RESUMO
Event-related potentials may offer more precision than behavioural measures for understanding the extent and timing of information processing difficulties that follow closed head injury (CHI). Behavioural tests consistently indicate a general reduction in cognitive function but lack adequate diagnostic or prognostic function. This study compares a group of seven CHI patients, in which time since injury varied between 1 and 5 years following injury, with 10 matched controls on a three-tone discrimination task. Abnormality in the processing of tones as early as 200 ms following their onset, as measured by the P2 and N2 components of the event-related potential, indicated a general difficulty with tone discrimination. This abnormality was obtained despite differing damage profiles over patients and is likely to be due to the diffuse aspects of damage normal in CHI. These results also indicate that functional deficits in CHI patients can extend up to 5 years or more. A correlation between P2/N2 amplitudes and time since injury, however, suggests that both these components normalize with the passage of time and offers the prospect of a sensitive, non-behavioural measure of recovery in cognitive processing.
Assuntos
Dano Encefálico Crônico/fisiopatologia , Córtex Cerebral/fisiologia , Eletroencefalografia/instrumentação , Traumatismos Cranianos Fechados/fisiopatologia , Transtornos Neurocognitivos/fisiopatologia , Processamento de Sinais Assistido por Computador/instrumentação , Adolescente , Adulto , Amnésia/diagnóstico , Amnésia/fisiopatologia , Dano Encefálico Crônico/diagnóstico , Potenciais Evocados Auditivos/fisiologia , Seguimentos , Traumatismos Cranianos Fechados/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Neurocognitivos/diagnóstico , Discriminação da Altura Tonal/fisiologia , Tempo de Reação/fisiologiaRESUMO
This study reports Auditory Verbal Learning Test (AVLT) data for 153 adults in age groups spanning seven decades, with approximately equal numbers of males and females and matched for intelligence, education, and occupation. Overall performance deteriorated with increased age, females performing better than males. Older subjects recalled fewer words, were more susceptible to information overload during input, showed diminished retrieval efficiency, and had a decline in memory for the source of items. In contrast, rate of learning, forgetting over 20-min, monitoring of recall, and interference effects remained stable across the age range.
