Cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome): meta-analysis of outcomes after medical and surgical treatments

The cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome) is marked by slow, insidious progression and a high incidence of dural ectasia in the lumbosacral spine. A high index of suspicion for this problem must be maintained when evaluating the patient with ankylosing spondylitis with a history of incontinence and neurologic deficit on examination. There has been disagreement in the literature as to whether surgical treatment is warranted for this condition. A meta-analysis was thus performed comparing outcomes with treatment regimens. Our results suggest that leaving these patients untreated or treating with steroids alone is inappropriate. Nonsteroidal antiinflammatory drugs may improve back pain but do not improve neurologic deficit. Surgical treatment of the dural ectasia, either by lumboperitoneal shunting or laminectomy, may improve neurologic dysfunction or halt the progression of neurologic deficit.

Dural ectasia and conventional radiography in the Marfan lumbosacral spine

OBJECTIVE

To determine how well conventional radiographic findings can predict the presence of dural ectasia in Marfan patients.

DESIGN AND PATIENTS

Twelve Marfan patients without dural ectasia and 21 Marfan patients with dural ectasia were included in the study. Five radiographic measurements were made of the lumbosacral spine: interpediculate distance, scalloping value, sagittal canal diameter, vertebral body width, and transverse process width.

RESULTS

The following measurements were significantly larger in patients with dural ectasia: interpediculate distances at L3-L4 levels (P<0.03); scalloping values at the L1 and L5 levels (P<0.05); sagittal diameters of the vertebral canal at L5-S1 (P<0.03); transverse process to width ratios at L2 (P<0.03). Criteria were developed for diagnosis of dural ectasia in Marfan patients. These included presence of one of the following: interpediculate distance at L4 > or = 38.0 mm, sagittal diameter at S1 > or = 18.0 mm, or scalloping value at L5 > or = 5.5 mm.

CONCLUSION

Dural ectasia in Marfan syndrome is commonly associated with several osseous changes that are observable on conventional radiographs of the lumbosacral spine. Conventional radiography can detect dural ectasia in patients with Marfan syndrome with a very high specificity (91.7%) but a low sensitivity (57.1%).

Pancreatic intraepithelial neoplasia: a new nomenclature and classification system for pancreatic duct lesions

Proliferative epithelial lesions in the smaller caliber pancreatic ducts and ductules have been the subject of numerous morphologic, clinical, and genetic studies; however, a standard nomenclature and diagnostic criteria for classifying these lesion have not been established. To evaluate the uniformity of existing systems for grading duct lesions in the pancreas, 35 microscopic slides with 35 representative duct lesions were sent to eight expert pathologists from the United States, Canada, and Europe. Kappa values for interobserver agreement could not be calculated initially because more than 70 different diagnostic terms were used by the eight pathologists. In several cases, the diagnoses rendered for a single duct lesion ranged from "hyperplasia," to "metaplasia," to "dysplasia," to "carcinoma in situ." This review therefore demonstrated the need for a standard nomenclature and classification system. Subsequently, during a working group meeting, the pathologists agreed to adopt a single standard system. The terminology pancreatic intraepithelial neoplasia (or PanIN) was selected, and diagnostic criteria for each grade of PanIN were established (http://pathology.jhu.edu/pancreas_panin). This new system was then evaluated by having the eight pathologists rereview the original 35 cases. Only seven different diagnoses were rendered, and kappa values of 0.43, 0.14, and 0.42 were obtained for PanINs 1, 2, and 3 respectively. Cases assigned other diagnoses (e.g., squamous metaplasia) collectively had a kappa value of 0.41. These results show both the potential of the classification system, and also the difficulty of classifying these lesions even with a consistent nomenclature. However, even when there is lack of consensus, having a restricted set of descriptions and terms allows a better understanding of the reasons for disagreement. It is suggested that we adopt and apply this system uniformly, with continued study of its reliability and use, and possibly further refinement. The acceptance of a standard classification system will facilitate the study of pancreatic duct lesions, and will lead ultimately to a better understanding of their biologic importance.

