The influence of initial spinal cord haematoma and cord compression on neurological grade improvement in acute traumatic spinal cord injury: A prospective observational study.

STUDY DESIGN: Prospective observational cohort study linked with administrative data. OBJECTIVES: Magnetic Resonance Imaging (MRI) is routinely performed after traumatic spinal cord injury (TSCI), facilitating early, accurate diagnosis to optimize clinical management. Prognosis from early MRI post-injury remains unclear, yet if available could guide early intervention. The aim of this study was to determine the association of spinal cord intramedullary haematoma and/or extent of cord compression evident on initial spine MRI with neurological grade change after TSCI. METHODS: Individuals with acute TSCI ≥16 years of age; MRI review. Neurological gradings (American Spinal Injury Association Impairment Scale (AIS)) were compared with initial MRI findings. Various MRI parameters were evaluated for prediction of neurological improvement pre-discharge. RESULTS: 120 subjects; 79% male, mean (SD) age 51.0 (17.7) years. Motor vehicle crashes (42.5%) and falls (40.0%) were the most common injury mechanisms. Intramedullary spinal cord haematoma was identified by MRI in 40.0% of patients and was associated with more severe neurologic injury (58.3% initially AIS A). Generalised linear regression showed higher maximum spinal cord compression (MSCC) was associated with lower likelihood of neurological improvement from initial assessment to follow up prior to rehabilitation discharge. Combined thoracic level injury, intramedullary haematoma, and MSCC > 25% resulted in almost 90% probability of pre-discharge AIS (grade A) remaining unchanged from admission assessment. CONCLUSIONS: MRI is a vital tool for evaluating the severity and extent of TSCI, assisting in appropriate management decision-making early in TSCI patient care. This study adds to the body of knowledge assisting clinicians in prognostication.

The Pain Course: exploring the feasibility of an internet-delivered pain management programme for adults with spinal cord injury.

STUDY DESIGN: Single-group feasibility clinical trial. OBJECTIVES: This study examined the feasibility and outcomes of a modified version of a validated internet-delivered pain management programme, the Pain Course, for adults with SCI. SETTING: Nationwide in Australia. METHODS: Sixty-eight adults participated in the programme, which comprises five online lessons and homework tasks that are systematically released over 8 weeks. Participants were supported through the course with weekly contact from a clinical psychologist. RESULTS: Eighty-five percent of participants provided data at post-treatment and 76% of participants completed all five lessons of the course. High levels of satisfaction were observed and relatively little clinician time (M = 93.16 min; SD = 52.76 min) was required per participant to provide the course. Preliminary evidence of clinical improvements in pain-related disability (ds ≥ 0.53.; avg. improvement ≥ 20%; Mdiff ≥ 7.77), depression (ds ≥ 0.44.; avg. improvement ≥ 24%; Mdiff ≥ 2.44), anxiety (ds ≥ 0.41.; avg. improvement ≥ 26%; Mdiff ≥ 1.8) and average pain intensity (ds ≥ 0.46.; avg. improvement ≥ 13%; Mdiff ≥ 0.71) were observed at post-treatment, which were maintained or further improved to 3-month follow-up. These improvements were reflected in overall improvements in self-reported satisfaction with life (ds ≥ 0.31; avg. improvement ≥ 25%; Mdiff ≥ 2.16) CONCLUSION: These findings highlight the potential of carefully developed internet-delivered interventions as an approach for overcoming barriers and increasing access to psychosocial care for adults with SCI. SPONSORSHIP: iCare Lifetime Care and Support Authority and the Australian National Health and Medical Research Council.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: introduction, methodology and recommendation overview.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: The objective was to develop the first Canadian clinical practice guidelines for the management of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The guidelines were developed in accordance with the Appraisal of Guidelines for Research and Evaluation II tool. A Steering Committee and Working Group reviewed the relevant evidence on neuropathic pain management (encompassing screening and diagnosis, treatment and models of care) after SCI. The quality of evidence was scored using Grading of Recommendations Assessment, Development and Evaluation (GRADE). A consensus process was followed to achieve agreement on recommendations and clinical considerations. RESULTS: The Working Group developed 12 recommendations for screening and diagnosis, 12 recommendations for treatment and 5 recommendations for models of care. Important clinical considerations accompany each recommendation. CONCLUSIONS: The Working Group recommendations for the management of neuropathic pain after SCI should be used to inform practice.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: Recommendations for treatment.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: To develop the first Canadian clinical practice guidelines for treatment of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The CanPainSCI Working Group reviewed the evidence for different treatment options and achieved consensus. The Working Group then developed clinical considerations for each recommendation. Recommendations for research are also included. RESULTS: Twelve recommendations were developed for the management of neuropathic pain after SCI. The recommendations address both pharmacologic and nonpharmacologic treatment modalities. CONCLUSIONS: An expert Working Group developed recommendations for the treatment of neuropathic pain after SCI that should be used to inform practice.

