Conscious perception and the modulatory role of dopamine: no effect of the dopamine D2 agonist cabergoline on visual masking, the attentional blink, and probabilistic discrimination.

RATIONALE: Conscious perception is thought to depend on global amplification of sensory input. In recent years, striatal dopamine has been proposed to be involved in gating information and conscious access, due to its modulatory influence on thalamocortical connectivity. OBJECTIVES: Since much of the evidence that implicates striatal dopamine is correlational, we conducted a double-blind crossover pharmacological study in which we administered cabergoline-a dopamine D2 agonist-and placebo to 30 healthy participants. Under both conditions, we subjected participants to several well-established experimental conscious-perception paradigms, such as backward masking and the attentional blink task. RESULTS: We found no evidence in support of an effect of cabergoline on conscious perception: key behavioral and event-related potential (ERP) findings associated with each of these tasks were unaffected by cabergoline. CONCLUSIONS: Our results cast doubt on a causal role for dopamine in visual perception. It remains an open possibility that dopamine has causal effects in other tasks, perhaps where perceptual uncertainty is more prominent.

[Challenges in the diagnostic management of fat embolism syndrome - from divergence in clinical presentation to diagnosis]. / Diagnostische uitdagingen van het vetemboliesyndroom.

This article discusses the diagnosis and management of two patients with cerebral fat embolism syndrome after traumatic femoral fractures. Fat embolism syndrome is a condition which is caused by fat globules in the systemic circulation; it most often occurs in patients with femoral fractures. Patients develop systemic dysfunction, particularly a triad of a petechial rash, respiratory and neurological dysfunction. The syndrome is characterized by a diverse clinical presentation which often necessitates a wide differential diagnosis. The pathogenesis of fat embolism syndrome has not yet been fully elucidated. Although it has been a formally recognised clinical diagnosis for years, new diagnostic imaging capabilities have provided a shift towards a visualisable disorder. Presently, there is no clear evidence and indication for dedicated treatment and therefore supportive measures remain the only treatment modality.

Risk factors for central bile duct injury complicating partial liver resection.

BACKGROUND: Bile duct injury is a serious complication following liver resection. Few studies have differentiated between leakage from small peripheral bile ducts and central bile duct injury (CBDI), defined as an injury leading to leakage or stenosis of the common bile duct, common hepatic duct, right or left hepatic duct. This study analysed the incidence, risk factors and consequences of CBDI in liver resection. METHODS: Patients undergoing liver resection between 1990 and 2007 were included in this study. Those having resection for bile duct-related pathology or trauma, or after liver transplantation were excluded. Characteristics and outcome variables were collected prospectively and analysed retrospectively. RESULTS: There were 19 instances of CBDI in 462 liver resections (4·1 per cent). One-third of patients with CBDI required surgical reintervention and construction of a hepaticojejunostomy. Resection type (P < 0·001), previous liver resection (P = 0·039) and intraoperative blood loss (P = 0·002) were associated with an increased risk of CBDI. Of all resection types, extended left hemihepatectomy was associated with the highest incidence of CBDI (2 of 9 procedures). CONCLUSION: Patients undergoing extended left hemihepatectomy or repeat hepatectomy were at increased risk of CBDI.