title: Evaluation of psychoacoustic tests and P300 event-related potentials in elderly patients with hyperhomocysteinemia.
abstract: OBJECTIVE
  Hyperhomocysteinemia as a risk factor for hearing impairment, neuronal damage and cognitive impairment in elderly patients is controversial and is limited by the small number of studies. The aim of this work was determine if elderly patients detected with hyperhomocysteinemia have an increased risk of developing abnormalities in the central auditory processes as compared with a group of patients with appropriate homocysteine levels, and to define the behaviour of psychoacoustic tests and long latency potentials (P300) in these patients.
  
  
  METHODS
  This was a cross-sectional, comparative and analytical study. We formed a group of patients with hyperhomocysteinemia and a control group with normal levels of homocysteine. All patients underwent audiometry, tympanometry and a selection of psychoacoustic tests (dichotic digits, low-pass filtered words, speech in noise and masking level difference), auditory evoked brainstem potentials and P300.
  
  
  RESULTS
  Patients with hyperhomocysteinemia had higher values in the test of masking level difference than did the control group (P=.049) and more protracted latency in P300 (P=.000).
  
  
  CONCLUSIONS
  Hyperhomocysteinemia is a factor that alters the central auditory functions. Alterations in psychoacoustic tests and disturbances in electrophysiological tests suggest that the central portion of the auditory pathway is affected in patients with hyperhomocysteinemia.
authors.affiliation: Departamento de Patología del Lenguaje y Procesamiento Central Auditivo, Instituto Nacional de Rehabilitación, México DF, México. serch_dl@hotmail.com
authors.forename: Sergio
authors.initials: S
authors.lastname: Díaz-Leines
authors.forename: Yolanda R
authors.initials: YR
authors.lastname: Peñaloza-López
authors.forename: Tirzo A
authors.initials: TA
authors.lastname: Serrano-Miranda
authors.forename: Blanca
authors.initials: B
authors.lastname: Flores-Ávalos
authors.forename: Martha T
authors.initials: MT
authors.lastname: Vidal-Ixta
authors.forename: Blanca
authors.initials: B
authors.lastname: Jiménez-Herrera
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D018913:Event-Related Potentials, P300; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011571:Psychoacoustics
keywords: Adulto mayor; Central auditory processing disorder; Desorden de procesamiento auditivo central; Elderly; Evoked brainstem auditory; Homocisteína; Homocysteine; P300 event-related potentials; Potenciales evocados auditivos de tallo cerebral; Potenciales relacionados a eventos P300