SPINAL CORD INJURY

Bladder Dysfunction in Multiple Sclerosis

Multiple sclerosis (MS) involves focal neural demyelmation with relative sparing of axons and resultant impaired nerve conduction. Demyelination commonly affects the posterolateral columns of the spinal cord, with the majority of patients having cervi cal cord involvement. Forty percent of patients have lumbar cord involvement and 18 percent have sacral cord involvement. The cerebral cortex and midbram may also be affected. Lesions in any of these areas can affect voiding function.

Renal tract ultrasonography for routine surveillance in spinal cord injury patients

OBJECTIVES

To report the efficacy of a urinary tract surveillance regime based on annual renal tract ultrasound without routine use of urodynamic testing (UDS) in our population of spinal cord injury (SCI) patients managed with clean intermittent catheterization (CIC).

METHODS

Data was gathered retrospectively from the records of 48 SCI patients (40 males and 8 females). After establishing a safe system with initial urodynamics, renal ultrasonography was done annually for surveillance. UDS was repeated only when patients presented with new symptoms. The primary endpoint was the report of ultrasound findings at last follow-up. Findings of dilatation, calculi, scarring, and reflux were noted.

RESULTS

Mean follow-up was 6.8 years. By final follow-up, pelvicaliectasis was present in 4 (8%) subjects. Mild-moderate hydronephrosis was present in 3 (6%) subjects: 1 stable and 2 (4%) new compared to initial assessment. No severe cases of hydronephrosis were noted. Six (13%) subjects had renal/ureteral calculi. No new cases of renal cortical scarring or thinning were noted. One (2%) subject had high-grade reflux on UDS secondary to a double J stent.

CONCLUSIONS

Data relating to the efficacy of sequential surveillance studies in SCI patients are scarce, thus there is great variability in urologic surveillance methods worldwide. Upper tract abnormalities detected in our patients were early consequences of acute obstruction rather than late manifestations of detrusor changes and could not have been prevented with more regular urodyamic testing. These results suggest that annual ultrasound monitoring without routine urodynamic testing is an effective surveillance strategy in SCI patients managed with CIC.

Usefulness of Dynamic Urethral Resistance Relation (DURR) measurement for differential diagnosis between static and dynamic urinary obstruction in male spinal cord injury patients

OBJECTIVE

To study the validity of Dynamic Urethral Resistance Relation (DURR) for differential diagnosis between static and dynamic urinay obstruction in male spinal cord injury patients.

METHODS

A case-control study was conducted. The case group consisted of 24 male patients with spinal cord injury, aged under 40 years, with detrusor-periurethral sphincter dyssynergia and bladder outlet obstruction (BOO) according to the urethral resistance factor (URA). The control group consisted of 24 male patients with no neurological lesions, aged over 49 years, diagnosis of benign prostatic hyperplasia (BPH) and BOO according to Schäfer's minimum urethral opening pressure (Pmuo) and the URA. A pressure/flow study was performed in both groups, and the DURR was recorded graphically.

RESULTS

Both groups showed significantly different DURR characteristics with respect to the number of spikes (higher in the case group), the intensity of the first three spikes and the maximum duration of the spikes (significantly longer in the case group). The patients in the case group had a DURR characterized by at least three spikes, located throughout the whole voiding cycle (pattern A). The patients in the control group had a DURR mainly characterized by a spike located at the start of micturition and a maximum second spike located at the end of micturition (pattern B).

CONCLUSIONS

Pattern A showed a sensitivity with respect to the dynamic obstruction of 79% and a specificity of 100%. The sensitivity of pattern B with respect to the diagnosis of static obstruction was 71% and the specificity was 100%.

Morphological changes of the neural cells after blast injury of spinal cord and neuroprotective effects of sodium beta-aescinate in rabbits

OBJECTIVE

Explosive blast neurotrauma is becoming more and more common not only in the military population but also in civilian life due to the ever-present threat of terrorism and accidents. However, little attention has been offered to the studies associated with blast wave-induced spinal cord injury in the literatures. The purpose of this study is to report a rabbit model of explosive blast injury to the spinal cord, to investigate the histological changes, focusing especially on apoptosis, and to reveal whether beta-aescinate (SA) has the neuroprotective effects against the blast injury.

