CT-guided percutaneous aspiration of Tarlov cyst as a useful diagnostic procedure prior to operative intervention

Summary Tarlov or perineural cysts are lesions of the nerve root most often found in the sacral region. Several authors recommend surgical treatment of symptomatic Tarlov cysts. However, successful surgical treatment is dependent on appropriate patient selection.In this article, we report three cases of a sacral perineural cyst, causing sciatic pain, and emphasize the usefulness of CT-guided percutaneous aspiration as an important diagnostic and prognostic procedure prior to definitive operative treatment.     

Various surgical treatments of chronic subdural hematoma and outcome in 172 patients: is membranectomy necessary?

BACKGROUND: The initial surgical management of chronic subdural hematoma (CSDH) is still controversial, and a standard therapy does not exist. Because of the advanced age and multiple medical problems of the patients, surgical therapy is frequently associated with complications. METHODS: A retrospective study was performed on 172 patients with CSDH, comparing the efficacy of three different primary surgical methods: drainage of hematoma through two different burr-holes without membranectomy (Group A, n = 38); enlarged craniectomy with a size of about 30 mm craniotomy with partial membranectomy and drainage (Group B, n = 121); and extended craniotomy with partial membranectomy and drainage (Group C, n = 13). RESULTS: Independent of surgical method, the general outcome of the patients was good. The rate of reoperation in the group of burr-hole drainage was 16%, slightly lower than in partial membranectomy with enlarged craniectomy or extended craniotomy with 18% and 23%, respectively. In patients with coagulopathy, the rate of reoperation was 41% (16/43), significantly higher than the rate in noncoagulopathic patients 12% (15/129). CONCLUSIONS: In this study, an extended surgical approach with partial membranectomy has no advantages regarding the rate of reoperation and the outcome. As initial treatment, burr-hole drainage with irrigation of the hematoma cavity and closed-system drainage is recommended. Extended craniotomy with membranectomy is now reserved for instances of acute rebleeding with solid hematoma.     

Mortality Among Workers Employed in the Titanium Dioxide Production Industry in Europe

OBJECTIVES: To assess the risk of lung cancer mortality related to occupational exposure to titanium dioxide (TiO2). METHODS: A mortality follow-up study of 15,017 workers (14,331 men) employed in 11 factories producing TiO2 in Europe. Exposure to TiO2 dust was reconstructed for each occupational title; exposure estimates were linked with the occupational history. Observed mortality was compared with national rates, and internal comparisons were based on multivariate Cox regression analysis. RESULTS: The cohort contributed 371,067 person-years of observation (3.3% were lost to follow-up and 0.7% emigrated). 2652 cohort members died during the follow-up, yielding standardized mortality ratios (SMRs) of 0.87 (95% confidence interval [CI] 0.83-0.90) among men and 0.58 (95% CI 0.40-0.82) among women. Among men, the SMR of lung cancer was significantly increased (1.23, 95% CI 1.10-1.38); however, mortality from lung cancer did not increase with duration of employment or estimated cumulative exposure to TiO2 dust. Data on smoking were available for over one third of cohort members. In three countries, the prevalence of smokers was higher among cohort members compared to the national populations. CONCLUSIONS: The results of the study do not suggest a carcinogenic effect of TiO2 dust on the human lung.     

Prevalence and prognostic significance of psychiatric disorders in patients evaluated for recurrent unexplained syncope

We aimed to assess the psychiatric profile and prognostic value of psychiatric disorders (PDs) in patients presenting with unexplained syncope. Forty patients with recurrent unexplained syncope referred for head-up tilt testing were compared with age- and sex-matched patients free of known chronic PDs referred for arrhythmia. All patients underwent a semistandardized psychiatry questionnaire (Mini-International Neuropsychiatric Interview) to assess their profile. Additional stress coping was performed to study adaptational processes to stressful situations. After tilt testing and psychiatric evaluation, a drug-free follow-up was performed in patients with syncope. Of the 80 patients who referred to the psychiatric interview, 40 had evidence of at least 1 psychiatric disorder. They were 26 patients (65%) in the syncope group and 14 patients (35%) in the control group (p = 0.01). Detailed analysis revealed a more frequent subprofile of anxiety and panic disorders in patients with syncope than in controls (30% vs 12% and 20% vs 10%, respectively), whereas the subprofile of depression was similar in both groups. Moreover, those with syncope were more likely to have a high anxiety index (25 +/- 5 vs 22 +/- 4, p = 0.004), and were more prone to avoidance-oriented coping strategies when experiencing undesirable life events than controls. Considering syncope patients, no difference could be found between the 25 with a positive tilt test and the 15 with a negative tilt test with respect to the number of syncopal episodes and psychiatric profile. After a 3-year drug-free follow-up, 15 patients (37.5%) had at least 1 recurrent syncope. The recurrence rate was similar in patients with positive and negative head-up tilt test results (9 of 25 vs 6 of 15, respectively). In contrast, the syncopal recurrence rate was higher in patients who fulfilled criteria for affective disorders (13 of 26 vs 2 of 14, 95% confidence interval 1.09 to 2.55, relative risk 1.7, p = 0.04). Thus, patients with recurrent unexplained syncope are more anxious and are more prone to panic disorders and avoidance-oriented coping strategies than control patients with arrhythmia. The presence of a psychiatric disorder is associated with an increased risk of recurrence. The outcome of such patients may be improved with recognition and treatment of PDs.     

