Flexion Model Simulating Spinal Cord Injury Without Radiographic Abnormality in Patients With Ossification of the Longitudinal Ligament: The Influence of Flexion Speed on the Cervical Spine

Background/Objective:

It is suspected that the speed of the motion of the spinal cord under static compression may be the cause of spinal cord injury (SCI). However, little is known about the relationship between the speed of the motion of the spinal cord and its stress distributions. The objective was to carry out a biomechanical study of SCI in patients with ossification of the longitudinal ligament without radiologic evidence of injury.

Methods:

A 3-dimensional finite element spinal cord model was established. After the application of static compression, the model underwent anterior flexion to simulate SCI in ossification of the longitudinal ligament patients without radiologic abnormality. Flexion of the spine was assumed to occur at 1 motor segment. Flexion angle was 5°, and flexion speeds were 0.5°/s, 5°/s, and 50°/s. Stress distributions inside of the spinal cord were evaluated.

Results:

Stresses on the spinal cord increased slightly after the application of 5° of flexion at a speed of 0.5°/s. Stresses became much higher at a speed of 5°/s and increased further at 50°s.

Conclusions:

The stress distribution of the spinal cord under static compression increased with faster flexion speed of the spinal cord. High-speed motion of the spinal cord under static compression may be one of the causes of SCI in the absence of radiologic abnormality.     

Biomechanical analysis of cervical spondylotic myelopathy: the influence of dynamic factors and morphometry of the spinal cord

Objective

Patients with cervical spondylotic myelopathy (CSM) have the same clinical symptoms that vary according to the degree of spinal cord compression and the cross-sectional cord shape. We used a three-dimensional finite element method (3D-FEM) to analyze the stress distributions of the spinal cord with neck extension under three cross-sectional cord shapes.

Methods

Experimental condition for the 3D-FEM spinal cord, ligamentum flavum, and anterior compression shape (central, lateral, and diffuse types) was established. To simulate neck extension, the spinal cord was extended by 20° and the ligamentum flavum was shifted distally according to movement of the cephalad lamina.

Results

The stress distribution in the spinal cord increased due to invagination of the ligamentum flavum into the neck extension. The range of stress distribution observed for the diffuse type was wider than for the central and lateral types. In addition, the stress distribution in the spinal cord was increased by the pincer movement of the ligamentum flavum and by the anterior compression of the spinal cord. The range of stress distribution observed for the diffuse type under antero-posterior compression was also wider than for the central and lateral types.

Conclusion

This simulation model showed that the clinical symptoms of CSM due to compression of the diffuse type may be stronger than for the central and lateral types. Therefore, careful follow-up is recommended for anterior compression of the spinal cord of diffuse type.     

Biomechanical study of the spinal cord in thoracic ossification of the posterior longitudinal ligament

Background

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy. This is often progressive and is not affected by conservative treatment. Therefore, decompressive surgery is usually chosen.

Objective

To conduct a stress analysis of the thoracic OPLL.

Methods

The three-dimensional finite element spinal cord model was established. We used local ossification angle (LOA) for the degree of compression of spinal cord. LOA was the medial angle at the intersection between a line from the superior posterior margin at the cranial vertebral body of maximum OPLL to the top of OPLL with beak type, and a line from the lower posterior margin at the caudal vertebral body of the maximum OPLL to the top of OPLL with beak type. LOA 20°, LOA 25°, and LOA 30° compression was applied to the spinal cord in a preoperative model, the posterior decompressive model, and a model for the development of kyphosis.

Results

In a preoperative model, at more than LOA 20° compression, high stress distributions in the spinal cord were observed. In a posterior decompressive model, the stresses were lower than in the preoperative model. In the model for development of kyphosis, high-stress distributions were observed in the spinal cord at more than LOA 20° compression.

Conclusions

Posterior decompression was an effective operative method. However, when the preoperative LOA is more than 20°, it is very likely that symptoms will worsen. If operation is performed at greater than LOA 20°, then correction of kyphosis by fixation of instruments or by forward decompression should be considered.     

Airway complications in traumatic lower cervical spinal cord injury: A retrospective study

Objective

To investigate risk factors for pneumonia in patients with traumatic lower cervical spinal cord injury.

