Search PubMed⌕ Search

Biomedical subjects

J K Light

Publications and source records attributed to J K Light.

At least 19 recordsLinked to original sources
PubMed1992

Detrusor function with lesions of the conus medullaris.

Conventional urodynamic evaluation is unable to distinguish between a pure conus lesion and one with concomitant cauda equina involvement. Lumbosacral evoked potentials to tibial nerve stimulation assesses the sensory root and dorsal horn interneurons of the L5 to S2 spinal cord segments. This allows for the diagnosis of a pure lesion of the conus medullaris with preservation of the sensory root response (R wave) with absence of the dorsal horn gray matter response (S wave). Urodynamic evaluation in 5 patients with a conus lesion showed a variety of detrusor responses ranging from hyperreflexia through areflexia with decreased compliance to areflexia with normal compliance. The ability to diagnose a pure conus lesion may have prognostic significance as newer modalities of treatment emerge, all of which require intact gray matter of the spinal cord.

Adult↗
PubMed1992

Detrusor function in suprasacral spinal cord injuries.

A total of 21 patients with chronic, stable suprasacral spinal cord injuries underwent a comprehensive neurological evaluation. A second lumbosacral lesion was excluded. The urodynamic findings were relatively constant as 95% of the patients showed detrusor hyperreflexia with elevated pressures, sphincteric dyssynergia and a competent bladder neck during the filling phase. The urodynamic findings of unexpected detrusor function in high spinal cord injury, for example areflexia and hypocontractility, should raise the clinician's suspicion that there is a lesion or dysfunction involving the sacral cord.

Adolescent↗
PubMed1992

Function of the conus medullaris and cauda equina in the early period following spinal cord injury and the relationship to recovery of detrusor function.

A total of 26 patients with an early suprasacral spinal cord injury underwent comprehensive neurourological evaluation to determine if there was any correlation between the return of detrusor function and neural function of the sacral cord. In addition, the incidence of a subclinical sacral neural dysfunction early after spinal cord injury was assessed. Lumbosacral evoked potentials to tibial nerve stimulation were used to assess the sensory root and cord gray matter of the L5 to S2 segments, while urodynamic evaluation was performed to assess detrusor function. Of those patients with normal lumbosacral evoked potentials 82% recovered detrusor contractility as opposed to 66% with abnormal evoked potentials. Four patients (23.5%) had persistent detrusor areflexia when studied 9 to 20 months following the acute injury. The potential problems attempting to correlate the neurophysiological and urodynamic studies are multiple and are extensively discussed. Despite these potential problems the return of detrusor function correlated well with associated normal lumbosacral evoked potentials suggesting that this test can be used in the early phase following spinal cord injury to predict return of bladder function, since it is independent of the level of spinal cord excitability. Of the patients studied 38% had coexistence of an occult lumbosacral dysfunction. This rate is higher than that found in the chronic stabilized spinal cord injury population (20.5%), since the cases in our study may represent a more severe lesion.

Adolescent↗
PubMed1992

Impact of the new cuff design on reliability of the AS800 artificial urinary sphincter.

The effect of 2 cuff design changes on the mechanical reliability of the current AS800 artificial urinary sphincter was assessed in 126 patients. The surface-treated cuff was introduced in 1983 and the narrow-back design was introduced in 1987. Mean followup for the surface-treated cuff was 40 months, while that for the narrow back was 27.2 months. The incidence of cuff leaks was 1.3%, while the revision rate for clinically significant pressure atrophy, in the absence of a bladder flap urethroplasty, was 2.3%. The overall revision rate for clinically significant pressure atrophy was 9%. No leaks involving the balloon or tubing occurred. The mechanical reliability of the current AS800 artificial urinary sphincter has improved significantly.

Evaluation Studies as Topic↗
PubMed1991

Spontaneous bladder rupture following augmentation enterocystoplasty.

Spontaneous bladder rupture following enterocystoplasty has been reported recently. The etiology remains unclear but appears to be multifactorial. The common factors among the reported patients are a high outlet resistance with total urinary continence and the presence of an augmented, dysfunctional native bladder. This combination may result in the development of high intravesical pressures or increased wall tension through several mechanisms, including over-filling and active contraction in the bowel or detrusor. The presence of an abnormal detrusor may cause the wall tension to be unevenly distributed toward the bowel segment. Diagnosis requires a high degree of suspicion and prompt laparotomy with closure of the defect. Prevention depends on maintaining low bladder volumes and, thus, pressures.

Adolescent↗
PubMed1991

Patients with lower motor spinal cord lesion: a decrease of vasoactive intestinal polypeptide, calcitonin gene-related peptide and substance P, but not neuropeptide Y and somatostatin-immunoreactive nerves in the detrusor muscle of the bladder.

