Exercise training augments brain function and reduces pain perception in adults with chronic pain: A systematic review of intervention studies.

Introduction: Chronic pain (CP) is a leading cause of disability worldwide. Pain may be measured using subjective questionnaires, but understanding the underlying physiology, such as brain function, could improve prognosis. Further, there has been a shift towards cost-effective lifestyle modification for the management of CP. Methods: We conducted a systematic review (Registration: #CRD42022331870) using articles retrieved from four databases (Pubmed, EMBASE, AMED, and CINAHL) to assess the effect of exercise on brain function and pain perception/quality of life in adults with CP. Results: Our search yielded 1879 articles; after exclusion, ten were included in the final review. Study participants were diagnosed with either osteoarthritis or fibromyalgia. However, two studies included "fibromyalgia and low back pain" or "fibromyalgia, back, and complex regional pain." Exercise interventions that were 12 weeks or longer (n = 8/10) altered brain function and improved pain and/or quality of life outcomes. The cortico-limbic pathway, default-mode network, and dorsolateral prefrontal cortex were key regions that experienced alterations post-intervention. All studies that reported an improvement in brain function also demonstrated an improvement in pain perception and/or quality of life. Discussion: Our review suggests that alterations in brain function, notably the cortico-limbic, default-mode and dorsolateral prefrontal cortex, may be responsible for the downstream improvements in the subjective experience of CP. Through appropriate programming (i.e., length of intervention), exercise may represent a viable option to manage CP via its positive influence on brain health.

Can prism adaptation effects generalize to wheelchair maneuvering?

BACKGROUND: While prism adaptation (PA) has been recognized as a promising tool for treating spatial neglect, implementation as a standard treatment in clinical care has been lagging. Limited evidence for the generalization of after-effects to everyday activities has been a barrier towards implementation. OBJECTIVES: This study examined whether a home-friendly standardized PA protocol (Peg-the-Mole, PTM) induces after-effects that can transfer to wheelchair maneuvering. We also examined the impact of using constant (1 starting hand position) or variable (3 starting hand positions) training conditions on the transfer of after-effects to wheelchair maneuvering. METHODS: Sixty participants were randomly assigned to one of four PTM conditions: 1) prisms/constant training; 2) prisms/variable training; 3) sham goggles/constant training; 4) sham goggles/variable training. RESULTS: The use of PTM with rightward shifting prisms induced after-effects on proprioceptive and visual pointing outcome tasks. Groups using PTM with prism goggles showed a leftward shift in their position within a wheelchair course and a reduction in the number of right-sided collisions. The training condition did not have an impact on the transfer of after-effects to wheelchair driving. CONCLUSION: PTM is a clinically appealing PA protocol that induces after-effects that can transfer to an everyday activity relevant to patients with neglect.

Clock Drawing Test in acute stroke and its relationship with long-term functional and cognitive outcomes.

Objective: The Clock Drawing Test (CDT) is commonly used as a screening tool for the assessment of dementia. The association between the CDT in acute stroke and long-term functional and cognitive outcomes in this population is unknown. The present prospective study is the first to examine if CDT scores in the acute stage after stroke are related to long-term outcomes and to compare the predictive ability of two scoring systems in a large sample of stroke patients. Method: A total of 340 patients admitted to an acute stroke unit were included in the present study. Separate stepwise multiple linear regression analyses were performed with eight independent variables (demographic/pre-stroke variables - age, sex, premorbid functioning; stroke-related variables - stroke severity, localization; cognitive variables - Orientation Test, CDT [2 scoring systems]), and four dependent variables administered one year post-stroke (Barthel Index, modified Rankin Scale, Reintegration to Normal Living index, Global Deterioration Scale). Results: Although both CDT scoring methods were related to all long-term outcome measures, the more comprehensive scoring system was the only baseline variable that significantly explained the variance in outcome measures in all four multiple regression models. Conclusion: Performance on the CDT in acute stroke is related to long-term outcomes including patients' degree of independence in performing activities of daily living, the degree to which they achieved reintegration into daily occupations, and the degree of cognitive decline observed one-year post-stroke. Future studies are needed to clarify the nature of the relationship between different CDT scoring systems and post-stroke outcomes.

