The role of clinical and demographic predictors for understanding the cognitive impairment in Spinal Cord Injury (SCI) patients.

STUDY DESIGN: Using a cross-sectional design, we extracted sociodemographic and clinical data from 488 Spinal Cord Injury (SCI) patients during their initial assessment before receiving intensive rehabilitation treatment. OBJECTIVES: The primary objectives of this study were to ascertain the prevalence of cognitive impairment in the study sample and specify the key clinical and demographic predictors of cognitive functioning in SCI patients. SETTING: Lucy Montoro Rehabilitation Institute (LMRI), University of Sao Paulo, Sao Paulo, Brazil. METHODS: We utilized independent univariate and multivariate regression models with the Montreal Cognitive Assessment (MoCA) scale, adapted for individuals with visual impairment. Moreover, we consider scores from the execution tasks (visuospatial/executive) as the dependent variable. RESULTS: Our findings demonstrate that approximately 80% of the evaluated study sample exhibited cognitive impairment. Through the multivariate regression models, we show that several factors, including age, education, depression levels, and the use of analgesics and/or opioids, are significant predictors of total cognitive scores. These factors are independent of the clinical features associated with SCI, such as age, sex, education, and time since the injury. CONCLUSIONS: The results indicate a high prevalence of significant cognitive impairment within the sample, with age, education, depression levels, and the use of analgesics and/or opioids emerging as the primary predictors of total cognitive scores, independent of the clinical features correlated to SCI. These findings hold significant implications for both clinical research and practice, offering valuable guidance for comprehensive management throughout hospitalization and rehabilitation.

Resting-state EEG as Biomarker of Maladaptive Motor Function and Depressive Profile in Stroke Patients.

Objective: Investigate the relationship between resting-state EEG-measured brain oscillations and clinical and demographic measures in Stroke patients. Methods: We performed a cross-sectional analysis of a cohort study (DEFINE cohort), Stroke arm, with 85 patients, considering demographic, clinical, and stroke characteristics. Resting-state EEG relative power from delta, theta, alpha, and beta oscillations were measured from the central region. Multivariate regression models were used for both affected and non-affected hemispheres. Results: Motor function was negatively associated with Delta and Theta oscillations, while positively associated with Alpha oscillations (both hemispheres). Similarly, cognition levels measured were negatively associated with Delta activity. Depression levels were negatively associated with Alpha activity specifically in the affected hemisphere, while positively associated with Beta activity in both hemispheres. Regarding pain measures, no significant association was observed, while CPM measure showed a positive association with Alpha activity in the non-affected hemisphere. Finally, we found that theta/alpha ratio was negatively associated with motor function and CPM scores. Conclusion: The results lead us to propose a framework for brain oscillations in stroke, whereas Delta and Beta would represent disrupted mal-adaptive brain plasticity and Theta and Alpha would represent compensatory and functional brain oscillations for motor and sensory deficits in stroke, respectively.

Distinct patterns of metabolic motor cortex activity for phantom and residual limb pain in people with amputations: A functional near-infrared spectroscopy study.