Design

Observational study, retrospective study.

Setting

Spinal cord unit in a maximum care hospital.

Methods

Thirty-seven patients with acute isolated traumatic spinal cord injury at levels C4–C8 and complete motor function injury (AIS A, B) treated from 2004 to 2010 met the criteria for inclusion in our retrospective analysis. The following parameters were considered: ventilation-specific parameters, re-intubation, creation of a tracheostomy, pneumonia, antibiotic treatment, and length of intensive care unit (ICU) stay and total hospitalization.

Results

Among the patients, 81% had primary invasive ventilation. In 78% of cases a tracheostomy was created; 3% of these cases were discharged with invasive ventilation and 28% with a tracheostomy without ventilation. Pneumonia according to Centers for Disease Control criteria occurred in 51% of cases within 21 ± 32 days of injury, and in 3% at a later date. The number of pre-existing conditions was significantly associated with pneumonia. Length of ICU stay was 25 ± 34 days, and average total hospital duration was 230 ± 144 days. Significant factors affecting the duration of ventilation were the number of pre-existing conditions and tetraplegia-specific complications.

Conclusions

Our results confirm that patients with traumatic lower cervical spinal cord injuries defined by lesion level and AIS constitute a homogeneous group. This group is characterized by a high rate of pneumonia during the first 4 weeks after injury. The number of pre-existing general conditions and spinal injury-specific comorbidities are the only risk factors identified for the development of pneumonia and/or duration of ventilation.     

Normal morphology, age-related changes and abnormal findings of the cervical spine. Part II: magnetic resonance imaging of over 1,200 asymptomatic subjects

Purpose

The aim of this study is to establish standard MRI values for the cervical spinal canal, dural tube, and spinal cord, to evaluate age-related changes in healthy subjects, and to assess the prevalence of abnormal findings in asymptomatic subjects.

Methods

The sagittal diameter of the spinal canal and the sagittal diameter and cross-sectional area of the dural tube and spinal cord were measured on MRIs of 1,211 healthy volunteers. These included at least 100 men and 100 women in each decade of life between the third (20s) and eighth (70s). Abnormal findings such as spinal cord compression and signal changes in the spinal cord were recorded.

Results

The sagittal diameter of the spinal canal was 11.2 ± 1.4 mm [mean ± standard deviation (SD)]/11.1 ± 1.4 mm (male/female) at the mid-C5 vertebral level, and 9.5 ± 1.8/9.6 ± 1.6 mm at the C5/6 disc level. The cross-sectional area of the spinal cord was 78.1 ± 9.4/74.4 ± 9.4 mm² at the mid-C5 level and 70.6 ± 11.7/68.9 ± 11.3 mm² at the C5/6 disc level. Both the sagittal diameter and the axial area of the dural tube and spinal cord tended to decrease with increasing age. This tendency was more marked at the level of the intervertebral discs than at the level of the vertebral bodies, especially at the C5/6 intervertebral disc level. The spinal cord occupation rate in the dural tube at the C5 vertebral body level averaged 58.3 ± 7.0%. Spinal cord compression was observed in 64 cases (5.3%) and a T2 high-signal change was observed in 28 cases (2.3%).

Conclusions

Using MRI data of 1,211 asymptomatic subjects, the standard values for the cervical spinal canal, dural tube, and spinal cord for healthy members of each sex and each decade of life and the age-related changes in these parameters were established. The relatively high prevalence of abnormal MRI findings of the cervical spine in asymptomatic individuals emphasizes the dangers of predicating operative decisions on diagnostic tests without precisely correlating these findings with clinical signs and symptoms.     

Ultrasonographic quantification of spinal cord and dural pulsations during cervical laminoplasty in patients with compressive myelopathy

Purpose

Pulsatile movements of the dura mater have been interpreted as a sign that the cord is free within the subarachnoid space, with no extrinsic compression. However, the association between restoration of pulsation and adequate decompression of the spinal cord has not been established. The present study investigated the relationship between the extent of spinal cord decompression and spinal cord and dural pulsations based on quantitative analysis of intraoperative ultrasonography (US).

