Pseudarthrosis after lumbar spine fusion: nonoperative salvage with pulsed electromagnetic fields

We studied 100 patients in whom symptomatic pseudarthrosis had been established at more than 9 months after lumbar spine fusion. All patients were treated with a pulsed electromagnetic field device worn consistently 2 hours a day for at least 90 days. Solid fusion was achieved in 67% of patients. Effectiveness was not statistically significantly different for patients with risk factors such as smoking, use of allograft, absence of fixation, or multilevel fusions. Treatment was equally effective for posterolateral fusions (66%) as with interbody fusions (69%). For patients with symptomatic pseudarthrosis after lumbar spine fusion, pulsed electromagnetic field stimulation is an effective nonoperative salvage approach to achieving fusion.     

Scorpion bite and multiple cerebral infarcts

Multiple cerebral infarcts, bilateral optic neuropathy with limb ischemia, following scorpion bite is documented. Vasospasm and autonomic storm due to envenomation is a plausible explanation for this symptom complex.     

Prevention for the older woman. A practical guide to managing risk of malignancies

As women live longer and anticipate good health during their later years, cancer screening becomes increasingly complex. Physicians receive discordant recommendations from medical societies, task forces, Medicare, and special interest groups about which cancers merit screening, how screening should be performed, the frequency of screening, and when screening should be discontinued. Female patients may receive confusing recommendations from their friends, the lay press, the Internet, and their own doctors. Given the proliferation of opinions and the limited data regarding the efficacy of cancer screening in older women, physicians must help their patients understand the potential benefits, limitations, and consequences of various cancer screenings for each individual woman.     

Using Bayesian tissue classification to improve the accuracy of vestibular schwannoma volume and growth measurement

BACKGROUND AND PURPOSE: True 3D measurements of tumor volume are time-consuming and subject to errors that are particularly pronounced in cases of small tumors. These problems complicate the routine clinical assessment of tumor growth rates. We examined the accuracy of currently available methods of size and growth measurement of vestibular schwannomas compared with that of a novel fast partial volume tissue classification algorithm. METHODS: Sixty-three patients with unilateral sporadic vestibular schwannomas underwent imaging. Thirty-eight of these patients underwent imaging two or more times at approximately 12-month intervals. Contrast-enhanced 3D T1-weighted images were used for all measurements. An experienced radiologist performed standard size estimations, including maximal diameter, elliptical area, perimeter, manually segmented area, intensity thresholded seeding volume, and manually segmented volume. A method for calculating volume was also used, incorporating Bayesian probability statistics to estimate partial volume effects. Manually segmented volume was obtained as a baseline standard measure. A computer-generated phantom exhibiting the intensity and partial volume characteristics of brain tissue, CSF, and intracanalicular vestibular schwannoma tissue was used to measure absolute accuracy of the standard technique and Bayesian partial volume segmentation. RESULTS: The Bayesian partial volume segmentation method showed the highest correlation (R(2) = 0.994) with the standard method, whereas the commonly used method of maximal diameter measurement showed poor correlation (R(2) = 0.732). Accuracy of Bayesian segmentation was shown to be more than twice that of manual segmentation, with an absolute accuracy of 5% (cf, 13%) and a remeasurement accuracy of 70 mm(3) (cf, 150 mm(3)). For the 38 patients who underwent imaging twice, definite tumor growth was shown for 12, potential growth for seven, no growth for 17, and definite shrinkage for two. CONCLUSION: Commonly used methods such as maximal diameter measurements do not provide adequate statistical accuracy with which to monitor tumor growth in patients with small vestibular schwannomas. Bayesian partial volume segmentation provides a more accurate and rapid method of volume and growth estimation. These differences in measurement accuracy translated into a significant improvement in clinical assessment, allowing identification of tumor growth in 10 of 12 cases that appeared to be static in size when manual segmentation techniques are used. The technique is quick to perform and suitable for use in routine clinical practice.     

