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Biomedical subjects

T Ducker

Publications and source records attributed to T Ducker.

9 recordsLinked to original sources
PubMed2000

A critical appraisal of the reporting of the National Acute Spinal Cord Injury Studies (II and III) of methylprednisolone in acute spinal cord injury.

From the beginning, the reporting of the results of National Acute Spinal Cord Injury Studies (NASCIS) II and III has been incomplete, leaving clinicians in the spinal cord injury (SCI) community to use or avoid using methylprednisolone in acute SCI on the basis of faith rather than a publicly developed scientific consensus. NASCIS II was initially reported by National Institutes of Health announcements, National Institutes of Health facsimiles to emergency room physicians, and the news media. The subsequent report in the New England Journal of Medicine implied that there was a positive result in the primary efficacy analysis for the entire 487 patient sample. However, this analysis was in fact negative, and the positive result was found only in a secondary analysis of the subgroup of patients who received treatment within 8 hours. In addition, that subgroup apparently had only 62 patients taking methylprednisolone and 67 receiving placebo. The NASCIS II and III reports embody specific choices of statistical methods that have strongly shaped the reporting of results but have not been adequately challenged or or even explained. These studies show statistical artifacts that call their results into question. In NASCIS II, the placebo group treated before 8 hours did poorly, not only when compared with the methylprednisolone group treated before 8 hours but even when compared with the placebo group treated after 8 hours. Thus, the positive result may have been caused by a weakness in the control group rather than any strength of methylprednisolone. In NASCIS III, a randomization imbalance occurred that allocated a disproportionate number of patients with no motor deficit (and therefore no chance for recovery) to the lower dose control group. When this imbalance is controlled for, much of the superiority of the higher dose group seems to disappear. The NASCIS group's decision to admit persons with minor SCIs with minimal or no motor deficit not only enables statistical artifacts it complicates the interpretation of results from the population actually sampled. Perhaps one half of the NASCIS III sample may have had at most a minor deficit. Thus, we do not know whether the results of these studies reflect the severely injured population to which they have been applied. The numbers, tables, and figures in the published reports are scant and are inconsistently defined, making it impossible even for professional statisticians to duplicate the analyses, to guess the effect of changes in assumptions, or to supply the missing parts of the picture. Nonetheless, even 9 years after NASCIS II, the primary data have not been made public. The reporting of the NASCIS studies has fallen far short of the guidelines of the ICH/FDA and of the Evidence-based Medicine Group. Despite the lucrative "off label" markets for methylprednisolone in SCI, no Food and Drug Association indication has been obtained. There has been no public process of validation. These shortcomings have denied physicians the chance to use confidently a drug that many were enthusiastic about and has left them in an intolerably ambiguous position in their therapeutic choices, in their legal exposure, and in their ability to perform further research to help their patients.

Acute Disease↗
PubMed1999

Outcome in patients with cervical radiculopathy. Prospective, multicenter study with independent clinical review.

STUDY DESIGN: The Cervical Spine Research Society study is a prospective, nonrandomized, multicenter investigation of patients with cervical spondylosis and disc disease. In this analysis, only patients who had radiculopathy without myelopathy as the predominant symptom were considered. OBJECTIVES: To determine demographics, surgeon treatment practices, and outcomes in patients with symptomatic radiculopathy. SUMMARY OF BACKGROUND DATA: Current data on patient demographics and treatment practices of surgeons do not exist. There are no published prospective studies in which outcomes, including pain, function, neurologic symptoms, and ability to perform activities of daily living, are systematically quantified. METHODS: Patients were recruited by participating Cervical Spine Research Society surgeons. Demographic, symptomologic, and functional patient data were compiled from surveys of patients and physicians completed at the time of initial examination, and outcomes were assessed from surveys of patients completed after treatment. Data were compiled and statistically analyzed by a blinded third party. RESULTS: Of the 503 patients enrolled by 41 CSRS surgeons, 246 (49%) had radiculopathy. Patients had a mean duration of symptoms of 26.7 months (range, 8 weeks to > 352 months) and a mean age of 48.1 +/- 12.42 years; 44.7% were female. Surgery was recommended for 86 (35%) of these patients. Of the 155 patients on whom there were follow-up data, 51 (33%) underwent surgery, whereas 104 (67%) received medical treatment. Surgically treated patients had a significant improvement in pain, neurologic symptoms, functional status, and ability to perform activities of daily living. A significant number of patients who underwent surgery reported persistent excruciating or horrible pain on follow-up (26%). Patients treated medically also had significant improvement in pain and overall functional status. CONCLUSIONS: In summary, this study represents the first in-depth, prospective outcome analysis of patients with cervical spondylotic and discogenic radiculopathy.

Activities of Daily Living↗
PubMed1992

Management of testicular seminoma following organ transplantation.

An increased incidence of malignancies has occurred in recipients of organ transplantation who are immunosuppressed. Although testicular cancers have been uncommon, seminomas are extremely rare. Two patients with long-standing diabetes mellitus and renal transplants developed clinical stage I seminoma of the testis. These patients posed a therapeutic problem with respect to the use of radiation therapy. In one, none was given because of a combination of kidney rejection and antibiotic-induced renal damage. The second patient received radiation therapy with shielding of the transplanted kidney. The surgical distortion of lymph node architecture increases the problems in the use of radiation therapy. Individual factors need to be considered in the use of postorchiectomy radiation therapy for seminoma in transplant patients.

Adult↗
PubMed1990

Multilevel lumbar laminotomies: an alternative to laminectomy in the treatment of lumbar stenosis.