Methods

Eighty-five consecutive patients (55 males, 30 females; mean age, 64 ± 13 years) who underwent cervical double-door laminoplasty to relieve compressive myelopathy were enrolled. Spinal cord decompression status was classified as: Type 1 (non-contact), the subarachnoid space was retained on the ventral side of the cord, Type 2 (contact and apart), the cord showed both contact with and separation from the anterior element of the cervical spine, or Type 3 (contact), the cord showed continuous contact with the anterior element of the cervical spine. Spinal cord and dura mater dynamics were quantitatively analyzed using automatic video-tracking software. Furthermore, the intensity of spinal and dural pulsation was compared with the recovery of motor function at 1 year after surgery as measured by increase in the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ).

Results

Spinal cord pulsation amplitude ranged from 0.01 to 0.84 mm (mean 0.30 ± 0.16 mm) and dural pulsation amplitude ranged from 0.01 to 0.38 mm (mean 0.14 ± 0.08 mm). Average spinal cord pulsation amplitude in Type 2 patients was significantly larger than that in the other groups, whereas, average dural pulsation amplitudes were similar for all three groups. There was a significant correlation between spinal cord and dural pulsation amplitudes in Type 1 patients, but not in Type 2 or Type 3 patients. Type 3 patients showed a particularly poor correlation between spinal cord and dural pulsations. Spinal cord pulsation amplitude was moderately correlated with the recovery of motor function evaluated by JOACMEQ.

Conclusion

The present results suggest that restoration of dural pulsation is not an adequate indicator of sufficient decompression of the spinal cord following a surgical procedure.     

Functional electrical stimulation post-spinal cord injury improves locomotion and increases afferent input into the central nervous system in rats

Background

Functional electrical stimulation (FES) has been found to be effective in restoring voluntary functions after spinal cord injury (SCI) and stroke. However, the central nervous system (CNS) changes that occur in as a result of this therapy are largely unknown.

Objective

To examine the effects of FES on the restoration of voluntary locomotor function of the CNS in a SCI rat model.

Methods

SCI rats were instrumented with chronic FES electrodes in the hindlimb muscles and were divided into two groups: (a) FES therapy and (b) sedentary. At day 7 post-SCI, the animals were assessed for locomotion performance by using a Basso, Beattie and Bresnahan (BBB) scale. They were then anesthetized for a terminal in vivo experiment. The lumbar spinal cord and somatosensory cortex were exposed and the instrumented muscles were stimulated electrically. Associated neurovascular responses in the CNS were recorded with an intrinsic optical imaging system.

Results

FES greatly improved locomotion recovery by day 7 post-SCI, as measured by BBB scores (P < 0.05): (a) FES 10 ± 2 and (b) controls 3 ± 1. Furthermore, the FES group showed a significant increase (P < 0.05) of neurovascular activation in the spinal cord and somatosensory cortex when the muscles were stimulated between 1 and 3 motor threshold (MT).

Conclusion

Hind limb rehabilitation with FES is an effective strategy to improve locomotion during the acute phase post-SCI. The results of this study indicate that after FES, the CNS preserves/acquires the capacity to respond to peripheral electrical stimulation.     

Modification of spasticity by transcutaneous spinal cord stimulation in individuals with incomplete spinal cord injury

Context/objective

To examine the effects of transcutaneous spinal cord stimulation (tSCS) on lower-limb spasticity.

Design

Interventional pilot study to produce preliminary data.

Setting

Department of Physical Medicine and Rehabilitation, Wilhelminenspital, Vienna, Austria.

Participants

Three subjects with chronic motor-incomplete spinal cord injury (SCI) who could walk ≥10 m.

Interventions

Two interconnected stimulating skin electrodes (Ø 5 cm) were placed paraspinally at the T11/T12 vertebral levels, and two rectangular electrodes (8 × 13 cm) on the abdomen for the reference. Biphasic 2 ms-width pulses were delivered at 50 Hz for 30 minutes at intensities producing paraesthesias but no motor responses in the lower limbs.

