'Progressive-onset' versus injury-associated discogenic low back pain: features of disc internal derangement in patients studied with provocation lumbar discography.

Chronic low back pain (LBP) can be 'progressive onset' or injury-related. This study compares the patient-reported cause of chronic LBP to features of disc internal derangement at painful concordant discs evaluated by provocation lumbar discography. Concordant LBP was identified in 114 patients with chronic LBP studied by provocation discography. LBP cause, discogram pain response and discogram/post-discogram CT features of internal derangement were retrospectively reviewed. 'Progressive-onset' LBP was reported in 32 (28%) patients, injury-related LBP in 75 (66%) with LBP equated to non-specific causes in seven. Injury-related LBP was more commonly identified in men (52 of 63 [83%]) with women reporting near-equal frequency of 'progressive-onset' (23 of 44 [52%]) and injury-related (21 of 44 [48%]) LBP (p=0.002). In 172 concordant painful discs, near-equal frequency of severely degenerative (Dallas grade-3: 82 of 172 [47.3%]) and full-thickness radial fissure discs (Dallas grade-3: 90 of 172 [52.7%]) were identified. Women with 'progressive-onset' LBP demonstrated more frequent severely degenerative discs (24 of 37 [65%]); women with injury-related LBP demonstrated more frequent radial-defect discs (21 of 31 [68%]; p=0.01). In men with injury-related LBP, severe degeneration-only (44 of 89 [49%]) and radial defect discs (45 of 89 [51%] were seen with equal frequency. In men with 'progressive-onset' LBP, radial defects are more common (11 of 15 [73%]). 'Progressive-onset' and injury-related chronic LBP subgroups are definable. Gender-related differences in incidence and internal derangement features at concordant discs are identified at discogram/post-discogram CT. These differences may have implications related to LBP origin/treatment-response.

Impact of dose hot spots on spinal cord tolerance following stereotactic body radiotherapy: a generalized biological effective dose analysis.

The purpose of this study was to investigate the effects of high-dose inhomogeneous irradiation to small volumes of spinal cord with a new generalized biological effective dose (gBED) analysis for spine stereotactic body radiotherapy (SBRT). The gBED was applied to spinal cord dosimetric data (contoured per the thecal sac) at specified volumes for a cohort of five patients with radiation-induced myelopathy (RM) and compared to nineteen patients without RM post-SBRT. The spinal cord gBED was calculated and normalized to a conventional 2-Gy equivalent dose fraction scheme (α/ß = 2 Gy for late toxicity). Differences between the conventional BED and those gBED calculations by accounting for small-volume dosing within the spinal cord was observed. Statistically significant differences in the mean gBED between the RM group and the non-RM group was observed both at the maximum point volume (gBED of 66 Gy vs. 37 Gy (p = 0.01), respectively) and at the 0.1 cm(3) volume (gBED of 53 Gy vs. 28 Gy (p = 0.01), respectively). No significant difference at the 0.1 cm(3) volume was observed based on the mean BED comparisons. No significant differences were observed at the larger 1 cm(3), 2 cm(3) or 5 cm(3) volumes for either BED or gBED comparisons. We conclude that differences in dose hot spots characteristics within small inhomogenously irradiated volumes of spinal cord can affect spinal cord tolerance following SBRT treatments.

Provocation lumbar diskography at previously fused levels.