The CanPain SCI Clinical Practice Guideline for Rehabilitation Management of Neuropathic Pain after Spinal Cord: recommendations for model systems of care.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: The project objectives were to develop the first Canadian recommendations on a model of care for the management of at- and below-level neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: On the basis of a review of the Accreditation Canada standards, the Steering Committee developed questions to guide the CanPainSCI Working Group when developing the recommendations. The Working Group agreed on recommendations through a consensus process. RESULTS: The Working Group developed five recommendations for the organization of neuropathic pain rehabilitation care in people with SCI. CONCLUSIONS: The Working Group recommendations for a model of care for at- and below-level neuropathic pain after SCI should be used to inform clinical practice.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: screening and diagnosis recommendations.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: To develop the first Canadian clinical practice guidelines for screening and diagnosis of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The CanPainSCI Working Group reviewed evidence to address clinical questions regarding screening and diagnosis of neuropathic pain after SCI. A consensus process was followed to achieve agreement on recommendations and clinical considerations. RESULTS: Twelve recommendations, based on expert consensus, were developed for the screening and diagnosis of neuropathic pain after SCI. The recommendations address methods for assessment, documentation tools, team member accountability, frequency of screening and considerations for diagnostic investigation. Important clinical considerations accompany each recommendation. CONCLUSIONS: The expert Working Group developed recommendations for the screening and diagnosis of neuropathic pain after SCI that should be used to inform practice.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part III: outcomes.

STUDY DESIGN: Focus Group. OBJECTIVES: To develop a unified, regional spinal cord injury (SCI) research strategy for Australia and New Zealand. SETTING: Australia. METHODS: A 1-day structured stakeholder dialogue was convened in 2013 in Melbourne, Australia, by the National Trauma Research Institute in collaboration with the SCI Network of Australia and New Zealand. Twenty-three experts participated, representing local and international research, clinical, consumer, advocacy, government policy and funding perspectives. Preparatory work synthesised evidence and articulated draft principles and options as a starting point for discussion. RESULTS: A regional SCI research strategy was proposed, whose objectives can be summarised under four themes. (1) Collaborative networks and strategic partnerships to increase efficiency, reduce duplication, build capacity and optimise research funding. (2) Research priority setting and coordination to manage competing studies. (3) Mechanisms for greater consumer engagement in research. (4) Resources and infrastructure to further develop SCI data registries, evaluate research translation and assess alignment of research strategy with stakeholder interests. These are consistent with contemporary international SCI research strategy development activities. CONCLUSION: This first step in a regional SCI research strategy has articulated objectives for further development by the wider SCI research community. The initiative has also reinforced the importance of coordinated, collective action in optimising outcomes following SCI.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part I: rapid review of SCI prioritisation literature.

