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Biomedical subjects

R D Guyer

Publications and source records attributed to R D Guyer.

35 records · Page 2Linked to original sources

The effect of sensory deprivation in the reduction of pain in patients with chronic low-back pain.

Patients who suffer from persistent pain for prolonged periods of time (6 months or more) are often influenced to an increasing extent by psychological factors. Patients begin to focus on their pain as the problem rather than its physical origin. This study evaluated the effectiveness of sensory deprivation in reducing pain in patients with chronic low-back pain. Sixty patients were divided into two groups of 30 patients each: One group underwent 1 hour of sensory deprivation; the other received a lecture on relaxation skills. In the group receiving sensory deprivation, statistically significant decreases in pain and stiffness were noted. Sensory deprivation is an effective treatment to reduce pain and thus interrupt the pain cycle in patients with chronic low-back pain.

Adult↗

Choice of lasers for minimally invasive spinal surgery.

Recently, there has been increased interest in less invasive spinal surgery techniques. This has led to the development of procedures such as automated percutaneous lumbar discectomy and arthroscopic microdiscectomy. Lasers are now used in many areas of medicine and may have applications in minimally invasive spinal surgery. A number of different laser systems have been evaluated for their effectiveness in removing disc tissue in the laboratory, but technical problems have limited their clinical use. Only the Nd:YAG (1,064 nm and 1,320 nm) and KTP (532 nm) systems have been used clinically. Unsuccessful clinical results were obtained with the 1,064 nm Nd:YAG, whereas the other two systems appeared to produce results similar to the present mechanical systems but required less time for disc removal. This paper discusses considerations for choosing a laser system for spinal applications and reviews the work performed in this area.

Arthroscopy↗

Pain provocation and disc deterioration by age. A CT/discography study in a low-back pain population.

The computed tomography (CT)/discograms and discographic pain provocation reports of 291 clinical patients, 790 discs (mean age, 38; range, 17-79) were collected. The CT/discograms were classified separating anular disruption and degeneration and recording the pain provoked during discography as no pain, dissimilar, similar, or exact reproduction of the patient's clinical pain. Nondegenerated discs usually were found to be painless, and deteriorated discs painful. The proportion of severely degenerated but painless discs increased with age, as did the discs producing dissimilar pain. This may help explain the poor correlation of low-back pain with radiographic degenerative changes reported in previous epidemiologic studies.

Adult↗

A comparison of CT/discography, pain response and radiographic disc height.

CT/discograms of 107 low-back patients were classified by annular degeneration, annular disruption, and pain response. These parameters were compared with the heights of the corresponding discs. Disc height correlated significantly with degenerative annular changes. Comparison of the painless and exact reproduction groups at the L5-S1 level showed a significant increase in exact pain reproduction in narrow discs compared with normal discs. Discs demonstrating slight degenerative changes were often painful but narrowing was detected only when degeneration increased to moderate or severe levels. Some severely degenerated discs were painless and only part of the severe group was narrow. Measuring disc height is a poor method for detecting early, painful degeneration changes.

Back Pain↗

Extraosseous spinal lesions mimicking disc disease.

To identify characteristics of patient presentation that would help distinguish extraosseous spinal tumors from the more common herniated disc, nine cases of intraspinal tumors were reviewed. These nine patients were identified in a group of 744 patients who presented with symptoms similar to disc herniation but failed to respond to conservative care and underwent spinal surgery. This study indicates that intraspinal tumor should be suspected in patients with the following characteristics: 1) painless neurological deficit; 2) night pain or pain which increases in the supine position; 3) pain disproportionate to that normally expected with lumbar disc disease; 4) no change in symptoms after successful surgery for herniated disc; 5) elevated spinal fluid protein; or 6) a teenager with symptoms of disc herniation. Myelography is an effective radiologic procedure for the diagnosis of spinal tumor but MRI should be equally effective if the procedure includes a scan of the conus as well as cauda equina.

Adolescent↗

Anterior lumbar interbody fusion.