Recurrent or persistent low back pain (LBP) after lumbar fusion can be related to many factors. We reviewed the provocation lumbar diskogram (PLD) features and redo-fusion outcome in our patients evaluated for recurrent/persistent LBP after technically successful fusion. LD was performed in 27 patients with recurrent/persistent LBP after prior successful lumbar surgical fusion (31 fused levels: single-level fusion-23; two-level fusion-4). PLD response and imaging characteristics at fused and non-fused levels were assessed including: intra-diskal lidocaine response, diskogram-image/post-diskogram CT appearance, presence/absence of diskographic contrast leakage, and evidence of fusion integrity or hardware failure. Outcomes in patients having redo-fusion were assessed. Concordant pain was encountered at 15 out of 23 (65%) single-level fusions, non-concordant pain in one fusion with non-painful response in seven. Adjacent-level concordant pain was identified in seven out of 23 (30%) patients (three of 15 with painful fused levels; four of seven with non-painful fusions). In two-level fusions, concordant pain was encountered at one fused level in each patient. In painful fused levels, leaking and contained disks were encountered with partial or complete pain elimination after intra-diskal lidocaine injection. In anterior fusions, space or contrast surrounding the cage was noted at five of 11 levels. Pseudoarthrosis was noted only with trans-sacral screw fusions. Redo-fusion in 13 patients resulted in significant improvement in nine and moderate improvement in one. Patients with recurrent/persistent LBP after technically successful fusion may have a diskogenic pain source at the surgically fused or adjacent level confirmed by lidocaine-assisted PLD.

Epidermoid cyst of the thoracic spine: case history.

Epidermoid cysts of the spinal cord are very rare tumors. We report a 31 year-old female who presented with a 5 months history of progressive lower extremity weakness and spasticity. Magnetic resonance imaging of the thoracic spine revealed a 2 cm intradural, extramedullary mass at the T4-5 level. A T4 and T5 osteoplastic laminotomy with complete removal of the intradural mass was performed. Intraoperative and final histological examination revealed an epidermoid cyst. Epidermoid cysts must be a consideration for intradural, extramedullary lesions of the spinal cord. Complete surgical resection offers the patient an opportunity for good neurologic outcome.

Diseases of the spine in South American mummies.

OBJECTIVE: The skulls and spinal columns of people from ancient civilizations, which frequently are found in a preserved state at archeological sites, can provide a large amount of information about these individuals' physical condition through paleopathological investigation. METHODS: This study represents the examination of more than 700 human remains dating back more than 8000 years that were recovered from archaeological excavations in the Andean region of southern Peru and northern Chile. RESULTS: Examples of congenital malformations, degenerative processes, infectious diseases, neoplasias, and traumatic diseases were discovered. Congenital anomalies such as spina bifida occulta were relatively common in these populations. No cases of meningomyelocele were discovered. The most common pathological findings were degenerative changes of the vertebral bodies. Large cervical and lumbar osteophytes were identified in some remains. Several cases of cervical spondylosis were determined to be the result of an occupational disease resulting from carrying heavy loads on the back. These heavy loads were supported by wearing around the forehead a tumpline, known as a capacho. The most common infectious disease process in the spine was due to tuberculosis. The diagnosis was made by radiological and histopathological studies, and in several cases the organism Mycobacterium tuberculosis was identified in the soft tissues. Metastatic lesions on the vertebral bodies were identified in a single case. Examples of traumatic spinal injury were rare. Compression fractures were noted infrequently. CONCLUSION: Diseases of the spinal column in the ancient inhabitants of the Andean region of South America were similar to those that affect the present-day population of that area.

Relationship between type of health insurance and time to inpatient rehabilitation placement for surgical subspecialty patients.

A significant proportion of patients on a neurosurgical service require inpatient rehabilitation placement after discharge. The relationship between the type of health insurance of the patient at the time of admission and the time to placement of patients has not previously been addressed. We prospectively studied all patients on the adult neurosurgical service at our hospital to determine whether the type of health insurance carried by patients is related to the time necessary to arrange acceptance into inpatient rehabilitation facilities. Ninety-one patients (51 men, 40 women; mean age, 56 years) admitted to the neurosurgery service during a 6-month period required inpatient rehabilitation placement after discharge. The time in days between the request for placement into a rehabilitation facility and the acceptance of the patient was examined. The mean time for placement of patients with and without health insurance at the time of admission was 0.8 days and 2.1 days, respectively (overall mean, 1.1 days) (P < .002). No statistically significant associations were found between age, sex, or race of the patient and the time to placement. In addition, there was no difference in the time to placement between those patients admitted as a result of trauma and those patients admitted for reasons other than trauma. These results indicate that among patients on a neurosurgical service, patients with private health insurance are accepted into inpatient rehabilitation approximately 1 day sooner than patients without private health insurance. Patients without private health insurance are delayed in their transfer to inpatient rehabilitation facilities and more aggressive inpatient rehabilitation. How this finding translates into an increase in cost of care or a decrease in patient outcomes is unknown.

