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<p>  </p> <p>Persons with a spinal cord injury (SCI) often suffer from secondary complications including the dysfunction of the autonomic nervous system below the level of injury. For persons with a SCI at or above T6, autonomic dysreflexia (AD) may be triggered by noxious stimulation below the level of injury causing rapid sympathetic hyperactivation, leading to paroxysmal hypertension. If AD is not recognized and managed promptly, this increase in blood pressure can lead to stroke, organ damage, and/or death. Currently, AD is only detected in clinical settings through continuous blood pressure monitoring. Recent studies have revealed that rapid detection of AD is possible by using extracted features from electrocardiogram (ECG) data collected non-invasively and applying a five-layer neural network.</p> <p>This project focuses on further characterization of physiological responses before and during AD to detect the overreaction of sympathetic nerve activity prior to the detrimental increase in hypertension. Using a rat model with implanted telemetry and noninvasive sensors, an acclimation protocol was developed to minimize noise and motion artifacts during data collection. We induced AD in a controlled manner using colorectal distention (CRD). We analyzed skin nerve activity (SKNA) and heart rate variability parameters in the time and frequency domain to improve the non-invasive detection of AD. A four-week acclimation protocol exposed a minimal increase in sympathetic activity during experimentation despite long periods of restraint. Results indicated an increase in SKNA features occurred about 18 seconds before the gold standard increase in blood pressure. Additionally, integrated SKNA features in the frequency domain quantified nerve activity and low frequency components were found to be dominant during AD, providing another parameter that could be included in an AD detection system to improve accuracy. In humans, SKNA may be used to alert patients of the onset of AD, allowing caretakers to respond quickly and make necessary changes to decrease the severe effects of AD.</p>

<P>To examine the effects of purported fiber-type transformation following spinal cord injury (SCI), twitch contractile properties of the soleus, tibialis anterior (TA) and thenar muscles were examined in individuals with chronic (> 4 years) SCI. Furthermore, the force-frequency relationship, fatigue and posttetanic potentiation (PTP) of the paralyzed TA muscle were also evaluated. Nine adults with SCI (22-59 yrs; lesion level C3-T2) and 9 age-and gender-matched able-bodied controls (AB) participated in this study.</P><P>On the first visit to the laboratory, the maximum twitch response for all three muscles was determined by delivering a series of single stimuli with gradually increasing intensity. For evaluation of PTP, tetanic stimulation (100Hz) was applied to the TA for 5 seconds followed by single twitches delivered at 5 seconds after tetanus and then at 30-second intervals for 4 minutes posttetanus. On a second visit, the force-frequency relationship (FFR) and 15Hz fatigue of the TA was evaluated. One second bursts ranging from 1-1OOHz were delivered randomly with 2 minutes of rest in between each frequency for assessment of FFR. Following a 1 0-minute rest period, the first fatigue protocol was given, consisting of 1-minute of tetanic stimulation at 15Hz. At the third session, the 30Hz fatigue of the TA was performed, consisting of 1-minute of tetanic stimulation at 30Hz.</P><P>In the soleus muscle, the AB had a higher peak twitch torque (PT) and M-wave amplitude compared to.the SCI group (14.2 ± 3.9Nm vs. 8.9 ± 6.1Nm; p = 0.058, and 13.5 ± 5.3mV and 5.5 ± 4.0mV; p < 0.05, respectively). Contractile speed was not significantly different between groups. Time to peak torque (TPT) was longer in AB (111.5 ± 15.4ms) compared to the SCI (76.7 ± 25.0ms; p<0.05) due to the larger twitches; however, the rates of torque development (RTD) were similar between groups. In the TA muscle, AB and SCI had similar PT (2.8 ± 0.5Nm and 3.2 ± 1.2Nm, respectively). TA contractile properties were faster in SCI, as seen by significantly shorter TPT and faster RTD (p<0.05). M-wave amplitude of AB was significantly greater than the SCI group, 8.3 ± 2.6mV versus 4.2 ± 1.7mV, respectively (p<0.05). Finally, in the thenar muscle, PT appeared to be smaller in AB compared to SCI, 1.7 ± 0.8Nm versus 2.9 ± 1.3Nm, respectively (p = 0.094). The RTD was faster in the SCI group compared to AB (p<0.05).