Autonomic dysreflexia and its urological implications: a review

Autonomic dysreflexia in spinal cord injury

Autonomic dysreflexia is a relatively common condition in people who have a spinal cord injury above the level of T6. It is a potentially life-threatening; without timely and effective treatment, it can have deleterious cardiophysiological and systemic consequences. It is therefore imperative for medical professionals to have a clear understanding of its acute management, and be prepared to provide support and education to those caring for at-risk patients. In this paper we provide practical guidance and supporting evidence regarding the management of autonomic dysreflexia in adults with spinal cord injury.

Medical emergency: rash, headache and spinal cord injury

A 49-year-old consultant medical oncologist, with a medical history of complete T5 spinal cord injury (March 1992) and long-term paralysis from the chest down, presented with shingles affecting the T7 dermatome. He also had a dull frontal headache, a feeling of agitation and increased blood pressure of 135/90 on a home blood pressure machine (higher than his usual blood pressure of 90/70). Having been taught about autonomic dysreflexia at the time of his initial spinal cord injury, he self-diagnosed autonomic dysreflexia caused by the noxious stimulus of shingles below his level of spinal cord injury. He self-administered a nifedipine 5 mg sublingual capsule to decrease his blood pressure before urgently seeing his general practitioner. Treatment of the shingles with acyclovir and analgesia successfully managed the problem and avoided hospital admission. This case highlights key aspects in treating autonomic dysreflexia and the value of doctor-patient partnership in doing so.

Muscle invasive bladder cancer presenting as recurrent autonomic dysreflexia - a wolf in wolf's clothing

Context: Autonomic dysreflexia is a potentially lethal condition experienced by spinal cord injury (SCI) patients. It has a wide range of causes, most of which are genitourinary in nature. However, there has been no documented case of primary bladder cancer as a trigger for recurrent autonomic dysreflexia. Findings: We present a case of a 51-year-old spinal cord injury patient with multiple presentations of autonomic dysreflexia. Work up revealed locally invasive bladder cancer, and following definitive surgery, his symptoms were alleviated. Conclusions: In SCI patients with recurrent AD, comprehensive work up with involvement of a specialized Urologist is required as AD may be the only presenting symptom of a serious underlying medical condition.

Autonomic dysreflexia after spinal cord injury: Systemic pathophysiology and methods of management

Traumatic spinal cord injury (SCI) has widespread physiological effects beyond the disruption of sensory and motor function, notably the loss of normal autonomic and cardiovascular control. Injury at or above the sixth thoracic spinal cord segment segregates critical spinal sympathetic neurons from supraspinal modulation which can result in a syndrome known as autonomic dysreflexia (AD). AD is defined as episodic hypertension and concomitant baroreflex-mediated bradycardia initiated by unmodulated sympathetic reflexes in the decentralized cord. This condition is often triggered by noxious yet unperceived visceral or somatic stimuli below the injury level and if severe enough can require immediate medical attention. Herein, we review the pathophysiological mechanisms germane to the development of AD, including maladaptive plasticity of neural circuits mediating abnormal sympathetic reflexes and hypersensitization of peripheral vasculature that collectively contribute to abnormal hemodynamics after SCI. Further, we discuss the systemic effects of recurrent AD and pharmacological treatments used to manage such episodes. Contemporary research avenues are then presented to better understand the relative contributions of underlying mechanisms and to elucidate the effects of recurring AD on cardiovascular and immune functions for developing more targeted and effective treatments to attenuate the development of this insidious syndrome following high-level SCI.

Autonomic hyperreflexia after spinal cord injury managed successfully with intravenous lidocaine: a case report

Background

Some paraplegic patients may wish undergo some surgical procedures, like urological procedures, without anesthesia. However, these patients can develop autonomic hyperreflexia if cystoscopy is performed without anesthesia.

Case presentation

We present a case of severe autonomic hyperreflexia in a 44-year-old male with spinal cord injury at the level of T4 during urologic procedure under sedation and analgesia successfully treated with intravenous lidocaine.

Conclusions

This case illustrates that patients with spinal cord injuries are likely to develop autonomic hyperreflexia during urological procedures performed without anesthesia. Health professionals should educate spinal cord injury patients regarding risks of this serious condition and be aware to prevent and manage autonomic hyperreflexia. In an acute episode, nifedipine, nitrates and captopril are the most commonly used and recommended agents. To our knowledge, this is the first case report of severe autonomic hyperreflexia treated successfully with intravenous lidocaine.

Intravesical Botulinum Toxin for Persistent Autonomic Dysreflexia in a Pediatric Patient

Introduction. We present a novel case of persistent autonomic dysreflexia in a pediatric spinal cord injury patient treated successfully with intravesical botulinum toxin. Study Design. A retrospective chart review of one patient seen at the Children's Hospital of Wisconsin from 2006 to 2012 was performed. Results. A pediatric spinal cord injury patient with known neurogenic bladder presented with severe hypertension consistent with autonomic dysreflexia. His symptoms and hypertension did not improve with conservative measures, and he necessitated ICU admission and antihypertensive drips. He was taken to the operating room for intravesical botulinum toxin for refractory bladder spasms. Following this, his symptoms abated, and he was weaned off IV antihypertensives and returned to his baseline state. His symptoms were improved for greater than six months. Conclusions. There are few treatment options for the management of refractory autonomic dysreflexia. Intravesical botulinum toxin has never been reported for this use. Dedicated research is warranted to assess its efficacy, as it was used successfully to abort autonomic dysreflexia in this patient.