Current surgical management of metastatic spinal disease.

Despite advances in the treatment of many malignancies, a large number of cancer patients will require evaluation and possible surgical intervention for lesions that have metastasized or directly invaded the spinal column. The need for heightened awareness of and aggressive early intervention for spinal metastases is underscored by many studies that have reported a relationship between pretreatment and posttreatment neurologic function in these patients. Recommendations for operative intervention should be made following an evaluation of the patient by multiple specialties, both medical and surgical. In the last decade, advances in surgical techniques for tumor decompression and spine stabilization, neurophysiologic monitoring, and anesthetic expertise have allowed surgeons to perform more extensive procedures with improved outcomes and reduced morbidity. This article will review the factors favoring an operative recommendation in patients with metastatic spinal disease, preoperative evaluation, and available surgical options. Patients with symptomatic spinal metastases should receive early surgical consultation as part of a multidisciplinary approach to their disease process.

Inhibition of peridural fibrosis after laminectomy using low-dose external beam radiation in a dog model.

OBJECTIVE: Clinical studies have demonstrated a significant association between the presence of extensive postlumbar discectomy peridural scar formation and the recurrence of low back and radicular pain. Low-dose perioperative radiation therapy has previously been demonstrated to inhibit peridural fibrosis after laminectomy in a rat model. The current study was designed to measure the effect of low-dose radiation on postlaminectomy peridural fibrosis development in a larger animal model. METHODS: Three dogs underwent a total of 12 lumbar hemilaminectomies. For each animal, two levels received 1) external beam radiation 24 hours before surgery, 2) surgery alone, or 3) radiation alone. Radiation was administered in a single fraction of 700 cGy using computed tomographic guidance for dosimetry planning. The isodose distribution was such that the dose conformed to the posterior epidural space with minimal exit dose to normal tissue. Port films were used to confirm the correct levels. Gadolinium-enhanced magnetic resonance imaging (MRI) of the lumbar spines was obtained before the animals were killed 12 weeks after surgery. The spines were harvested, and axial sections through the laminectomy defect were stained with hematoxylin and eosin and Masson's trichrome. All specimens were evaluated for extent of fibrosis along the dura, density of fibrosis, nerve root entrapment, and sublaminar fibrosis. RESULTS: There were no complications from the surgery, and no new neurological deficits were noted. There was a statistically significant difference between the irradiated and nonirradiated groups regarding the extent of fibrosis (P = 0.001) and the density of fibroblasts (P = 0.001). There was also a marked difference in nerve root entrapment (P = 0.182) and the presence of sublaminar fibrosis (P = 0.061) between the treatment and control groups. MRI revealed less gadolinium enhancement at the irradiated levels compared with the nonirradiated levels, confirming the usefulness of MRI in predicting the degree of epidural fibrosis. CONCLUSION: Low-dose external beam radiation therapy administered 24 hours before laminectomy in a dog model significantly decreased the extent and density of peridural fibrosis as well as nerve root entrapment and sublaminar fibrosis. This treatment strategy may be efficacious in patients with recurrent radicular pain after lumbar discectomy that is thought to be secondary to peridural fibrosis on the basis of gadolinium-enhanced MRI studies, and who might benefit from reoperation for nerve root decompression.

A formal risk assessment of silicone breast implants.