</P><P>Evaluation of FFR revealed that the curve of the SCI was shifted to the left of that of AB. The F50 (frequency required to elicit 50% of maximum peak torque) was significantly lower in the SCI compared to AB, 6.7 ± 3.4Hz and 16.7 ± 4.1Hz, respectively (p<0.05). Following the fatigue protocols, SCI group tended to fatigue more rapidly and to a greater extent than AB at both frequencies, however this was only significant at 15Hz. The M-wave declined with fatigue (30Hz) in both groups, but this decline tended to be more rapid in SCI.</P><P>For the assessment of PTP, both groups started off with similar baseline twitches in their TA muscle (2.7 ± 0.3Nm and 2.9 ± 0.8Nm, respectively). At 5 seconds following tetanus, PT was significantly greater in both groups, but the amount of potentiation was greater in SCI versus AB (p = 0.058). Over the 4-min recovery period, PT declined in both groups until it was no longer significantly greater than baseline by 3 minutes 30 seconds. The potentiated twitch of both groups was faster than at baseline. RTD increased significantly by an average of 56% in the AB group and 91% in the SCI group and was significantly greater in SCI compared with AB at 30-150 seconds post-tetanus (p<0.05). At 5 seconds post-tetanus, RTR was significantly faster in both groups and had increased by 77% and 53% in the AB and SCI groups, respectively. The recovery ofRTD and R TR over the 4 minutes occurred more rapidly in AB versus SCI.</P><P>In conclusion, changes in contractile properties following SCI differ between muscle groups; faster contractile properties indicative of fiber type transformation are more evident in TA and thenar muscle groups, compared with the soleus. The smaller M-waves seen in the lower extremities support the significant muscle atrophy following SCI. Furthermore, the predicted transformation towards a higher proportion of fast-twitch fibers following paralysis was supported by a trend for decreased fatigue resistance and significantly greater PTP in the SCI group. The FFR data, however, did not support this predicted fiber type transformation, shifting to the left instead of the right. This leftward shift of FFR has been reported in other paralyzed human muscle presenting with faster contractile speeds; the mechanisms behind this warrant further investigation.</P> / Thesis / Master of Science (MSc)

The primary motor cortex (M1) contains a somatotopic progression with highly overlapping areas outputting to muscles of the upper limb. This organization is modified by muscle activity and neurological injury such as spinal cord injury (SCI). To date, bilateral M1 organization in controls and SCI has been minimally explored, and no study has examined the cortical territory that directs output to multiple muscles thought to be involved in movement synergies. An initial study was conducted to characterize the bilateral organization and representational overlap for muscles of the upper limb in incomplete spinal cord injury relative to uninjured individuals. Differences in symmetry and amount of overlapping territory were observed between groups, possibly reflecting differences in synergistic muscle use. The second study examined transcallosal communication between the two motor cortices and its role in dynamically modulating motor representations during unilateral contraction. The depth of interhemispheric inhibition (IHI) was examined in a muscle of the right hand by delivering a conditioning stimulus to ipsilateral M1 followed by a test stimulus to contralateral M1. Reduced IHI corresponded to larger cortical territory, a relationship that existed for both contralateral and ipsilateral contraction. These data demonstrate that the magnitude of IHI in a hand muscle predicts the size of the cortical territory occupied by that muscle. We present a mechanistic model to explain these findings that further elucidate the role of interhemispheric communication in shaping motor output. This interaction between transcallosal inhibition and motor output may act as a component to experience-dependent plasticity within M1. By targeting this interaction, it may be possible to facilitate motor learning and performance or promote recovery of function following neurological injury. Further study examining the role of various intracortical circuits on representational plasticity and modulation of these interactions may yield advances in both basic and clinical neuroscience. / Thesis / Master of Science (MSc)

