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Urological Findings in Patients with Neurosurgically Treated Tethered Spinal Cord
0022-534 7 /93/1496-1510$03.00/0 THE JOURNAL OF UROLOGY Copyright© 1993 by AMERICAN UROLOGICAL ASSOCIATION, INC.
Vol. 149, 1510-1511, June 1993
Printed in U.S.A.
UROLOGICAL FINDINGS IN PATIENTS WITH NEUROSURGICALLY TREATED TETHERED SPINAL CORD A. J. GROSS, T. MICHAEL, F. GODEMAN, K. WEIGEL AND H. HULAND From the Urologische Klinik, Universitiitskrankenhaus Eppendorf Hamburg, and Neurochirurgische Klinik, Klinikum Steglitz der FU Berlin and Neuropiidiatrische Abteilung, Universitiitsklinikum R. Virchow (KA VH) der FU Berlin, Berlin, Germany
ABSTRACT
We studied 42 consecutive patients with spina bifida to ascertain the urological relevance of the tethered spinal cord in this condition. We evaluated 35 patients before untethering and 21 with pathological findings after untethering. The main difference after untethering was an increase in bladder capacity in 10 of 17 patients. The general clinical condition improved in 13 patients, was stable in 5 and became worse in 3. KEY WORDS: pediatrics, urodynamics, spina bifida occulta, spinal cord
Tethering of the spinal cord is a common finding in myelodysplastic patients. The condition is caused by intravertebral fixation of the spinal cord and has various neurological consequences. The first signs or symptoms may occur during growth and mechanical alteration. Treatment of patients with a tethered spinal cord focuses mainly on orthopedic and neurourological findings, ranging from undetected conditions to the initial presenting symptom, for example increasing urinary incontinence. Our interest focused on the types of urological findings that occur and on whether they are consistent. We also examined the influence of surgical untethering on the urological findings. PATIENTS AND METHODS
There are approximately 350 patients with spina bifida treated at our institution. Between 1988 and 1990, 42 patients, including some from other hospitals (19 male and 23 female patients less than 1 to 27 years old, mean age 6.4 years, in the overt spinal dysraphism group and less than 1 to 8 years old, mean age 2.3 years, in the occult dysraphism group) presented with a tethered spinal cord. A total of 32 patients had a secondary tethered cord syndrome after closure of a meningomyelocele. Of the remaining patients 10 had occult spinal dysraphism. Both groups are of a different anatomical backround and the neurosurgical treatment is not necessarily the same but the symptoms are usually similar. Therefore, they are both described in this study. Of the 42 patients 4 had urological symptoms as the initial problem, consisting mainly of a new onset of either stress or urge incontinence combined in all cases with more frequent urinary tract infections. The initial symptoms in the remaining patients were orthopedic conditions or pain. We examined 35 patients urologically preoperatively and 21 with pathological urological findings also were examined postoperatively. The patients underwent microscopic neurosurgical untethering of the spinal cord. Myelolysis was performed microscopically with resection of epidermoids and lipofibroma. In every case the defect was between the L2 and S3 vertebrae combined with an open spinal canal. Postoperative examination usually was done within 4 weeks after untethering. Our review concentrates on those patients. Of the 21 patients 18 had a secondary tethered cord syndrome and 3 had occult spinal dysraphism. Evaluation included neurological examination, urodynamic studies, radiological studies and completion of a patient questionnaire. Urological studies included cystometrography to Accepted for publication November 6, 1992 Read at annual meeting of American Urological Association, Washington, D.C., May 10-14, 1992.