Outcome measures

The Wartenberg pendulum test and neurological recordings of surface-electromyography (EMG) were used to assess effects on exaggerated reflex excitability. Non-functional co-activation during volitional movement was evaluated. The timed 10-m walk test provided measures of clinical function.

Results

The index of spasticity derived from the pendulum test changed from 0.8 ± 0.4 pre- to 0.9 ± 0.3 post-stimulation, with an improvement in the subject with the lowest pre-stimulation index. Exaggerated reflex responsiveness was decreased after tSCS across all subjects, with the most profound effect on passive lower-limb movement (pre- to post-tSCS EMG ratio: 0.2 ± 0.1), as was non-functional co-activation during voluntary movement. Gait speed values increased in two subjects by 39%.

Conclusion

These preliminary results suggest that tSCS, similar to epidurally delivered stimulation, may be used for spasticity control, without negatively impacting residual motor control in incomplete SCI. Further study in a larger population is warranted.     

Curcumin modulates TLR4/NF-κB inflammatory signaling pathway following traumatic spinal cord injury in rats

Background

Curcumin, a polyphenolic compound extracted from the plant turmeric, has protective effects on spinal cord injury (SCI) through attenuation of inflammatory response. This study was designed to detect whether curcumin modulates toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) inflammatory signaling pathway in the injured rat spinal cord following SCI.

Methods

Adult male Sprague–Dawley rats were subjected to laminectomy at T8–T9 and compression with a vascular clip. There were three groups: (a) sham group; (b) SCI group; and (g) SCI + curcumin group. We measured TLR4 gene and protein expression by real-time polymerase chain reaction and western blot analysis; NF-κB activity by electrophoretic mobility shift assay, inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by wet/dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis.

Results

The results showed that SCI induced the up-regulation of TLR4, NF-κB, and inflammatory cytokines in the injured rat spinal cord. Treatment with curcumin following SCI markedly down-regulated the levels of these agents related to the TLR4/NF-κB inflammatory signaling pathway. Administration of curcumin also significantly ameliorated SCI induced hind limb locomotion deficits, spinal cord edema, and apoptosis.

Conclusions

Post-SCI curcumin administration attenuates the TLR4/NF-κB inflammatory signaling pathway in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome following SCI.     

Experiences with pins and rubber band traction in the treatment of proximal interphalangeal joint contracture

BACKGROUND:

Proximal interphalangeal joint (PIPJ) contracture is a difficult problem to treat regardless of etiology. Although numerous interventions have been recommended, published results are mediocre at best.

OBJECTIVE:

The authors describe their experience and results of using a modification of pins and rubber band traction (PRBT) – applying a dynamic extension apparatus to a contracted PIPJ using the constant traction force in a stretched rubber (elastic) band.

METHOD:

A retrospective review of patients treated with this method was performed, and the results are presented. The technique itself is described, and clinical photographs illustrate the method.

RESULTS:

Mean PIPJ flexion contracture before PRBT was 82° (range 60° to 110°). The full correction of eight contracted PIPJs in seven patients was achieved, in a mean of 17.8 days (range 14 to 31 days). At one month postremoval of PRBT, the mean PIPJ flexion contracture was 22.8° (range 0° to 46°).

DISCUSSION:

The method is compared with previously described methods of PIPJ contracture correction, whether surgical or splinting; the latter may be static, dynamic or a combination of the two. The results of previously published studies are discussed and compared with the method described.

CONCLUSION:

The present method is a powerful and effective simplification of a previously described method of correcting PIPJ contractures. This technique is simple, ‘low-tech’ and can be applied under local anesthetic; the authors believe it offers a useful adjunct to surgical release.     

Physical exercise improves arterial stiffness after spinal cord injury

Objective/background

Aortic pulse wave velocity (PWV), the gold-standard assessment of central arterial stiffness, has prognostic value for cardiovascular disease risk in able-bodied individuals. The aim of this study was to compare aortic PWV in athletes and non-athletes with spinal cord injury (SCI).

Design

Cross-sectional comparison.