Spinal cord injury (SCI) is a debilitating event that leads to either complete or partial paralysis, sensory loss and loss of autonomic control below the level of neurological interruption. Consequent to the physiological changes that accompany the sustenance of a SCI, many affected individuals experience increased risk of developing cardiovascular disease. In addition, although not experienced by all individuals with SCI, decreased quality of life and depression are more common in these individuals than in the able-bodied population. Participation in regular exercise has been investigated as a way to decrease both cardiovascular risk and depressive symptoms in able-bodied individuals, however a relatively small number of similar investigations have been performed in individuals with SCI. The current study examined the effects of a training protocol that incorporated arm ergomety and resistance training, two relatively inexpensive and accessible exercise modalities, on blood lipid variables (high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), total cholesterol (TC), triglycerides (TG) and HDLITC ratio), fasting blood glucose (FBG) and psychological well being (PWB). Baseline blood measures were obtained via fingerstick, and were subjected to automated analysis (Cholestech L.D.X, Cholestech, Hayward, CA). Resting systolic (SBP) and diastolic (DBP) were obtained via auscultation, while resting heart rate (HR) was obtained using either chest electrodes or an ear clip HR monitor. Three successively more difficult, 6-minute bouts of arm ergometry were performed, during which were monitored HR, arm rating of perceived exertion (ARPE) and total body rating of perceived exertion (TRPE). Systolic blood pressure and DBP were measured via auscultation immediately following each exercise session. Two minutes of rest were allowed between arm ergometry bouts. Psychological measures including the Center for Epidemiologic Studies depression scale (CES-D) (Radloff, 1977), an adaptation of Cantril's ladder of life satisfaction (Cantril, 1965), the Perceived Stress Scale (PSS) (Cohen et al., 1983), a bodily pain question from the Short-Form 36-Item Health Survey (SF-36) (Ware and Sherbourne, 1992), the modified Exercise-Induced Feeling Inventory (EFI-C) (Rejeski et al., 1999) and perceived control questions from the Beliefs Scale (BS) (Shnek et al., 1997) were administered in interview format. One repetition maximum (1 RM) lifts were determined for chest press, shoulder flexion and elbow flexion. Participants were matched on the basis of Coli ratings (Coli et al., 1998) and years post injury (+/-10 years post) and then randomized to either exercise (EX) or control (C) groups. Subsequently EX participants took part in an exercise protocol that entailed the twice-weekly training of cardiovascular endurance and strength. During each exercise session, participants performed two bouts of arm ergometry and two resistance training exercises for shoulder musculature, elbow flexors, elbow extensors, chest musculature, wrist flexors, wrist extensors and back musculature, respectively. Duration of arm ergometry was adjusted according to individual participant tolerance, while work load was manipulated in order to attempt to elicit TRPE scores of approximately 3. Two sets of 15 repetitions of the resistance training exercises were performed during each of the first 6-8 sessions, in order to facilitate injury-free adjustment to resistance training. Subsequently, 3 sets of 10 repetitions were performed, with relatively heavier weights, in order to maximize improvements in strength. Control participants were asked to refrain from initiating a regular exercise program during the course of the study. Post-testing occurred 3 months following the acquisition of baseline measures for the C group, and following the completion of between 22 to 24 exercise sessions for the EX group. No significant changes in blood lipid variables, FBG or indices of PWB occurred during the course of the study. However, favourable baseline values for absolute blood data, FBG and PWB may have made improvements difficult. Improved arm ergometry tolerance was indicated in EX participants by significant differences in percentage improvement of ARPE at the conclusion of the study. Statistically significant improvements in strength were not observed for the EX group, except in the case of left elbow flexion; however, trends were observed that suggested increased strength in the EX group in comparison with the C group following the completion of the experimental protocol. Several recommendations are provided regarding the performance of future research examining the effects of arm ergometry and resistance training exercise on cardiovascular risk and PWB in individuals with SCI. / Thesis / Master of Science (MS)

