Frontiers in Neuroscience (Dec 2015)

Early-stage white matter lesions detected by multispectral MRI segmentation predict progressive cognitive decline

  • Hanna eJokinen,
  • Nicolau eGonçalves,
  • Ricardo eVigário,
  • Jari eLipsanen,
  • Franz eFazekas,
  • Reinhold eSchmidt,
  • Frederik eBarkhof,
  • Sofia eMadureira,
  • Ana eVerdelho,
  • Domenico eInzitari,
  • Leonardo ePantoni,
  • Timo eErkinjuntti

DOI
https://doi.org/10.3389/fnins.2015.00455
Journal volume & issue
Vol. 9

Abstract

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White matter lesions (WML) are the main brain imaging surrogate of cerebral small-vessel disease. A new MRI tissue segmentation method, based on a discriminative clustering approach without explicit model-based added prior, detects partial WML volumes, likely representing very early-stage changes in normal-appearing brain tissue. This study investigated how the different stages of WML, from a pre-visible stage to fully developed lesions, predict future cognitive decline. MRI scans of 78 subjects, aged 65-84 years, from the Leukoaraiosis and Disability (LADIS) study were analyzed using a self-supervised multispectral segmentation algorithm to identify tissue types and partial WML volumes. Each lesion voxel was classified as having a small (33%), intermediate (66%), or high (100%) proportion of lesion tissue. The subjects were evaluated with detailed clinical and neuropsychological assessments at baseline and at three annual follow-up visits. We found that voxels with small partial WML predicted lower executive function compound scores at baseline, and steeper decline of executive scores in follow-up, independently of the demographics and the conventionally estimated hyperintensity volume on fluid-attenuated inversion recovery images. The intermediate and fully developed lesions were related to impairments in multiple cognitive domains including executive functions, processing speed, memory and global cognitive function. In conclusion, early-stage partial WML, still too faint to be clearly detectable on conventional MRI, already predict executive dysfunction and progressive cognitive decline regardless of the conventionally evaluated WML load. These findings advance early recognition of small vessel disease and incipient vascular cognitive impairment.

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