Successful pregnancy in a woman with paraplegia

Pregnancy is a rare occurrence in patients suffering from spinal cord injury (SCI). Pregnancy in these patients presents unique challenges to obstetric care providers, who need to become familiar with the general principles of care in this setting. SCI alters the function of multiple organ systems and chronic medical conditions are common in this patient population. Certain medical complications such as urinary tract infections and autonomic hyper-reflexia, or autonomic dysreflexia, are expectable and can be managed successfully. A multidisciplinary team should care for delivery in these patients. The authors present a case of a pregnancy in a paraplegic woman whose lesion was at the level of T4. She received epidural analgesia and had a caesarian section. From this case, the authors aim to point out the specific concerns of the management of pregnancy and delivery in this setting emphasising the importance of a multidisciplinary team, specially obstetricians and anaesthetists.

Urodynamic Management of Neurogenic Bladder in Spinal Cord Injury

BACKGROUND

A spinal cord injury is devastating and produces profound changes in the life style of the individual and his family. It is difficult to predict bladder and sphincter behaviour on the basis of clinical somatic neurological deficits.

METHODS

A prospective study of 100 spinal cord injury patients was conducted to establish a bladder management protocol. The urodynamic variables were assessed frequently. Clean Intermittent Catheterization (CIC) along with antimuscarinic drugs was instituted and response monitored. Nonresponders were offered Intradetrusor Botulinum toxin.

RESULT

Spinal shock lasted for upto six months and only 8% could be converted to CIC during the acute phase. A total of 82% patients underwent three to four urodynamic studies which revealed an increase in cystometric capacity and a decrease in the maximum detrusor pressures. This lowered the incidence of incontinence episodes and prevented upper urinary tract damage. Botulinum toxin provided only temporary relief.

CONCLUSION

Aggressive management of neurogenic bladder (NB) dysfunction is a crucial component of the rehabilitation programme for spinal cord injury patients. Repeated urodynamic studies are an essential aid in managing the evolving nature of the bladder dysfunction. Meticulous bladder management protocol can prevent upper urinary tract complications.

Complicated urinary tract infection in adults

BACKGROUND

Complicated urinary tract infection occurs in individuals with functional or structural abnormalities of the genitourinary tract.

OBJECTIVE

To review current knowledge relevant to complicated urinary tract infection, and to provide evidence-based recommendations for management.

METHODS

The literature was reviewed through a PubMed search, and additional articles were identified by journal reference review. A draft guideline was prepared and critically reviewed by members of the Association of Medical Microbiology and Infectious Disease Canada Guidelines Committee, with modifications incorporated following the review.

RESULTS

Many urological abnormalities may be associated with complicated urinary infection. There is a wide spectrum of potential infecting organisms, and isolated bacteria tend to be more resistant to antimicrobial therapy. Morbidity and infection outcomes in subjects with complicated urinary infection are principally determined by the underlying abnormality rather than the infection. Principles of management include uniform collection of a urine specimen for culture before antimicrobial therapy, characterization of the underlying genitourinary abnormality, and nontreatment of asymptomatic bacteriuria except before an invasive genitourinary procedure. The antimicrobial regimen is determined by clinical presentation, patient tolerance, renal function and known or anticipated infecting organisms. If the underlying abnormality contributing to the urinary infection cannot be corrected, then early post-treatment recurrence of infection is anticipated.

CONCLUSIONS

The management of complicated urinary infection is individualized depending on patient variables and the infecting organism. Further clinical investigations are necessary to assist in determining optimal antimicrobial regimens.

The role of medial gastrocnemius free flap in coverage of ischial pressure sore in paraplegic patients

Pressure sores, and especially ischial pressure sores, are a serious concern in the life of paraplegic patients. The treatment of this pathology is obviously surgery, and several local flaps can be used for coverage. However, recurrent pressure sores in an active patient can be frustrating if all local flaps have been used. Free flaps are therefore the next option. In our experience, the free medial gastrocnemius musculocutaneous flap is the best option. This paper reports the closure of ischial pressure sores with a free medial gastrocnemius flap, the patient selection criteria used, and the postoperative care provided.

Recognition and effective management of autonomic dysreflexia in spinal cord injuries

Autonomic dysreflexia is a potentially life-threatening hypertensive medical emergency that occurs most often in spinal cord-injured individuals with spinal lesions at or above the mid-thoracic spinal cord level. It is a condition that remains poorly recognised outside of spinal cord injury centres, which may result in adverse outcomes including mortality from potentially delayed diagnosis and treatment. Acute autonomic dysreflexia is characterised by severe paroxysmal hypertension associated with throbbing headaches, profuse sweating, nasal stuffiness, flushing of the skin above the level of the lesion, bradycardia, apprehension and anxiety, which is sometimes accompanied by cognitive impairment. The key to effective management is prevention of the condition, by recognition and avoidance of factors that initiate the condition. When it occurs, immediate recognition and reversal of trigger factors along with prompt administration of pharmacological treatment is of paramount importance in order to prevent complications, which include intracranial and retinal haemorrhage, convulsions, cardiac irregularities and death. Promising data from recent animal studies may hold the key to future treatment options.