Methods

Aortic PWV was assessed in 20 individuals with motor-complete, chronic SCI (C2–T5; 18 ± 8 years post-injury) using applanation tonometry at the carotid and femoral arterial sites. Ten elite hand-cyclists were matched for sex to 10 non-athletes; age and time since injury were comparable between the groups. Heart rate and discrete brachial blood pressure measurements were collected throughout testing.

Outcome measures

Aortic PWV, blood pressure, heart rate.

Results

Aortic PWV was significantly lower in athletes vs. non-athletes (6.9 ± 1.0 vs. 8.7 ± 2.5 m/second, P = 0.044). There were no significant between-group differences in resting supine mean arterial blood pressure (91 ± 19 vs. 81 ± 10 mmHg) and heart rate (60 ± 10 vs. 58 ± 6 b.p.m.).

Conclusion

Athletes with SCI exhibited improved central arterial stiffness compared to non-athletes, which is in agreement with the previous able-bodied literature. This finding implies that chronic exercise training may improve arterial health and potentially lower cardiovascular disease risk in the SCI population.     

Full-endoscopic cervical arcocristectomy for the treatment of spinal stenosis: results of a cadaver study

Purpose

Cervical spondylotic myelopathy is a multifactorial disease that is directly correlated by the degree of spinal stenosis. Surgery remains the best therapy. A posterior approach is often recommended in patients with multilevel dorsal cervical compression. Aim of the present experimental study was to evaluate the feasibility of a full-endoscopic arcocristectomy in a cadaver study.

Methods

We performed full-endoscopic arcocristectomy on ten formalin-fixed human cervical specimens. Before and after decompression we obtained high-resolution computerized tomography (CT) data to evaluate the diameter of the cervical spinal canal.

Results

Overall, surgery was possible on 55 segments in ten cadaver specimens. A mean increase of 4.1 mm (±1.2 mm) in the sagittal diameter of the cervical spinal canal could be achieved (p < 0.05, t test).

Conclusions

The full-endoscopic arcrocristectomy is feasible and achieves a sufficient decompression. This minimal invasive technique protects most of the dorsal structures and therefore probably preserves biomechanical functions, which has to be proven in future studies.     

Pre-procedural antibiotics for endoscopic urological procedures: Initial experience in individuals with spinal cord injury and asymptomatic bacteriuria

Objective

The objective of this study was to compare the safety, efficacy, quality-of-life impact, and costs of a single dose or a longer course of pre-procedural antibiotics prior to elective endoscopic urological procedures in individuals with spinal cord injury and disorders (SCI/D) and asymptomatic bacteriuria.

Design

A prospective observational study.

Setting

Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA.

Participants

Sixty persons with SCI/D and asymptomatic bacteriuria scheduled to undergo elective endoscopic urological procedures.

Interventions

A single pre-procedural dose of antibiotics vs. a 3–5-day course of pre-procedural antibiotics.

Outcome measures

Objective and subjective measures of health, costs, and quality of life.

Results

There were no significant differences in vital signs, leukocytosis, adverse events, and overall satisfaction in individuals who received short-course vs. long-course antibiotics. There was a significant decrease in antibiotic cost (33.1 ± 47.6 vs. 3.6 ± 6.1 US$, P = 0.01) for individuals in the short-course group. In addition, there was greater pre-procedural anxiety (18 vs. 0%, P < 0.05) for individuals who received long-course antibiotics.

Conclusion

SCI/D individuals with asymptomatic bacteriuria may be able to safely undergo most endoscopic urological procedures with a single dose of pre-procedural antibiotics. However, further research is required and even appropriate pre-procedural antibiotics may not prevent severe infections.     

Reliability of the sit-up test in individuals with spinal cord injury

Objective

To determine the day-to-day reliability of blood pressure responses during a sit-up test in individuals with a traumatic spinal cord injury (SCI).

Design

Within-subject, repeated measures design.

Setting

Community outpatient assessments at a research laboratory at the University of British Columbia.

Participants

Five men and three women with traumatic SCI (age: 31 ± 6 years; C4-T11; American Spinal Injury Association Impairment Scale A-B; 1–17 years post-injury).

Outcome measure

Maximum change in systolic (ΔSBP) and diastolic (ΔDBP) blood pressure upon passively moving from a supine to seated position.

