RESUMO
BACKGROUND: The aim of the current study was to investigate the cognitive correlates of repetitive transcranial magnetic stimulation (rTMS) in 10 treatment-resistant depression patients. METHODS: Patients received forty 20-min sessions of fast-frequency (10 Hz) rTMS of the left dorsolateral prefrontal cortex (DLPFC) over 20 days. Concept-shift ability (accuracy and duration of performance) was assessed daily with a Modified Concept-Shifting Task (mCST) in patients and in eight healthy volunteers. General cognitive functioning test (Repeatable Battery for the Assessment of Neuropsychological Status; RBANS), Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HAM-D) were applied before the first and after the last rTMS. RESULTS: Compared to before rTMS on the first 10 days, the patients performed the mCST significantly more accurately after rTMS on the last 10 days (p < .001, partial eta squared=.78) while the same comparison in healthy volunteers was not statistically significant (p = .256, partial eta squared=.18). A significant improvement in immediate memory on RBANS and reduction in BDI and HAM-D scores were also observed after the last compared to before the first rTMS. CONCLUSION: The rTMS is associated with an improvement in selective cognitive functions that is not explained by practice effects on tasks administered repeatedly. TRIAL REGISTRATION: Name: "Repetitive Transcranial Magnetic Stimulation (rTMS) in the treatment of depression, assessed with HAM-D over a four week period."URL: www.actr.org.au REGISTRATION NUMBER: ACTRN012605000145606.
Assuntos
Transtornos Cognitivos/terapia , Transtorno Depressivo Resistente a Tratamento/terapia , Córtex Pré-Frontal/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Adulto , Transtornos Cognitivos/etiologia , Transtorno Depressivo Resistente a Tratamento/complicações , Eletroencefalografia/métodos , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Projetos Piloto , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Fatores de Tempo , Estimulação Magnética Transcraniana/instrumentação , Adulto JovemRESUMO
BACKGROUND: Trail-making tests, such as the Concept Shifting Task (CST), can be used to test the effects of treatment on cognitive performance over time in various neuropsychological disorders. However, cognitive performance in such experimental designs might improve as a result of the practice obtained during repeated testing rather than the treatment itself. The current study investigated if practice affects the accuracy and duration of performance on the repeatedly administered Concept Shifting Task modified to make it resistant to practice (mCST). The mCST was administered to 54 healthy participants twice a day, before and after a short break, for eight days. RESULTS: The ANOVA and meta-analysis showed that there was no improvement in the mCST accuracy on the last vs. the first trial (Hedges' g = .14, p = .221) or within the session (after vs. before the break on all days; g = .01, p = .922). However, the participants performed the task faster on the last vs. the first trial (g = -.75, p < .001) and after vs. before the break on all days (g = -.12, p = .002). CONCLUSIONS: Repeated administration of the mCST does not affect the accuracy of performance on the test. However, practice might contribute to faster performance on the mCST over time and within each session.