Transurethral Sphincterotomy Provides Significant Relief in Autonomic Dysreflexia in Spinal Cord Injured Male Patients: Long-Term Followup Results

PURPOSE

An evaluation of the results of transurethral sphincterotomy in spinal cord injured patients for the relief of autonomic dysreflexia is presented.

MATERIALS AND METHODS

The study describes experience with the treatment of 46 consecutive spinal cord injured males presenting with frequent symptoms of autonomic dysreflexia and inadequate voiding. The selection criteria include patients injured above the thoracic 6 level with subjective symptoms of autonomic dysreflexia who did not want to be catheterized or were unable to perform intermittent catheterization. Patients were studied with complex urodynamics before and at least 3 months after undergoing transurethral sphincterotomy. During cystometrogram the maximum increase in systolic and diastolic blood pressure was recorded. After transurethral sphincterotomy patients were followed for a mean of 5.4+/-3.1 years (range 1 to 12).

RESULTS

There was subjective relief in autonomic dysreflexia following transurethral sphincterotomy in all patients, which correlated well with a significant decrease in systolic and diastolic blood pressure (p<0.0001). Mean decrease in maximal systolic and diastolic blood pressure after transurethral sphincterotomy was 55+/-25 and 29+/-17 mm Hg, respectively. Mean post-void residual urine decreased significantly from 233+/-151 to 136+/-0.34 ml after transurethral sphincterotomy. However, there was no significant change in mean maximum voiding pressures.

CONCLUSIONS

Blood pressure monitoring during cystometrogram provides an objective assessment of the presence of autonomic dysreflexia due to neurogenic bladder dysfunction, enabling better therapeutic management to control autonomic dysreflexia. Persistence of significant autonomic dysreflexia needs urodynamic evaluation if other factors for autonomic dysreflexia have been excluded.

Is There a Relationship between Chronic Bladder Dysfunction and Somatic Symptoms in other Body Regions? 1. Clinical Observations

OBJECTIVE

Investigation of patients with chronic bladder dysfunction regarding associated general symptoms and complaints in the cervico-facial, upper and lower extremity regions.

PATIENTS AND METHODS

We retrospectively evaluated history, physical and special neurourological examination and urodynamic studies in 213 patients with non-neurogenic bladder dysfunction.

RESULTS

22 patients out of 213 patients with chronic bladder dysfunction reported reproducible associated symptoms involving the temporo-mandibular joint, the distal forearm/hand or feet and headache. There was an obvious clinical connection regarding the severity of bladder dysfunction and associated symptoms and possible relief of both by successful treatment.

CONCLUSION

Symptomatic lower urinary tract dysfunction may accompanied by specific muscular and or sensory disturbances in different areas of the body. These associated pathologies in patients without neurological disease can be explained by functional changes in a complex autonomic peripheral and central nervous network.

Autonomic dysreflexia: the forgotten medical emergency

Autonomic dysreflexia (AD) is a potentially dangerous complication of spinal cord injury (SCI). In AD, an individual's blood pressure may rise to dangerous levels and, if not treated, can lead to stroke and possibly death. All medical personnel, especially those interacting with SCI patients, must have a good understanding of its aetiology, complications and emergency management.

Prevalence and etiology of autonomic dysreflexia in children with spinal cord injuries

OBJECTIVE

To delineate the prevalence, etiologies, clinical manifestations, complications, and management of autonomic dysreflexia in individuals who sustained spinal cord injury (SCI) as children.

METHOD

Retrospective chart review.

PARTICIPANTS

All individuals with > or = T6 SCI who were injured at 13 years of age or younger and who were cared for at one pediatric SCI program.

OUTCOME MEASURES

Outcome measures included prevalence, etiologic factors, and symptoms of autonomic dysreflexia as documented in both inpatient and outpatient records. Blood pressure and heart rate for observed episodes of autonomic dysreflexia also were recorded.

RESULTS

Of 121 participants who met the study criteria, 62 (51%) had experienced autonomic dysreflexia. The most common causes of dysreflexia were urologic (75%) and bowel impaction (18%), and the distribution of causative factors were similar in the 3 age ranges (0-5 years, 6-13 years, and 14-21 years). For all age groups, the most common symptoms were facial flushing (43%), headaches (24%), sweating (15%), and piloerection (14%). However, headaches (5%) and piloerection (0%), were uncommonly seen in children 5 years of age and younger. For observed episodes of autonomic dysreflexia, the majority (93%) demonstrated blood pressure elevations consistent with published guidelines, 50% experienced tachycardia, and 12.5% experienced bradycardia. Autonomic dysreflexia was significantly more common in individuals with complete lesions and in those who were injured between 6 and 13 years old compared with those injured at a younger age. Individuals with cervical injuries were not at significantly higher risk of dysreflexia than were those with upper thoracic level injuries. However, among individuals with complete lesions, autonomic dysreflexia was significantly more common in those with tetraplegia.

