How doctors diagnose diseases and prescribe treatments: an fMRI study of diagnostic salience

Understanding the brain mechanisms involved in diagnostic reasoning may contribute to the development of methods that reduce errors in medical practice. In this study we identified similar brain systems for diagnosing diseases, prescribing treatments, and naming animals and objects using written information as stimuli. Employing time resolved modeling of blood oxygen level dependent (BOLD) responses enabled time resolved (400 milliseconds epochs) analyses. With this approach it was possible to study neural processes during successive stages of decision making. Our results showed that highly diagnostic information, reducing uncertainty about the diagnosis, decreased monitoring activity in the frontoparietal attentional network and may contribute to premature diagnostic closure, an important cause of diagnostic errors. We observed an unexpected and remarkable switch of BOLD activity within a right lateralized set of brain regions related to awareness and auditory monitoring at the point of responding. We propose that this neurophysiological response is the neural substrate of awareness of one’s own (verbal) response. Our results highlight the intimate relation between attentional mechanisms, uncertainty, and decision making and may assist the advance of approaches to prevent premature diagnostic closure

Prevalence of stroke and associated disability in Brazil: National Health Survey - 2013

There is scarce data about prevalence of stroke in Brazil. The National Health Survey (PNS) is a community-based epidemiological survey, with a nationally representative sample to assess the absolute numbers with respective prevalence rates of stroke and post-stroke disabilities. It was estimated 2,231.000 stroke and 568,000 stroke cases with severe disabilities. The point prevalences was 1.6% and 1.4% in men and women, respectively. The prevalences of post-stroke disabilities were 29.5% for men and 21.5% for women. Stroke prevalence rates increased with aging, low education level, among people living in urban areas with no difference according to self-reported skin color. The degree of post-stroke disability was not statistically different according to sex, race, education level or living area. This new data from PNS show high stroke prevalence rates especially in older individuals without formal education and urban dweller, but the degree of stroke disability was not determined by the sociodemographic characteristics of the Brazilian population