In 1992, the United States Food and Drug Administration (FDA) announced that breast implants filled with silicone gel would be available only through controlled clinical studies despite the fact that they had been used for mammoplasty in millions of women around the world for more than 30 years. The safety of silicone gel breast implants had come into question after several reports on a possible association between the implants and subsequent development of connective-tissue diseases. Risk assessment refers to the systematic, scientific characterization of potential adverse effects of human exposures to hazardous agents or activities. The following risk assessment is intended to review the current scientific evidence for the safety of silicone gel-filled breast implants since the FDA's decision in 1992. There now appears ample evidence from the scientific literature for the safety of these prostheses.

Inhibition of peridural fibrosis after laminectomy using low-dose external beam radiation in a rat model.

OBJECTIVE: Clinical studies have revealed a significant association between the presence of extensive postlumbar discectomy peridural scar formation and the reoccurrence of low back and radicular pain. Low-dose perioperative radiation therapy has been shown to inhibit scar formation. Its effect on peridural fibrosis, however, has not been studied. METHODS: Thirty male Sprague-Dawley rats underwent L5 laminectomies. Ten rats each received a single fraction of 700-cGy external beam radiation to the lumbar spine 24 hours before surgery; 10 rats each received 700 cGy 24 hours after surgery. The remaining 10 rats served as a control group. All of the rats were killed 30 days after surgery. The spines were harvested, and axial histological sections through the laminectomy defect were evaluated. Each specimen was scored for extent, density, and arachnoidal involvement by fibrosis. RESULTS: There was a statistically significant difference between the treatment and control groups regarding the extent of fibrosis along the dura (P < 0.001), the density of fibroblasts (P < 0.005), and the arachnoid involvement (P < 0.01). There was no difference in fibrosis reduction between the groups receiving pre- and postlaminectomy radiation. CONCLUSION: Low-dose external beam radiation therapy administered before or after laminectomy in a rat model significantly decreases the extent, density, and arachnoidal involvement of peridural fibrosis. This technique may improve the outcome of patients who undergo reoperations for recurrent radicular and/or low back pain after successful lumbar discectomy in whom there is a significant amount of peridural fibrosis.

Silicone breast implants: an oncologic perspective.

In 1992, the FDA decided that silicone gel-filled breast implants would be available only through controlled clinical studies, despite the fact that they had been used for mammoplasty in millions of women around the world for more than 30 years. The safety of silicone breast implants had been called into question after several reports of a possible association between the implants and the subsequent development of connective tissue diseases. Such reports led to general public concern fueled by popular media attention and multiple class-action lawsuits against the product's manufacturers. It was in this climate that the FDA was forced to make its decision. This article reviews current scientific evidence on the safety of silicone gel-filled breast implants. Issues pertinent to oncology are highlighted. These include the possible carcinogenic effect of silicone gel, the safety of irradiating breasts with silicone implants, and the ability to mammographically image the implanted breast.

Outcomes research: a review.

PURPOSE: The purpose of this article is to review the history of the medical outcomes movement as well as the methodologies used in outcomes research. CONCEPT: Outcomes research refers to a genre of clinical investigation that emphasizes the measurement of patient health outcomes, including the patient's symptoms, functional status, quality of life, satisfaction with treatment, and health care costs. RATIONALE: Outcomes research evolved from studies that demonstrated the presence of wide geographic variations in the practice of medicine and surgery. Such differences in utilization were unaccompanied by any discernible difference in patient outcomes. With escalating health care costs, there has been a growing interest in measuring the outcomes of medical intervention to determine the quality and appropriateness of medical care. DISCUSSION: Outcomes may be measured both directly and indirectly, over differing periods of time, and with varying degrees of objectivity, reliability, and validity. Current research has focused on quality of life issues, which include the extent to which a patient's usual or expected physical, emotional, and social well-being have been affected by a medical condition or treatment. The true value of health care can be determined only by a systematic examination of patient outcomes. To accomplish this goal, methods are required that are relatively unfamiliar to many clinical researchers. Future clinical research should include patient-oriented outcome measures that would otherwise focus solely on physiological or anatomic outcomes. Such information will be essential in determining which medical and surgical treatment strategies should be abandoned and which will gain acceptance in the future.