METHODS

Adult male New Zealand white rabbits were randomly divided into sham group, experimental group and SA group. All rabbits except the sham group were exposed to the detonation, produced by the blast tube containing 0.7 g cyclotrimethylene trinitramine, with the mean peak overpressure of 50.4 MP focused on the dorsal surface of T9-T10 level. After evaluation of the neurologic function, spinal cord of the rabbits was removed at 8 h, 1, 3, 7, 14 or 30 days and the H&E staining, EM examination, DNA gel electrophoresis and TUNEL were progressively performed.

RESULTS

The study demonstrated the occurrence of both necrosis and apoptosis at the lesion site. Moreover, the SA therapy could not only improve the neurologic outcomes (P<0.05) but also reduce the loss of motoneuron and TUNEL-positive rate (P<0.05).

CONCLUSIONS

In the rabbit model of explosive blast injury to the spinal cord, the coexistent apoptotic and necrotic changes in cells was confirmed and the SA had neuroprotective effects to the blast injury of the spinal cord in rabbits. This is the first report in which the histological characteristics and drug treatment of the blast injury to the spinal cord is demonstrated.

Investigation of the dose-dependent neuroprotective effects of agmatine in experimental spinal cord injury: a prospective randomized and placebo-control trial

OBJECT

No definitive treatment for spinal cord injuries (SCIs) exists, and more research is required. The use of agmatine [4-(aminobutyl)-guanidine-NH2-CH2-CH2-CH2-CH2-NH-C(-NH2)(=NH)], a guanidinium compound formed by decarboxylation of L-arginine by arginine decarboxylase, is a neurotransmitter-neuromodulator with both N-methyl-D-aspartate receptor (NMDAR)-antagonizing and nitric oxide synthase (NOS)-inhibiting activities. The purpose of this study was to demonstrate the dose-dependent activity of agmatine, an inducible NOS (iNOS) inhibitor and selective NMDAR antagonist, on biochemical and functional recovery in an experimental rat SCI model.

METHODS

This study involved 40 Wistar albino male rats. The rats were subjected to sleep-awake cycles for 7 days before surgery. In each group, general anesthesia was induced by a 60-mg/kg ketamine injection. For the surgical SCI model, a Yaşargil aneurysm clip was placed in the spinal cord. The study was conducted in the following four main groups: Group I (control group) laminectomy only; Group II, trauma-only group and SCI; Group III, laminectomy, SCI and agmatine 50 mg/kg for 10 days; and Group IV, laminectomy, SCI, and agmatine 100 mg/kg for 10 days. On Day 1, no statistical difference was observed in any group (p < 0.005, analysis of variance [ANOVA] and the Fisher protected least significant difference [PLSD]). On Day 2, no statistical difference was noted among Groups II, III, and IV (p = 0.27, p = 0.42, and p = 0.76, respectively; ANOVA and Fisher PLSD). Beginning on Day 3, recovery in Groups III and IV differed significantly from that in Group II (p < 0.005, ANOVA and Fisher PLSD), and a statistically significant difference between Groups III and IV was observed, which also was present on Days 5, 7, and 10 (p = 0.003, p = 0.0024, and p = 0.0036, respectively; ANOVA and Fisher PLSD). Several observations were noteworthy: motor function scores were reduced significantly in the spinal cord-injured rats compared with the controls (p < 0.005); on Day 1, the agreement of motor function scores in rats in each SCI group indicated that the traumatic event had been replicated equally across all groups (p = 0.59, p = 0.59, and p = 0.28); a statistically significant difference in motor function scores developed on Day 3 between the rats subjected to trauma alone (Group II) and those treated with agmatine (Groups III and IV) (p < 0.005); and no statistically significant intergroup difference in motor function existed at any postinjury interval between the 50- and 100-mg/kg/day agmatine-treated rats (p > 0.005).

CONCLUSIONS

Agmatine administration following SCI was shown to reduce NO levels significantly. No statistically significant intergroup difference in the reduction of NO levels was found between rats treated with 50- and 100-mg/kg/day doses of agmatine. Administration of a 100-mg/kg/day dose of agmatine reduced the NO levels to those measured in controls. The authors conclude that with additional studies into the role of agmatine, this drug may be helpful in the treatment of patients with SCIs.

