ABSTRACT
INTRODUCTION AND OBJECTIVES: 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.
Subject(s)
Event-Related Potentials, P300 , Hearing Disorders/diagnosis , Hyperhomocysteinemia/physiopathology , Psychoacoustics , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Hearing Disorders/etiology , Humans , Hyperhomocysteinemia/complications , Male , Middle Aged , Prospective StudiesABSTRACT
Se investigó un caso con alexia pura sin agrafia, secundaria a un infarto cerebral occipital. Se presentó, clínicamente, con una amaurosis bilateral de 2 h de duración, seguida de una marcada dificultad para la lectura, la cual era interpretada por el paciente como un déficit para la visión cercana y por los oftalmólogos y optometristas como una presbiopía. Se constató la ausencia de la onda P-300 en el estudio del componente endógeno de los potenciales relacionados con eventos (PRE) con tareas de discriminación fonética y su registro normal con tareas de discriminación gráfica. Así se confirmó el diagnóstico cliniconeurofisiológico de alexia pura sin agrafia mediante este método no invasivo, que estudia el proceso cognitivo cerebral.
A case of pure alexia without agraphia after en occipital cerebral infarction was presented. It clinically manifested with a bilateral amaurosis of 2 hours, followed by a marked difficulty for reading, which was interpreted by the patient as a visual deficit and by the ophthalmologists and optometrists as a presbyopia. The absence of the P-300 wave was proved in the study of the endogenous component of the event-related potentials (ERP) by using phonetic discrimination tasks and their normal record with graphic discrimination tasks. Thus, the cliniconeurophysiological diagnosis of pure alexia without agraphia was confirmed by this non-invasive method that studies the cerebral cognitive process.