evaluate compliance, involuntary detrusor contractions, bladder volume and desire to void; clinical evaluation (use of diapers and history of urinary tract infections), and radiological examination to evaluate vesicoureteral reflux. Urodynamic studies were performed on 6-channel instruments using contrast medium (500 ml. iodine contrast medium plus 250 ml. sodium chloride) for cystometrography. A 9 Ch. double lumen catheter was used to obtain intravesical bladder pressure and a rectal balloon was placed as reference to measure intra-abdominal pressure. Simultaneously, we performed pelvic floor electromyography with patch electrodes. Filling during cystography was slow (less than 15 ml. per minute). X-rays were taken before examination, at 50 ml. during examination and when patients reported urological sensations. The ability or desire to void was noted, and total bladder capacity, bladder compliance during filling and detrusor-sphincter dysynergia were recorded. The frequency of urinary tract infections was also recorded. RESULTS
Of the 42 patients who underwent neurosurgical untethering 4 had undergone at least 1 prior untethering procedure. Patients who did not undergo prior untethering were treated conservatively until the operation. The interval between repeated untethering procedures was 6 months to 2 years. Of the 35 patients who underwent urological examination preoperatively 21 had urological symptoms (as initial symptoms in 4). A total of 11 patients could specify the desire to void preoperatively and 1 of them became worse after untethering, while 3 others improved in this respect. Of 17 patients in whom the bladder volume was decreased until the leakage volume was reached preoperatively 12 improved, 4 were stable and 1 became worse. Involuntary detrusor contractions were noted preoperatively in 15 patients (uninhibited in 9). This symptom was diminished in 6 patients postoperatively. Of the 15 patients with symptoms of hyperreflexia the bladder capacity increased in 10, was stable in 4 and worsened in 1. Compliance was considered pathological (less than 15 ml.fem. water) in 14 patients preoperatively, and became normal postoperatively in 1, improved in 8 and remained stable in 5. Compliance was normal (greater than 15 ml.fem. water) in 9 patients preoperatively, and remained stable postoperatively in 6 and worsened in 3. Two patients with external sphincter insufficiency preoperatively and postoperatively had stable bladder capacity. Clinically (with respect to sensations of incontinence, use of diapers and frequency of urinary tract infections), 13 patients improved, 4 became worse, 17 were unchanged and 1 had a mixed response postoperatively. Uroradiological findings changed in only 2 patients: 1 showed vesicoureteral reflux
1510
NEUROSURGICALLY TREATED TETHERED SPINAL CORD
preoperatively but not after untethering, and 1 had the opposite sequence (see table). DISCUSSION
Normal voiding relies on a complex neurophysiological system between the cerebral cortex and the sacral spinal cord. 1- 4 Any lesion in this area results in neurourolog~cal changes, 'Yhic~ are clearly understood in the case of spmal ~ord lesions. However alterations in tethered spinal cord patients also frequently ;roduce uropathological findings. 5 The tethered spinal cord is a pathological fixation of the spinal cord in the ve~ebral column. All patients with overt spina bifida have scars m the area of the dysraphism due to the postpartum surgical closure of the lesion. In this operation additional lesions may be set. In patients with spina bifida occulta scarring is not necessarily present. However, scarring may occur and nerve~ may be fi~ed to bone structures. As the patient grows mechamcal stretchmg causes ischemia and consequent deterioration of spinal cord function. Sophisticated neuroradiological examinations make detection of the latter group easier. 6 Symptoms and neurosurgical treatment of both ~oup~ may be simila~ and, t?erefore, they are both described m this study. All_ patients with overt spina bifida suffer from the tethered spmal co~d._ Howe~er, untethering must be performed only when there 1s 1mmed1ate worsening of the symptoms. At our institution less than 10% Results (not all parameters were evaluable in every patient) No. Cystometrogram: Compliance (pathological less than 15 ml./cm. water): Preop. Postop. normal Postop. improved Postop. stable Involuntary detrusor contractions: Preop. Postop. Decreased bladder vol.: Preop. Postop. improved Postop. stable Postop. worse Desire to void (21 pts. total): Preop. present Postop. present Preop. absent Postop. absent Clinical evaluation: Better Worse Unchanged Mixed response Radiological findings: Vesicoureteral reflux diminished Vesicoureteral reflux appeared newly
14 1 8 5
15 9
17 12 4
1 11 10
10 7
13 4
17 1
1511
of the patients must undergo this procedure. Urologi~a~ ~ndings in these patients vary widely from normal to the m1tial presenting symptoms and they can be the first symptoms of a complex problem. Of our patients 40% have urological problems (10% as the initial symptoms). It is not known whether the symptoms are due to the myelodyplasia or whether they constitute a secondary tethered cord syndrome. Long-term preoperative observation and notation of changes in the pattern of urinary dysfunction would be helpful.7 However, it seems impossible to name the exact time of onset of patient problems: 1 subgroup cannot express themselves du~ to their young age and the difference from normal to pathological findings is fluent. In both cases untethering was performed and our results are based on the influence of myelysis. After untethering most patients improved urologically but none became urologically normal. The greatest benefit of untethering is an increase in bladder volume and, consequently, a greater chance of remaining dry for a given period. For patients unable to void after untethering clean intermittent catheterization seems to be more acceptable than a high frequency ofincontinence. 8 Not much attention has been paid to fecal incontinence, which also is common in patients with a tethered spinal cord. The co~dition seems to be easier to manage with diet but more attent10n to this matter is certainly important. A secondary tethered spinal cord has a worse prognosis a~d it beco~es even worse with surgical treatment. The quest10n remams as to when untethering should be performed in these patients (as early as possible or until symptoms occur?). 7 REFERENCES