CONCLUSION

Autonomic dysreflexia has a similar prevalence in pediatric-onset SCI compared with the adult SCI population. Dysreflexia is diagnosed less commonly in infants and preschool-aged children, and these 2 populations may present with more subtle signs and symptoms.

Autonomic Dysreflexia After Intramuscular Injection in Traumatic Tetraplegia

Autonomic dysreflexia is a syndrome of massive imbalance of reflex sympathetic discharge occurring in patients with spinal cord lesion above the splanchnic outflow (T6). It is characterized by a sudden onset and severe increase in blood pressure and is potentially life threatening. The most common causes are bladder and rectum distention. In this case study, we report an autonomic dysreflexia case that developed after intramuscular injection in a 29-yr-old tetraplegic patient with C5 American Spinal Injury Association grade A lesion. After careful scrutiny of English literature, this clinical manifestation seems to be an unusual event.

Obstetric Management of the Patient With Spinal Cord Injury

Pregnancies in spinal cord-injured patients present unique clinical challenges to obstetric providers. Spinal cord injury (SCI) alters the function of multiple organ systems, and chronic medical conditions are extremely common in this patient population. Autonomic dysreflexia (ADR) is a potentially life-threatening complication of SCI, usually involving patients with spinal cord lesions at or above the T6 level. Intrapartum care of women with SCI is particularly complicated, and labor is the period during which ADR is most likely to arise. A multidisciplinary team in a unit capable of invasive hemodynamic monitoring should deliver these patients. Epidural anesthesia should be administered early in labor to prevent ADR. If proper precautions are taken, most patients with SCI will have successful vaginal deliveries at term.

[Autonomic hyperreflexia induced by sacral root stimulation is detected by spectral analysis of the EEG]

PURPOSE

To compare spectral analysis of the electrocardiogram (ECG) with mean arterial pressure (MAP) and heart rate (HR) monitoring in the detection of autonomic hyperreflexia (AHR) induced by sacral root stimulation.

METHODS

Ten spinal cord injured patients scheduled for implantation of a sacral root stimulator for bladder retention were included. Under target controlled anesthesia with propofol 4 micro g*mL(-1) and remifentanil 4 ng*mL(-1), the patients were placed in the knee chest position. The sacral roots were exposed by laminectomy (L2-S1) and their function assessed by electrostimulation under urodynamic and cardiovascular monitoring. Online power spectrum densities were calculated from the ECG R-R interval by the MemCalc(TM) software using the maximum entropy method. Low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4 Hz) spectra were associated with sympathetic and parasympathetic activities respectively. The most extreme value of each variable was noted before and during each stimulation. A difference ( triangle up ) of more than 10% signified AHR. The comparison ( triangle up LF vs triangle up MAP and triangle up HF vs triangle up HR) was done by a concordance test with a kappa coefficient (k): -1 = total discordance to 1 = total concordance.

RESULTS

AHR was detected in six patients as an increase in LF and MAP (n = 4); an increase in LF, HF, MAP with a decrease in HR (n = 2). The detection delay was 5.3 +/- 1 sec (LF, HF) and 10.4 +/- 1.2 sec (MAP and HR). Concordance was 85% (LF vs MAP: k = 0.7) and 90% (HF vs HR: k = 0.8).

CONCLUSION

AHR induced by sacral root stimulation is detected by spectral analysis of the ECG earlier than MAP and HR. Other studies are needed to confirm these results.

Effect of KW-7158, a putative afferent nerve inhibitor, on bladder and vesico-vascular reflexes in rats

The effects of KW-7158, a putative afferent nerve inhibitor, on reflex bladder activity and vesico-vascular reflexes were evaluated in urethane anesthetized SD rats with normal and xylene-irritated bladders. The bladder was filled with saline until the appearance of large amplitude spontaneous bladder contractions (LA-BC). Vesico-vascular reflexes were measured as increases in systolic arterial blood pressure during LA-BC or when the bladder was distended by a range of pressures. In normal rats, KW-7158 (10 and 100 microg/kg, i.v.) did not alter the amplitude or volume threshold for inducing LA-BC but increased the intercontraction interval. After xylene-irritation, which decreased volume threshold and intercontraction interval and induced small amplitude bladder contractions, KW-7158 increased volume threshold (65%) and intercontraction interval (150%) and decreased the number of small amplitude bladder contractions. Vesico-vascular reflexes induced during LA-BC or by bladder distension were suppressed (19.4-100%) by KW-7158. The effect of KW-7158 to depress vesico-vascular reflexes as well as xylene-induced bladder hyperactivity without altering the amplitude of contractions is consistent with the view that the drug affects reflex bladder activity at least in part by depressing afferent pathways.