Understanding detrusor sphincter dyssynergia—significance of chronology

OBJECTIVES

To evaluate in patients with spinal cord injury (SCI) and detrusor sphincter dyssynergia (DSD) whether the onset of external urethral sphincter (EUS) contractions precedes or follows the onset of bladder contractions and to address the issue of potential therapeutic approaches based on the understanding of DSD chronology.

METHODS

A retrospective review of video-urodynamic recordings of patients with SCI that demonstrated both untreated neurogenic overactive bladder and DSD, from January 2002 to December 2003, was performed. Delay A was defined as the period between the onset of an EUS pressure increase and the onset of a bladder pressure increase and delay B as the period between the onset of a urethral sphincter pressure increase and the moment at which the bladder pressure increase reached 10 cm H2O greater than the baseline value.

RESULTS

Twenty patients with traumatic SCI matched all inclusion criteria. Delay A was positive (EUS contracted first) in 16 (80%) of 20 patients. The mean time for delay A was 2.2 seconds. A positive association was found among a positive delay A, the completeness of the spinal lesion, and continuous DSD type. Delay B was positive in all 20 patients (100%). The mean time for delay B was 7.6 seconds.

CONCLUSIONS

In most patients with SCI and DSD, the EUS contraction started before the onset of the bladder contraction. Additionally, in all patients with SCI, the EUS contraction started before the critical part of the bladder contraction. A pathophysiologic hypothesis for such chronology is discussed. A potential therapeutic application would be to use urethral sphincter activity to trigger inhibition of bladder contractions (conditional neuromodulation) and treat the neurogenic overactive bladder.

Caspase inhibitors as neuroprotective agents

Apoptotic neuronal cell death has been demonstrated to occur in the central nervous system (CNS), following both acute injury and during chronic neurodegenerative conditions. Currently, the majority of experimental evidence for a role of caspases in CNS damage has been established following acute neuronal insults, including ischaemic stroke, traumatic brain injury and spinal cord injury. In vitro and in vivo models have been used to demonstrate caspase activation, and treatment with available caspase inhibitors can provide significant protection. Overall, acute neuronal injury represents a major unmet medical need and caspase inhibitors may be an attractive approach to preserve neuronal function by extending the therapeutic window and providing long-term neuroprotection. Currently, several inhibitors are in preclinical drug development and this review summarises recent advances in the development of novel caspase inhibitors for the treatment of acute neuronal injury.

Effect of the trauma mechanism on the bladder-sphincteric behavior after spinal cord injury

STUDY DESIGN

Retrospective study.

OBJECTIVE

To determine if spinal cord injuries due to gunshot wounds (GW) are associated with different bladder and sphincteric behavior compared to other trauma mechanisms.

SETTING

Spinal injury center, Brazilian university hospital.

METHODS

We retrospectively evaluated the records and urodynamic studies of 71 patients with spinal cord injury (SCI) referred to the Brazilian National Spinal Cord Injury Center over the year 2000, and compared the bladder-sphincteric pattern of patients with injuries caused by GW with those caused by other trauma mechanisms.

RESULTS

The causes of SCI were (1) gunshot wounds (31 patients: 43.7%); (2) motor vehicle accidents (16 patients: 22.5%); (3) falls (16 patients: 22.5%) and (4) diving (three patients: 4.2%). In five patients (7.1%) the causes were unusual trauma mechanisms like stab wound (one patient) and direct trauma in vigorous sports (two patients) or fights (two patients). The levels of the injuries were cervical in 22 patients (31.0%), thoracic in 39 (54.9%) and lumbar in 10 (14.1%). Detrusor hyperreflexia with detrusor-sphincter dyssynergia was present in 65% of the patients overall and in 76% of the thoracic gunshot wounded. Areflexia occurred in 20% of the patients and in 16% of thoracic injured patients with gunshots. Detrusor hyperreflexia with detrusor-sphincter dyssynergia was the pattern encountered in 50% of the individuals suffering from SCI because of other mechanisms and areflexia was present in 35.8%. There was no statistical difference between GW patients and other mechanisms according to bladder and sphincter functions.