1. Blaivas, J. G.: The neurophysiology of micturition: a clinical study of 550 patients. J. Urol., 127: 958, 1982. 2. Bradley, W. E. and Conway, C. J.: Bladder representation in the pontine-mesencephalic reticular formation. Exp. Neurol., 16: 237, 1966. 3. Fletcher, T. F. and Bradley, W. E.: Neuroanatomy of the bladderurethra. J. Urol., 119: 153, 1978. 4. Kaplan, S. A., Chancellor, M. B. and Blaivas, J. G.: Bladder and sphincter behavior in patients with spinal cord lesions. J. Urol., 146: 113, 1991. 5. Kaplan, W. E., McLone, D. G. and Richards, I.: The urological manifestations of the tethered spinal cord. J. Urol., part 2, 140: 1285, 1988. . 6. Naidich, T. P., McLone, D. G. and Harwood-Nash, D. C.: Spmal dysraphism. In: Modern Neuroradiology: Computed Tomography of the Spine and Spinal Cord. Edited by T. H. Newton and D. G. Pott. San Anselmo, California: Clavadel Press, vol. 1, chapt. 17,pp. 299-354, 1983. 7. Toet, M., van Goo!, J. D., Witkamp, T. and van Wieringen, H.: Spina bifida aperta and the tethered cord syndrome. Eur. J. Ped. Surg., suppl. I, 1: 48, 1991. . 8. McGuire, E. J., Woodside, J. R., Borden, T. A. and Weiss, R. M.: Prognostic value of urodynamic testing in myelodysplastic patients. J. Urol., 126: 205, 1981.
Vol. 149, 1510-1511, June 1993
Printed in U.S.A.
UROLOGICAL FINDINGS IN PATIENTS WITH NEUROSURGICALLY TREATED TETHERED SPINAL CORD A. J. GROSS, T. MICHAEL, F. GODEMAN, K. WEIGEL AND H. HULAND From the Urologische Klinik, Universitiitskrankenhaus Eppendorf Hamburg, and Neurochirurgische Klinik, Klinikum Steglitz der FU Berlin and Neuropiidiatrische Abteilung, Universitiitsklinikum R. Virchow (KA VH) der FU Berlin, Berlin, Germany
ABSTRACT
We studied 42 consecutive patients with spina bifida to ascertain the urological relevance of the tethered spinal cord in this condition. We evaluated 35 patients before untethering and 21 with pathological findings after untethering. The main difference after untethering was an increase in bladder capacity in 10 of 17 patients. The general clinical condition improved in 13 patients, was stable in 5 and became worse in 3. KEY WORDS: pediatrics, urodynamics, spina bifida occulta, spinal cord
Tethering of the spinal cord is a common finding in myelodysplastic patients. The condition is caused by intravertebral fixation of the spinal cord and has various neurological consequences. The first signs or symptoms may occur during growth and mechanical alteration. Treatment of patients with a tethered spinal cord focuses mainly on orthopedic and neurourological findings, ranging from undetected conditions to the initial presenting symptom, for example increasing urinary incontinence. Our interest focused on the types of urological findings that occur and on whether they are consistent. We also examined the influence of surgical untethering on the urological findings. PATIENTS AND METHODS
There are approximately 350 patients with spina bifida treated at our institution. Between 1988 and 1990, 42 patients, including some from other hospitals (19 male and 23 female patients less than 1 to 27 years old, mean age 6.4 years, in the overt spinal dysraphism group and less than 1 to 8 years old, mean age 2.3 years, in the occult dysraphism group) presented with a tethered spinal cord. A total of 32 patients had a secondary tethered cord syndrome after closure of a meningomyelocele. Of the remaining patients 10 had occult spinal dysraphism. Both groups are of a different anatomical backround and the neurosurgical treatment is not necessarily the same but the symptoms are usually similar. Therefore, they are both described in this study. Of the 42 patients 4 had urological symptoms as the initial problem, consisting mainly of a new onset of either stress or urge incontinence combined in all cases with more frequent urinary tract infections. The initial symptoms in the remaining patients were orthopedic conditions or pain. We examined 35 patients urologically preoperatively and 21 with pathological urological findings also were examined postoperatively. The patients underwent microscopic neurosurgical untethering of the spinal cord. Myelolysis was performed microscopically with resection of epidermoids and lipofibroma. In every case the defect was between the L2 and S3 vertebrae combined with an open spinal canal. Postoperative examination usually was done within 4 weeks after untethering. Our review concentrates on those patients. Of the 21 patients 18 had a secondary tethered cord syndrome and 3 had occult spinal dysraphism. Evaluation included neurological examination, urodynamic studies, radiological studies and completion of a patient questionnaire. Urological studies included cystometrography to Accepted for publication November 6, 1992 Read at annual meeting of American Urological Association, Washington, D.C., May 10-14, 1992.