BACKGROUND: Phantom pain limb (PLP) has gained more attention due to the large number of people with amputations around the world and growing knowledge of the pain process, although its mechanisms are not completely understood. OBJECTIVES: The aim of this study was to understand, in patients with amputations, the association between PLP and residual limb pain (RLP), and the brain metabolic response in cortical motor circuits, using functional near-infrared spectroscopy (fNIRS). METHODS: Sixty participants were recruited from the rehabilitation program in São Paulo, Brazil. Included patients were aged over 18 years, with traumatic unilateral lower-limb amputation, with PLP for at least 3 months after full recovery from amputation surgery. PLP and RLP levels were measured using visual analogue scales. fNIRS was performed during motor execution and motor mirror tasks for 20 s. In order to highlight possible variables related to variation in pain measures, univariate linear regression analyses were performed for both experimental conditions, resulting in four fNIRS variables (two hemispheres x two experimental conditions). Later, in order to test the topographic specificity of the models, eight multivariate regression analyses were performed (two pain scales x two experimental conditions x two hemispheres), including the primary motor cortex (PMC) related channel as an independent variable as well as five other channels related to the premotor area, supplementary area, and somatosensory cortex. All models were controlled for age, sex, ethnicity, and education. RESULTS: We found that: i) there is an asymmetric metabolic activation during motor execution and mirror task between hemispheres (with a predominance that is ipsilateral to the amputated limb), ii) increased metabolic response in the PMC ipsilateral to the amputation is associated with increased PLP (during both experimental tasks), while increased metabolic response in the contralateral PMC is associated with increased RLP (during the mirror motor task only); ii) increased metabolic activity of the ipsilateral premotor region is associated with increased PLP during the motor mirror task; iii) RLP was only associated with higher metabolic activity in the contralateral PMC and lower metabolic activity in the ipsilateral inferior frontal region during motor mirror task, but PLP was associated with higher metabolic activity during both tasks. CONCLUSION: These results suggest there is both task and region specificity for the association between the brain metabolic response and the two different types of post-amputation pain. The metabolic predominance that is ipsilateral to the amputated limb during both tasks was associated with higher levels of PLP, suggesting a cortical motor network activity imbalance due to potential interhemispheric compensatory mechanisms. The present work contributes to the understanding of the underlying topographical patterns in the motor-related circuits associated with pain after amputations.

Factors associated with pain pressure threshold in both local and remote sites in knee osteoarthritis.

BACKGROUND: Knee osteoarthritis (KOA) is a prevalent condition, and its most frequent symptom is pain that often leads to disability. Pain sensitization is a core feature of KOA, and it can be measured through quantitative sensory testing protocols such as pain pressure threshold (PPT). However, there is a lack of understanding about the factors that may influence changes in PPTs in the KOA population. OBJECTIVE: To explore the clinical and functional factors associated with PPTs in a sample of people with chronic KOA pain and to compare models of local (knees) and remote (thenar regions) sites. DESIGN: Cross-sectional analysis of a prospective cohort. SETTING: Primary care in public institution. PARTICIPANTS: 113 adults with KOA. INTERVENTION: N/A. MAIN OUTCOME MEASURES: Multivariable regression analyses evaluating demographic, clinical, and functional variables that could be associated with local and remote PPTs (main outcomes) were performed. RESULTS: Both thenar region (adjusted-R2 : 0.29) and knee (adjusted-R2 : 0.45) models had the same significant negative association with being a female, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain levels (thenar: ß: -0.15, p = .002; knee: ß: -0.2, p < .001), and the 10-Meter Walking Test (thenar: ß: -0.05, p = .038; knee: ß: -0.08, p = .004). A small significant positive association with depressive symptoms was identified in both models, which acted as a confounder for WOMAC pain and was likely affected by unmeasured confounders. CONCLUSIONS: PPTs in KOA pain are associated with functional outcomes such as the 10-Meter Walking Test and activity-related pain intensity; thus more disability is associated with smaller pain thresholds. Similarity between models may suggest central sensitization.

OPRM1 and BDNF polymorphisms associated with a compensatory neurophysiologic signature in knee osteoarthritis patients.