The effects of prism adaptation on daily life activities in patients with visuospatial neglect: a systematic review.

Studies that have investigated prism adaptation (PA) effects on symptoms of visuospatial neglect have primarily used neuropsychological tests as outcome measures. An important question that remains to be answered is whether PA effects translate into improvements in patients' daily life activities. In the present review, we examined systematically the evidence for the effect of PA treatment on daily life activities in patients with neglect. Two authors independently assessed the methodological quality of 25 intervention and 1 follow-up studies using validated scales. PA effects were evaluated for reading/writing, activities of daily living (ADL) direct tests, ADL questionnaires, and navigation tests. Studies were evaluated as being of excellent (n = 1), good (n = 12), fair (n = 10), or poor (n = 3) quality. Among the 26 articles, a total of 32 measurements showed significant PA effects (one measurement from a study of excellent quality, 17 from studies of good quality, 10 from studies of fair quality, four from studies of poor quality), whereas non-significant effects were found in 15 measurements (two from a study of excellent quality, three from studies of good quality, eight from studies of fair quality, two from studies of poor quality). There is some evidence suggesting that PA can improve daily functioning, particularly as measured by reading/writing and ADL direct tests. The impact of several variables on PA effects should be investigated further including sample heterogeneity and time since injury.

A unilateral medial frontal cortical lesion impairs trial and error learning without visual control.

There is considerable debate regarding the involvement of the medial frontal cortex in motor and cognitive functions. Recent neuroimaging data suggest a fundamental underlying process that links the motor and cognitive roles of the mid-cingulate cortex (MCC), namely the processing of feedback during trial and error learning in the cingulate motor region that is related to the modality of the feedback. These data suggest that the specific motor context of a task may be a critical determinant of how its outcome is processed in the MCC. We assessed a patient before and after surgery for brain tumour removal in the medial frontal cortex, and a group of matched control subjects. Subjects had to find by trial and error the stimulus associated with the correct feedback amongst four or five similar stimuli. Subjects performed the task in two different visuo-motor contexts: with the response pad and hand visible and with no sight of either pad or hand. The patient showed a selective impairment in this task relative to control subjects in the hardest conditions and the impairment was most marked when the response pad and the hand were not visible. The results support a specific role of the medial frontal cortex in the construction of a sensorimotor representation of choices and related feedback by encoding the contingency between an efference copy of the action and its outcome.

Development of a new computerized prism adaptation procedure for visuo-spatial neglect.

BACKGROUND: Prism adaptation (PA) is a promising rehabilitation technique for visuo-spatial neglect. However, PA effects are often inconsistent across studies and the clinical application of this technique has been limited. The purpose of the present studies was to validate an easily standardized, home-friendly, and game-like PA technique (Peg-the-Mole) with healthy participants as a first step toward clinical development. NEW METHOD: In study 1, we used Peg-the-Mole with 32 participants wearing prism or sham goggles to investigate whether this procedure can induce significant after-effects on midline judgment and pointing tasks. In study 2, we compared Peg-the-Mole to a typical PA protocol in 42 participants for after-effects and level of enjoyment and to determine if the after-effects generalize to a throwing task. RESULTS AND COMPARISON WITH EXISTING METHOD: Study 1 showed that Peg-the-Mole induced significant after-effects on all outcome measures. Study 2 demonstrated that after-effects induced by Peg-the-Mole were equivalent to those induced by the typical PA procedure on all outcome measures. Peg-the-Mole was rated as more enjoyable than the typical procedure. CONCLUSIONS: Peg-the-Mole is a new computerized PA procedure that can be easily standardized and successfully used to induce significant after-effects. The present findings demonstrate that alterations can be made to the typical PA procedure to make it easier to use and more enjoyable, factors that could increase treatment availability, adherence and intensity.

Dissociation within the frontoparietal network in verbal working memory: a parametric functional magnetic resonance imaging study.