STUDY DESIGN: This is a rapid evidence review. OBJECTIVES: The objective of this study was to gain an overview of the volume, nature and findings of studies regarding priorities for spinal cord injury (SCI) research. SETTING: A worldwide literature search was conducted. METHODS: Six medical literature databases and Google Scholar were searched for reviews in which the primary aim was to identify SCI research priorities. RESULTS: Two systematic reviews were identified-one of quantitative and one of qualitative studies. The quality of the reviews was variable. Collectively, the reviews identified 31 primary studies; 24 quantitative studies totalling 5262 participants and 7 qualitative studies totalling 120 participants. Despite the difference in research paradigms, there was convergence in review findings in the areas of body impairments and relationships. The vast majority of literature within the reviews focused on the SCI patient perspective. CONCLUSION: The reviews inform specific research topics and highlight other important research considerations, most notably those pertaining to SCI patients' perspectives on quality of life, which may be of use in determining meaningful research outcome measures. The views of other SCI research stakeholders such as researchers, clinicians, policymakers, funders and carers would help shape a bigger picture of SCI research priorities, ultimately optimising research outputs and translation into clinical practice and health policy change. Review findings informed subsequent activities in developing a regional SCI research strategy, as described in two companion papers. SPONSORSHIP: This project was funded by the Victorian Transport Accident Commission and the Australian and New Zealand SCI Network.

Life expectancy after spinal cord injury: a 50-year study.

STUDY DESIGN: Cohort of incident cases from 1955 to 2006. OBJECTIVES: To analyse acute and long-term mortality, estimate life expectancy and identify survival patterns of individuals experiencing traumatic spinal cord injury (SCI). SETTING: Specialised SCI unit in Australia. METHODS: Data for patients with traumatic SCI admitted to a spinal unit in Sydney, Australia between January 1955 and June 2006 were collated and deaths confirmed. Cumulative survival probability was estimated using life-table techniques and mortality rates were calculated from the number of deaths and aggregate years of exposure. Standardised mortality ratios (SMRs) were estimated from the ratio of observed to expected number of deaths. Life expectancy was then estimated using adjusted attained age-specific mortality rates. RESULTS: From 2014 persons, 88 persons with tetraplegia (8.2%) and 38 persons with paraplegia (4.1%) died within 12 months of injury, most often with complete C1-4 tetraplegia. Among first-year survivors, overall 40-year survival rates were 47 and 62% for persons with tetraplegia and paraplegia, respectively. The most significant increases in mortality were seen in those with tetraplegia and American Spinal Injury Association Impairment Scale (AIS) grades A-C lesions, with SMRs between 5.4 and 9.0 for people <50 years, reducing with advancing attained age. Estimated life expectancies from 25 to 65 years ranged between 69-64%, 74-65%, 88-91% and 97-96% for C1-4 AIS A-C, C5-8 A-C, T1-S5 A-C and all AIS D lesions, respectively. CONCLUSION: Survival related strongly to extent of neurological impairment. Future research should focus on identifying contextual factors, personal or environmental, that may contribute to the reduced life expectancy after SCI.

The pre-hospital epidemiology and management of spinal cord injuries in New South Wales: 2004-2008.