OBJECTIVE: The present study investigated the relationship between three genetic polymorphisms of OPRM1 (rs1799971 - A118G and rs1799972 - C17T) and BDNF (rs6265 - C196T) and EEG-measured brain oscillations in Knee Osteoarthritis (KOA) patients. MATERIALS AND METHODS: We performed a cross-sectional analysis of a cohort study (DEFINE cohort), KOA arm, with 66 patients, considering demographic (age, sex, and education), clinical (pain intensity and duration), OPRM1 (rs1799971 - A118G and rs1799972 - C17T) and BDNF (rs6265 - C196T) genotypes, and electrophysiological measures. Brain oscillations relative power from Delta, Theta, Alpha, Low Alpha, High Alpha, Beta, Low Beta and High Beta oscillations were measured during resting state EEG. Multivariate regression models were used to explore the main brain oscillation predictors of the three genetic polymorphisms. RESULTS: Our findings demonstrate that Theta and Low Beta oscillations are associated with the variant allele of OPRM1-rs1799971 (A118G) on left frontal and left central regions, respectively, while Alpha brain oscillation is associated with variant genotypes (CT/TT) of BDNF-rs6265 on frontal (decrease of oscillation power) and left central (increase of oscillation power) regions. No significant model was found for OPRM1-rs1799972 (C17T) in addition to the inclusion of pain intensity as a significant predictor of this last model. CONCLUSION: One potential interpretation for these findings is that polymorphisms of OPRM1 - that is involved with endogenous pain control - lead to increased compensatory oscillatory mechanisms, characterized by increased theta oscillations. Along the same line, polymorphisms of the BDNF lead to decreased alpha oscillations in the frontal area, likely also reflecting the disruption of resting states to also compensate for the increased injury associated with knee OA. It is possible that these polymorphisms require additional brain adaption to the knee OA related injury.

Neurophysiological biomarkers of motor improvement from Constraint-Induced Movement Therapy and Robot-Assisted Therapy in participants with stroke.

Background: The mechanism of stroke recovery is related to the reorganization of cerebral activity that can be enhanced by rehabilitation therapy. Two well established treatments are Robot-Assisted Therapy (RT) and Constraint-Induced Movement Therapy (CIMT), however, it is unknown whether there is a difference in the neuroplastic changes induced by these therapies, and if the modifications are related to motor improvement. Therefore, this study aims to identify neurophysiological biomarkers related to motor improvement of participants with chronic stroke that received RT or CIMT, and to test whether there is a difference in neuronal changes induced by these two therapies. Methods: This study included participants with chronic stroke that took part in a pilot experiment to compare CIMT vs. RT. Neurophysiological evaluations were performed with electroencephalography (EEG) and transcranial magnetic stimulation (TMS), pre and post rehabilitation therapy. Motor function was measured by the Wolf Motor Function Test (WMFT) and Fugl-Meyer Assessment Upper Limb (FMA-UL). Results: Twenty-seven participants with chronic stroke completed the present study [mean age of 58.8 years (SD ± 13.6), mean time since stroke of 18.2 months (SD ± 9.6)]. We found that changes in motor threshold (MT) and motor evoked potential (MEP) in the lesioned hemisphere have a positive and negative correlation with WMFT improvement, respectively. The absolute change in alpha peak in the unlesioned hemisphere and the absolute change of the alpha ratio (unlesioned/lesioned hemisphere) is negatively correlated with WMFT improvement. The decrease of EEG power ratio (increase in the lesioned hemisphere and decrease in the unlesioned hemisphere) for high alpha bandwidths is correlated with better improvement in WMFT. The variable "type of treatment (RT or CIMT)" was not significant in the models. Conclusion: Our results suggest that distinct treatments (RT and CIMT) have similar neuroplastic mechanisms of recovery. Moreover, motor improvements in participants with chronic stroke are related to decreases of cortical excitability in the lesioned hemisphere measured with TMS. Furthermore, the balance of both EEG power and EEG alpha peak frequency in the lesioned hemisphere is related to motor improvement.

Functional and Neural Correlates Associated with Conditioned Pain Modulation in Patients with Chronic Knee Osteoarthritis Pain: A Cross-Sectional Study.

Background: In this study, we aimed to assess the factors that predict a dysfunctional conditioned pain modulation (CPM) in chronic knee OA. Methods: This is a cross-sectional analysis of patients with chronic knee OA from a prospective cohort study in Brazil (n = 85). We performed linear and logistic multivariate regression models using the purposeful selection approach to test the relationship between the CPM in both knees (average) as a dependent variable and demographics, clinical, and neurophysiological as independent variables. Results: A significant negative association between WOMAC pain scores and CPM (ß: -0.13) was found. This association was modified by the subjects' race, being stronger in the non-white subjects. In our logistic regression models, pain intensity indexed with the WOMAC pain scale remained a significant association with dichotomized CPM. Furthermore, a significant CPM association with balance, indexed with the Berg Balance score, was evidenced (ß: 0.04). Neurophysiological variables showed a significant negative relationship with CPM, such as the relative power of delta oscillations in the frontal area (ß: -3.11) and central area (ß: -3.23). There was no significant relationship between CPM and the following domains: cognitive, emotion, sleep, opioid receptor polymorphisms, and intrinsic variables of OA disease. There was no association of CPM with TMS-indexed inhibitory markers. Conclusions: These results may indicate that less function of the pain descending inhibitory system in patients with OA is correlated with higher activity-related pain (WOMAC), less balance, and cortical plasticity especially with increased low-frequency (delta) brain oscillations. These associations seem modified by race.

Neuroplasticity changes in knee osteoarthritis (KOA) indexed by event-related desynchronization/synchronization during a motor inhibition task.

PURPOSE: Event-related desynchronisation (ERD) and event-related synchronisation (ERS) reflect pain perception and integration of the nociceptive sensory inputs. This may contribute to the understanding of how neurophysiological markers of Knee Osteoarthritis (KOA) patients can differ from control individuals, which would improve aspects such as prediction and prognosis. We performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, compared with 65 control participants. The study aimed to examine possible differences between ERD and ERS in control participants compared to Knee Osteoarthritis (KOA) patients when adjusting for important covariates. MATERIALS AND METHODS: We performed independent multivariate regression models considering as dependent variables the power value related to ERD and ERS for four different sensorimotor tasks (Motor Execution, Motor Imagery, Active Observation and Passive Observation) and four sensorimotor oscillations (Alpha, Beta, Low Beta, and High Beta), each model, controlled by age and sex. RESULTS: We demonstrate that the differences between KOA and healthy subjects are frequency specific, as most differences are in the beta bandwidth range. Also, we observed that subjects in the KOA group had significantly higher ERD and ERS. This may be correlated to the amount of lack of brain organisation and a subsequent attempt at compensation induced by KOA. CONCLUSIONS: Our findings strengthen the notion that subjects with KOA have a higher degree of brain plasticity changes that are also likely correlated to the degree of compensation and behavioural dysfunction.

Robotic-Assisted Gait Training (RAGT) in Stroke Rehabilitation: A Pilot Study.

Objective: To compare the effects of 2 types of robotic-assisted gait training (RAGT) devices that have been used in stroke rehabilitation. Design: Retrospective cohort. Setting: Rehabilitation hospital. Participants: 24 community dwelling people with stroke (N=24). Interventions: RAGT with either an exoskeleton (Lokomat) (mean age=53.8 years; 30% men; mean duration of stroke =17.8 months) or an end-effector (G-EO) (mean age=50.5 years; 77.8% men; mean duration of stroke =13.11) delivered 3 times per week (36 sessions total). Main Outcome Measures: The following tests/scales were employed before and after RAGT: Functional Ambulation Categories (FACs), timed Up and Go (TUG), 10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), Trunk Impairment Scale, Dynamic Gait Index (DGI), Berg Balance Scale (BBS), and ability to climb stairs (time to climb 6 steps of 15 cm each; ability to climb stairs). Results: There were 5 dropouts, all from the G-EO group. At the end, 10 participants in the Lokomat and 9 in the G-EO group completed the intervention. From pre- to post-RAGT, G-EO patients improved on all functional tests/scales, whereas Lokomat patients improved only on the TUG, DGI, and BBS. Most patients showed improvements above the relative smallest real difference in the TUG, 10MWT, and 6MWT. Conclusions: Both end-effectors and exoskeletons may improve clinically relevant aspects of walking function. However, this study had a small sample, was retrospective, non-randomized, and had a significant number of drop-outs, therefore its findings should be interpreted carefully. Future studies are needed for investigating potential differences in clinical results, side effects, contraindications, and cost effectiveness between these 2 different types of RAGT.

The cerebellum is causally involved in episodic memory under aging.

Episodic memory decline is a major signature of both normal and pathological aging. Many neural regions have been implicated in the processes subserving both episodic memory and typical aging decline. Here, we demonstrate that the cerebellum is causally involved episodic memory under aging. We show that a 12-day neurostimulation program delivered to the right cerebellum led to improvements in episodic memory performance under healthy aging that long outlast the stimulation period - healthy elderly individuals show episodic memory improvement both immediately after the intervention program and in a 4-month follow-up. These results demonstrate the causal relevance of the cerebellum in processes associated with long-term episodic memory, potentially highlighting its role in regulating and maintaining cognitive processing. Moreover, they point to the importance of non-pharmacological interventions that prevent or diminish cognitive decline in healthy aging.

Association of Mu opioid receptor (A118G) and BDNF (G196A) polymorphisms with rehabilitation-induced cortical inhibition and analgesic response in chronic osteoarthritis pain.

Background/objective: Chronic pain due to osteoarthritis (OA) is a prevalent cause of global disability. New biomarkers are needed to improve treatment allocation, and genetic polymorphisms are promising candidates. Method: We aimed to assess the association of OPRM1 (A118G and C17T) and brain-derived neurotrophic factor (BDNF [G196A]) polymorphisms with pain-related outcomes and motor cortex excitability metrics (measured by transcranial magnetic stimulation) in 113 knee OA patients with chronic pain. We performed adjusted multivariate regression analyses to compare carriers versus non-carriers in terms of clinical and neurophysiological characteristics at baseline, and treatment response (pain reduction and increased cortical inhibitory tonus) after rehabilitation. Results: Compared to non-carriers, participants with polymorphisms on both OPRM1 (A118G) and BDNF (G196A) genes were less likely to improve pain after rehabilitation (85 and 72% fewer odds of improvement, respectively). Likewise, both carriers of OPRM1 polymorphisms (A118G and C17T) were also less likely to improve cortical inhibition (short intracortical inhibition [SICI], and intracortical facilitation [ICF], respectively). While pain and cortical inhibition improvement did not correlate in the total sample, the presence of OPRM1 (A118G) and BDNF (G196A) polymorphisms moderated this relationship. Conclusions: These results underscore the promising role of combining genetic and neurophysiological markers to endotype the treatment response in this population.

The Institute of Physical Medicine and Rehabilitation, Hospital das Clínicas University of São Paulo School of Medicine comprehensive rehabilitation program for elderly people with knee osteoarthritis.

Background: Knee osteoarthritis (OA) is a leading cause of disability in the elderly population. Chronic disabling pain is associated with maladaptive neuroplastic changes in brain networks, commonly associated with central sensitization. The main clinical features of nociplastic pain conditions include combined peripheral and central sensitization, and it is crucial to recognize this type of pain, as it responds to different therapies than nociceptive and neuropathic pain. Objective: To report the effect of the Institute of Physical Medicine and Rehabilitation (IMREA) comprehensive rehabilitation program to reduce pain and to improve functioning in elderly people with knee OA, under the DEFINE cohort. Methods: This is a retrospective observational cohort of 96 patients with knee OA, recruited from October 2018 to December 2019. All patients were evaluated by a trained multidisciplinary team using the Kellgren Lawrence classification, bilateral knee ultrasonography, the visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, rigidity and difficulty scores, the Timed Up and Go Test (TUG), 10-m and 6-min walking test (10 and 6 MWT), Berg Balance Scale, isokinetic dynamometry for knee extension and flexion strength, and pain pressure thresholds. The rehabilitation program included paraspinous lidocaine blocks, focal extracorporeal shockwaves combined with radial pressure waves and functional electrical stimulation according to individual needs. The baseline was compred with the treatment results with a paired t-test. Results: The study sample is composed of 96 participants, mostly females (n = 81, 84.38%), with bilateral osteoarthritis (n = 91, 94.79%), and a mean age of 68.89 (SD 9.73) years. Functional improvement was observed in TUG (p = 0.019), 6-mwt (p = 0.033), right knee flexion strength (p < 0.0001), WOMAC rigidity and difficulty domains (p < 0.0001). Pain was reduced from baseline as measured by WOMAC pain domain (p < 0.0001), VAS for both knees (p < 0.0001), and SF-36 pain domain (p < 0.0001). Pressure pain threshold was modified above the patella (p = 0.005 and p = 0.002 for right and left knees, respectively), at the patellar tendons (p = 0.015 and p = 0.010 for right and left patellar tendons, respectively), left S2 dermatome (p = 0.017), and L1-L2 (p = 0.008). Conclusions: The IMREA comprehensive rehabilitation program improved functioning and reduced disabling pain in elderly people with knee OA. We highlight the relevance and discuss the implementation of our intervention protocol. Although this is an open cohort study, it is important to note the significant improvement with this clinical protocol.

Motor event-related synchronization as an inhibitory biomarker of pain severity, sensitivity, and chronicity in patients with knee osteoarthritis.

OBJECTIVE: The study aimed to examine the clinical and neurophysiological predictors of motor event-related desynchronization (ERD) and synchronization (ERS) in patients with chronic pain due to knee osteoarthritis (KOA). METHODS: We performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, including demographic, functionality, genetic and neurophysiological measures. ERD/ERS was evaluated during hand motor tasks (motor execution, active and passive observation, and imagery). Multivariate regression models were used to explore predictors of ERD/ERS. RESULTS: Although we found an altered ERD/ERS pattern during motor execution and active observation, the ERS pattern could only be clearly differentiated after passive observation.`. We found no predictors of ERD (excitatory biomarker). For ERS (inhibitory biomarker), our results showed that the main predictors differ across EEG frequency bands. Considering pain measures, we found that visual analogue scale (VAS, right knee) and chronicity of pain negatively predict low beta and high beta ERS, respectively. Pain threshold was positively correlated with alpha ERS, while 36-Item Short Form Survey (SF-36) emotional domain positively predicted beta ERS. Regarding transcranial magnetic stimulation (TMS) markers, intracortical inhibition (ICF) negatively predicted beta and low beta ERS, and left hemisphere cortical silent period (CSP) negatively predicted low beta ERS. CONCLUSION: Considering that higher power of ERS indicates a stronger cortical organization and inhibitory drive, our results show that limitation of activities due to emotional factors, lower pain threshold, higher VAS pain, and longer duration of pain are associated with lower ERS power (in alpha and beta frequencies), thus indicating a lower inhibitory drive. In the same direction, a lower inhibitory drive as indicated by higher ERS power is associated with higher ICF amplitude. Although there was a negative association between ERS and CSP, this may indicate that ICF values are adjusting CSP results. Our findings support the idea that a less organized cortical response as indicated by changes to the ERS is associated with higher pain correlates in subjects with KOA.

Predictors of the Health-Related Quality of Life (HRQOL) in SF-36 in Knee Osteoarthritis Patients: A Multimodal Model With Moderators and Mediators.

Purpose The study aimed to examine associations between the 36-item short form health survey (SF-36) in clinical and neurophysiological measures to identify its predictors in patients with knee osteoarthritis (KOA) in a rehabilitation program. Methods We analyzed data from our cohort study (DEFINE cohort). We analyzed data from our KOA arm, with 107 patients, including clinical assessments, demographic data, pain scales, motor function (Timed Up and Go Test (TUG), 10 meters walk test, and 6-minute walk), balance (BBS), sleepiness (ESS), and Transcranial Magnetic Stimulation (TMS) and Electroencephalography (EEG). Results Our results showed 83.19% of patients were female with an average age of 68.6 years and an average number of days of pain was 96 days; around 31.86% were using more than five medications per day. Regarding the multimodal model to explain SF-36, the main variables relevant to the quality of life (QoL) were related to emotional aspects, such as anxiety and depression. Moreover, our study added findings with polymorphism (OPRM1/rs1799971) predicting mental aspects. Cognitive variables were important in predicting the mental health, emotional, and social support dimensions of the SF-36. In the physical domain, pain-related variables predominantly predicted QoL in these relationships. The domain of vitality significantly predicted all dimensions studied, except for mental and general health. Conclusion The results help in understanding the aspects that contribute to QoL and are discussed considering the general literature on physical rehabilitation and specific to this clinical group. Furthermore, the statistical methods allowed us to explore and effectively understand the dimensions related to QoL.

Effect of transcutaneous abdominal electrical stimulation in people with constipation due to spinal cord injuries: a pilot study.

OBJECTIVE: To evaluate the effect of abdominal electrical stimulation (EE) on bowel movement frequency and feces consistency and expelled amount in people with constipation due to spinal cord injuries (SCI). METHOD: This is an experimental, crossover, randomized pilot study with two treatment groups: conventional intestinal rehabilitation and conventional rehabilitation associated with EE via 8- and 20-Hz Functional Electrical Stimulation (FES) of the abdominal muscles. Both groups were followed for two weeks with daily 30-minute EE sessions. Participants were hospitalized in a rehabilitation institute in the municipality of São Paulo. Data were analyzed using descriptive and inferential statistics. RESULTS: This study included 10 people with SCI, of which most were male (70%), with a mean age of 39 years (SD = 16.37). EE, associated with conventional treatment, was more effective in increasing defecation frequency (p = 0.029) and amount of feces expelled (p = 0.031). CONCLUSION: Abdominal EE, associated with conventional treatment, helped to increase defecation frequency and amount of feces expelled in people with constipation due to SCI. This pilot study will serve as the basis for a future clinical trial with greater sampling and statistical evidence.

Clinical and demographic predictors of symptoms of depression and anxiety in patients with spinal cord injury.

Spinal Cord Injury (SCI) is a condition whose consequences can impact the physical, emotional, and social aspects of patient's life, including Depression and Anxiety disorders. STUDY DESIGN: Using a cross-sectional design, sociodemographic and clinical data were extracted from 556 SCI patients at the time of initial assessment, prior to intensive rehabilitation treatment at the local rehabilitation institute. OBJECTIVES: Identify the predictive and multivariate relationship between different sociodemographic and clinical variables of Depression and Anxiety symptoms in SCI patients. SETTING: Lucy Montoro Rehabilitation Institute (LMRI), University of Sao Paulo, Sao Paulo, Brazil. METHODS: We performed independent univariate and multivariate regression models using the Hospital Anxiety and Depression Scale (HADS) as dependent variable. RESULTS: Symptoms of depression and anxiety present in SCI patients negatively correlate with the level of independence for locomotion, personal hygiene, bowel control, social interaction measured by the Functional Independence Scale (FIM), type of medication in use and the Language subtest of the MoCA Scale. Unlike previous studies, we did not find a relationship with the use of alcohol and illicit drugs, injury levels, etiological diagnosis or duration of injury. For the anxiety models, the main predictor was Depression symptoms, with SCI-related aspects not being significant. It was found that characteristics of the FIM Scale and cognitive aspects of the MoCA Scale were the main predictors of symptoms of Depression. Characteristics of the injury and motor deficit were not statistically significant. CONCLUSIONS: These findings can potentially be used to guide clinical practices to identify patients at higher risk of experiencing symptoms of Depression and Anxiety.

EEG theta and beta bands as brain oscillations for different knee osteoarthritis phenotypes according to disease severity.

This study aims to investigate the multivariate relationship between different sociodemographic, clinical, and neurophysiological variables with resting-state, high-definition, EEG spectral power in subjects with chronic knee osteoarthritis (OA) pain. This was a cross-sectional study. Sociodemographic and clinical data were collected from 66 knee OA subjects. To identify associated factors, we performed independent univariate and multivariate regression models by frequency bands (delta, theta, alpha, beta, low-beta, and high-beta) and by pre-defined regions (frontal, central, and parietal). From adjusted multivariate models, we found that: (1) increased frontocentral high-beta power and reduced central theta activity are positively correlated with pain intensity (ß = 0.012, 95% CI 0.004-0.020; and ß = - 0.008; 95% CI 0.014 to - 0.003; respectively); (2) delta and alpha oscillations have a direct relationship with higher cortical inhibition; (3) diffuse increased power at low frequencies (delta and theta) are associated with poor cognition, aging, and depressive symptoms; and (4) higher alpha and beta power over sensorimotor areas seem to be a maladaptive compensatory mechanism to poor motor function and severe joint degeneration. Subjects with higher pain intensity and higher OA severity (likely subjects with maladaptive compensatory mechanisms to severe OA) have higher frontocentral beta power and lower theta activity. On the other hand, subjects with less OA severity and less pain have higher theta oscillations power. These associations showed the potential role of brain oscillations as a marker of pain intensity and clinical phenotypes in chronic knee OA patients. Besides, they suggest a potential compensatory mechanism of these two brain oscillators according to OA severity.

Specific Electroencephalographic Signatures for Pain and Descending Pain Inhibitory System in Spinal Cord Injury.

OBJECTIVES: The pain related to spinal cord injury (SCI) is difficult to treat, and it is associated with significant morbidity. One aspect to improve therapeutics is to explore markers of pain and its correlates in SCI. METHODS: In this cross-sectional neurophysiological analysis of a randomized, double-blind controlled trial, 39 patients with SCI were included. We analyzed conditioned pain modulation (CPM) efficiency as the index of the descending pain inhibitory system, EEG variables, and clinical pain levels as measured by the Visual Analogue Scale. Regression analyses were performed to assess the relationship among EEG variables, pain levels, and CPM. RESULTS: We included 39 SCI patients, 74% reported SCI-related pain. We found that (1) less alpha and beta power are related to pain presence, (2) less alpha and beta power are associated with higher pain levels among patients with pain, (3) patients with pain have decreased peak alpha-theta frequency compared to no-pain group, (4) more relative theta power are related to the presence of low CPM efficiency, (5) higher relative theta power is associated with lower CPM efficiency. CONCLUSIONS: Our results confirm and provide additional data on the relationship between decreased alpha and beta frequencies and higher pain levels. One important finding, though, was a specific and different EEG signature for the descending inhibitory pain system, as we showed that increased theta EEG power is related to decreased CPM efficiency; suggesting that, although low CPM efficiency plays a major role in pain in these participants, it does seem to be associated with a specific oscillatory brain rhythm different from clinical pain. These findings have significant implications for future research on EEG-based biomarkers of pain in post-SCI and new interventions as neurofeedback to manage pain in this population.

Functional Changes in Cortical Activity of Patients Submitted to Knee Osteoarthritis Treatment: An Exploratory Pilot Study.

INTRODUCTION: There is evidence that brain plasticity is the central mechanism involved in the functional recovery process of patients with knee osteoarthritis. Studies involving the analysis of central nervous system mechanisms of pain control and recovery could provide more data on future therapeutic approaches. OBJECTIVE: The aim of the study was to explore possible functional changes in cortical activity of patients submitted to knee osteoarthritis standardized pain treatment using electroencephalography. METHODOLOGY: Ten patients with clinical and radiological diagnosis of painful knee unilateral or bilateral osteoarthritis were recruited to participate in clinical (Pain's Visual Analog Scale), radiological (Kellgren-Lawrence Scale), and neurophysiological (electroencephalography) assessments to evaluate cortical activity during cortical pain modulation activity. The clinical and neurophysiological analyses were performed before and after standardized pain treatment. RESULTS: Eight patients participated in this study. A significant improvement in pain perception and relative increase in interhemispheric connectivity after therapies was observed. In electroencephalography analysis, tests with real movement showed a relative increase in density directed at Graph's analysis. CONCLUSIONS: Relative increase density directed measures at connectivity analysis in electroencephalography after pain treatment can be possible parameters to be explored in future research with a larger number of patients.