Results

The average values for ΔSBP were –11 ± 13 mmHg (range –38 to 3 mmHg) for visit 1, and −12 ± 8 mmHg (range −26 to −1 mmHg) for visit 2. The average values for ΔDBP were −9 ± 8 mmHg (range -21 to 0 mmHg) for visit 1, and –13 ± 8 mmHg (range –29 to –3 mmHg) for visit 2. The ΔSBP demonstrated substantial reliability with an intraclass correlation coefficient of 0.79 (P = 0.006; 95% CI 0.250–0.953), while the ΔDBP demonstrated almost perfect reliability with an intraclass correlation coefficient of 0.92 (P < 0.001; 95% CI 0.645–0.983). The smallest detectable differences in ΔSBP and ΔDBP were 7 mmHg and 6 mmHg, respectively.

Conclusion

Blood pressure responses to the sit-up test are reliable in individuals with SCI, which supports its implementation as a practical bedside assessment for orthostatic hypotension in this at risk population.     

Whole-body Vibration at Thoracic Resonance Induces Sustained Pain and Widespread Cervical Neuroinflammation in the Rat

Background

Whole-body vibration (WBV) is associated with back and neck pain in military personnel and civilians. However, the role of vibration frequency and the physiological mechanisms involved in pain symptoms are unknown.

Questions/purposes

This study asked the following questions: (1) What is the resonance frequency of the rat spine for WBV along the spinal axis, and how does frequency of WBV alter the extent of spinal compression/extension? (2) Does a single WBV exposure at resonance induce pain that is sustained? (3) Does WBV at resonance alter the protein kinase C epsilon (PKCε) response in the dorsal root ganglia (DRG)? (4) Does WBV at resonance alter expression of calcitonin gene-related peptide (CGRP) in the spinal dorsal horn? (5) Does WBV at resonance alter the spinal neuroimmune responses that regulate pain?

Methods

Resonance of the rat (410 ± 34 g, n = 9) was measured by imposing WBV at frequencies from 3 to 15 Hz. Separate groups (317 ± 20 g, n = 10/treatment) underwent WBV at resonance (8 Hz) or at a nonresonant frequency (15 Hz). Behavioral sensitivity was assessed throughout to measure pain, and PKCε in the DRG was quantified as well as spinal CGRP, glial activation, and cytokine levels at Day 14.

Results

Accelerometer-based thoracic transmissibility peaks at 8 Hz (1.86 ± 0.19) and 9 Hz (1.95 ± 0.19, mean difference [MD] 0.290 ± 0.266, p < 0.03), whereas the video-based thoracic transmissibility peaks at 8 Hz (1.90 ± 0.27), 9 Hz (2.07 ± 0.20), and 10 Hz (1.80 ± 0.25, MD 0.359 ± 0.284, p < 0.01). WBV at 8 Hz produces more cervical extension (0.745 ± 0.582 mm, MD 0.242 ± 0.214, p < 0.03) and compression (0.870 ± 0.676 mm, MD 0.326 ± 0.261, p < 0.02) than 15 Hz (extension, 0.503 ± 0.279 mm; compression, 0.544 ± 0.400 mm). Pain is longer lasting (through Day 14) and more robust (p < 0.01) after WBV at the resonant frequency (8 Hz) compared with 15 Hz WBV. PKCε in the nociceptors of the DRG increases according to the severity of WBV with greatest increases after 8 Hz WBV (p < 0.03). However, spinal CGRP, cytokines, and glial activation are only evident after painful WBV at resonance.

Conclusions

WBV at resonance produces long-lasting pain and widespread activation of a host of nociceptive and neuroimmune responses as compared with WBV at a nonresonance condition. Based on this work, future investigations into the temporal and regional neuroimmune response to resonant WBV in both genders would be useful.

Clinical Relevance

Although WBV is a major issue affecting the military population, there is little insight about its mechanisms of injury and pain. The neuroimmune responses produced by WBV are similar to other pain states, suggesting that pain from WBV may be mediated by similar mechanisms as other neuropathic pain conditions. This mechanistic insight suggests WBV-induced injury and pain may be tempered by antiinflammatory intervention.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-015-4315-9) contains supplementary material, which is available to authorized users.     