The lumbar interpediculate distance is widened in adults with the Marfan syndrome: data from 32 cases

32 patients with Marfan syndrome, diagnosed with DePaepe's criteria, volunteered for this study. All patients underwent standard anteroposterior radiographs of the lumbar spine. Interpediculate distances (IPD) at each level were compared to those of previously established norms. Criteria were developed to determine the presence of Marfan using "cut-off values" for the IPDs at each lumbar level. The IPDs were significantly larger in the Marfan patients at all lumbar levels. Cut-off values were calculated setting the specificity at 95% at each lumbar level. The cut-off value at L4 yielded the greatest sensitivity. We conclude that the IPDs are widened in patients with Marfan syndrome. The IPD at L4 is a good criterion for Marfan with specificity of 95% and sensitivity of 75%. One must consider using this as a skeletal criterion or a screening tool for Marfan.

Latent class model diagnosis

In many areas of medical research, such as psychiatry and gerontology, latent class variables are used to classify individuals into disease categories, often with the intention of hierarchical modeling. Problems arise when it is not clear how many disease classes are appropriate, creating a need for model selection and diagnostic techniques. Previous work has shown that the Pearson chi 2 statistic and the log-likelihood ratio G2 statistic are not valid test statistics for evaluating latent class models. Other methods, such as information criteria, provide decision rules without providing explicit information about where discrepancies occur between a model and the data. Identifiability issues further complicate these problems. This paper develops procedures for assessing Markov chain Monte Carlo convergence and model diagnosis and for selecting the number of categories for the latent variable based on evidence in the data using Markov chain Monte Carlo techniques. Simulations and a psychiatric example are presented to demonstrate the effective use of these methods.

Predicting the risk of mobility difficulty in older women with screening nomograms: the Women's Health and Aging Study II

BACKGROUND

A major obstacle to screening for early mobility disability (ie, mobility difficulty), a major public health concern, is the lack of a method that identifies those who are at high risk. The goal of this study was to develop easy-to-use clinical nomograms for estimation of the probability of incident mobility difficulty.

METHODS

We conducted a population-based prospective study using data from 266 high physically and cognitively functioning older women, aged 70 to 80 years, who were free of mobility disability at the baseline evaluation of the Women's Health and Aging Study II. The outcome measure was incident mobility disability within 18 months, defined as self-reported difficulty walking 0.8 km, climbing 10 steps, or transferring from or into a car or bus. Logistic regression and receiver operating characteristic curve analyses were used for evaluation of the optimal combination of self-reported and performance-based mobility measures. Bootstrap sampling and estimation was used for validation.

RESULTS

Predictive nomograms were developed based on a final model that included 3 simple-to-obtain measures of preclinical disability: self-report of modification in mobility tasks without having difficulty with them, one-leg stance balance, and time to walk 1 m at a usual pace. Final model accuracy (as estimated by the area under the receiver operating characteristic curve) was 73% (SE = 0.04). Validation analysis confirmed the high accuracy of these nomograms.

CONCLUSIONS

An original tool was developed for assessment of the risk of mobility difficulty in older women that can be used to assist physicians and researchers in deciding which women to target for preventive interventions.

Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes

STUDY DESIGN

A meta-analysis of surgical outcomes of cauda equina syndrome secondary to lumbar disc herniation.

OBJECTIVES

To determine the relationship between time to decompression after onset of cauda equina syndrome and clinical outcome, and to identify preoperative variables that were associated with outcomes.

SUMMARY OF BACKGROUND DATA

The timing of surgical decompression for cauda equina syndrome is controversial. Although most surgeons recommend emergent decompression, results in certain studies show that delayed surgery may provide a satisfactory outcome.