Intraoperative hypothermia and ventricular shunt infections.

Several recent studies have demonstrated a relationship between intraoperative hypothermia and postoperative infection. A study was therefore conducted to evaluate the relationship between intraoperative hypothermia and ventricular shunt infections. Sixty-eight children who underwent ventricular shunt placement, including revisions, over a six year period subsequently developed a shunt infection (overall shunt infection rate of 5%). Mean age was 8 years (range, neonate to 20 years). The last 74 children who underwent ventricular shunt placement without subsequent infection served as a comparison group. The anesthetic records of all cases were reviewed to determine the lowest core temperature recorded during the surgical procedure. The lowest core temperature varied from 33.9 degrees C to 37.7 degrees C (mean 36.0 degrees C). Hypothermia was defined as a temperature less than 35.1 degrees C. No relationship was found between hypothermia and the subsequent occurrence of a shunt infection (P = 0.45). When those children less than 2 years old were excluded from analysis, there was a trend towards statistical significance (P = 0.07). In summary, this study failed to show any significant relationship between the occurrence of intraoperative hypothermia and subsequent ventriculoperitoneal shunt infection in a group of pediatric patients.

Intrathecal baclofen infusion and subsequent orthopedic surgery in patients with spastic cerebral palsy.

UNLABELLED: Intrathecal baclofen infusion (IBI) is an effective treatment for spasticity secondary to cerebral palsy (CP). OBJECT: To assess the need for orthopedic surgery of the lower extremities in such cases, the authors retrospectively reviewed the outcome in 48 patients with spastic CP who were treated with IBI. METHODS: Pumps were placed in 40 patients (84%) suffering from spastic quadriplegia and eight patients (16%) with spastic diplegia. The patients' ages ranged from 5 to 43 years (mean 15 years). The mean follow-up period was 53 months (range 24-94 months). The mean baclofen dosage was 306 microg/day (range 25-1350 microg/day). At the time of pump placement, subsequent orthopedic surgery was planned in 28 patients (58%); however, only 10 (21%) underwent surgery after IBI therapy. In all 10 cases, the surgical procedure was planned at the time of initial evaluation for IBI therapy. In the remaining 18 patients, who did not subsequently undergo their planned orthopedic operation, it was believed that their lower-extremity spasticity had improved to the degree that intervention was no longer indicated. In addition, although six patients had undergone multiple orthopedic operations before their spasticity was treated, no patient required more than one operation after IBI treatment for spasticity. CONCLUSIONS: The authors conclude that IBI for treatment of spastic CP reduces the need for subsequent orthopedic surgery for the effects of lower-extremity spasticity. In patients with spastic CP and lower-extremity contractures, spasticity should be treated before orthopedic procedures are performed.

Diseases of the skull in pre-Columbian South American mummies.

OBJECTIVE: The majority of paleopathological investigations focus on the study of the skull. This is because the skull is the most frequently preserved part of the human body recovered from archaeological excavations. From studying the skull, a variety of information can be obtained regarding the individual, such as sex, age, nutritional status, and other disease processes, if present. METHODS: This study represents the examination of more than 700 human skulls recovered from archaeological excavations from the Andean region of southern Peru and northern Chile and dating back more than 8000 years. RESULTS: A variety of skull abnormalities were encountered. The nonmetric variables of Huschke's foramina and palatine tori were common. Cranial deformation was observed in more than 85% of the cases. There were two cases of sagittal synostosis. Iron deficiency anemia resulting in porotic hyperostosis of the skull was evident in certain cultures. Exostoses of the external auditory canal resulting from chronic otitis was evident only among coastal populations. One skull demonstrated a periostitis consistent with Treponema infection. Trephination was encountered only in the skulls from Peru. Fifty-four cases of skull fractures were observed, half of which showed evidence of healing. Finally, only two cases of neoplastic skull lesions were encountered. CONCLUSION: The study of the human skull alone provides a large amount of information regarding the health and diseases of ancient populations.