Cardiac arrhythmias the first month after acute traumatic spinal cord injury

Objective

Cardiovascular complications including cardiac arrest and arrhythmias remain a clinical challenge in the management of acute traumatic spinal cord injury (SCI). Still, there is a lack of knowledge regarding the characteristics of arrhythmias in patients with acute traumatic SCI. The aim of this prospective observational study was to investigate the occurrence of cardiac arrhythmias and cardiac arrests in patients with acute traumatic SCI.

Methods

As early as possible after SCI 24-hour Holter monitoring was performed. Additional Holter recordings were performed 1, 2, 3, and 4 weeks after SCI. Furthermore, 12-lead electrocardiograms (ECGs) were obtained shortly after SCI and at 4 weeks.

Results

Thirty patients were included. Bradycardia (heart rate (HR) <50 b.p.m.) was present in 17–35% of the patients with cervical (C1–C8) SCI (n = 24) within the first 14 days. In the following 14 days, the occurrence was 22–32%. Bradycardia in the thoracic (Th1–Th12) SCI group (n = 6) was present in 17–33% during the observation period. The differences between the two groups were not statistically significant. The mean minimum HR was significantly lower in the cervical group compared with the thoracic group both on 12-lead ECGs obtained shortly after SCI (P = 0.030) and at 4 weeks (P = 0.041).

Conclusion

Many patients with cervical SCI experience arrhythmias such as bradycardia, sinus node arrest, supraventricular tachycardia, and more rarely cardiac arrest the first month after SCI. Apart from sinus node arrests and limited bradycardia, no arrhythmias were seen in patients with thoracic SCI. Standard 12-lead ECGs will often miss the high prevalence these arrhythmias have.     

Evaluation of bone mineral loss in patients with chronic traumatic spinal cord injury in Iran

Objectives

We described the associations between demographic and injury-related factors on bone mineral density (BMD) of the spine and the hip among adult patients with chronic spinal cord injury (SCI).

Design

BMD in spinal and femoral bone sites were assessed. Multivariate analysis was performed to evaluate the relationship between anthropometric and injury-related factors with BMD. Serum level and amount of dietary intake of calcium, phosphor, and 25-hydroxy vitamin D were measured.

Setting

A referral tertiary rehabilitation center in Iran.

Participants

Patients with SCI who had no previous history of endocrine disorders and were not on specific medications entered the investigation. Those with non-traumatic SCI, pregnant, or with substance dependency were excluded as well.

Interventions

No interventions were applied.

Main study outcome measures

Dual X-ray absorptiometry was performed to estimate BMD. Body mass index was positively associated with higher femoral (P < 0.01, r = 0.56) and hip (P < 0.0001, r = 0.82) BMD only in female participants. The high prevalence of vitamin D deficiency (60%) was noticeable.

Results

Older male patients revealed lower BMD only in spinal vertebrae (P < 0.02, r = −0.21). A significant higher BMD loss in lumbar vertebras in male patients with complete spinal cord lesion (P < 0.009) was detected. Spinal reduction of BMD was more severe when the level of injury was above T6 (P < 0.02).

Conclusion

Along with the clarification of age, gender, post injury duration, and the other factors'' effect on the BMD in the SCI patients, here we have also shown the noticeable prevalence of the 25-hydoxy vitamin D deficiency in these patients which needs attention.     

Relationship between nutritional status and mortality during the first 2 weeks following treatment for cervical spinal cord injury

Background

The effects of nutrition on the mortality of cervical spinal cord injury (CSCI) patients, unlike other risk factors, are poorly documented.

Objective

The relationship between dynamic nutritional status change and mortality in patients treated for CSCI was investigated.

Methods

A retrospective study of 128 patients treated for CSCI at the Beijing Army General Hospital was conducted between March 2006 and March 2011. Age, spinal segment damage (C1–C4 and C5–C7), American Spinal Injury Association (ASIA) grade, hospitalization duration, ventilatory support, and serum protein levels (total protein, serum albumin, and serum prealbumin) were assessed during early-stage treatment (<14 days). Survival (n = 109) and death (n = 19) groups were assigned by final disposition of acute hospitalization.