METHODS

A meta-analysis was performed to determine the correlation between timing of decompression and clinical outcome. One hundred four citations were reviewed, and 42 met the inclusion criteria. Preoperative and postoperative data were recorded. Length of time to surgery was broken down into five groups: less than 24 hours, 24-48 hours, 2-10 days, 11 days to 1 month, and more than 1 month. Logistic regression was used to determine the association between preoperative variables and postoperative outcomes.

RESULTS

Outcomes were analyzed in 322 patients. Preoperative chronic back pain was associated with poorer outcomes in urinary and rectal function, and preoperative rectal dysfunction was associated with worsened outcome in urinary continence. In addition, increasing age was associated with poorer postoperative sexual function. No significant improvement in surgical outcome was identified with intervention less than 24 hours from the onset of cauda equina syndrome compared with patients treated within 24-48 hours. Similarly, no difference in outcome occurred in patients treated more than 48 hours after the onset of symptoms. Significant differences, however, were found in resolution of sensory and motor deficits as well as urinary and rectal function in patients treated within 48 hours compared with those treated more than 48 hours after onset of symptoms.

CONCLUSIONS

There was a significant advantage to treating patients within 48 hours versus more than 48 hours after the onset of cauda equina syndrome. A significant improvement in sensory and motor deficits as well as urinary and rectal function occurred in patients who underwent decompression within 48 hours versus after 48 hours.

Dural ectasia in the Marfan syndrome: MR and CT findings and criteria

PURPOSE

To create criteria for detecting dural ectasia on MR or CT images in adult Marfan patients.

METHODS

Images were analyzed using a workstation. Parameters that predicted dural ectasia were included in our criteria.

RESULTS

Major criteria include: (1) width of dural sac below L5 > width above L4; (2) anterior sacral meningocele. Minor criteria include: (1) L5 nerve root sleeve diameter > 6.5 mm and (2) S1 scalloping > 3.5. Dural ectasia exists if 1 major or 2 minor criteria are present.

CONCLUSION

MR and CT diagnose dural ectasia with high specificity and sensitivity. Our criteria accurately diagnose dural ectasia in adult Marfan patients.

Negative control of flagellum synthesis in Pseudomonas aeruginosa is modulated by the alternative sigma factor AlgT (AlgU)

Many respiratory isolates of Pseudomonas aeruginosa from cystic fibrosis patients are mucoid (alginate producing) yet lack flagella. It was hypothesized that an alginate regulator inhibits flagellar gene expression. Mutations in algB, algR, and algT resulted in nonmucoid derivatives, yet algT mutants expressed flagella. AlgT-dependent control of flagellum synthesis occurred through inhibition of fliC but not rpoN transcription.

Public, animal, and environmental health implications of aquaculture

Aquaculture is important to the United States and the world's fishery system. Both import and export markets for aquaculture products will expand and increase as research begins to remove physiologic and other animal husbandry barriers. Overfishing of wild stock will necessitate supplementation and replenishment through aquaculture. The aquaculture industry must have a better understanding of the impact of the "shrouded" public and animal health issues: technology ignorance, abuse, and neglect. Cross-pollination and cross-training of public health and aquaculture personnel in the effect of public health, animal health, and environmental health on aquaculture are also needed. Future aquaculture development programs require an integrated Gestalt public health approach to ensure that aquaculture does not cause unacceptable risks to public or environmental health and negate the potential economic and nutritional benefits of aquaculture.

Survey of the U.S. Gulf Coast for the presence of Clostridium botulinum

In sediments and animals collected during warm weather months between Key West, Fla., and Brownsville, Tex., Clostridium botulinum, predominantly type E, was demonstrable. Incidence was somewhat higher in the eastern Gulf animals, but the organism was present to the southernmost limits of both Texas and Florida. Types A and F were never detected in warm weather. No bottom type or any single species seemed exclusively vulnerable. In samples collected during colder weather, the east-west incidence differential was minimized in animals but not in sediments, overall incidence was lowered, all known types were present, and type E no longer predominated. Detection by fluorescent-antibody techniques was found to be inadequate.