The expression of Fos-labeled spinal neurons in response to colorectal distension is enhanced after chronic spinal cord transection in the rat

The present study used Fos-like immunoreactivity to examine neuronal activation in response to colorectal distension in rats at 1 day or 30 days following spinal cord transection or sham transection. Fifty-five Wistar rats were anesthetized and an incision was made to expose the T(5) spinal segment. The dura was reflected away in all rats and a complete transection at the rostral end of the T(5) segment was given to the lesioned group. At 1 day (acute) or 30 days (chronic) post-surgery, conscious rats were subjected to a 2 h period of intermittent colorectal distension. Rats were perfused and spinal segments L(5)-S(2) were removed and processed for Fos-like immunoreactivity. Spinal cord transection alone had no effect on Fos-labeling in either acute or chronic rats. In acute rats, colorectal distension produced significant increases in Fos-labeling in the superficial and deep dorsal horn regions. In chronic rats, colorectal distension produced a three-fold increase in Fos-labeled neurons that was manifest throughout all laminar regions. These results indicate that the number of neurons expressing Fos in response to colorectal distension is much greater after a chronic spinal cord transection than after an acute transection. Since Fos is an indicator of neuronal activation, the results show that many more neurons become active in response to colorectal distension following a chronic spinal injury. This suggests that a functional reorganization of spinal circuits occurs following chronic spinal cord transection. This may ultimately result in altered visceral and somatic functions associated with spinal cord injury in humans.

Analysis of the afferent limb of the vesicovascular reflex using neurotoxins, resiniferatoxin and capsaicin

The afferent limb of the vesicovascular reflex (VV-R) evoked by distension or contraction of the urinary bladder (UB) was studied in urethane-anesthetized female rats by examining the changes in VV-R after administration of C-fiber afferent neurotoxins [capsaicin and resiniferatoxin (RTX)]. Systemic arterial blood pressure increased parallel (5.1 to 53.7 mmHg) with graded increases in UB pressure (20 to 80 cm H(2)O) or during UB contractions. The arterial pressor response to UB distension was significantly reduced (60-85%) by acute or chronic (4 days earlier) intravesical administration of RTX (100-1,000 nM) or by capsaicin (125 mg/kg sc) pretreatment (4 days earlier). Chronic neurotoxin treatments also increased the volume threshold (>100%) for eliciting micturition in anesthetized rats but did not change voiding pressure. Acute RTX treatment (10-50 nM) did not alter the arterial pressor response during reflex UB contractions, whereas higher concentrations of RTX (100-1,000 nM) blocked reflex bladder contractions. It is concluded that VV-R is triggered primarily by distension- and contraction-sensitive C-fiber afferents located, respectively, near the luminal surface and deeper in the muscle layers of the bladder.

Cardiovascular consequences of loss of supraspinal control of the sympathetic nervous system after spinal cord injury

Spinal cord injury (SCI) with resultant quadriplegia or high paraplegia is associated with significant dysfunction of the sympathetic nervous system. This alteration of sympathetic nervous system activity occurs as a consequence of loss of supraspinal control of the sympathetic nervous system and is further complicated by at least three subsequent phenomena that occur below the level of SCI: reduced overall sympathetic activity, morphologic changes in sympathetic preganglionic neurons, and peripheral alpha-adrenoceptor hyperresponsiveness. Reduced sympathetic activity below the level of SCI appears to result in orthostatic hypotension, low resting blood pressure, loss of diurnal fluctuation of blood pressure, reflex bradycardia, and, rarely, cardiac arrest. Peripheral alpha-adrenoceptor hyperresponsiveness likely accounts for some, if not the majority, of the excessive pressor response in autonomic dysreflexia and may also contribute to decreased blood flow in the peripheral microcirculation, potentially increasing susceptibility to pressure sores. What has yet to be established is whether this alpha-adrenoceptor hyperresponsiveness is a consequence of receptor hypersensitivity or a failure of presynaptic reuptake of noradrenaline at the receptor level. Better understanding of the pathophysiology of sympathetic nervous system dysfunction after high-level SCI should allow development of more effective measures to manage clinical complications.

Treatment of detrusor sphincter dyssynergia by transperineal injection of botulinum toxin

Detrusor-sphincter dyssynergia is an involuntary contraction of the external urethral sphincter during the detrusor contraction. It causes voiding dysfunction and can lead to urologic complications such as hydroureteronephrosis and renal failure. Patients with spinal cord injuries are particularly vulnerable. Botulinum toxin has been used via cystoscopy to decrease the activity of the external urethral sphincter. This report describes the treatment of 5 tetraplegic patients by single transperineal injections of botulinum toxin for detrusor-sphincter dyssynergia, proved by a urodynamic study with electromyography. A total of 15 injections was given, resulting in improved bladder function in all patients. Urodynamic assessment after treatment showed an increase of the functional detrusor capacity and a decrease of the maximal detrusor pressure during voiding. These results confirm the consideration of botulinum toxin as a treatment for detrusor sphincter dyssynergia. A single transperineal injection is a valuable, less invasive treatment using a cystoscopic technique.

