Grey and white matter changes across the amyotrophic lateral sclerosis-frontotemporal dementia continuum

PLoS One. 2012;7(8):e43993. doi: 10.1371/journal.pone.0043993. Epub 2012 Aug 29.

Abstract

There is increasing evidence that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a clinical, pathological and genetic continuum with patients of one disease exhibiting features of the other. Nevertheless, to date, the underlying grey matter and white matter changes across the ALS-FTD disease continuum have not been explored. In this study fifty-three participants with ALS (n = 10), ALS-FTD (n = 10) and behavioural variant FTD (bvFTD; n = 15) as well as controls (n = 18), underwent detailed clinical assessment plus structural imaging using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analysis of magnetic resonance brain imaging to examine grey and white matter differences and commonalities across the continuum. Importantly, patient groups were matched for age, education, gender and disease duration. VBM and DTI results showed that changes in the ALS group were confined mainly to the motor cortex and anterior cingulate as well as their underlying white matter tracts. ALS-FTD and bvFTD showed widespread grey matter and white matter changes involving frontal and temporal lobes. Extensive prefrontal cortex changes emerged as a marker for bvFTD compared to other subtypes, while ALS-FTD could be distinguished from ALS by additional temporal lobe grey and white matter changes. Finally, ALS could be mainly distinguished from the other two groups by corticospinal tract degeneration. The present study shows for the first time that FTD and ALS overlap in anterior cingulate, motor cortex and related white matter tract changes across the whole continuum. Nevertheless, frontal and temporal atrophy as well as corticospinal tract degeneration emerged as marker for subtype classification, which will inform future diagnosis and target disease management across the continuum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis / pathology*
  • Amyotrophic Lateral Sclerosis / physiopathology
  • Atrophy
  • Behavior / physiology
  • Brain / pathology*
  • Brain / physiopathology
  • Case-Control Studies
  • Cognition
  • Diffusion Tensor Imaging
  • Female
  • Frontotemporal Dementia / pathology*
  • Frontotemporal Dementia / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Motor Cortex / pathology
  • Motor Cortex / physiopathology
  • Prefrontal Cortex / pathology
  • Prefrontal Cortex / physiopathology
  • Pyramidal Tracts / pathology
  • Pyramidal Tracts / physiopathology

Supplementary concepts

  • Frontotemporal Dementia With Motor Neuron Disease

Grant support

PL is supported by Comisión Nacional de Investigación Científica y Tecnológica, Government of Chile (CONICYT scholarship) and Faculty of Medicine, University of Chile; EM is supported by an NHMRC post-doctoral fellowship (1016399); JRB is supported by the NHMRC; MCK is supported by the NHMRC; JRH is supported by an Australian Research Council Federation Fellowship (FF077622); and MH is supported by an Australian Research Council Research Fellowship (DP110104202). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.