evaluate compliance, involuntary detrusor contractions, bladder volume and desire to void; clinical evaluation (use of diapers and history of urinary tract infections), and radiological examination to evaluate vesicoureteral reflux. Urodynamic studies were performed on 6-channel instruments using contrast medium (500 ml. iodine contrast medium plus 250 ml. sodium chloride) for cystometrography. A 9 Ch. double lumen catheter was used to obtain intravesical bladder pressure and a rectal balloon was placed as reference to measure intra-abdominal pressure. Simultaneously, we performed pelvic floor electromyography with patch electrodes. Filling during cystography was slow (less than 15 ml. per minute). X-rays were taken before examination, at 50 ml. during examination and when patients reported urological sensations. The ability or desire to void was noted, and total bladder capacity, bladder compliance during filling and detrusor-sphincter dysynergia were recorded. The frequency of urinary tract infections was also recorded. RESULTS
Of the 42 patients who underwent neurosurgical untethering 4 had undergone at least 1 prior untethering procedure. Patients who did not undergo prior untethering were treated conservatively until the operation. The interval between repeated untethering procedures was 6 months to 2 years. Of the 35 patients who underwent urological examination preoperatively 21 had urological symptoms (as initial symptoms in 4). A total of 11 patients could specify the desire to void preoperatively and 1 of them became worse after untethering, while 3 others improved in this respect. Of 17 patients in whom the bladder volume was decreased until the leakage volume was reached preoperatively 12 improved, 4 were stable and 1 became worse. Involuntary detrusor contractions were noted preoperatively in 15 patients (uninhibited in 9). This symptom was diminished in 6 patients postoperatively. Of the 15 patients with symptoms of hyperreflexia the bladder capacity increased in 10, was stable in 4 and worsened in 1. Compliance was considered pathological (less than 15 ml.fem. water) in 14 patients preoperatively, and became normal postoperatively in 1, improved in 8 and remained stable in 5. Compliance was normal (greater than 15 ml.fem. water) in 9 patients preoperatively, and remained stable postoperatively in 6 and worsened in 3. Two patients with external sphincter insufficiency preoperatively and postoperatively had stable bladder capacity. Clinically (with respect to sensations of incontinence, use of diapers and frequency of urinary tract infections), 13 patients improved, 4 became worse, 17 were unchanged and 1 had a mixed response postoperatively. Uroradiological findings changed in only 2 patients: 1 showed vesicoureteral reflux
1510
NEUROSURGICALLY TREATED TETHERED SPINAL CORD
preoperatively but not after untethering, and 1 had the opposite sequence (see table). DISCUSSION
Normal voiding relies on a complex neurophysiological system between the cerebral cortex and the sacral spinal cord. 1- 4 Any lesion in this area results in neurourolog~cal changes, 'Yhic~ are clearly understood in the case of spmal ~ord lesions. However alterations in tethered spinal cord patients also frequently ;roduce uropathological findings. 5 The tethered spinal cord is a pathological fixation of the spinal cord in the ve~ebral column. All patients with overt spina bifida have scars m the area of the dysraphism due to the postpartum surgical closure of the lesion. In this operation additional lesions may be set. In patients with spina bifida occulta scarring is not necessarily present. However, scarring may occur and nerve~ may be fi~ed to bone structures. As the patient grows mechamcal stretchmg causes ischemia and consequent deterioration of spinal cord function. Sophisticated neuroradiological examinations make detection of the latter group easier. 