title: Cognitive deficits in amyotrophic lateral sclerosis evaluated by event-related potentials.
abstract: OBJECTIVE
  To determine the cognitive profiles in non-demented, relatively less handicapped patients with early-stage sporadic amyotrophic lateral sclerosis (ALS) by using neuropsychological tests, event-related potentials (ERPs) and clinical scale.
  
  
  METHODS
  We recruited 19 patients with sporadic ALS (eight with limb-onset, 11 with bulbar-onset) and 19 controls. In addition to the mini-mental state examination and the Wechsler adult intelligence scale-revised, we assessed the frontal lobe function with Wisconsin card sorting test, Stroop test and trail making test. We used auditory 'oddball' counting paradigm for the ERPs under 20-channel electroencephalogram (EEG) recording. Global field power (GFP) was computed, and its peak amplitudes and latencies of N1/N2/P3 were determined. The results of ERP and neuropsychological tests were correlated with respiratory function and clinical scale.
  
  
  RESULTS
  No global cognitive impairment except for subtle frontal dysfunction was detected, although N1/N2/P3 GFP latencies were significantly prolonged in ALS patients than in the controls. Vital capacity correlated with P3 GFP amplitude, and the relative bulbar functional rating scale correlated with P3 GFP latency.
  
  
  CONCLUSIONS
  Our findings indicated the presence of sub-clinical cognitive deficits in non-demented, sporadic ALS patients. In addition, clinical sub-types and respiratory function dependently influenced cognitive function in patients with sporadic ALS.
  
  
  CONCLUSIONS
  ERP confirmed cognitive impairment in patients with sporadic ALS.
authors.affiliation: Department of Neurology, Dokkyo Medical University, Kitakobayashi 880, Mibu, Tochigi 321-0293, Japan. tomo0317@krb.biglobe.ne.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ogawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata