Predicting health preference in chronic spinal cord injury

Feedback control of upright seating with functional neuromuscular stimulation during a reaching task after spinal cord injury: a feasibility study

BACKGROUND

Restoring or improving seated stability after spinal cord injury (SCI) can improve the ability to perform activities of daily living by providing a dynamic, yet stable, base for upper extremity motion. Seated stability can be obtained with activation of the otherwise paralyzed trunk and hip musculature with neural stimulation, which has been shown to extend upper limb reach and improve seated posture.

METHODS

We implemented a proportional, integral, derivative (PID) controller to maintain upright seated posture by simultaneously modulating both forward flexion and lateral bending with functional neuromuscular stimulation. The controller was tested with a functional reaching task meant to require trunk movements and impart internal perturbations through rapid changes in inertia due to acquiring, moving, and replacing objects with one upper extremity. Five subjects with SCI at various injury levels who had received implanted stimulators targeting their trunk and hip muscles participated in the study. Each subject was asked to move a weighted jar radially from a center home station to one of three target stations. The task was performed with the controller active, inactive, or with a constant low level of neural stimulation. Trunk pitch (flexion) and roll (lateral bending) angles were measured with motion capture and plotted against each other to generate elliptical movement profiles for each task and condition. Postural sway was quantified by calculating the ellipse area. Additionally, the mean effective reach (distance between the shoulder and wrist) and the time required to return to an upright posture was determined during reaching movements.

RESULTS

Postural sway was reduced by the controller in two of the subjects, and mean effective reach was increased in three subjects and decreased for one. Analysis of the major direction of motion showed return to upright movements were quickened by 0.17 to 0.32 s. A 15 to 25% improvement over low/no stimulation was observed for four subjects.

CONCLUSION

These results suggest that feedback control of neural stimulation is a viable way to maintain upright seated posture by facilitating trunk movements necessary to complete reaching tasks in individuals with SCI. Replication of these findings on a larger number of subjects would be necessary for generalization to the various segments of the SCI population.

Feedback Control of Upright Seating with Functional Neuromuscular Stimulation during a Functional Task after Spinal Cord Injury: A Case Study

Seated stability is a major concern of individuals with trunk paralysis. Trunk paralysis is commonly caused by spinal cord injuries (SCI) at or above the thoracic spine. Current methods to improve stability restrict the movement of the user by constraining their trunk to an upright position. Feedback control of functional neuromuscular stimulation (FNS) can help maintain seated stability while still allowing the user to perform movements to accomplish functional tasks. In this study, an individual with a SCI (C7, AIS B) and an implanted stimulator capable of recruiting trunk and hip musculature unilaterally moved a weighted jar on a countertop to and from three prescribed stations directly in front, laterally, and across midline. For comparison, the tasks were performed with constant baseline stimulation and with feedback modulated stimulation based on the tilt of the trunk obtained from an external accelerometer fed into two PID controllers; one for forward trunk pitch and the other for lateral roll. The trunk pitch and roll angles were obtained through motion capture cameras and various measures of postural sway (95% fitted ellipse area, root mean squared (RMS), path length) and the repeatability (coefficient of variation (CoV), variance ratio (VR)) were calculated. Feedback control significantly increased RMS of trunk movement along the major axis of the fitted ellipse, but decreased RMS values during bending along the minor axis of motion. As a result, the fitted ellipse area decreased when deploying the jar to one of the stations and increased with the other two. The CoV indicated reduced variation in the presence of feedback controlled stimulation for all stations, and VR showed higher repeatability in trunk pitch. Plots of the trunk pitch and roll revealed a faster return to upright motion due to feedback stimulation.Clinical relevance- Feedback control in combination with FNS is a viable method to improve seated stability while still allowing dynamic movements in individuals with a SCI, thus addressing a major concern of the population.

Prevalence of comorbidities and secondary health conditions among the Finnish population with spinal cord injury

Study design

A cross-sectional study.

Objectives

To explore the prevalence of comorbidities, secondary health conditions (SHCs), and multimorbidity in the Finnish population with spinal cord injury (SCI).

Setting

The data were collected from the Finnish Spinal Cord Injury Study (FinSCI). Participants were identified from three SCI outpatient clinics responsible for the lifelong follow-up of persons with SCI in Finland, (n = 884 participants, response rate; 50%).

Methods

The FinSCI-questionnaire included a question from the National Study of Health, Well-being, and Service (FinSote) for screening 12 comorbidities. The reference data of the general population for that question were received from the Finnish Institute for Health and Welfare. The Spinal Cord Injury Secondary Condition Scale (SCI-SCS) was used to screen 16 SHCs. The data were analysed with univariate testing and multivariable negative binomial regression modelling.

Results

The most common comorbidities were high blood pressure/hypertension (38%), back problems (28%), and high cholesterol (22%). The most common SHCs were joint and muscle pain (81%), muscle spasms (74%), chronic pain (71%), and bowel problems (71%). The prevalence of comorbidities was highest among persons aged ≥76 years (mean; 2.0; scale range; 0–12). The prevalence of SHCs was highest in the severity of SCI group C1–4 AIS A, B, and C (mean; 8.9; scale range; 0–16).

Conclusions

Further research on geriatrics in SCI, non-traumatic SCI, and knowledge of the needs of persons with cervical lesion AIS A, B, or C is required, due to the fact that the prevalence of multimorbidity is high in these groups.

Considerations on the psychometric properties and validity of the Spinal Cord Injury Secondary Conditons Scale

STUDY DESIGN

Cross-sectional validation study.

OBJECTIVES

Explore psychometric properties of Spinal Cord Injury Secondary Conditions Scale (SCI-SCS).

SETTING

Two Scandinavian rehabilitation centres.

METHODS

Included were 224 consecutive patients attending regular follow-up at least 1 year after a traumatic SCI. Mean age was 49.6 (SD 14.9) years. SCI-SCS floor and ceiling effect examined. Construct validity was investigated by confirmatory factor analysis and correlation analysis, and reliability by Cronbach's alpha.

RESULTS

SCI-SCS showed no floor or ceiling effect. Two out of four earlier reported latent factors ("Genitourinary and bowel", "Muscle structures and pain") were confirmed. The global Cronbach's alpha of SCI-SCS was 0.65 and 0.22-0.61 for the four latent factors. The SCI-SCS sum score showed low correlation to quality of life (QoL) measured by EQ5 VAS (r_s = -0.47, p < 0.001). Likewise, the sum score correlations to QoL-general and QoL-physical health (International SCI QoL Basic Dataset) were low (r_s = -0.36, p < 0.001 and r_s = -0.37, p < 0.001, respectively). The scale item Muscle Spasms correlated moderately to ratings on Spasm Frequency (r_s = 0.59, p < 0.001) and Spasm Intensity (r_s = 0.56, p < 0.001) scales. Chronic Pain and Joint and Muscle Pain correlated to patient reported number of pain sites and level of pain (International SCI Pain Basic Dataset 1.0) (r_s = 0.31 p < 0.001 and r_s = 0.47, p < 0.001, respectively).

CONCLUSION

SCI-SCS is a relevant instrument for giving clinicians and researchers an overview of the individual recent experiences with secondary conditions. However, the instrument could benefit from a clearer definition of the construct secondary conditions, a scale revision and a consideration of whether to add other experienced secondary conditions.

Use of Regression Tree Analysis for Predicting the Functional Outcome after Traumatic Spinal Cord Injury

Predicting the long-term functional outcome after traumatic spinal cord injury (TSCI) is needed to adapt medical strategies and plan an optimized rehabilitation. This study investigates the use of regression trees for the development of predictive models based on acute clinical and demographic predictors. This prospective study was performed on 172 patients hospitalized after TSCI. Functional outcome was quantified using the Spinal Cord Independence Measure (SCIM) collected within the first-year post-injury. Age, delay before surgery, and Injury Severity Score (ISS) were considered as continuous predictors whereas energy of injury, trauma mechanisms, neurological level of injury, injury severity, occurrence of early spasticity, urinary tract infection, pressure ulcer, and pneumonia were coded as categorical inputs. A simplified model was built using only American Spinal Injury Association Impairment Scale grade, neurological level, energy, and age as predictor and was compared to a more complex model considering all 11 predictors mentioned above. The models built using 4 and 11 predictors were found to explain 51.4% and 62.3% of the variance of the SCIM total score after validation, respectively. Severity of the neurological deficit at admission was found to be the most important predictor. Other important predictors were the ISS, age, neurological level, and delay before surgery. Regression trees offer promising performances for predicting the functional outcome after a TSCI. It could help to determine the number and type of predictors leading to a prediction model of the functional outcome that can be used clinically in the future.

Experiences of secondary health conditions amongst people with spinal cord injury in South Africa: A qualitative study

Background

Secondary health conditions (SHCs) such as pain, pressure sores, sexual problems, bowel and bladder problems are prevalent throughout the lifespan of people with spinal cord injury (SCI). Studies have reported that SHCs decrease life expectancy and increase health care costs. Studies on the lived experience of SHCs are, however, limited.

Objectives

To explore the experiences of SHCs amongst people with SCI in a public rehabilitation hospital in South Africa.

Method

Face-to-face semi-structured interviews were conducted with people with SCI from August 2018 to July 2019. All interviews were transcribed verbatim and analysed using a content analysis approach.

Results

Seventeen people with SCI were interviewed. Participants experienced a range of SHCs. The most common experienced SHC was pain (94%). The main theme that emerged from the analysis was 'the impact of secondary health conditions on health and well-being'. The categories linked to the impact were SHCs co-occurrence and how SHCs limit function, restrict participation, affect mental health and disrupt lives.

Conclusion

We found that SHCs were enormously impactful on our participants' lives and health, as illustrated by their stories of fear, embarrassment and shame. Understanding people with SCI experiences of SHCs can enhance communication between people with SCI and health professionals and may help develop prevention strategies.

Clinical implications

To enhance patient-centred care, health professionals are encouraged to actively listen to patients' experiences of illness and the impact on health and wellbeing.

Identifying and classifying quality of life tools for neurogenic bladder function after spinal cord injury: A systematic review

OBJECTIVE

To identify and classify quality of life (QoL) tools for assessing the influence of neurogenic bladder after spinal cord injury/disease (SCI).

DESIGN

Systematic Review Methods: Medline/Pubmed, CINAHL, and PsycInfo were searched using terms related to SCI, neurogenic bladder and QoL. Studies that assessed the influence neurogenic bladder on QoL (or related construct) in samples consisting of ≥50% individuals with SCI were included. Two independent reviewers screened titles and abstracts of 368 identified references; 118 full-text articles were assessed for eligibility, and 42 studies were included. Two reviewers independently classified outcomes as objective (societal viewpoint) or subjective (patient perspective) using a QoL framework.

RESULTS

Ten objective QoL measures were identified, with the Medical Outcomes Short Form (SF-36/SF-12) used most frequently. Fourteen subjective QoL measures were identified; 8 were specific to neurogenic bladder. Psychometric evidence for SCI-specific neurogenic bladder QoL tools was reported for the Quality of Life Index (QLI), Qualiveen, Bladder Complications Scale, Spinal Cord Injury-Quality of Life (SCI-QOL) Bladder Management Difficulties, and the SCI-QOL Bladder Management Difficulties-Short Form. The QLI and Qualiveen showed sensitivity to neurogenic bladder in experimental designs.

CONCLUSION

Several objective and subjective tools exist to assess the influence of neurogenic bladder on QoL in SCI. The QLI and Qualiveen, both subjective tools, were the only validated SCI-specific tools that showed sensitivity to neurogenic bladder. Further validation of existing subjective SCI-specific outcomes is needed. Research to validate objective measures of QoL would be useful for informing practice and policy related to resource allocation for bladder care post-SCI.