This is a report of 85 patients who underwent anterior lumbar interbody fusion (ALIF) for treatment of painful disc disruption (PDD) or symptomatic pseudarthrosis. The fusion rate was 80% by disc. The pseudarthrosis rate increased from 16% at L5-S1 to 21% and 31% at L4-5 and L3-4, respectively. There was a significant increase in pseudarthrosis rate in patients who smoked more than one pack per day. There was no difference in the fusion rate whether autogenous or cadaveric iliac crest graft or dowel versus tricortical block graft was used. Sixty-eight percent of patients were "able to work" after ALIF. The complication rate was low and retrograde ejaculation occurred in only one patient.

Adult↗

Proplast reconstruction of iliac crest defects.

Proplast reconstruction of iliac crest defects resulting from bone grafts taken for anterior lumbar and cervical fusions is described. The procedure improves the cosmetic result, prevents postoperative muscle herniation and may decrease postoperative donor site pain. It is a simple procedure with low complication rate when performed in the manner described.

Humans↗

Disc deterioration in low-back syndromes. A prospective, multi-center CT/discography study.

Disc deterioration and pain provocation in different low-back pain syndromes was studied using computed tomography (CT) discography. Data were prospectively collected for 300 patients (816 discs). Patients were classified by their pre-discography diagnosis of disc herniation (DH), degenerated disc (DD), lumbar syndrome (LS), lumbar radicular syndrome (LRS), or other. The CT/discograms were classified by discographic pain response, the amount of degeneration and annular disruption. Eighty-two percent of DH patients, 80% of DD, 56% of LS, and 59% of LRS patients had both positive discographic pain provocation and moderate or severe disc deterioration. The study indicates that intradiscal pathology plays a major role in nonspecific low-back pain syndromes.

Back Pain↗

Discitis after discography.

A series of nine patients with post-discography discitis were evaluated to help delineate the clinical course. The most consistent sign was the marked exacerbation of neck or back pain. This then was followed by an elevated sedimentation rate at an average of 20 days, followed by a positive bone scan at an average of 33 days. Of note is that seven patients initially had negative bone scans at an average of 18 days. Five out of nine patients had changes on plain roentgenograms between 14 and 51 days after discography. Magnetic resonance imaging was performed in six patients; two of these patients were scanned twice. Three scans were negative and five were positive (2 patients initially had negative scans that later became positive). The course of lumbar discitis ranged from 8 to 11 weeks, and cervical discitis from 6 to 7 weeks, with the latter usually resulting in spontaneous fusion.

Adult↗

Dallas discogram description. A new classification of CT/discography in low-back disorders.

A new classification method for CT/discography was developed. The Dallas discogram description (DDD) related five separate categories of information. Degeneration and annular disruption were regarded as separate phenomena. Additionally, provoked pain response, contrast volume, and miscellaneous information were recorded. Discogram findings of 59 patients with low-back and/or leg pain were graded according to the new method and compared with standard methods using routine anteroposterior and lateral discographic images. Findings from routine discography and CT/discography were graded and correlated with myelographic and plain computerized axial tomography (CAT) scans. This study demonstrated that the contrast-enhanced axial view provided by CT/discography served as a useful projection for demonstrating disc pathology. CT/discography analyzed according to DDD offered a more sensitive discriminator of disc degeneration from annular disruption (disc protrusion/leaking). This evaluation can be recommended as the procedure of choice when revision of spine surgery is considered or when there is an equivocal or negative correlation between clinical information and myelography or CAT scan.

Adult↗

The relationship of pain provocation to lumbar disc deterioration as seen by CT/discography.

The CT/discographic findings from 225 discs in 91 low-back pain patients were compared to the pain provocation during the injection of contrast into the disc. The radiographic appearance of disc deterioration demonstrating disc degeneration and annular disruption of each disc was classified separately using a fourpoint scale: normal, slight, moderate, or severe. Pain reaction to the discogram at each level was recorded as follows: no pain, dissimilar pain, similar pain, or exact reproduction of the patient's clinical pain. This more precise analysis demonstrated a significant relationship between pain and deterioration of discs. The CT/discogram presents an axial view of the disc that allows a subgrouping of disc deterioration that can discriminate between peripheral deterioration (degeneration) and internal deterioration (disruption). The disruption supposedly occurs earlier and is more likely to be the source of exact pain reproduction.