Concomitant increase in activity within the mid-dorsolateral prefrontal cortex (MDLFC) and the posterior parietal cortex (PPC) is observed in most functional neuroimaging studies of working memory (Collette et al., 1999; Gerton et al., 2004; Sun et al., 2005; Postle et al., 2006; Champod and Petrides, 2007; Emery et al., 2008). Despite broad consensus on the importance of these two brain regions in working memory, their unique contribution, especially that of the PPC, remains a matter of heated debate (Paulesu et al., 1993; Smith and Jonides, 1998; Postle et al., 1999; Berryhill and Olson, 2008). The main objective of the present parametric event-related functional magnetic resonance imaging study was to examine the hypothesis that the cortex in the intraparietal sulcus region in the PPC is involved in the manipulation (i.e., rearrangement) of verbal information in working memory and to dissociate the involvement of this brain region from that of the MDLFC in working memory processes. The results demonstrated a linear increase in activity within the MDLFC during the manipulation and monitoring of a linearly increasing number of words in working memory. In sharp contrast, there was a linear increase in activity within the PPC during the manipulation but not the monitoring of a linearly increasing number of words. This study provides the first parametric dissociation of activation in these two cortical regions indicating a crucial role of the PPC in the manipulation of information in working memory, with the MDLFC playing a major role in monitoring this information.

Preoperative functional magnetic resonance imaging assessment of higher-order cognitive function in patients undergoing surgery for brain tumors.

OBJECT: Resection of brain tumors has been shown to increase patient survival. The extent of the possible resection, however, depends on whether the tumor has invaded brain regions important for motor, sensory, or cognitive processes and whether the brain tissue surrounding the tumor maintains its functional role. The goal of the present study was to develop new pre- and intraoperative tools to specifically assess the function of the rostral part of the dorsal premotor cortex (PMdr) in 4 patients with brain tumors close to this region. METHODS: Using functional magnetic resonance (fMR) imaging and a task developed to assess accurate selection between competing responses based on conditional rules, the authors preoperatively assessed the function of the PMdr in 4 patients with brain tumors close to this region. In 1 patient, the authors developed an intraoperative procedure to assess performance on the task during the tumor resection. RESULTS: Preoperative fMR imaging data showed specific activity increases in the vicinity of the tumors, that is, in the PMdr. As confirmed by postoperative structural MR imaging, the extent of the tumor resection was optimal and the functional region within the PMdr was preserved. Furthermore, patients exhibited no postoperative deficits during task performance, demonstrating that the function was preserved. Intraoperative behavioral results demonstrated that the cognitive processes underlying performance on the task remained intact throughout the tumor resection. CONCLUSIONS: These findings suggest that preoperative fMR imaging, together with intraoperative behavioral evaluation, may be a useful paradigm to assist neurosurgeons in preserving cognitive function in patients with brain tumors.

Dissociable roles of the posterior parietal and the prefrontal cortex in manipulation and monitoring processes.

Numerous functional neuroimaging studies reported increased activity in the middorsolateral prefrontal cortex (MDLFC) and the posterior parietal cortex (PPC) during the performance of working memory tasks. However, the role of the PPC in working memory is not understood and, although there is strong evidence that the MDLFC is involved in the monitoring of information in working memory, it is also often stated that it is involved in the manipulation of such information. This event-related functional magnetic resonance imaging study compared brain activity during the performance of working memory trials in which either monitoring or manipulation of information was required. The results show that the PPC is centrally involved in manipulation processes, whereas activation of the MDLFC is related to the monitoring of the information that is being manipulated. This study provides dissociation of activation in these two regions and, thus, succeeds in further specifying their relative contribution to working memory.

Local morphology predicts functional organization of the dorsal premotor region in the human brain.

A confusing picture of the functional organization of the dorsal premotor region of the human brain emerged when functional neuroimaging studies that either examined visuomotor hand conditional activity or attempted to localize the human frontal eye field reported activity increases at the same general location, namely the junction of the superior precentral sulcus with the superior frontal sulcus. The present functional magnetic resonance imaging study examined visuomotor hand conditional activity and the locus of the frontal eye field as defined by a standard task, on a subject-by-subject basis, to clarify their location and reveal relationships between the pattern of local morphology and functional activity. The results demonstrate that visuomotor hand conditional activity and the frontal eye field lie within distinct parts of the superior precentral sulcus, revealing an organization of the human premotor cortex consistent with that observed in experimental studies in the monkey.