6 Symptoms and neurosurgical treatment of both ~oup~ may be simila~ and, t?erefore, they are both described m this study. All_ patients with overt spina bifida suffer from the tethered spmal co~d._ Howe~er, untethering must be performed only when there 1s 1mmed1ate worsening of the symptoms. At our institution less than 10% Results (not all parameters were evaluable in every patient) No. Cystometrogram: Compliance (pathological less than 15 ml./cm. water): Preop. Postop. normal Postop. improved Postop. stable Involuntary detrusor contractions: Preop. Postop. Decreased bladder vol.: Preop. Postop. improved Postop. stable Postop. worse Desire to void (21 pts. total): Preop. present Postop. present Preop. absent Postop. absent Clinical evaluation: Better Worse Unchanged Mixed response Radiological findings: Vesicoureteral reflux diminished Vesicoureteral reflux appeared newly
14 1 8 5
15 9
17 12 4
1 11 10
10 7
13 4
17 1
1511
of the patients must undergo this procedure. Urologi~a~ ~ndings in these patients vary widely from normal to the m1tial presenting symptoms and they can be the first symptoms of a complex problem. Of our patients 40% have urological problems (10% as the initial symptoms). It is not known whether the symptoms are due to the myelodyplasia or whether they constitute a secondary tethered cord syndrome. Long-term preoperative observation and notation of changes in the pattern of urinary dysfunction would be helpful.7 However, it seems impossible to name the exact time of onset of patient problems: 1 subgroup cannot express themselves du~ to their young age and the difference from normal to pathological findings is fluent. In both cases untethering was performed and our results are based on the influence of myelysis. After untethering most patients improved urologically but none became urologically normal. The greatest benefit of untethering is an increase in bladder volume and, consequently, a greater chance of remaining dry for a given period. For patients unable to void after untethering clean intermittent catheterization seems to be more acceptable than a high frequency ofincontinence. 8 Not much attention has been paid to fecal incontinence, which also is common in patients with a tethered spinal cord. The co~dition seems to be easier to manage with diet but more attent10n to this matter is certainly important. A secondary tethered spinal cord has a worse prognosis a~d it beco~es even worse with surgical treatment. The quest10n remams as to when untethering should be performed in these patients (as early as possible or until symptoms occur?). 7 REFERENCES
1. Blaivas, J. G.: The neurophysiology of micturition: a clinical study of 550 patients. J. Urol., 127: 958, 1982. 2. Bradley, W. E. and Conway, C. J.: Bladder representation in the pontine-mesencephalic reticular formation. Exp. Neurol., 16: 237, 1966. 3. Fletcher, T. F. and Bradley, W. E.: Neuroanatomy of the bladderurethra. J. Urol., 119: 153, 1978. 4. Kaplan, S. A., Chancellor, M. B. and Blaivas, J. G.: Bladder and sphincter behavior in patients with spinal cord lesions. J. Urol., 146: 113, 1991. 5. Kaplan, W. E., McLone, D. G. and Richards, I.: The urological manifestations of the tethered spinal cord. J. Urol., part 2, 140: 1285, 1988. . 6. Naidich, T. P., McLone, D. G. and Harwood-Nash, D. C.: Spmal dysraphism. In: Modern Neuroradiology: Computed Tomography of the Spine and Spinal Cord. Edited by T. H. Newton and D. G. Pott. San Anselmo, California: Clavadel Press, vol. 1, chapt. 17,pp. 299-354, 1983. 7. Toet, M., van Goo!, J. D., Witkamp, T. and van Wieringen, H.: Spina bifida aperta and the tethered cord syndrome. Eur. J. Ped. Surg., suppl. I, 1: 48, 1991. . 8. McGuire, E. J., Woodside, J. R., Borden, T. A. and Weiss, R. M.: Prognostic value of urodynamic testing in myelodysplastic patients. J. Urol., 126: 205, 1981.