Contemporary urologic management of patients with spinal cord injury

Urologic management strategies in patients with spinal cord injury are discussed herein, and the underlying pathophysiology and urodynamic principles are emphasized. Contemporary management of the spinal cord-injured bladder has allowed for near-elimination of renal failure as the primary cause of long-term morbidity in these patients; low urine storage, sterile urine, and effective emptying are imperative for good long-term results.

Does postsynaptic alpha 1-adrenergic receptor supersensitivity contribute to autonomic dysreflexia?

Quadriplegics often experience periods of severe hypertension known as autonomic dysreflexia. Clinically, these events have been well documented, but the mechanisms for mediating autonomic dysreflexia remain unclear. We used a chronic rat model to investigate the potential development of supersensitivity at postsynaptic alpha 1-adrenergic receptors as a contributing factor to the exaggerated sympathetic response characteristic of autonomic dysreflexia. Adult male Wistar and Sprague-Dawley rats were anesthetized and given spinal transection at T5. After 30 days, rats were reanesthetized and arterial and venous catheters implanted. Twenty-four hours later, colorectal distension (CRD) was used to evoke autonomic dysreflexia in conscious, spinalized rats. To gauge changes in alpha 1-receptor sensitivity, we assessed mean arterial pressure (MAP) in response to intravenous phenylephrine (PE) infusions. No consistent differences were observed between intact and spinalized rats. Therefore, supersensitivity of alpha 1-receptors cannot completely account for the hypertensive bouts associated with autonomic dysreflexia. In addition, while attempting to develop an appropriate model for autonomic dysreflexia, we discovered that spinalized Wistar rats exhibited MAP responses characteristic of autonomic dysreflexia, whereas lesioned Sprague-Dawley rats did not, when subjected to CRD. Thus Wistar rats provide a better animal model for autonomic dysreflexia.

Free plasma catecholamines in spinal cord injured persons with different injury levels at rest and during exercise

Spinal cord lesion leads to an interruption of pathways from brain to the peripheral sympathetic nervous system, which results in pathological changes in sympathetic innervation. Free epinephrine (E), norepinephrine (NE) and dopamine (DA) were measured in 30 tetraplegics (TETRA), 15 high-lesion paraplegics (T1 and T4, HPARA), 15 paraplegics with injuries between T5 and T10 (MPARA), 15 low-lesion paraplegics (below T10, LPARA) and 16 non-handicapped control persons (C) at rest, at 60 and 100% of maximal oxygen consumption during graded wheelchair ergometry (WCE). The TETRA showed significant lower E and NE levels at rest and only slight increases during physical exercise. The E and NE concentrations of the paraplegics with a lesion below T5 were significantly higher than those of the high-lesion paraplegics, as well as those of the control persons at every point in the study. All paraplegics and the control persons showed, at submaximal and maximal exercise, a significant increase in NE. Only a slight increase in E in HAPRA was shown. No differences were found at rest and during exercise in E and NE levels in the MPARA and LPARA. No significant differences were found in the dopamine concentration at rest or during exercise for any of the groups. In summary, different levels of lesion and the resulting interruption to sympathetic pathways in the spinal cord are decisive factors in the degree of impairment of sympathetic innervation in SCI persons. Tetraplegics show less preganglionic resting activity because of interruption of impulses from central centers and no considerable stimulation of the sympathetic nervous system during maximal exercise. Individuals with high paraplegia have a partial impairment of catecholamine release, especially of epinephrine, at rest and during exercise. Paraplegics with a lesion level below T5 showed an augmented basal and exercise-induced upper spinal thoracic sympathetic activity in comparison to control persons.

Results of the treatment of neurogenic bladder dysfunction in spinal cord injury by sacral posterior root rhizotomy and anterior sacral root stimulation

PURPOSE

We evaluated the results of treatment of neurogenic bladder dysfunction in spinal cord injury by sacral posterior root rhizotomy and anterior sacral root stimulation using the Finetech-Brindley stimulator.

MATERIALS AND METHODS

In 52 patients with spinal cord lesions and urological problems due to hyperreflexia of the bladder complete posterior sacral root rhizotomy was performed and a Finetech-Brindley sacral anterior root stimulator was implanted. All patients were evaluated and followed with a strict protocol. A minimal 6-month followup is available in 47 cases.

RESULTS

Complete continence was achieved in 43 of the 47 patients with 6 months of followup. A significant increase in bladder capacity was attained in all patients. Residual urine significantly decreased, resulting in a decreased incidence of urinary tract infections. In 2 patients upper tract dilatation resolved. In 3 patients rhizotomy was incomplete and higher sectioning of the roots was necessary. One implant had to be removed because of infection.

CONCLUSIONS

The treatment of neurogenic bladder dysfunction in spinal cord injury by anterior sacral root stimulation with the Finetech-Brindley stimulator in combination with sacral posterior root rhizotomy provides excellent results with limited morbidity.

