Marcello Spinella

NORMATIVE DATA AND A SHORT FORM OF THE BARRATT IMPULSIVENESS SCALE

The Barratt Impulsiveness Scale is one of the most commonly used scales to measure impulsivity. It has demonstrated validity in several neuropsychiatric populations and correlates with objective neuropsychological measures and impulsivity-related behaviors in healthy individuals. Neuroimaging studies show that BIS scores relate to prefrontal structure and function, as well as central serotonergic function. This study reports normative data and demographic influences in a community sample (n = 700). A 15-item short form of the BIS (BIS 15) is presented that retains the 3-factor structure (nonplanning, motor impulsivity, and attention impulsivity), and maintained good reliability and validity.

Herbal Medicines and Epilepsy: The Potential for Benefit and Adverse Effects☆

The widespread availability and use of herbal medicines raise the potential for adverse effects in the epilepsy population. Herbal sedatives (kava, valerian, chamomile, passionflower) may potentiate the effects of antiepileptic medications, increasing their sedative and cognitive effects. Despite some antiseizure effects in animal models, they should not be used in place of standard seizure medications because efficacy has not been established. Anecdotal, uncontrolled observations suggest that herbal stimulants containing ephedrine (ephedra or ma huang) and caffeine (cocoa, coffee, tea, maté, guarana, cola or kola) can exacerbate seizures in people with epilepsy, especially when taken in combination. Ginkgo and ginseng may also exacerbate seizures although the evidence for this is similarly anecdotal and uncertain. St. Johns wort has the potential to alter medication pharmacokinetics and the seizure threshold. The essential oils of many plants contain epileptogenic compounds. There is mixed evidence for evening primrose and borage lowering the seizure threshold. Education of both health care providers and patients is the best way to avoid unintentional and unnecessary adverse reactions to herbal medicines.

Neurobehavioral correlates of impulsivity: evidence of prefrontal involvement.

Impulsivity is associated with the functioning of prefrontal-subcortical circuits particularly, the orbitofrontal circuit, which is shown in neuro-imaging studies of neurological and psychological disorders. Objective behavioral measures, such as go/no-go, antisaccades, and delayed alternation, have demonstrated sensitivity to prefrontal function. This study examined the relationship between orbitofrontal-sensitive measures and impulsivity in healthy adults, as measured by the Barratt Impulsiveness Scale-11 (BIS). Go/no-go and antisaccades correlated positively and delayed alternations correlated negatively with BIS subscales, even after controlling for demographic influences. The results add to the validity of the BIS and support a role for prefrontal cortex in impulse control

Relationship between drug use and prefrontal-associated traits

The prefrontal cortex plays an important role in the strategic and emotional regulation of behavior. Both cognitive and neuroimaging studies have implicated prefrontal cortex in processes of reward and addiction. Prefrontal‐associated neurobehavioral traits may be measured psychometrically with the Frontal Systems Behavior Scale (FrSBe), so it was hypothesized that self‐ratings on this instrument would correlate with parameters of psychoactive drug use in a community sample. Modest but significant correlations were found for various parameters of tobacco use, even after controlling for demographic variables. Significant differences were noted in the mean scores when non‐users were compared with users of cannabis, major stimulants (e.g. cocaine, amphetamine), and dissociative hallucinogens (e.g. phencyclidine, ketamine) and polysubstance use, particularly with the Disinhibition subscale. Smokers rated greater dysfunction than non‐smokers on all three subscales, with ex‐smokers showing intermediate ratings between the two. Polysubstance users showed greater dysfunction on the Disinhibition subscale compared to non‐polysubstance users. In summary, this study further supports a relationship between prefrontal dysfunction and drug use in normal individuals, convergently with other methodologies for studying addiction.

SELF-RATED EXECUTIVE FUNCTION: DEVELOPMENT OF THE EXECUTIVE FUNCTION INDEX

There are several self-rating executive function (SREF) measures in existence that were developed solely in clinical populations or which sample a limited range of executive functions. The Executive Function Index (EFI) was developed here in a normal population with five subscales derived through factor analysis: Motivational Drive, Strategic Planning, Organization, Impulse Control, and Empathy. The content of three second order factors is consistent with the functions mediated by dorsolateral, orbitofrontal, and medial prefrontal circuits. Intrascale reliability and demographic relationships are reported as well as strong correlations with other SREF measures validated in clinical and neuroimaging studies. This brief measure provides a quick and efficient means of collecting data in large samples in order to test hypotheses regarding the role of prefrontal systems in various aspects of behavior and to corroborate findings of other methods, such as objective tests and functional neuroimaging.