CONCLUSIONS

There was a substantial overlap of bladder and sphincteric behaviors between patients with different levels of spinal injuries, but the trauma mechanism was not important to determine the bladder and sphincteric functions.

Non-surgical management of spinal cord injury

Spinal cord injury remains a devastating neurological condition with limited therapeutic opportunities. Since decompressive surgery and high-dose methylprednisolone have limited utility for most patients, spinal cord injury clearly represents a major medical challenge. Experimental evidence has suggested that secondary cellular injury processes may be a realistic target for therapeutic intervention with the goal of inhibiting the progression of detrimental changes that normally follows traumatic injury to the cord. Preventing or reducing this delayed cellular injury may alone improve neurological recovery or facilitate future regenerative approaches to the injured cord. This review summarises recent advances in the development of pharmacological agents targeting the acute phase of spinal cord injury as well as potential strategies to facilitate regeneration of the spinal cord.

Coadministration of methylprednisolone with hypertonic saline solution improves overall neurological function and survival rates in a chronic model of spinal cord injury

OBJECTIVE

We previously demonstrated that administration of 7.5% hypertonic saline (HS) significantly improved spinal cord blood flow and neurological outcomes after spinal cord injury. The aim of this study was to determine whether hypertonicity would enhance the effects of methylprednisolone (MP), further improving neurological function.

METHODS

Rat spinal cords were compressed for 10 minutes with 50 g of weight, and neurological function was assessed for 28 days, using the Basso-Beattie-Bresnahan locomotor rating scale. The control group received an intravenous injection of isotonic saline (IS) (5 ml/kg). Group 1 received an intravenous injection of 7.5% HS (5 ml/kg). Group 2 received an intravenous injection of MP (30 mg/kg) and IS (5 ml/kg). Group 3 received an intravenous injection of MP (30 mg/kg) administered with 7.5% HS (5 ml/kg).

RESULTS

At 24 hours after spinal cord injury, the combination of MP plus HS provided significant (P < 0.01) neurological improvements, compared with all other treatment groups. At 10 days after injury, the animals that had received MP plus HS exhibited significantly (P < 0.01) higher Basso-Beattie-Bresnahan scores, compared with the MP plus IS and control groups. The median survival time was significantly (P < 0.01) increased for the MP plus HS group (28 d), compared with the MP plus IS group (16 d). Because of the dramatic decrease in survival rates at 28 days after injury, there was a significant (P < 0.01) difference in neurological function only between the MP plus HS group and the control group.

CONCLUSION

The results indicate that the administration of HS may enhance the delivery of MP and prevent immunosuppression, leading to improvements in overall neurological function and survival rates after spinal cord injury.

Randomized trial of sildenafil for the treatment of erectile dysfunction in spinal cord injury. Sildenafil Study Group

Erectile dysfunction is a common complication of spinal cord injury. This double-blind, placebo-controlled, two-way crossover study assessed the efficacy and safety of oral sildenafil in men with erectile dysfunction caused by traumatic spinal cord injury. A total of 178 men (mean age, 38 years) received placebo or sildenafil 1 hour before sexual activity for 6 weeks; after a 2-week washout period, the men received the alternate treatment for 6 weeks. The 50-mg starting dose could be adjusted to 100 or 25 mg based on efficacy and tolerability. Efficacy was assessed by using global efficacy questions, the International Index of Erectile Function (IIEF), and a patient log of erectile activity. Of 143 men with residual erectile function at baseline, 111 (78%) reported improved erections and preferred sildenafil to placebo. For all men (including those who reported no residual erectile function at baseline), 127 of 168 (76%) reported improved erections and preferred sildenafil to placebo. For all men, 132 of 166 (80%) reported that sildenafil improved sexual intercourse compared with 17 of 166 men (10%) reporting improvement with placebo. IIEF questions assessing the ability to achieve and maintain erections and satisfaction with sexual intercourse demonstrated significant improvement with sildenafil. Sildenafil was well tolerated, with a low rate of discontinuation because of treatment-related adverse events (2% vs 1% for placebo). Oral sildenafil is an effective and well-tolerated treatment for erectile dysfunction caused by spinal cord injury.