title: Impaired cognitive flexibility in amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  Up to half of patients with amyotrophic lateral sclerosis (ALS) may have cognitive difficulty, but most cognitive measures are confounded by a motor component. Studies relating impaired cognition in ALS to disease in gray matter and white matter are rare. Our objective was to assess executive function in patients with ALS using a simple, untimed measure with minimal motor demands, and to relate performance to structural disease.
  
  
  METHODS
  We gave the Visual-Verbal Test to 56 patients with ALS and 29 matched healthy controls. This brief, untimed measure of cognitive flexibility first assesses participants' ability to identify a feature shared by 3 of 4 simple geometric designs. The participants' cognitive flexibility is challenged when they are next asked to identify a different feature shared by another combination of 3 of the same 4 geometric designs. In a subset of 17 patients who underwent magnetic resonance imaging, regression analyses related test performance to gray matter atrophy and reduced white matter fractional anisotropy.
  
  
  RESULTS
  The patients with ALS showed significant impairment in cognitive flexibility (P<0.01), with 48.2% making an error on the test. Regression analyses related impaired cognitive flexibility to gray matter atrophy in inferior frontal and insular regions, and to reduced fractional anisotropy in white matter projections in the inferior fronto-occipital and uncinate fasciculi and corpus callosum.
  
  
  CONCLUSIONS
  Our patients with ALS had impaired cognitive flexibility on an untimed measure with minimal motor demands, a finding related in part to a large-scale frontal network that is degraded in ALS.
authors: *Department of Psychology, Villanova University, Villanova, Pennsylvania †Department of Neurology and Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, Pennsylvania.
authors: Jessica
authors: J
authors: Evans
authors: Christopher
authors: C
authors: Olm
authors: Leo
authors: L
authors: McCluskey
authors: Lauren
authors: L
authors: Elman
authors: Ashley
authors: A
authors: Boller
authors: Eileen
authors: E
authors: Moran
authors: Katya
authors: K
authors: Rascovsky
authors: Teagan
authors: T
authors: Bisbing
authors: Corey T
authors: CT
authors: McMillan
authors: Murray
authors: M
authors: Grossman
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000523:psychology*; D016880:Anisotropy; D001284:Atrophy / Q000175:diagnosis; D016022:Case-Control Studies; D003071:Cognition; D060825:Cognitive Dysfunction / Q000209:etiology*; D056344:Executive Function; D005260:Female; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D014705:Verbal Behavior; D066127:White Matter / Q000473:pathology