Differential SPECT activation patterns associated with PASAT performance may indicate frontocerebellar functional dissociation in chronic mild traumatic brain injury.

UNLABELLED: Patients with mild traumatic brain injury (TBI) often complain of cognitive fatigue during the chronic recovery phase. The Paced Auditory Serial Addition Test (PASAT) is a complex psychologic measure that may demonstrate subtle deficiencies in higher cognitive functions. The purpose of this study was to investigate the brain activation of regional cerebral blood flow (rCBF) with PASAT in patients with mild TBI to explore mechanisms for the cognitive fatigue. METHODS: Two groups consisting of 15 patients with mild TBI and 15 healthy control subjects underwent (99m)Tc-ethylene cysteine dimer SPECT at rest and during PASAT on a separate day. Cortical rCBF was extracted using a 3-dimensional stereotactic surface projection and statistically analyzed to identify areas of activation, which were compared with PASAT performance scores. RESULTS: Image analysis demonstrated a difference in the pattern of activation between patients with mild TBI and healthy control subjects. Healthy control subjects activated the superior temporal cortex (Brodmann area [BA] 22) bilaterally, the precentral gyrus (BA 9) on the left, and the precentral gyrus (BA 6) and cerebellum bilaterally. Patients with mild TBI demonstrated a larger area of supratentorial activation (BAs 9, 10, 13, and 46) but a smaller area of activation in the cerebellum, indicating frontocerebellar dissociation. CONCLUSION: Patients with mild TBI and cognitive fatigue demonstrated a different pattern of activation during PASAT. Frontocerebellar dissociation may explain cognitive impairment and cognitive fatigue in the chronic recovery phase of mild traumatic brain injury.

The Teen Marijuana Check-Up: An In-School Protocol for Eliciting Voluntary Self-Assessment of Marijuana Use.

Given the prevalence of regular marijuana use among adolescents and associated risks for adverse consequences to functioning, effective interventions are needed that are tailored for this population. To date, most such counseling approaches have relied on non-voluntary participation by adolescent marijuana smokers and the outcomes have been only modestly successful. The Teen Marijuana Check-Up is a brief motivational enhancement intervention publicized as a non-pressured and confidential opportunity for the teen marijuana smoker to "take stock" of his/her use. The intervention is designed for in-school implementation and intended to elicit the teen's voluntary participation. This paper highlights the manner in which adolescents are recruited, key intervention elements, the nature of the counseling style utilized, and clinical challenges. The outcomes of two trials with this intervention are briefly discussed.

The violent or agitated patient.

Violent and agitated patients are high risk because they may pose a physical threat to the staff, may harm themselves, and may have dangerous comorbidities and illness that are causing the violence. The emergency physician must quickly control these behaviors, and thoroughly identify and treat their etiology, while simultaneously protecting the patients' rights and reducing the risks of injury to themselves, other patients, and medical staff. This article highlights potentially high-risk situations and describes corresponding mitigation tactics.