Surgical treatment and prophylaxis of parastomal hernias

Despite the progress concerning operative techniques, parastomal hernias remain a surgical challenge. The high risk for recurrence demands precise indications for operative repair. Mesh implants reduce the recurrence rate. Among such procedures, the retromuscular mesh augmentation represents an established method, whereas the value of other techniques still has to be defined. Also, the prophylactic use of meshes is able to reduce the incidence of parastomal hernias. With regard to short- and long-term complications, their general recommendation must be proven in further studies.     

Lateralised visual attention is unrelated to language lateralisation, and not influenced by task difficulty - a functional transcranial Doppler study

Historically, most theoretical accounts of hemispheric specialisation have proposed a single underlying factor that leads to left hemisphere language and right hemisphere visuospatial processing in the majority of people. More recently empirical evidence has started to challenge this view, suggesting lateralisation of language and visuospatial attention are independent. However, so far studies did not control for a possible confound, task difficulty. For this study, 20 healthy right-handed volunteers underwent functional laterality assessment using functional transcranial Doppler ultrasound (fTCD). We assessed laterality using both a word generation task and a novel variation of the visuospatial landmark task that can be adjusted along two dimensions of difficulty (temporal and spatial). The visuospatial laterality measures were highly intercorrelated and unaffected by task difficulty. Furthermore, there was no correlation between visuospatial and verbal lateralisation within individuals - neither qualitatively (in direction of lateralisation), nor quantitatively (in laterality index size). These results substantiate a growing body of evidence suggesting multiple independent biases leading to the hemispheric lateralisation of different cognitive domains, thus further questioning previously accepted models of laterality development and evolution.