A comparison of the effects of parental risk markers on pre- and perinatal variables in multiple patient cohorts with fetal alcohol syndrome, autism, Tourette syndrome, and sudden infant death syndrome: an enviromic analysis

The prevalence and magnitude of effect of individual risk markers for specific developmental disorders vary widely across diagnostic category. The four study cohorts for this project were patients from four diagnostic registries in North Dakota for fetal alcohol syndrome (FAS), autism, sudden infant death syndrome (SIDS), and Tourette syndrome. These four cohorts were used to estimate prevalence and magnitude of effect of parental risk markers in patients with developmental disabilities. Cases with North Dakota birth certificates were matched with controls. Using birth certificate data, we then examined five parental risk markers for each cohort and estimated direct and indirect effects for each risk marker by cohort. The authors found two significant paternal risk markers (age in SIDS and education in FAS). Significant maternal markers were age in SIDS, education in FAS, autism, and SIDS. Marital status was a significant risk marker in FAS. Effect sizes were estimated using paired t tests, odds ratios, and population attributable risk (PAR) for both direct and indirect effects for each marker. We estimated both direct and indirect effects to allow for direct comparisons of the differential effect estimates of each of these markers. The direct effect of parental markers differs across diagnostic cohorts of patients. Use of cohorts from similar denominator populations obtained from prevalence studies is a useful methodological tool for estimating the prevalence and magnitude of effect of risk markers.     

Fetal alcohol syndrome prevention: annual and cumulative cost savings

Fetal alcohol syndrome (FAS) is a common developmental disability. FAS is thought to be 100% preventable. While this is a theoretical truth, a prevention rate of 100% appears unlikely in the near future. However, several prevention strategies are available. In this paper, we examine the potential cost savings from prevention of one case of FAS each year in the state of North Dakota.

We utilized the North Dakota Health Claims Database to examine annual cost of health care for children birth through 21 years of age with FAS and controls.

The mean annual cost of health care for children birth through 21 years of age with FAS was US$2842 (n=45). This is US$2342 per capita more than the annual average cost of care for children in North Dakota who do not have FAS (US$500 per year).

Prevention of one case of FAS per year in North Dakota would result in a cost savings of US$128,810 in 10 years and US$491,820 after 20 years. After 10 years of prevention, the annual savings in health care costs alone for one case of FAS would be US$23,420.     

Cell density ratios in a foveal patch in macaque retina

We examine the assumptions that the fovea contains equal numbers of inner (invaginating or ON) and outer (flat or OFF) midget bipolar cells and equal numbers of inner and outer diffuse bipolar cells. Based on reconstruction from electron photomicrographs of serial thin sections through the fovea of a macaque monkey, we reject both assumptions. First, every foveal L and M cone is presynaptic to one inner and one outer midget bipolar cell; however, S cones are presynaptic to one outer but no inner midget bipolar cell. Second, we measure the density of all foveal cells in the same patch of fovea, affording accurate cell density ratios. For each foveal cone pedicle, at a density of 26,500 mm(-2), there is close to one (0.88) outer diffuse bipolar cell but only 0.40 inner diffuse bipolar cells. This asymmetry may be related to differences in resolution and sensitivity for light increments and decrements. We also find one (1.01) Müller cell, one (1.01) amacrine cell in the inner nuclear layer, and close to one (0.83) horizontal cell for each cone pedicle. In addition, for each S cone, there are two inner S-cone bipolar cells and two small bistratified ganglion cells. In total, there are 3.4 cone bipolar cells per cone but only 2.6 ganglion cells per cone. The latter ratio is enough to accommodate one midget ganglion cell for each midget bipolar cell.