Specimens of the detrusor muscle of the bladder from four patients with lower motor neurone lesion and three patients with carcinoma of the bladder used as "controls", were studied immunohistochemically for vasoactive intestinal polypeptide, neuropeptide Y, calcitonin-gene related peptide, substance P and somatostatin. The greatest density of nerves in the bladder from "control" patients contained neuropeptide Y, followed in a decreasing order by vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P and somatostatin. Neuropeptide Y- and vasoactive intestinal polypeptide-immunoreactive nerves were found throughout the smooth muscle and the base of the mucosa, while calcitonin gene-related peptide-, substance P- and somatostatin-immunoreactive nerves were found predominantly in nerve bundles with a few single fibres at the base of the mucosa. Vasoactive intestinal polypeptide-, neuropeptide Y- and calcitonin gene-related peptide-immunoreactive nerves were also located around blood vessels. In patients with lower motor neurone lesion, there was a decrease in the density of vasoactive intestinal polypeptide-, calcitonin gene-related peptide- and substance P-immunoreactive nerves, but there was little change in neuropeptide Y- or somatostatin-immunoreactive nerves. Urinary retention, bladder areflexia and deficient sensation may be directly linked to neuropeptide neuropathy in patients with lower motor neurone lesion.

Adult↗
PubMed1991

Continence mechanisms following continent urinary diversion and orthotopic bladder replacement.

It is obvious that significant advances have been made in reconstruction of the lower urinary tract following radical pelvic surgery. In contrast to the standard ileal loop, patients no have an option to void per urethra, have social continence and avoid self-intermittent catheterization in the presence of an abdominal stoma. Further refinements in construction of the continence mechanism will undoubtedly occur in the future.

Animals↗
PubMed1991

Candida pyelonephritis complicating traumatic C5 quadriplegia: diagnosis and management.

We present the first reported case of Candida pyelonephritis in a spinal cord injured patient. In addition to multiple courses of empiric antibiotics, the neurogenic bladder and alteration in cell-mediated immunity found in spinal cord injured patients may have increased this patient's susceptibility to fungal disease. A 50-year-old patient with C5 motor functional quadriplegia developed Candid albicans pyelonephritis while undergoing rehabilitation. The patient had several surgical procedures and multiple courses of antibiotic therapy during acute hospitalization. He continued to have a hectic fever curve, leukocytosis with increased band forms, lethargy, and progressive uremia during rehabilitation. Successful investigation of the patient's condition included assessment of serologic tests for Candida precipitin antigen; multiple blood and urine cultures; exclusion of other causes of hectic fever; abdominal computerized tomogram, which revealed a left kidney hypodensity with irregular margins; and a retrograde pyelogram, which demonstrated multiple renal pelvic-filling defects. Cystoscopically placed ureteral stents, which relieved the genitourinary obstruction, drained gross pus from which Candida albicans was cultured; the patient was treated with amphotericin B and showed clinical improvement. Pathogenesis, presentation, diagnosis, and treatment of Candida pyelonephritis are reviewed.

Algorithms↗
PubMed1990

Total bladder replacement in the male and female using the ileocolonic segment (LeBag).

A group of 11 patients, 2 female and 9 male, underwent total bladder replacement using the ileocolonic segment (LeBag technique) with anastomosis of the bowel to the urethra. The diagnosis was invasive bladder cancer in 10 patients and severe intractable interstitial cystitis in 1. The surgical technique in the male patients was modified to simplify the procedure. The 2 female patients underwent insertion of an artificial sphincter around the bowel segment for a continence mechanism. One patient died 6 weeks post-operatively from a severe coagulopathy. Five of the 9 male patients are continent day and night, relying on their own residual sphincter mechanism, but the remaining 4 required insertion of the artificial urinary sphincter to achieve social continence. The surviving female patient is totally continent. All patients have voiding intervals of 4 to 6 h during the day and are thus continent both day and night, but in some cases the artificial sphincter was necessary to achieve this. Loss of the normal bladder-sphincter reflexes following cystectomy may account for the high incidence of nocturnal incontinence observed in most series. Total bladder replacement is now possible in both male and female patients, thus avoiding an abdominal stoma.

Adult↗
PubMed1989

Management of urinary incontinence after prostatectomy with the artificial urinary sphincter.

A total of 37 patients underwent implantation of the artificial urinary sphincter for urinary incontinence after prostatectomy. Followup was 4 to 96 months, with a mean of 37 months. Social continence was achieved in 94.5 per cent of the patients. No abnormality of detrusor function was found in any patient. Prior pelvic irradiation appears to increase the risk of cuff erosion. Routine nocturnal deactivation of the device together with primary deactivation is recommended to decrease the incidence of cuff erosion in this patient group.

