No Change in Executive Performance in ALS Patients: A Longitudinal Neuropsychological Study

Neurodegener Dis. 2016;16(3-4):184-91. doi: 10.1159/000440957. Epub 2015 Nov 28.

Abstract

Background/aims: A substantial proportion of amyotrophic lateral sclerosis (ALS) patients develop cognitive impairments. Longitudinal investigations of cognition in ALS have shown mixed results. While some authors report that cognitive performance remains stable as the disease progresses, others have found evidence for deterioration in various domains. Our objective was to investigate cognitive performance in ALS longitudinally, using the example of executive functions.

Methods: 93 ALS patients and 73 age-, sex- and education-matched healthy controls underwent up to four neuropsychological evaluations, separated by 3- to 6-month intervals. We examined whether performance declined longitudinally on seven tests assessing various sub-components of executive functioning. Furthermore, we assigned an executive-performance-based 'cognitive status' to each participant for every evaluation, examining whether cognitive deterioration (if present) was modulated by their baseline cognitive status and whether cognitive status changed over time.

Results: Regardless of their cognitive status at baseline, ALS patients showed no significant decline in the sub-components of executive functioning.

Conclusion: Our findings imply that the executive deficits which develop in some ALS patients emerge before motor symptoms and remain stable after an initial decline. The discrepancy between this trajectory and the progressive decline in motor functions may result from a differential vulnerability of motor and non-motor prefrontal neurons to the pathomechanism of ALS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Amyotrophic Lateral Sclerosis / epidemiology
  • Amyotrophic Lateral Sclerosis / psychology*
  • Cognition
  • Disease Progression
  • Educational Status
  • Executive Function*
  • Female
  • Follow-Up Studies
  • Germany / epidemiology
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Time Factors