Altered social decision making in patients with chronic pain.

BACKGROUND: Chronic pain affects up to 20% of the population, impairs quality of life and reduces social participation. Previous research reported that pain-related perceived injustice covaries with these negative consequences. The current study probed whether chronic pain patients responded more strongly to disadvantageous social inequity than healthy individuals. METHODS: We administered the Ultimatum Game, a neuroeconomic social exchange game, where a sum of money is split between two players to a large sample of patients with chronic pain disorder with somatic and psychological factors (n = 102) and healthy controls (n = 101). Anonymised, and in truth experimentally controlled, co-players proposed a split, and our participants either accepted or rejected these offers. RESULTS: Chronic pain patients were hypersensitive to disadvantageous inequity and punished their co-players for proposed unequal splits more often than healthy controls. Furthermore, this systematic shift in social decision making was independent of patients' performance on tests of executive functions and risk-sensitive (non-social) decision making . CONCLUSIONS: Our findings indicate that chronic pain is associated with anomalies in social decision making (compared to healthy controls) and hypersensitivity to social inequity that is likely to negatively impact social partaking and thereby the quality of life.

A decision-neuroscientific intervention to improve cognitive recovery after stroke.

Functional recovery after stroke is dose-dependent on the amount of rehabilitative training. However, rehabilitative training is subject to motivational hurdles. Decision neuroscience formalizes drivers and dampers of behaviour and provides strategies for tipping motivational trade-offs and behaviour change. Here, we used one such strategy, upfront voluntary choice restriction ('precommitment'), and tested if it can increase the amount of self-directed rehabilitative training in severely impaired stroke patients. In this randomized controlled study, stroke patients with working memory deficits (n = 83) were prescribed daily self-directed gamified cognitive training as an add-on to standard therapy during post-acute inpatient neurorehabilitation. Patients allocated to the precommitment intervention could choose to restrict competing options to self-directed training, specifically the possibility to meet visitors. This upfront choice restriction was opted for by all patients in the intervention group and highly effective. Patients in the precommitment group performed the prescribed self-directed gamified cognitive training twice as often as control group patients who were not offered precommitment [on 50% versus 21% of days, Pcorr = 0.004, d = 0.87, 95% confidence interval (CI95%) = 0.31 to 1.42], and, as a consequence, reached a 3-fold higher total training dose (90.21 versus 33.60 min, Pcorr = 0.004, d = 0.83, CI95% = 0.27 to 1.38). Moreover, add-on self-directed cognitive training was associated with stronger improvements in visuospatial and verbal working memory performance (Pcorr = 0.002, d = 0.72 and Pcorr = 0.036, d = 0.62). Our neuroscientific decision add-on intervention strongly increased the amount of effective cognitive training performed by severely impaired stroke patients. These results warrant a full clinical trial to link decision-based neuroscientific interventions directly with clinical outcome.

Frequency and nature of pain in patients undergoing neurorehabilitation.

OBJECTIVE: This prospective study investigated the extent to which patients undergoing neurorehabilitation reported pain, how this pain developed during inpatient stay and whether patients were treated accordingly (using pain medication). METHODS: The extent of pain, performance in daily activities, with a focus on possible impairment from pain, and pain medication were assessed at the beginning and the end of neurorehabilitation treatment. Overall 584 patients, with various neurological diagnoses, such as stroke, intracerebral hemorrhage, polyneuropathy, etc. were classified into four groups based on whether they reported having "no pain," "mild pain," "moderate pain," or "severe pain." All patients received conventional neurorehabilitation therapy in the Mauritius Hospital, Germany. RESULTS: A total of 149 patients had clinically relevant pain at the beginning of their inpatient stay, at a group level this did not change significantly during the treatment period. At the end of inpatient stay, a slight increase was noted in patients reporting pain. Overall 164 patients suffered from moderate or severe pain, operationalized of pain scores >3 on the visual analog scale. A total of 145 patients who had pain at the end of inpatient stay, did not receive pain medication. There was a weak negative association between pain at baseline and activities of daily living at the end of the treatment period, such that, patients with higher pain levels tended to showed lower Barthel Index scores at the end. CONCLUSION: In our study, about one-third of patients suffered from clinically relevant pain during neurorehabilitation treatment and most of them did not receive any pain medication.