Prospective trial of a predictive algorithm to transplant cadaver kidneys into highly sensitized patients

BACKGROUND: The difficulty of transplanting sensitized patients increases proportionally to the panel reactive antibody (PRA) titer. Because of the high likelihood of a positive final crossmatch, these patients are often excluded from a prospective transplant unless there is a 0 HLA-A, -B, -DR mismatch. To address this problem, we developed a computerized algorithm, termed the Kentucky Antibody Testing System (KATS), that predicts class I HLA antigens that would be both "unacceptable" and "acceptable" to the recipient. This report describes the results of a prospective trial among voluntarily participating centers that agreed to share kidneys based on the KATS predictions for patients whose PRA exceeded 40%. METHODS: The results of three antibody screens on each patient were compared with the HLA phenotypes of the cells in the panel in 2x2 tables with calculation of chi-square and correlation coefficient statistics. Private, broad, and public antigens were identified and a list of acceptable and unacceptable antigens were entered into the UNOS computer for each patient listed in the KATS sharing algorithm. RESULTS: Of the total 418 patients meeting the inclusion/exclusion criteria, the largest single group submitted was Black-not-of-Hispanic-origin females. The mean PRA of the patients was 72%. The first transplant via KATS allocation was performed on March 8, 1997. Between that time and the last transplant on July 31, 2000, 145 kidneys were offered to the participating centers and 48 transplants were performed. Of the many reasons listed for not accepting an offer or not transplanting the shared kidney into its intended recipient, only two occurred because of a positive T cell crossmatch and six because of a positive B cell crossmatch. As compared to all other high PRA patients within Southeastern Organ Procurement Foundation who were transplanted during the study period, they were more likely to be non-Caucasian, to be less well matched for private HLA-A, B, and DR antigens, and to have waited for a longer time than the other groups. Although there was a higher incidence of delayed graft function, there was no significant difference in cold ischemia, rejection episodes, or patient or graft survival. CONCLUSIONS: We conclude that KATS, or some other system to prospectively identify a list of acceptable and unacceptable HLA antigens, could improve the access of highly sensitized patients to a successful kidney transplant.     

Discussing breast cancer and hormone replacement therapy with women

Although the results of the Women's Health Initiative showed an increased risk of breast cancer in women taking hormone replacement therapy (HRT), the absolute risk is very low. We discuss limitations of the study, questions that remain, and how to discuss the study with women at average risk and high risk for breast cancer.     

The case for hormone replacement: new studies that should inform the debate

The Women's Health Initiative found that the risks of hormone replacement therapy (HRT) exceeded its benefits in a large group of older postmenopausal women, but did not consider the efficacy of HRT in relieving vasomotor symptoms. Another recent study found that low-dose HRT was as effective as standard-dose HRT while causing fewer side effects. Smaller studies suggest that HRT may improve depression. HRT is not to be used for cardiovascular risk reduction. Genetic testing may point the way to more rational use of HRT.     

Treatment response in late-onset depression: relationship to neuropsychological, neuroradiological and vascular risk factors

BACKGROUND: Late-onset depressive disorder is associated with white matter lesions and neuropsychological deficits that in some studies are linked to a poorer outcome for depression. Some white matter lesions may be vascular in origin. This study investigated the relationship between response or non-response to antidepressant monotherapy and neuropsychological function, structural brain measures and vascular factors. METHOD: This was a case control study. Fifty patients with late-onset major depressive disorder (29 who were responders to antidepressant monotherapy and 21 who were not) were compared with 35 non-depressed control subjects. Measures included assessment of vascular risk factors, neuropsychological testing and a magnetic resonance imaging (MRI) scan. RESULTS: After adjustment for depressed mood and medication at evaluation, both patient groups had significantly more impairment compared to control subjects on verbal learning tasks involving immediate or delayed recall. Patients who did not respond to antidepressant monotherapy had significantly poorer performance than controls on tests involving visuospatial ability, language, word recognition and tests of executive function, whereas there were no differences between control subjects and responders. On two tests of executive function (verbal fluency and the Stroop test) non-responders scored significantly worse than responders. There were no significant group differences on MRI measures of atrophy or of white matter lesions apart from a higher periventricular hyperintensity score in non-responders compared to controls. There were no group differences on measures of vascular disease. CONCLUSION: The results lend support to the emerging evidence that resistance to treatment in late-onset depression may be associated with impaired executive function. Subtle cerebrovascular mechanisms may be involved.