Results

The survival group evidenced no significant changes in total protein levels during early-stage treatment, although these values decreased in the death group. Serum prealbumin and albumin levels significantly declined by treatment day 1 and throughout treatment (P < 0.05). By days 3–5 and thereafter, significantly lower serum proteins were observed in the death group compared to the survival group (P < 0.05). Multiple segment damage, elevated ASIA, and longer ventilatory support duration were more prevalent in the death group (P < 0.001)

Conclusions

Lower serum protein levels associated with hypoproteinemia and malnutrition are significant indicators of mortality in patients with CSCI, along with higher levels of lesions, elevated ASIA grades, and longer ventilatory support durations. Early corrective action for hypoalbuminemia may help to reduce mortality in patients with CSCI.     

Assessment of passive knee stiffness and viscosity in individuals with spinal cord injury using pendulum test

Objective

Stiffness and viscosity represent passive resistances to joint motion related with the structural properties of the joint tissue and of the musculotendinous complex. Both parameters can be affected in patients with spinal cord injury (SCI). The purpose of this study was to measure passive knee stiffness and viscosity in patients with SCI with paraplegia and healthy subjects using Wartenberg pendulum test.

Design

Non-experimental, cross-sectional, case–control design.

Setting

An outpatient physical therapy clinic, University of social welfare and Rehabilitation Science, Iran.

Patients

A sample of convenience sample of 30 subjects participated in the study. Subjects were categorized into two groups: individuals with paraplegic SCI (n = 15, age: 34.60 ± 9.18 years) and 15 able-bodied individuals as control group (n = 15, age: 30.66 ± 11.13 years).

Interventions

Not applicable.

Main measures

Passive pendulum test of Wartenberg was used to measure passive viscous-elastic parameters of the knee (stiffness, viscosity) in all subjects.

Results

Statistical analysis (independent t-test) revealed significant difference in the joint stiffness between healthy subjects and those with paraplegic SCI (P = 0.01). However, no significant difference was found in the viscosity between two groups (P = 0.17). Except for first peak flexion angle, all other displacement kinematic parameters exhibited no statistically significant difference between normal subjects and subjects with SCI.

Conclusions

Patients with SCI have significantly greater joint stiffness compared to able-bodied subjects.     

Longitudinal relationship between wheelchair exercise capacity and life satisfaction in patients with spinal cord injury: A cohort study in the Netherlands

Objective

To examine the relationship between wheelchair exercise capacity and life satisfaction in persons with spinal cord injury from the start of active inpatient rehabilitation up to 5 years after discharge.

Design

Prospective cohort study.

Subjects

Persons with spinal cord injury, aged 18–65 years, and wheelchair dependent at least for long distances.

Method

Measurements at the start of active rehabilitation, after 3 months, at discharge from inpatient rehabilitation, and 1 and 5 years after discharge. A peak wheelchair exercise test was performed to record peak oxygen uptake (VO_2peak) and peak power output (PO_peak). Life satisfaction was measured as current life satisfaction and change of life satisfaction in comparison with life after spinal cord injury. Relationships between (changes in) exercise capacity and (changes in) life satisfaction were analyzed random coefficient analysis, corrected for possible confounders (age, gender, level of lesion, functional status, secondary impairments, pain, and sports activity) if necessary.

Results

Of 225 persons included, 130 attended two or more peak exercise tests, who were include in the analyses. Mean age at start was 39 years, 75% were male, 73% had paraplegia, and 76% had a traumatic lesion. Mean PO_peak increased during the study from 32.9 to 55.9 Watts, mean VO_2peak from 1.02  to 1.38 l/minute, and mean life satisfaction from 5.7 to 7.8. An increase of PO_peak with 10 W was associated with a 0.3-point increase of life satisfaction (P = 0.01). An increase of VO_2peak with 0.1 l/minute was associated with a 0.1-point increase of life satisfaction (P = 0.049).

Conclusion

High(er) wheelchair exercise capacity is related to high(er) life satisfaction in spinal cord injury patients.