Aged↗
PubMed1989

Adrenergic innervation of the striated muscle of the intrinsic external urethral sphincter from patients with lower motor spinal cord lesion.

The adrenergic innervation of smooth and striated muscle components of the intrinsic external urethral sphincter from patients with suprasacral lesions and detrusor-sphincter dyssynergia has been described previously, when no adrenergic nerves were found associated with striated muscle fibers. In our study the intrinsic external urethral sphincter from patients with lower motor neuron lesions and detrusor areflexia was studied histochemically using the glyoxylic acid method to visualize catecholamines. Varicose adrenergic nerves were demonstrated in the smooth muscle. Adrenergic nerve fibers also were found along the edge of individual striated muscle fibers as well as around striated muscle bundles. Blood vessels in both regions of the urethral sphincter were innervated by adrenergic nerves. We conclude that in patients with lower motor neuron lesions and detrusor areflexia there is a substantial invasion by adrenergic nerve fibers in relation to smooth and striated muscle in the urethra, although the function of the nerve fibers is not known.

Adrenergic Fibers↗
PubMed1989

Long-term clinical results using the artificial urinary sphincter around bowel.

Four patients are presented in whom bowel was used to reconstruct a bladder. As a sphincteric mechanism was absent in all 4, the cuff from the artificial urinary sphincter was placed around the bowel to provide continence. This allowed for "normal" urination. The longest follow-up period was 11 years and the shortest 1.5 years. Both clinical and experimental data show that bowel will tolerate compression from the artificial urinary sphincter provided infection does not supervene and the pressure does not exceed 80 cm of water.

Child↗
PubMed1988

Male urinary incontinence. What do you do?

Urinary incontinence is a common ailment in men. Treatment, although readily available, is often overlooked. An understanding of the anatomy and physiology of the continence mechanism aids in proper diagnostic evaluation. Determination of the cause involves a complete history and physical examination, urodynamic studies, and radiologic tests. Treatment of incontinence is based on the specific cause. In general, conservative management with pharmacologic manipulation is the primary form of treatment. Surgical intervention, when indicated, offers a high success rate, particularly since the advent of the artificial urinary sphincter.

Humans↗
PubMed1988

Intramural ganglia in the human urethra.

The urethras from five patients with a thoracic or cervical spinal cord lesion and one patient with carcinoma of the bladder were studied immunohistochemically for neuropeptide Y and vasoactive intestinal polypeptide. Autonomic ganglia, containing two to 21 nerve cell bodies, were found in the smooth and striated muscle regions of the intrinsic external urethral sphincter; they were present rarely in the distal urethra and were absent from the prostatic urethra. Neuropeptide Y immunoreactivity was observed in some of the nerve cell bodies (diameter 25 to 50 microns). Vasoactive intestinal polypeptide immunoreactivity was observed in small cells (diameter 15 to 25 microns.) in the urethral smooth muscle and in the walls of blood vessels that resembled small intensely fluorescent cells but may be nerve cell bodies. Both neuropeptide Y- and vasoactive intestinal polypeptide-immunoreactive nerve fibres were found in the smooth muscle and around blood vessels in the urethra of all patients. Both types of peptide-containing nerves were found associated with striated muscle of the intrinsic external urethral sphincter in patients with spinal cord injury, but only vasoactive intestinal polypeptide-immunoreactive nerves were found in the patient with carcinoma of the bladder in this region. The functions of the autonomic ganglia and vasoactive intestinal polypeptide- and neuropeptide Y-immunoreactive nerves in the human urethra remain to be elucidated.

Fluorescent Antibody Technique↗
PubMed1988

Spinal cord lesions at different levels affect either the adrenergic or vasoactive intestinal polypeptide-immunoreactive nerves in the human urethra.

The urethras from 1 patient with cervical (C1-2) and 2 patients with thoracic (T10) spinal cord lesions were studied histochemically and immunohistochemically for adrenergic and vasoactive intestinal polypeptide-immunoreactive nerves. Dense vasoactive intestinal polypeptide-immunoreactive but not adrenergic nerves were found in the urethral smooth muscle, around the blood vessels and at the base of the mucosa in the patients with thoracic lesions. In contrast, adrenergic but not vasoactive intestinal polypeptide-immunoreactive nerves were found associated with the smooth muscle of the urethra and around the blood vessels in the patient with a cervical lesion. In patients with cervical or thoracic lesions neither adrenergic nor vasoactive intestinal polypeptide-immunoreactive nerves were found around striated muscle fibers of the intrinsic external urethral sphincter. The results are discussed in relation to the possible function of these nerves in the urethra of patients with autonomic dysreflexia and detrusor-sphincter dyssynergia.

Adult↗