CONTEXT: Patients who have sustained a traumatic spinal cord injury require appropriate management in the immediate post-injury period for both survival and to reduce the chances of costly and disabling permanent neurological deficits. Emerging time-critical neuroprotective therapies require the prompt recognition and transfer of patients to a specialised centre for early intervention. METHODS: The Ambulance Research Institute, with the New South Wales State Spinal Cord Injury Service retrospectively linked prehospital data to spinal cord injury unit (SCIU) outcome data for all 324 patients transported by ambulance and subsequently admitted to a SCIU with a persisting traumatic spinal cord injury (SCI) between January 2004 and June 2008, with the aim of identifying factors that impact on the provision of timely and appropriate care. RESULTS: Paramedics appropriately managed 88% of SCI patients. Only 4.9% of patients had initial vital signs potentially indicative of neurological injury. The median time to a SCIU was 12h, with 60% of patients undergoing multiple transfers. The odds of reaching a SCIU in over 24h were 1.71 times greater for patients injured in a major city (95% CI 1.00-2.90) in comparison to other areas of NSW. More SCI patients with multiple trauma experienced delays in reaching a SCIU (59%), compared to patients with isolated SCI (40%; p=0.039). Patients initially transported to a designated major trauma centre were more likely to be delayed in reaching a SCIU, regardless of whether their injury was an isolated SCI or associated with multiple trauma, compared with other patients. Patients who took greater than 24h to reach a SCIU were 2.5 times more likely to develop a secondary complication (95% CI 1.51-4.17, p=0.0004). Patients who sustained their SCI as a result of a low fall were older and less likely to have their SCI identified and treated early, with less than half of this group reaching a SCIU within 24h compared with other SCI patients (OR 0.42, 95% CI 0.19-0.93, p=0.004). CONCLUSION: Early recognition, appropriate prehospital management, triage, timely and appropriate interfacility transfers of all SCI patients are critical for access to specialised care and reducing preventable complications. Elderly fallers present particular challenges to early identification.

Electrical stimulation plus progressive resistance training for leg strength in spinal cord injury: a randomized controlled trial.

STUDY DESIGN: A randomized controlled trial. OBJECTIVES: To determine the effectiveness of electrical stimulation (ES)-evoked muscle contractions superimposed on progressive resistance training (PRT) for increasing voluntary strength in the quadriceps muscles of people with spinal cord injuries (SCI). SETTING: Sydney, Australia. METHODS: A total of 20 people with established SCI and neurologically induced weakness of the quadriceps muscles participated in the trial. Participants were randomized between experimental and control groups. Volunteers in the experimental group received ES superimposed on PRT to the quadriceps muscles of one leg thrice weekly for 8 weeks. Participants in the control group received no intervention. Assessments occurred at the beginning and at the end of the 8-week period. The four primary outcomes were voluntary strength (Nm) and endurance (fatigue ratio) as well as the performance and satisfaction items of the Canadian Occupational Performance Measure (COPM; points). RESULTS: The between-group mean differences (95% confidence interval (CI)) for voluntary strength and endurance were 14 Nm (1-27; P=0.034) and 0.1 (-0.1 to 0.3; P=0.221), respectively. The between-group median differences (95% CI) for the performance and satisfaction items of the COPM were 1.7 points (-0.2 to 3.2; P=0.103) and 1.4 points (-0.1 to 4.6; P=0.058), respectively. CONCLUSION: ES superimposed on PRT improves voluntary strength, although there is uncertainty about whether the size of the treatment effect is clinically important. The relative effectiveness of ES and PRT is yet to be determined.

Training unsupported sitting in people with chronic spinal cord injuries: a randomized controlled trial.

STUDY DESIGN: Randomized, assessor-blinded trial. OBJECTIVES: To evaluate the effectiveness of a 6-week task-specific training programme on the abilities of people with chronic spinal cord injuries to sit unsupported. SETTING: NSW, Australia. METHODS: Thirty adults with spinal cord injuries of at least 1-year duration were recruited. Participants in the training group (n=15) performed up to 1 h of task-specific training three times a week for 6 weeks. Participants in the control group (n=15) did not receive any training or additional therapy. Primary outcome measures were the Canadian Occupational Performance Measure (COPM), and tests of Upper Body Sway, Maximal Balance Range and donning and doffing a T-shirt (the T-shirt test). RESULTS: The between-group mean difference (95% confidence interval) for the maximal balance range was 64 mm (95% confidence interval 20 to 108 mm; P=0.006). There were no significant between-group mean differences for the COPM and the Upper Body Sway and T-shirt tests. CONCLUSIONS: This trial shows initial support for intensive task-specific training for improving the abilities of people with chronic spinal cord injuries to sit unsupported, although the real-world implications of the observed treatment effects are yet to be determined.