Oncology in the era of managed care.

The field of oncology, both with regards to clinical care as well as research, is rapidly changing in response to the current changes in our health care delivery system. Cancer is the second leading cause of death in the United States, exceeded only by heart disease. Cancer care, including screening, diagnosis, treatment, and supportive care, consumes approximately 15% of all health care costs in the United States. The National Cancer Institute estimates the overall costs for cancer at $104 billion per year. Despite the increasing incidence of cancer, federal funding for cancer research has actually declined. Managed care's emphasis on cost reduction is threatening all aspects of the care of patients with cancer. Along these same lines, clinical research support has been dramatically affected by managed care. The major critical issues in the future will be guaranteed access of patients to high-quality cancer care, access to qualified clinical trials, promotion of cancer prevention programs, and support of professional education in oncology. The American Cancer Society estimates that in 1997, 1,382,400 new cases of cancer are expected to be diagnosed in the United States. This year alone, 560,000 Americans are expected to die of cancer. Cancer is the second leading cause of death in the United States, exceeded only by heart disease. One of every four deaths in the United States is due to cancer. The field of oncology, both with regards to clinical care as well as research, is rapidly changing in response to the current changes in our health care delivery system. This paper will address how these changes are having a major impact on the practice of cancer care in the United States.

Primary parafalcine chondrosarcoma in a child.

Intracranial cartilaginous tumors are rare lesions, usually arising from the skull base in older individuals. We report the case of a 12-year-old girl with a low-grade type chondrosarcoma arising from the falx cerebri. To our knowledge this is the first such case reported in a child. She was treated with gross total surgical resection followed by external beam radiation because there was evidence of dural infiltration by tumor in and around the superior sagittal sinus. The patient remains progression free 9 months after surgery.

Clinical practice guidelines and their role in quality of care assessments.

Clinical practice guidelines may be defined as systematically developed statements to assist practitioner and patient decisions about appropriate healthcare for specific clinical conditions. The practice guideline is a management plan that enables healthcare providers to make sequential decisions about testing or therapy in a given clinical situation. Given the heterogeneity of disease presentations and the complexity of making therapeutic decisions, the development of guidelines in neurosurgery presents unique problems and challenges. Clinical practice guidelines were developed in part as a method for the assessment of quality of medical care processes. Practice guidelines serve as a tool for comparisons to be made within and between healthcare delivery systems. The implementation of guidelines also allows for the acquisition of clinical and financial data that provide for outcomes analysis and other types of information. The characterization of patterns of care in different institutions and the relationship between patterns of care and outcomes will in the future allow for quality improvement, enable physicians to offer predictability and accountability to third-party interests, and contribute to an understanding of how to offer the best care to neurosurgical patients. The author provides an overview of clinical practice guidelines and illustrates their role in the assessment of quality of patient care, demonstrates how they fit into the methodology of quality assessments, and underscores the importances of practice quidelines for the development of disease management systems.

Isolated deep cerebral venous thrombosis treated by direct endovascular thrombolysis.

BACKGROUND: Isolated thrombosis of the deep cerebral venous system is very rare and is associated with a poor prognosis. Antithrombin III (AT III) deficiency is a disorder of hypercoagulability associated with deep venous thrombosis and recurrent pulmonary emboli. We report a case of an 18-year-old man who presented with spontaneous thrombosis of the deep cerebral veins and straight dural sinus as the initial presentation of a previously undiagnosed AT III deficiency. METHODS: The patient was managed using direct endovascular infusion of the fibrinolytic agent urokinase followed by intravenous heparin. RESULTS: The technique was successful in establishing patency of the deep cerebral venous system. The patient experienced a good clinical outcome. CONCLUSIONS: Direct endovascular thrombolysis is a potentially effective management strategy for isolated thrombosis of the deep cerebral venous system.