Beyond a Differential Diagnosis: Cognitive and Morphometric Decoding of Information Processing Speed in Senior Adults with DSM-5 Mild Neurocognitive Disorders

J Alzheimers Dis. 2017;58(3):927-937. doi: 10.3233/JAD-161122.


Background: Processing speed has been highlighted as a diagnostic item for neurocognitive disorders (NCD) in DSM-5. The utility of information processing speed (IPS) enclosed with multiscale constructs in the diagnosis of NCD warrants exploration.

Objective: We aimed to investigate the IPS with two types of measurements in the patients with NCD due to vascular disease (NCD-vascular) and NCD due to Alzheimer's disease (NCD-AD), and examine the associations between IPS measures and morphometric features.

Methods: The IPS was evaluated using trail making test (TMT) and flanker test (n = 204). Direct scores, derived scores, and reaction time (RT) were used as IPS measures. Further, surface-based morphometry cortical volume was calculated in a subsample (n = 44) with structural MRI data.

Results: All IPS measures showed a significant value to differentiate NCD patients from healthy subjects. Only mean RT could distinguish NCD-AD from NCD-vascular groups. TMT-B score and difference score were correlated with gray matter volume (GMV) of inferior frontal gyrus, precuneus and superior temporal cortex. Mean RT was associated with the GMV of post-central gyrus (r = -0.327, p = 0.035), and executive speed was associated with inferior frontal cortex (r = -0.475, p = 0.001), cingulate gyrus (r = -0.497, p = 0.001), and superior temporal gyrus (r = -0.36, p = 0.019).

Conclusion: The cognitive and morphometric correlates of IPS measures indicate that complex IPS might be decomposed into the domain-specific components with corresponding neural underpinnings. Our findings may also provide essential insights into the diagnostic item of NCD.

Keywords: Gray matter volume; information processing speed; morphometry; neurocognitive disorders; reaction time; trail making test.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / pathology
  • Aging / psychology
  • Alzheimer Disease / complications
  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / psychology
  • Area Under Curve
  • Brain / diagnostic imaging
  • Cohort Studies
  • Diagnosis, Differential
  • Diagnostic and Statistical Manual of Mental Disorders
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Mental Processes*
  • Neurocognitive Disorders / complications
  • Neurocognitive Disorders / diagnosis*
  • Neuropsychological Tests*
  • ROC Curve
  • Reaction Time