Contribution of alpha- and beta- adrenoceptors and neuropeptide-Y to autonomic dysreflexia

Modest increases in urinary bladder pressure result in acute hypertensive episodes in humans with spinal cord lesions above T5. The underlying mechanisms of this condition, referred to as autonomic dysreflexia, are not well understood. The aim of this study was to characterize the contribution of alpha- and beta-adrenoceptors as well as circulating neuropeptide-Y (NPY) to the pressor response to bladder distension in conscious cervical spinal rats. Rats were chronically instrumented with arterial and venous catheters. After 2-3 days, a complete spinal transection (C7) was performed, and the urinary bladder was catheterized: 24 h later, mean arterial pressure (MAP) responses to 5 min bladder distensions (+40) were measured under control conditions and after administration of specific autonomic antagonists. To assess the contribution of alpha and beta adrenergic mechanisms the alpha antagonist prazosin (0.45 mg/kg i.v.) and beta antagonist, propranolol (4 mg/kg i.v.), were administered individually or together. Blood samples were taken before, during and after bladder distension for determination of plasma NPY by radioimmunoassay. The pressor response to bladder distension was approximately 30 mmHg under control conditions. The response was attenuated (-38%), but not abolished, by prazosin. A similar attenuation (-41%) was observed with propranolol. There were no changes in plasma NPY in response to bladder distension. Finally, the pressor response was completely abolished by combined alpha- and beta-adrenergic blockade. These results suggest that autonomic dysreflexia is mediated exclusively by adrenergic receptors in the spinal rat. Moreover, both alpha and beta adrenergic receptors contribute to the pressor response induced by bladder distension in the conscious cervical spinal rat.

Autonomic dysreflexia in a rat model spinal cord injury and the effect of pharmacologic agents

The object of this study was to develop a spinal cord injury (SCI) rat model for autonomic dysreflexia (AD), assessing the effect of alpha-adrenergic and calcium channel blockade and to determine the relationship of detrusor-external sphincter dyssynergia (DESD) to the development of AD. A laminectomy was performed in male rats at the T4 or T10 level and a controlled 50 g cm blunt SCI was induced using an impounder. Four weeks after injury, changes in arterial blood pressure and heart rate were monitored while simultaneous cystometry (CMG) and pelvic floor electromography (EMG) were performed in vivo in sham (control) and spinal cord injured rats. The effects of terazosin (0.1 mg/kg), diltiazem (0.5 mg/kg), and oxybutynin chloride (0.1 mg/kg) on hemodynamic changes were assessed independently. Both T4 and T10 SCI rat displayed evidence of DESD (enhanced pelvic floor EMG activity at cystometric capacity) while control rats did not. Only T4 injured rats exhibited evidence of AD, with mean blood pressure elevations from 82.9 +/- 13.6 to 93.9 +/- 11.3 mm Hg (P < 0.01) and a mean heart rate decrease from 332.2 +/- 56.5 to 311.1 +/- 54.5 beats/min (P = 0.02) at cystometric capacity. The intravenous administration of terazosin or diltiazem abolished the AD response during CMG. The administration of oxybutynin exhibited the ability to increase bladder capacity and improve compliance in all 3 groups but did not blunt AD. The rat model of SCI effectively reproduced hemodynamic changes consistent with the AD complex in T4 level SCI but not T10 level SCI animals, despite incomplete lesions. Blockade with either an alpha-1 or a calcium channel antagonist effectively ablated the AD response to bladder distention. Anticholinergic agents had no effect on AD. DESD frequently accompanies autonomic dysreflexia, although the development of AD is not a prerequisite for DESD.

Long-term follow-up of sphincterotomy in the treatment of autonomic dysreflexia

Autonomic dysreflexia (AD) is a syndrome affecting a majority of patients with high spinal cord lesions. An association between AD and detrusor-sphincter dyssynergia (DSD) is often seen. Between 1980 and 1988 we performed 51 transurethral sphincterotomies in 38 patients. Twelve of these patients underwent procedures primarily for the prevention of AD related to bladder distension. This study presents their long-term follow-up. One patient was lost to follow-up secondary to unrelated death; the remaining 11 patients were followed on average 117.5 months (94-154) after the initial operative procedure. Repeat sphincterotomy was required in 9 of 11 patients (82%). Six (66%) of these were performed within 24 months. One patient (11%) required delayed sphincterotomy greater than 100 months from the initial procedure. Overall, sphincterotomy was successful in controlling symptoms of AD in 10 of 11 (91%) patients. No major complications were recorded. Sphincterotomy is a safe and effective treatment for AD associated with DSD, however long-term urologic follow-up and management are necessary.

Flexible cystoscopy in spinal cord injury. Review article

Endoscopy of the urinary tract remains the cornerstone of urological therapy. Over the years, continued refinement of the endoscopic instruments has permitted a progressive increase in the number and methods of their application. The development of the smaller diameter, flexible endoscopes represents the greatest advance in urological endoscopy. Their characteristics permit greater versatility with less traumatic procedures, increasing patient comfort and minimizing iatrogenic injury. Spinal cord injury (SCI) patients are a select group, which require special attention when undergoing endoscopic procedures. Often a contracted bladder or poorly controlled muscle spasms make the SCI patient difficult to endoscopic using conventional rigid instruments. Furthermore, autonomic dysreflexia is a significant concern during traumatic urinary tract instrumentation. This communication will discuss the applications of flexible cystoscopy, including novel techniques, which can be useful in SCI patients.