Neuropathic pain and primary somatosensory cortex reorganization following spinal cord injury.

The most obvious impairments associated with spinal cord injury (SCI) are loss of sensation and motor control. However, many subjects with SCI also develop persistent neuropathic pain below the injury which is often severe, debilitating and refractory to treatment. The underlying mechanisms of persistent neuropathic SCI pain remain poorly understood. Reports in amputees describing phantom limb pain demonstrate a positive correlation between pain intensity and the amount of primary somatosensory cortex (S1) reorganization. Of note, this S1 reorganization has also been shown to reverse with pain reduction. It is unknown whether a similar association between S1 reorganization and pain intensity exists in subjects with SCI. The aim of this investigation was to determine whether the degree of S1 reorganization following SCI correlated with on-going neuropathic pain intensity. In 20 complete SCI subjects (10 with neuropathic pain, 10 without neuropathic pain) and 21 control subjects without SCI, the somatosensory cortex was mapped using functional magnetic resonance imaging during light brushing of the right little finger, thumb and lip. S1 reorganization was demonstrated in SCI subjects with the little finger activation point moving medially towards the S1 region that would normally innervate the legs. The amount of S1 reorganization in subjects with SCI significantly correlated with on-going pain intensity levels. This study provides evidence of a link between the degree of cortical reorganization and the intensity of persistent neuropathic pain following SCI. Strategies aimed at reversing somatosensory cortical reorganization may have therapeutic potential in central neuropathic pain.

Benefits of FES gait in a spinal cord injured population.

STUDY DESIGN: Review. OBJECTIVES: This review article investigated the objective evidence of benefits derived from functional electrical stimulation (FES)-assisted gait for people with spinal cord injury (SCI). Both FES and gait have been proposed to promote not only augmented health and fitness, but specific ambulatory outcomes for individuals with neurological disabilities. However, due to small sample sizes and the lack of functionality of the intervention, it has not been widely used in clinical practice. This review assessed whether there is sufficient evidence to encourage a more widespread deployment of FES gait within the rehabilitation community. METHODS: Hand searches and online data collection were performed in Medline and Science Direct. Specific search terms used included SCI/paralysis/paraplegia and tetraplegia with electrical stimulation/FES, gait and walking. RESULTS: The searches generated 532 papers. Of these papers, 496 were excluded and 36 papers were included in the review. Many reported benefits were not carefully investigated, and small sample sizes or different methodologies resulted in insufficient evidence to draw definitive conclusions. CONCLUSIONS: FES gait can enhance gait, muscle strength and cardiorespiratory fitness for people with SCI. However, these benefits are dependent on the nature of the injury and further research is required to generalize these results to the widespread population of SCI individuals. Proof of the functionality and further evidence of the benefits of FES gait will assist in FES gait gaining clinical acceptance.

Envelope gating and noise shaping in populations of noisy neurons.

Narrowband signals have fast and slow time scales. The transmission of narrowband signal features on both times cales, by spiking neurons, is demonstrated experimentally and theoretically. The interaction of the narrowband input and the threshold nonlinearity may create out-of-band interference, hindering the transmission of signals in a low-frequency range. The resultant out-of-band signal is the "envelope," or time-varying modulation of the narrowband signal. The levels of noise and nonlinearity intrinsic to the neuron gate transmission on the slow "envelope" time scale. When a narrowband and a distinct slow signal drive the neuron, the slow signal may be poorly transmitted. Increasing intrinsic noise in an averaging network removes the envelope in favor of the slow signal, paradoxically increasing the signal-to-noise ratio. These gating effects are generic for threshold and excitable systems.

Spinal-injured neuropathic bladder antisepsis (SINBA) trial.