Adult↗

The detection and prevention of pulmonary embolism in total hip replacement. A study comparing aspirin and low-dose warfarin.

Because of the controversy surrounding prophylaxis for thromboembolism after total hip surgery, we undertook a prospective study comparing the results of the administration of aspirin with that of low doses of warfarin in 194 patients (200 hips) undergoing total hip replacement. The incidences of both clinically apparent and silent (asymptomatic) pulmonary emboli were determined using the objective criteria of preoperative and postoperative levels of arterial blood gases, chest roentgenograms, electrocardiograms, and perfusion lung scans. With this surveillance plan, the accuracy of diagnosis of clinically symptomatic pulmonary emboli was improved and the detection of otherwise silent pulmonary emboli became possible. The group of patients who received low doses of warfarin showed a 6 per cent total incidence of pulmonary emboli compared with a 19 per cent incidence in the group receiving aspirin (p less than 0.05). There was, however, no significant difference when the incidences of only the clinically suspected emboli were compared, the rates for the two groups being 5 and 8 per cent, respectively (p greater than 0.05). There was also no significant difference between men and women with regard to the prophylactic efficacy of aspirin in preventing pulmonary embolism.

Aspirin↗

The use of presurgical psychological screening to predict the outcome of spine surgery.

BACKGROUND CONTEXT: Several previous studies have shown that psychosocial factors can influence the outcome of elective spine surgery. PURPOSE: The purpose of the current study was to determine how well a presurgical screening instrument could predict surgical outcome. STUDY DESIGN/SETTING: The study was conducted by staff of a psychologist's office. They performed preoperative screening for spine surgery candidates and collected the follow-up data. PATIENT SAMPLE: Presurgical screening and follow-up data collection was performed on 204 patients who underwent laminectomy/discectomy (n=118) or fusion (n=86) of the lumbar spine. OUTCOME MEASURES: The outcome measures used in the study were visual analog pain scales, the Oswestry Disability Questionnaire, and medication use. METHODS: A semi-structured interview and psychometric testing were used to identify specific, quantifiable psychological, and "medical" risk factors for poor surgical outcome. A presurgical psychological screening (PPS) scorecard was completed for each patient, assessing whether the patient had a high or low level of risk on these psychological and medical dimensions. Based on the scorecard, an overall surgical prognosis of "good," "fair," or "poor" was generated. RESULTS: Results showed spine surgery led to significant overall improvements in pain, functional ability, and medication use. Medical and psychological risk levels were significantly related to outcome, with the poorest results obtained by patients having both high psychological and medical risk. Further, the accuracy of PPS surgical prognosis in predicting overall outcome was 82%. Only 9 of 53 patients predicted to have poor outcome achieved fair or good results from spine surgery. CONCLUSIONS: These findings suggest that PPS should become a more routine part of the evaluation of chronic pain patients in whom spine surgery is being considered.

Adult↗

Alar transverse process impingement of the L5 spinal nerve: the far-out syndrome.

This syndrome occurs in two types of patients: (1) the elderly person with degenerative scoliosis and (2) a somewhat younger adult population with isthmic spondylolisthesis and at least 20% slip. On plain radiograph, the Ferguson view (25 degrees caudocephalic) is best for visualizing the condition, however, CT is by far the best diagnostic tool. To show this far laterally, the "window" on the CT scanner must be opened wider than usual. Both coronal and parasagittal views will demonstrate the condition, but the coronal is the most valuable. Symptoms are classical spinal nerve compression. Usually it is the L5/S1 level that is involved, but other levels can be. At surgery, it is most important that nerve decompression be carried far enough laterally. This can mean sacrificing the lower half of the pedicle and the entire transverse process. Part of the body of S1 and of the sacral ala can be removed if the surgeon prefers. Because so much bone is removed, instability is a factor to be seriously considered. How to decompress adequately and still maintain stability often poses a most difficult problem.

Adult↗