The purpose of this study was to determine the effects of cessation of a 12-month thrice-weekly body-weight supported treadmill training (BWSTT) program on functional ambulation and aspects of health-related quality of life (HRQL) in individuals with incomplete SCI. Twelve men and women (aged 22-55) with chronic (> 1 year post-injury) incomplete SCI (ASIA B or C) returned for follow-up (FOL) testing 37 weeks (SD 2.1) following their final scheduled BWSTT session. Functional ambulation was compared based on: i) required percentage of body-weight support (%BWS) on the treadmill, ii) preferred treadmill speed and iii) overground walking. Evaluation of HRQL included measures of: i) satisfaction with life, ii) perceived ability to perform activities of daily living (ADL), iii) perceptions of health, and iv) depressive symptomology. Participants were invited to participate in once-weekly BWSTT and twice-weekly fitness training during the FOL period (37 sessions); the actual number of BWSTT sessions attended was only 11.6 (range 0-29) and the total days of exercise was 29.1 (range 0-75). The 12-month BWSTT program resulted in a decrease in the required %BWS (73±10% to 19±12%; p<.01), an increase in treadmill speed (0.5±0.3 to 1.4±0.8 km/h; p<.01), improved overground walking in 4 individuals, and improved group satisfaction with life (p<.05). At FOL, %BWS increased to 35±14% (p<.01), but was still less than at pre-training (p<.01). There were no differences between 12-month and FOL scores on any HRQL-related measures. High exercise adherence during the FOL period had a strong correlation with a positive percent change in perceived ability to perform ADL (r = .70; p<.05), as well as non-significant trends with positive percent change in perceptions of health and negative percent change in depressive symptomology (r = .49; p=.13 and r = .51; p=.ll, respectively). Therefore, even with very limited access to the BWS treadmill, much of the improvement in treadmill walking ability and satisfaction with life following long-term BWSTT in individuals with incomplete SCI can be retained for at least 8 months. Continued exercise participation, however, may contribute to maintain or further improve aspects of HRQL in this population. / Thesis / Master of Science (MS)

Impaired wound healing in SCI patients contributes to the progression in severity of PIs. Best practice guidelines suggest that surgical flap reconstruction is an option for chronic stage 4 PIs that have failed to heal with more conservative measures, but little is known about the epidemiology of surgically reconstructed PIs in SCI patients. Rates of surgical wound complications are high, and cost of management is extensive. Accordingly, this study aims to establish a systematic approach for identifying SCI patients with surgically reconstructed PIs, to facilitate study of predictors of sustained wound closure, quantify costs of surgical reconstruction, and evaluate efficiency of treatment and recovery options. To address gaps in the literature, this study’s objectives were: (1) estimate surgical reconstruction hospital costs for stage 4 PIs in SCI patients and characterize the relationship of demographic, socioeconomic and lifestyle factors to cost at discharge, (2) explore a standardized method of identifying these cases in large databases, (3) identify and validate risk factors for complications at discharge from wound care follow-up, and (4) identify long-term cost and health care utilization of persons with SCI who have undergone surgical flap closure. It proved difficult to identify our own cohort of patients using administrative codes applied, making population-based study using administrative data less than ideal. Factors associated with open incision at three-to-six weeks post-index surgery included number of nursing visits in the previous year, and revision surgery within the six-week follow-up period. The cost of persons with SCI and PI was high one year prior to surgery (look-back) and almost double in the first year look-back. However, significant cost and health care utilization was demonstrated in Year 2 and 3 post-index surgery. Further prospective studies exploring models of health care delivery and addressing some of modifiable risk factors may improve cost-effectiveness and outcomes. / Thesis / Doctor of Philosophy (PhD) / Pressure ulcers, also known as pressure injuries (PI) or bedsores, are a common secondary complication in persons with spinal cord injury (SCI). While surgical closure is an option offered to patients, little is known about the long-term outcomes, including cost and use of health care services following the surgery. Risk factors for complications following surgery are known from a physical/co-morbidity/technique perspective, but environmental and behavioural factors have not been included these studies, and the use of health care administrative databases to accurately identify these patients for research has not been studied. A historical cohort study was conducted at one tertiary care centre in Toronto, Canada to identify known cases of SCI and PI reconstruction. Hospital codes were recorded in an algorithm used to evaluate the accuracy in identifying the known cases in the database. Health care usage and costs were also recorded, and risk factors for complications were also evaluated.