OBJECTIVE: To determine whether Methenamine Hippurate (MH) or cranberry tablets prevent urinary tract infections (UTI) in people with neuropathic bladder following spinal cord injury (SCI). STUDY DESIGN: Double-blind factorial-design randomized controlled trial (RCT) with 2 year recruitment period from November 2000 and 6 month follow-up. SETTING: In total, 543 eligible predominantly community dwelling patients were invited to participate in the study, of whom 305 (56%) agreed. METHODS: Eligible participants were people with SCI with neurogenic bladder and stable bladder management. All regimens were indistinguishable in appearance and taste. The dose of MH used was 1 g twice-daily. The dose of cranberry used was 800 mg twice-daily. The main outcome measure was the time to occurrence of a symptomatic UTI. RESULTS: Multivariate analysis revealed that patients randomized to MH did not have a significantly longer UTI-free period compared to placebo (HR 0.96, 95% CI: 0.68-1.35, P=0.75). Patients randomized to cranberry likewise did not have significantly longer UTI-free period compared to placebo (HR 0.93, 95% CI: 0.67-1.31, P=0.70). CONCLUSION: There is no benefit in the prevention of UTI from the addition of MH or cranberry tablets to the usual regimen of patients with neuropathic bladder following SCI.

Five additional mobility and locomotor items to improve responsiveness of the FIM in wheelchair-dependent individuals with spinal cord injury.

STUDY DESIGN: Repeated-measures design. OBJECTIVES: To assess the validity and responsiveness of five additional mobility and locomotor (5-AML) items when used in conjunction with the Functional Independence Measure (FIM) for assessing the mobility and locomotor function of individuals with spinal cord injury (SCI). SETTING: Specialised acute spinal and rehabilitation units in Sydney, Australia. METHODS: A previously published scale comprising five key mobility and locomotor skills was further refined. The five items included a bed mobility and vertical (floor-to-chair) transfer item and three wheelchair propulsion items (pushing 200 m over flat ground, pushing up a ramp and negotiating a kerb). A total of 43 eligible patients with SCI (ASIA A-C impairment) admitted consecutively to two acute SCI units in Sydney between 1999 and 2002 were recruited, with four being lost to follow-up. Locomotor and mobility outcomes were measured at regular intervals for up to 6 months with the FIM and the 5-AML. Construct validity of the 5-AML was assessed by testing ability of items to discriminate between different impairment groups (tetraplegia and paraplegia). Item responsiveness was assessed by analysing ability to detect changes in mobility and locomotor function over time. Factor analysis techniques were used to test the hypothesis that the 5-AML, when used in conjunction with the FIM, provides a more sensitive measure of mobility and locomotor function than the FIM alone. RESULTS: The 5-AML items were shown to be valid and responsive, measuring aspects of 'real world' mobility and locomotor function not reflected by the FIM. The bed mobility item was highly responsive to change over time for the tetraplegic group, but quickly reached a ceiling in the paraplegic group. The vertical (floor-to-chair) transfer item showed greater responsiveness over time and less ceiling effect for the paraplegic group than any of the FIM locomotor or mobility items. The three wheelchair propulsion items better discriminated between people with tetraplegia and paraplegia, and were more sensitive to changes in locomotor ability over the 6-month period than FIM locomotor items. Results of a preliminary factor analysis indicated that the 5-AML items measure different aspects of mobility and locomotor function than the FIM. CONCLUSION: The 5-AML items, when used in conjunction with the FIM, provides better delineation of function between people with tetraplegia and paraplegia and provides a more responsive measure of change in function over time than the FIM alone.

A proposed algorithm for the management of pain following spinal cord injury.