Hypomania induced by herbal and pharmaceutical psychotropic medicines following mild traumatic brain injury

The use of herbal medicines has become a very common practice. While many are safe enough to be available over-the-counter, they may pose risks due to interactions with pharmaceutical medications and effects in specific clinical populations. The case of a female patient with a history of mild traumatic brain injury and resulting depression is presented. She experienced hypomania after adding St Johns wort and Ginkgo biloba to her regimen of fluoxetine and buspirone, which remitted after discontinuation of the herbal medicines. Implications for interactions between various psychopharmacologic agents, including herbal medicines and selective serotonin reuptake inhibitors (SSRIs), as well as the need for appropriate patient and health care provider education are discussed.

EXECUTIVE PERSONALITY TRAITS AND EATING BEHAVIOR

Eating disorders, such as anorexia, bulimia, and binge eating disorder, commonly involve a dysregulation of behavior (e.g., a lack or excess of inhibition and impulsive eating patterns) that is suggestive of prefrontal dysfunction. Functional neuro-imaging studies show that prefrontal-subcortical systems play a role in eating behavior and appetite in healthy individuals, and that people with eating disorders have altered activity in these systems. Eating behavior is often disturbed by illnesses and injuries that impinge upon prefrontal-subcortical systems. This study examined relationships between executive functioning and eating behavior in healthy individuals using validated behavioral rating scales (Frontal Systems Behavior Scale and Eating Inventory). Correlations demonstrated that increased dysexecutive traits were associated with disinhibited eating and greater food cravings. There was also a positive association with cognitive restraint of eating, suggesting that increased compensatory behaviors follow disinhibited eating. These psychometric findings reinforce those of other methodologies, supporting a role for prefrontal systems in eating

Clinical Case Report HYPERSEXUALITY AND DYSEXECUTIVE SYNDROME AFTER A THALAMIC INFARCT

Hypersexuality can result from insults to several neuroanatomical structures that regulate sexual behavior. A case is presented of an adult male with a thalamic infarct resulting in a paramedian thalamic syndrome, consisting of hypersomnolence, confabulatory anterograde amnesia (including reduplicative paramnesia), vertical gaze deficits, and hypophonic speech. A dysexecutive syndrome also manifested, consisting of social disinhibition, apathy, witzelsucht, motor inhibition deficits, and environmental dependence. Hypersexuality uncharacteristic of his premorbid behavior was evident in instances of exhibitionism, public masturbation, and verbal sexual obscenities. In contrast to the few previous reports of hypersexuality following thalamic infarct, this case neither involved mania nor hemichorea. The relevance of the mediodorsal thalamic nucleus in limbic and prefrontal circuits is discussed.

A RELATIONSHIP BETWEEN SMELL IDENTIFICATION AND EMPATHY

Olfaction is a sense that has close relationships with the limbic system and emotion. Empathy is a vicarious feeling of others emotional states. The two functions are known to be subserved by common neuroanatomical structures, including orbitofrontal cortex, mediodorsal thalamus, and the amygdala. This study demonstrates a correlation between smell identification and empathy, using the Mehrabian and Epstein Empathy Questionnaire and Alberta Smell Test. Right nostril smell identification correlated with empathy, whereas the left nostril did not. Given the predominantly ipsilateral representation in the olfactory system, this is in accordance with right hemisphere dominance for emotional functions and empathy. Further, the emotional component of empathy (feeling another s emotions) correlated with smell, whereas a cognitive component (comprehending another s emotions) did not. This study is the first to demonstrate a relationship between empathy and smell in normal subjects, suggesting common neural substrates.

PREFRONTAL SYSTEM DYSFUNCTION AND CREDIT CARD DEBT

Credit card use often involves a disadvantageous allocation of finances because they allow for spending beyond means and buying on impulse. Accordingly they are associated with increased bankruptcy, anxiety, stress, and health problems. Mounting evidence from functional neuroimaging and clinical studies implicates prefrontal-subcortical systems in processing financial information. This study examined the relationship of credit card debt and executive functions using the Frontal System Behavior Scale (FRSBE). After removing the influences of demographic variables (age, sex, education, and income), credit card debt was associated with the Executive Dysfunction scale, but not the Apathy or Disinhibition scales. This suggests that processes of conceptualizing and organizing finances are most relevant to credit card debt, and implicates dorsolateral prefrontal dysfunction.