Prospective comparison of external sphincter balloon dilatation and prosthesis placement with external sphincterotomy in spinal cord injured men

The purpose of our investigation was to compare external sphincterotomy, the traditional method of treatment of detrusor-external sphincter dyssynergia (DESD), with two newer methods, balloon dilatation or internal stenting of the external sphincter. Sixty-one spinal cord injured (SCI) men were prospectively evaluated. The indications for treatment were DESD and voiding pressure greater than 60 cmH2O demonstrated during video-urodynamic study. Twenty patients were treated with balloon dilatation of the external sphincter, 26 with an internal stent prosthesis, and 15 with traditional external sphincterotomy. Age and duration of SCI were similar among the three treatment groups. A significant decrease in both voiding pressure and residual urine from presurgery levels persisted during the follow-up period of 3 to 26 months (mean, 15 months) in all three groups. Bladder capacity remained constant, renal function improved or stabilized, and autonomic dysreflexia (AD) improved in all three groups. Balloon dilatation and prosthesis placement are associated with a significantly shorter length of surgery (p = 0.045), length of hospitalization (p = 0.005), decrease in hospitalization cost (p = 0.01), and decrease in hemoglobin postoperatively (p = 0.046) when compared to external sphincterotomy. Complications of stent insertion included device migration (three patients) and secondary bladder neck obstruction (two patients). In the balloon dilatation group, three recurrent sphincter obstructions, one case of bleeding requiring transfusion, and one case of bulbous urethral stricture occurred. After external sphincterotomy, two patients developed recurrent obstruction, two required blood transfusion, and 1 patient noted erectile dysfunction. Balloon dilatation and prosthesis placement both proved to be as effective as external sphincterotomy in the treatment of DESD.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective evaluation of terazosin for the treatment of autonomic dysreflexia

Terazosin was evaluated in 21 normotensive spinal cord injured patients with autonomic dysreflexia. The patients were followed for 3 months during which the autonomic dysreflexia severity and frequency were evaluated. Autonomic dysreflexia severity mean score was significantly improved when measured at baseline and at 1 week, 1 month and 3 months (10.3 +/- 4.2, 5.08 +/- 2.3, 3.83 +/- 2.5 and 4.5 +/- 1.4, respectively, p < 0.0005). No statistically significant change was seen in erectile function and blood pressure. Three patients complained of fatigue, 1 of whom had the dosage reduced from 5 to 2.5 mg. daily. Terazosin appears to be effective in preventing serious harm from autonomic dysreflexia without erectile function impairment. The effectiveness is significant in the first week and remains for at least 3 months.

Flexible cystoscopy during urodynamic evaluation of spinal cord-injured patients

Eighty-one consecutive flexible cystoscopic examinations were performed on 69 patients with spinal cord injury (SCI) at the time of their urodynamic study. The indications for cystoscopy included hematuria, recurrent urinary tract infections, symptoms of bladder outlet obstruction, the presence of an intraurethral sphincter stent requiring evaluation, neurogenic vesical dysfunction requiring endourodynamic study (cystometrogram through the working port of the flexible cystoscope), or bladder calculi. Flexible cystoscopy was accomplished in all patients, whether lying supine or seated in a wheelchair (N = 16). Only 6 of 39 patients with previous episodes of autonomic dysreflexia became hypertensive during cystoscopy. When a urodynamic catheter could not be inserted, the flexible cystoscope was particularly useful in defining the urethral anatomy or obstruction and in performing endourodynamic evaluation. The only complication was the development of febrile urinary tract infection in four patients. The flexible cystoscope is a valuable tool in the urodynamic laboratory caring for patients with SCI and is effective for use in endourodynamics, especially when patient positioning or catheter placement is difficult. The procedure is well tolerated, causes minimal stimulation leading to the development of autonomic dysreflexia, and provides accurate cystometric data.

Urinary bladder innervation in male rat: termination of primary afferents in the spinal cord as determined by transganglionic transport of WGA-HRP

The distribution of afferents innervating the urinary bladder in the spinal cord of male rats has been studied with the axonal tracer horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) injected into various portions of one side of the urinary bladder (dome, body, base, or neck) and other pelvic organs (prostate and rectum). Labeled neurons were found in dorsal root ganglia of the lumbosacral cord (L1-S3, peak in S1-S2). The strongest and most extensive transganglionic labeling of primary afferents resulted after injections in the body of the bladder. Primary afferents were observed bilaterally in Lissauer's tract and laminae I-II at the apex of the dorsal horn, from L6 to S3. The projection extended laterally up to the sacral parasympathetic nucleus and medially up to the gray matter dorsal to the central canal, where they formed a plexus of fibers and terminals. Deposits in the dome and base of the bladder labeled more heavily the medial projection, while the least intense projection was seen after injections in the bladder neck. Our results indicate a common pattern of termination of primary afferents from the bladder, although some topographical differences exist.