STUDY DESIGN: Review. OBJECTIVES: To review published articles on the assessment, diagnosis and treatment of pain following spinal cord injury (SCI) and to synthesise evidence from these materials to formulate and propose a systematic approach to management. METHODS: Relevant articles regarding the treatment of pain were identified from electronic databases using the search terms (('spinal cord injury' or 'spinal cord injuries') and 'pain') and both ('treatment') and ('randomised controlled trials'). Relevant articles were also identified through citations in indexed journal publications and book chapters on this topic. RESULTS: Review of the literature indicates that there are a large variety of treatments used in the management of pain following SCI with a small number supported by strong evidence for effectiveness. A treatment algorithm is proposed based on identification of underlying pain contributors and application of appropriate treatment. CONCLUSION: Although there are relatively few studies clearly indicating efficacy in this population, an algorithm for the management of pain following SCI might assist to maximise our effectiveness in the treatment of this condition. It is recognised that choice of treatment is also determined by factors such as medication availability, cost and side effects as well as the preferences and characteristics of the person being treated. Nevertheless, an algorithm is proposed as a way to synthesise our current level of knowledge, identify gaps for further study and aid in the management of this difficult problem.

Patterns of morbidity and rehospitalisation following spinal cord injury.

STUDY DESIGN: Longitudinal, descriptive design. OBJECTIVES: The aim of this study was to investigate the frequency, cause and duration of rehospitalisations in individuals with spinal cord injury (SCI) living in the community. SETTING: Australian spinal cord injury unit in collaboration with State Health Department. METHODS: A data set was created by linking records from the NSW Department of Health Inpatient Statistics Collection between 1989-1990 and 1999-2000 with data from the Royal North Shore Hospital (RNSH) Spinal Cord Injuries Database using probabilistic record linkage techniques. Records excluded were nontraumatic injuries, age <16 years, spinal column injury without neurological deficit, full recovery (ASIA Grade E) and index admission not at RNSH. Descriptive statistics and time to readmission using survival analysis, stratified by ASIA impairment grade, were calculated. RESULTS: Over the 10-year period, 253 persons (58.6%) required one or more spinal-related readmissions, accounting for 977 rehospitalisations and 15,127 bed-days (average length of stay (ALOS) 15.5 days; median 5 days). The most frequent causes for rehospitalisation were genitourinary (24.1% of readmissions), gastrointestinal (11.0%), further rehabilitation (11.0%), skin-related (8.9%), musculoskeletal (8.6%) and psychiatric disorders (6.8%). Pressure sores accounted for only 6.6% of all readmissions, however, contributed a disproportionate number of bed-days (27.9%), with an ALOS of 65.9 (median 49) days and over 50% of readmissions (33 out of 64) occurred in only nine individuals aged under 30 years. Age, level and completeness of neurological impairment, all influenced differential rates of readmission depending on the type of complication. Overall rehospitalisation rates were high in the first 4 years after initial treatment episode, averaging 0.64 readmissions (12.6 bed-days) per person at risk in the first year and fluctuating between 0.52 and 0.61 readmissions (5.1-8.3 bed-days) per person at risk per year between the second to fourth years, before trending downwards to reach 0.35 readmissions (2.0 bed-days) as 10th year approaches. Time to readmission was influenced by degree of impairment, with significantly fewer people readmitted for ASIA D (43.2%) versus ASIA A, B and C (55.2-67.0%) impairments (P<0.0001). The mean duration to first readmission was 46 months overall, however, differed significantly between persons with ASIA A-C impairments (26-36 months) and ASIA D impairment (60 months). CONCLUSION: Identifying rates, causes and patterns of morbidity is important for future resource allocation and targeting preventative measures. For instance, the late complication of pressure sores in a small subgroup of young males, consuming disproportionately large resources, warrants further research to better understand the complex psychosocial and environmental factors involved and to develop effective countermeasures.

Firing statistics of a neuron model driven by long-range correlated noise.

We study the statistics of the firing patterns of a perfect integrate and fire neuron model driven by additive long-range correlated Ornstein-Uhlenbeck noise. Using a quasistatic weak noise approximation we obtain expressions for the interspike interval (ISI) probability density, the power spectral density, and the spike count Fano factor. We find unimodal, long-tailed ISI densities, Lorenzian power spectra at low frequencies, and a minimum in the Fano factor as a function of counting time. The implications of these results for signal detection are discussed.