RESUMO
Recent research revealed decreased access to semantic and associative networks in acute cocaine withdrawal. In autism, such behavioral outcomes are associated with decreased functional connectivity using functional magnetic resonance imaging. Therefore, we wished to determine whether connectivity is also decreased in acute cocaine withdrawal. Eight subjects in acute cocaine withdrawal were compared to controls for connectivity in language areas while performing a task involving categorization of words according to semantic and phonological relatedness. Acute withdrawal subjects had significantly less overall connectivity during semantic relatedness, and a trend towards less connectivity during phonological relatedness. Of potential future interest is whether this might serve as an imaging marker for treatment in patients.
Assuntos
Córtex Cerebral/fisiopatologia , Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Vias Neurais/fisiopatologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Aprendizagem Verbal/fisiologia , Doença Aguda , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Neuroimagem Funcional , Humanos , Idioma , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Vias Neurais/efeitos dos fármacos , Fonética , Projetos Piloto , Valores de Referência , Semântica , Comportamento Verbal/fisiologia , Adulto JovemRESUMO
Upregulated noradrenergic activity occurs early in cocaine withdrawal. Our previous work revealed impaired cognitive flexibility in acute cocaine withdrawal, a cognitive domain that appears to be modulated by noradrenergic activity. Therefore, we wished to determine the effect of beta-adrenergic antagonists on cognitive performance in acute cocaine withdrawal. Eleven subjects acutely withdrawing from cocaine were tested in this pilot study on tasks of cognitive flexibility as well as word fluency, attention, verbal memory, and spatial memory, off and on propranolol in a double-blinded manner. Propranolol significantly benefited certain aspects of cognitive flexibility in acute cocaine withdrawal, and improved some measures of verbal fluency and verbal recall. Cocaine withdrawal treatment is characterized by high failure rates. Further research is needed to determine the role this finding of a reversible cognitive impairment in cocaine withdrawal has in treatment.
Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Transtornos Relacionados ao Uso de Cocaína/complicações , Cognição/efeitos dos fármacos , Resolução de Problemas/efeitos dos fármacos , Propranolol/farmacologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Doença Aguda , Adaptação Psicológica/efeitos dos fármacos , Adulto , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Desempenho Psicomotor/efeitos dos fármacos , Semântica , Fatores Sexuais , Estatísticas não Paramétricas , Síndrome de Abstinência a Substâncias/etiologia , Comportamento Verbal/efeitos dos fármacos , Aprendizagem Verbal/efeitos dos fármacosRESUMO
UNLABELLED: To perform a pilot study to examine a range of cognitive flexibility tasks early in cocaine withdrawal. BACKGROUND: Previous neuropsychological investigations of cocaine withdrawal have conflicted regarding whether impaired cognitive flexibility occurs. However, most studies have examined patients later in withdrawal. Anxiety and yohimbine-induced panic are greatest early in withdrawal, and both anxiety and increased noradrenergic tone can impair cognitive flexibility. METHOD: Twelve patients acutely withdrawing from cocaine were compared with gender-, age-, and estimated premorbid intelligence-matched control subjects on tests of cognitive flexibility as well as verbal fluency, verbal memory, spatial memory, and attention. RESULTS: As predicted, impairments were found on the cognitive flexibility tasks. Impairments also were present in verbal fluency and verbal memory but not spatial memory or attention. CONCLUSIONS: We propose that the cognitive flexibility impairment may relate to the increased noradrenergic activation recently described in cocaine withdrawal. Impairments on verbal tasks may also relate to an impaired flexibility in the search of semantic networks. Further research will explore the effects of pharmacologic manipulation of the noradrenergic system on cognition in acute withdrawal. Recently, propranolol has been shown to benefit patients in cocaine withdrawal. Further research will explore whether impaired cognitive flexibility related to altered noradrenergic tone could serve as a mechanism for this treatment response.
