD
authors.lastname: Dorresteijn
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Ewoud J
authors.initials: EJ
authors.lastname: van Dijk
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Centre for Neuroscience and Centre for Cognition, Radboud University Nijmegen, Nijmegen, the Netherlands; Department of Medical Psychology, Radboud university medical centre, Nijmegen, the Netherlands.
authors.forename: Roy P C
authors.initials: RP
authors.lastname: Kessels
authors.affiliation: Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, the Netherlands.
authors.forename: Frank-Erik
authors.initials: FE
authors.lastname: de Leeuw
mesh_terms: D016880:Anisotropy; D016022:Case-Control Studies; D003710:Demography; D004058:Diffusion; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D009929:Organ Size; D020521:Stroke / Q000150:complications*; D013788:Thalamus / Q000473:pathology; D013997:Time Factors; D055815:Young Adult