A Quantitative Meta-analysis of Olfactory Dysfunction in Epilepsy.

Olfactory dysfunction in epilepsy is well-documented in several olfactory domains. However, the clinical specificity of these deficits remains unknown. The aim of this systematic meta-analysis was to determine which domains of olfactory ability were most impaired in individuals with epilepsy, and to assess moderating factors affecting olfactory ability. Extant peer-reviewed literature on olfaction in epilepsy were identified via a computerized literature search using PubMed, MEDLINE, PsycInfo, and Google Scholar databases. Twenty-one articles met inclusion criteria. These studies included a total of 912 patients with epilepsy and 794 healthy comparison subjects. Included studies measured olfaction using tests of odor identification, discrimination, memory, and detection threshold in patients with different types of epilepsy, including temporal lobe epilepsy (TLE), mixed frontal epilepsy (M-F), and mixed epilepsy (MIX). Olfactory deficits were robust in patients with epilepsy when compared to healthy individuals, with effect sizes in the moderate to large range for several olfactory domains, including odor identification (d = -1.59), memory (d = -1.10), discrimination (d = -1.04), and detection threshold (d = -0.58). Olfactory deficits were most prominent in patients with TLE and M-F epilepsy. Amongst patients with epilepsy, sex, age, smoking status, education, handedness, and age of illness onset were significantly related to olfactory performance. Overall, these meta-analytic findings indicate that the olfactory system is compromised in epilepsy and suggest that detailed neurobiological investigations of the olfactory system may provide further insight into this disorder.

Factors that predict adolescent motivation for substance abuse treatment.

Many adolescent substance abusers enter treatment because of external pressures and thus lack motivation to change their behavior and engage in treatment. Because an understanding of adolescent motivation may contribute to improved treatment, an investigation of factors that predict motivation was undertaken with youth admitted to an adolescent outpatient substance abuse treatment program (N=196). At admission, these subjects received a comprehensive biopsychosocial assessment. Using multiple regression analysis, factors considered to potentially predict motivation were assessed. Of the factors examined, those that involved experiencing various negative consequences of substance use emerged as important predictors of motivation, whereas severity of substance use did not. Diminished awareness of negative consequences of use was consonant with lower motivation, suggesting the importance of interventions to help youth recognize negative consequences of their substance use. Interventions to enhance motivation are likely to become more important as the juvenile justice system increasingly refers troubled youth to treatment.