Background: Quantitative imaging surrogates of myelin and axonal integrity using magnetization transfer and diffusion tensor imaging may provide beneficial prognostic details on long-term post-surgical recovery in dogs with spinal cord injury (SCI) secondary to intervertebral disc herniation (IVDH). Hypothesis: Magnetization transfer ratio (MTR), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA) will be significantly different in patients with a successful outcome compared to patients with an unsuccessful outcome. Animals: 61 dogs with SCI secondary to IVDH were included in the final analysis. All dogs had to undergo surgical correction for SCI secondary to IVDH and be followed out for 12 weeks. Methods: Prospective cohort study. MTR, MD, AD, RD, and FA were calculated in dogs with SCI secondary to IVDH. A Wilcoxon signed-rank test was used to compare MTR, MD, AD, RD, and FA values between patients with a successful outcome and patients with an unsuccessful outcome. Statistical significance was set at p<0.05. For quantitative imaging surrogates with a significant relationship with outcome, a receiver operator characteristic (ROC) curve analysis was performed and the sensitivity and specificity for predicting successful outcome. Results: MTR (p=0.0013) was significantly lower in patients with a successful outcome compared to patients with an unsuccessful outcome. FA (p=0.435) was not significantly between groups. MD (p=0.0006), AD (p=0.0008) and RD (p=0.0002) were significantly higher in patients with a successful outcome compared to patients with an unsuccessful outcome. ROC curves were performed for MTR, AD and RD. If MTR was ≤ 53, AD ≥ 1.7 × 10-3mm2/s or RD ≥ 0.37 × 10-3 mm2/s, this resulted in a sensitivity of 96.3% and specificity of 100 in predicting a successful outcome. Conclusion and clinical relevance: MTR, MD, AD, and RD were helpful in predicting successful outcome in canine patients with surgically treated SCI secondary to IVDH. A larger cohort is needed for further evaluation. / Master of Science / Background: Certain magnetic resonance imaging (MRI) techniques can provide information about the severity of spinal cord injury. The information obtained from these MRI techniques can be helpful in predicting prognosis in dogs with intervertebral disc disease (IVDD). Hypothesis: We hypothesized that the measurements obtained from these MRI techniques would be able to predict the patients who would be able to walk following surgery (good long-term outcome), versus the patients who did not regain the ability to walk following surgery (poor long-term outcome). Animals: 62 MRIs were performed on dogs with IVDD in our study and were followed out for 12 weeks following surgery to assess long-term outcome. Results: Of the 5 MRI techniques investigated, 4 of the techniques were found to be helpful in predicted long-term outcome. When these techniques were combined, the ability to predict long-term outcome improved. Using the combined technique, all 53 patients predicted to have a good long-term had a good long-term outcome. For patients with a poor long-term outcome, 9 were predicted to have a poor long-term outcome, but only 7 patients had a poor long-term outcome. Conclusion and clinical relevance: MRI can be helpful in predicting long-term outcome in dogs with IVDD following surgery. A larger population of dogs is needed for further evaluation.

Sexual function in men with Spinal Cord Injury (SCI) is usually affected to a greater or lesser extent, depending on the type of injury and physiological prerequisites. Social contexts and psychological factors are other aspects that affect sexual function. Sexual dysfunction can lead to an impaired quality of life, depression and other illnesses. Aim: To study reported experiences of sexual function in men with SCI who have participated in The Nordic Spinal Injury Registry (NSCIR) five years follow-up. Design: Quantitative method consisting of a register study based on secondary data. Setting: Information collected from units at Linköping and Umeå, which are two of Sweden's six units of the County Councils' Centers for Spinal Cord Injuries. Sample: Eighty-two men with SCI between ages 19-81 years (mean age: 48 years). Method: A Study of NSCIR´s five years follow-ups regarding the questionnaires for Sexual function and Socio-demographic. Results: Fifty-nine percent (34/58) reported that sexual function was unsatisfactory in relation to intercourse. Almost 80% (55/69) reported experiencing sexual desire after injury. Fifty-four percent (38/70) reported engaging in sexual activity. Conclusions: The results are useful in the aim of developing Spinal Cord Injury care to optimize sexual rehabilitation for men with SCI and to provide a basis for confident and satisfactory sexuality and a better quality of life.

Diploma thesis "Influence of regular training of spinal cord patients in Lokomat system on particular spatio-temporal parameters of their walk." is a theoretical-empirical case report. Theoretical part deals with the neuroanatomy of the spinal cord, control, analysis and possibilities of check up of physiological walk. This part is concluded by the summary of entries about the Lokomat system, its basic technical equipment, advantages / disadvantages, indications/ contra-indications of its use in practice. The empirical part deals with the examination of the influence of the training in Lokomat system on the walk of the patients with incomplete spinal cord lesion. The main subject of the research is to monitor the changes in particular spatio-temporal parameters of walk (gait speed, stride length, stride time, single support time). Powered by TCPDF (www.tcpdf.org)