The traditional treatment for lumbar stenosis is a wide laminectomy. This procedure has a high success rate and a low, but not insignificant, incidence of complications. Recently, however, a better understanding of the pathophysiology of spondylotic lumbar stenosis has led several authors to propose a more limited decompression directed specifically toward the offending area of compression. Over the past 5 years, we have treated 32 patients with lumbar stenosis using decompressive laminotomies. Our patients all had focal lateral recess stenosis that was diagnosed by computed tomography or magnetic resonance imaging. We performed decompressive laminotomies and foraminotomies at appropriate levels. This procedure is less disruptive than a full laminectomy and, in experienced hands, requires less operating time. At last follow-up, 90% of the patients so treated reported an excellent outcome--namely, total relief of symptoms and/or return to normal daily activities. There was no significant postoperative morbidity or mortality. We conclude that in a selected subgroup of patients with lumbar stenosis, multilevel laminotomies may be an acceptable alternative to laminectomy.

Adult↗
PubMed1988

Multilevel lumbar laminotomies for focal spinal stenosis: case report.

We describe a case of spondylotic lumbar spinal stenosis in an infirm elderly patient successfully treated with multilevel laminotomies. This procedure is less stressful to patients than a full laminectomy. In a selected subgroup of patients with "hourglass" spondylotic stenosis, it may provide adequate decompression.

Aged↗
PubMed1986

Failure of stabilization of the spine with methylmethacrylate. A retrospective analysis of twenty-four cases.

Twenty-four patients who had a major complication after attempted stabilization of the spine with methylmethacrylate were referred for treatment. The initial instability that necessitated stabilization was caused by a traumatic condition in fifteen of these patients and by a metastatic tumor in nine. The average length of time before failure of fixation was 208.3 days for the patients who had a traumatic condition and 193.7 days for those who had a neoplasm. In eleven patients a progressive neural deficit developed postoperatively, and in six others the recovery of neural function was possibly hindered by the cement. A deep wound infection developed in six patients, and in five of them treatment by removal of the methylmethacrylate and metal, followed by a prolonged period of cervical traction, was required. Loosening and failure of fixation was the most common complication--it occurred in twelve of the fifteen patients who had a traumatic lesion and in eight of the nine who had a neoplasm. Salvage operations that included removal of the cement and conventional bone-grafting procedures were performed in eleven of the twelve patients who had loosening associated with a traumatic lesion and in six of the eight who had loosening and a tumor. Stability was restored in every patient. Improved long-term results can be achieved by using grafts of iliac bone and triple-wire stabilization methods (a midline wiring between the spinous processes and two iliac-crest grafts, one on each side, wired to the posterior elements) instead of methacrylate in the primary treatment of traumatic injuries. The treatment of choice for instability caused by neoplastic destruction of two or more vertebral bodies includes a construct of methylmethacrylate anteriorly. However, if cement is used, early augmentation with posterior fusion of the spine and stabilization should be considered. As a rule, combined anterior and posterior stabilization is recommended for the reconstruction of a spine that is unstable due to neoplastic destruction. In general, whenever methylmethacrylate is used for spinal stabilization, it should be augmented with grafts of iliac bone to provide long-term stability.

Adult↗
PubMed1983

Evaluation of regeneration of nerve and reinnervation of skeletal muscle in the hibernating ground squirrel.

The retrograde transport of HRP was used to determine the status of axonal transport in the peroneal and sciatic nerves of hibernating and nonhibernating ground squirrels following crush of the peroneal nerve at 10 to 12 mm (SNS) or sciatic nerve at 33 to 35 mm (LNS) from its entrance into the extensor muscle. The ability of the proximal segment to reestablish axonal continuity and thus neuromuscular transmission was also studied. Two weeks to 3 months after nerve crush the extensor muscles were injected with HRP. We found that during hibernation no axonal transport across the site of crush was seen even after 3 months and that regeneration of the nerve during this period was minimal. Evidence of slight regeneration seen at 90 days could be due to periods of awaking of the animals during their natural hibernation cycle. In these animals HRP deposits were seen only in the nerve distal to crush, i.e., between crush site and muscle. In the nonhibernating squirrels, axoplasmic flow was reestablished at the site of injury as early as 2 weeks after crush, and HRP could be detected in the spinal cord in motoneurons of the ipsilateral ventral horn at spinal levels L3 to L5. In one hibernating animal the peroneal nerve was crushed at the distal site (SNS) and also the spinal cord was injured by dropping a weight. After nerve crush and the spinal cord injury the hibernating state could not be maintained and the animal stayed awake 22 days. The time course of regeneration of the nerve in that animal was similar to that seen in nonhibernating squirrels. After nerve crush in nonhibernating animals, reaction product was also found in sensory cell bodies of dorsal root ganglia as well as in terminals in the substantia gelatinosa of the spinal cord at the same levels. Thus, the axonal transport occurs in hibernating and non-hibernating squirrels in both sensory and motor nerve fibers. The extensor muscle fibers of the hibernating squirrels showed substantial membrane depolarization 90 days after crush. Action potentials from these fibers could be obtained from 15 to 35 days only through stimulating the nerve segment distal to the crush. Stimulation of the proximal nerve segment did not evoke muscle activity. These results demonstrate that nerve regeneration was nearly abolished during hibernation and that blockade of axonal transport continued across a region of nerve crush for the duration of the hibernating period.

Animals↗
PubMed1977

Elevated CSF gamma globulins with cerebral "glioma.".

A patient with a six-year history of seizures and a shorter history of a progressive hemiparesis, had a glioma. A partial frontal lobectomy was performed. The cerebrospinal fluid, 38 days post-operatively, prior to irradiation, had an increase in gamma globulins. Following cranial irradiation the CSF gamma globulin level returned to normal and the hemiparesis disappeared. The significance of these CSF changes is discussed.

Brain Neoplasms↗