Specific phobia is the most prevalent of the anxiety disorders. Although there have been relatively few studies of its psychobiology and pharmacotherapy, there is a rich laboratory of literature on fear conditioning and extinction and a clear evolutionary perspective. Advances in the cognitive-affective neuroscience of fear processing may ultimately lead to new approaches to the clinical management of phobias.

A case of pure mutism without pseudobulbar palsy and other neurological findings resulting from simultaneous bilateral lenticulostriate artery territory infarction is presented. A 45-year-old woman suffered a transient ischemic attack with nonfluent aphasia and right hemiparesis. Six months later, she developed pure mutism without oral apraxia, pseudobulbar signs, and motor deficits. Magnetic resonance imaging revealed bilateral infarction in the lentiform nucleus regions. In the available data, there is only one report of simultaneous bilateral lenticulostriate infarction.To date, in all reported cases of mutism of subcortical vascular origin there are also various degrees of pseudobulbar signs and motor deficits and the responsible lesions are mostly consecutive.The case presented here is the first to show pure vascular mutism without other neurological findings.

Objective: To describe a case of marijuanainduced delirium and the techniques used to detect psychoactive agents and metabolites in urine.

Methods: A case of delirium following involuntary ingestion of cannabis is described. A urine sample was analyzed applying various chemical procedures, using high-resolution gas chromatography coupled with mass spectrometry technique. 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid was quantified by the methodology for steroids and cannabis.

Results: A 26-year-old man was hospitalized with severe agitation and psychotic behavior 36 hours after suspected involuntary ingestion of cannabis contained in a brigadeiro, a typical Brazilian cookie, consumed during a party. Treatment with neuroleptics resulted in complete regression of the symptoms over 2 weeks. The urine sample revealed marijuana ingestion, demonstrated by the presence of its metabolite, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid in

Conclusion: Severe delirium can follow oral ingestion of cannabis integrated into homemade cookies.

This article reviews the current state of magnetic resonance imaging techniques as applied to bipolar disorder. Addressed are conventional methods of structural neuroimaging and recently developed techniques. This latter group comprises volumetric analysis, voxel-based morphometry, the assessment of T2 white matter hyperintensities, shape analysis, cortical surface-based analysis, and diffusion tensor imaging. Structural analysis methods used in magnetic resonance imaging develop exponentially, and now present opportunities to identify disease-specific neuroanatomic alterations. Greater acuity and complementarity in measuring these alterations has led to the generation of further hypotheses regarding the pathophysiology of bipolar disorder. Included in the summary of findings is consideration of a resulting neuroanatomic model. Integrative issues and future directions in this relatively young field, including multi-modal approaches enabling us to produce more comprehensive results, are discussed.

Abnormalities in brain activation using functional magnetic resonance imaging (fMRI) during cognitive and emotional tasks have been identified in bipolar disorder patients, in frontal, subcortical and limbic regions. Several studies also indicate that mood state may be differentiated by lateralization of brain activation in fronto-limbic regions. The interpretation of fMRI studies in bipolar disorder is limited by the choice of regions of interest, medication effects, comorbidity, and task performance. These studies suggest that there is a complex alteration in regions important for neural networks underlying cognition and emotional processing in bipolar disorder. However, measuring changes in specific brain regions does not identify how these neural networks are affected. New analytical techniques of fMRI data are needed in order to resolve some of these issues and identify how changes in neural networks relate to cognitive and emotional processing in bipolar disorder.

Introduction: Children and adolescents with bipolar disorder often present with higher rates of mixed episodes, rapid cycling, and co-occurring attention-deficit/hyperactivity disorder than adults with bipolar disorder. It is unclear whether the differences in clinical presentation between youth and adults with bipolar disorder are due to differences in underlying etiologies or developmental differences in symptom manifestation. Neuroimaging studies of children and adolescents with bipolar disorder may clarify whether neurobiological abnormalities associated with early-and adult-onset bipolar disorder are distinct. Moreover, children and adolescents with bipolar disorder are typically closer to their illness onset than bipolar adults, providing a window of opportunity for identifying core neurobiological characteristics of the illness (ie, disease biomarkers) that are independent of repeated affective episodes and other confounding factors associated with illness course.

Methods: Peer-reviewed publications of neuroimaging studies of bipolar children and adolescents were reviewed.

Results: Structural, neurochemical, and neurofunctional abnormalities in prefrontal and medical temporal and subcortical limbic structures, including the striatum, amygdala, and possibly hippocampus, are present in children and adolescents with bipolar disorder.

Conclusion: Differences between neurobiological abnormalities in bipolar youth and adults as well as recommendations for future research directions are discussed.

Bipolar disorder is a common psychiatric condition with significant associated morbidity and mortality. Despite its significance, the neurophysiology and neuropathology of this illness is incompletely understood. Recent advances in neuroimaging techniques have helped to begin clarifying these areas. Specifically, bipolar disorder appears to arise from abnormalities within discrete brain networks (eg, the anterior limbic network). The expression of the symptoms of bipolar disorder does not appear to result from single, localized brain lesions, but rather are emergent properties of dysfunction of these brain networks. As neuroimaging techniques continue to improve, the underlying neural basis of bipolar disorder will be clarified.