This study examined quantitative EEGs of six individuals with chronic pain and compared them to an age- and gender-matched normative database of healthy control subjects in an attempt to discern whether a particular pattern of resting state EEG activity is associated with chronic pain. In the chronic pain group, significantly reduced absolute power was seen in delta and theta bandwidths at frontal sites in the eyes-closed condition. In the eyes-open condition, significantly reduced absolute power was seen in delta, theta, and alpha bandwidths at frontal, central, and temporal sites, and increased relative high beta power was seen in the parietal region. Reduced theta/high beta and delta/high beta ratios were seen in the parietal region. Quantitative EEG neuromarkers of chronic pain are suggested.

Brain-derived neurotrophic factor (BDNF), a neurotrophin involved in the regulation of food intake and body weight, has been implicated in the development and maintenance of Anorexia nervosa (AN). The majority of previous studies reported lower BDNF levels in acutely underweight AN patients (acAN) and increasing levels after weight rehabilitation. Here, we investigated serum BDNF concentrations in the largest known AN sample to date, both before and after weight restoration therapy. Serum BDNF was measured in 259 female volunteers: 77 in-patient acAN participants of the restrictive type (47 reassessed after short-term weight rehabilitation), 62 individuals long-term recovered from AN, and 120 healthy controls. We validated our findings in a post-hoc mega-analysis in which we reanalyzed combined data from the current sample and those from our previous study on BDNF in AN (combined sample: 389 participants). All analyses carefully accounted for known determinants of BDNF (age, sex, storage time of blood samples). We further assessed relationships with relevant clinical variables (body-mass-index, physical activity, symptoms). Contrary to our hypotheses, we found zero significant differences in either cross-sectional or longitudinal comparisons and no significant relationships with clinical variables. Together, our study suggests that BDNF may not be a reliable state- or trait-marker in AN after all.