Is intraoperative neurophysiological monitoring valuable predicting postoperative neurological recovery?

OBJECTIVES: We investigated the ability of intraoperative neurophysiological monitoring to predict postoperative neurological recovery in intradural-extramedullary spinal cord tumors. METHODS: From 2010 to 2014, we operated on 173 intradural-extramedullary spinal cord tumor patients with intraoperative neurophysiological monitoring. We retrospectively compared preoperative and postoperative clinical status using a modified McCormick grading scale and correlated with intraoperative neurophysiological monitoring. We followed patients for at least 1 year and correlated neurological outcomes with intraoperative changes in intraoperative neurophysiological monitoring. We then compared the degree of intraoperative neurophysiological monitoring change with the duration of the neurological deficit. RESULTS: Monitorability was 92% and 57% with transcranial motor-evoked potential and somatosensory-evoked potential modalities, respectively. Waveform attenuation on transcranial motor-evoked potentials was detected in 8.17% of cases. For somatosensory-evoked potentials, waveform attenuation was detected in 7% of the patients. A multimodality approach incorporating any transcranial motor-evoked potential changes had a sensitivity of 0.91 and a specificity of 0.98. The McCormick grade scale increased until 1 month in patients with alarm criteria on transcranial motor-evoked potentials (P<0.05). CONCLUSIONS: Patients suffered neurological deterioration in case of abolishment or >50% irreversible attenuation of the waveform in transcranial motor-evoked potentials. All patients gradually recovered after 1 postoperative month with alarm criteria from 50% to 80% irreversible amplitude drop on transcranial motor-evoked potentials.

Longevity of direct restorations in stress-bearing posterior cavities: a retrospective study.

The aims of this retrospective clinical study were to compare the longevities of direct posterior amalgam restorations (AMs) and resin composite restorations (RCs) that were subjected to occlusal stresses and to investigate variables predictive of their outcome. A total of 269 AMs and RCs filled in Class I and II cavities of posterior teeth were evaluated with Kaplan-Meier survival estimator and multivariate Cox proportional hazard model. Seventy-one retreated restorations were reviewed from dental records. The other 198 restorations still in use were evaluated according to modified US Public Health Service (USPHS) criteria by two investigators. The longevity of RCs was significantly lower than that of AMs (AM = 8.7 years and RC = 5.0 years, p<0.05), especially in molars. The prognostic variables, such as age, restorative material, tooth type, operator group, diagnosis, cavity classification, and gender, affected the longevity of the restorations (multivariate Cox regression analysis, p<0.05). However, among the restorations working in oral cavities, their clinical performance evaluated with modified USPHS criteria showed no statistical difference between both restoratives. In contrast to the short longevity of RCs relative to AMs, the clinical performance of RCs working in oral cavities was observed to be not different from that of AMs. This suggests that once a RC starts to fail, it happens in a rapid progression. As posterior esthetic restorations, RCs must be observed carefully with periodic follow-ups for early detection and timely repair of failures.

A retrospective clinical study of cervical restorations: longevity and failure-prognostic variables.

The aim of this retrospective clinical study was to compare the longevity of cervical restorations between resin composite (RC) and glass ionomer (GI) and to investigate variables predictive of their outcome. The clinical performance of the two restorative materials in function was compared using the ratings of the modified United States Public Health Service (USPHS) criteria. A total of 479 cervical restorations were included in the study. Ninety-one already-replaced restorations were reviewed from dental records. The other 388 restorations still in function were evaluated according to the modified USPHS criteria by two investigators. Longevity and prognostic variables were analyzed with the Kaplan-Meier survival analysis and multivariate Cox proportional hazard model. The clinical performances of the two materials were evaluated according to the ratings of the USPHS criteria and compared using the Pearson chi-square test and Fisher exact test. The longevity was not significantly different between RC and GI (median survival time, 10.4 ± 0.7 and 11.5 ± 1.1 years, respectively). The main reasons for failure were loss of retention (82.2%) and secondary caries (17.8%). The longevity of cervical restoration was significantly influenced by tooth group and operator group (Wald test, p<0.05), while material, gender, presence or absence of systemic diseases, arch, and reason for treatment did not affect the longevity. Contrary to the longevity, the clinical performance of RC was superior to GI in the criteria of retention, marginal discoloration, and marginal adaptation, but similar in secondary caries, wear, and postoperative sensitivity.

Decreased expression of collagen and fibronectin genes in striae distensae tissue.

Striae distensae are characterized by a thinning of connective tissue stroma to produce linear, atrophic-appearing skin. Excessive adrenocortical activity, genetic factors and inherited defects of connective tissues, etc. are important causative factors in the formation of striae distensae, but the basic aetiology is not known. Total RNA was extracted from skin biopsies of five patients with striae distensae. The expression of genes coding for types I and III procollagen, elastin, fibronectin and beta-actin were studied and compared with those of four sex- and age-matched healthy individuals. The percentages of types I and III procollagen mRNA were 9.9 +/- 2.9% (mean +/- s.d.) and 10.6 +/- 1.6%, respectively, of the corresponding controls. The value for fibronectin mRNA in striae distensae was 7.3 +/- 1.8% of the control. The steady-state ratio fibronectin/type I procollagen mRNAs was 0.12 +/- 0.01 in striae distensae and 0.18 +/- 0.01 in the control. These observations suggest that expression of collagens, elastin and fibronectin genes are apparently decreased, and that there is a marked alteration of fibroblast metabolism, in striae distensae.

Percutaneous absorption-enhancing activity of urea derivatives.

The effect of urea and urea derivatives on the percutaneous absorption of salicylic acid and sodium salicylate through the skin of rabbit from petrolatum ointment was investigated. It was found that addition of urea or urea derivatives to the ointment base significantly increased the percutaneous absorption of the drugs in proportion to the concentration of the additive. The percutaneous absorption-enhancing activities of these compounds were that urea derivatives with the more and longer alkyl substituents showed the stronger activities. These activities of urea and urea derivatives were ascribed to the binding of these compounds with the lipids and proteins of the stratum corneum of the skin and the swelling of the tissues, which leads to the reduction of the barrier property of the layer. The preliminary skin irritation test showed that urea and urea derivatives were quite non-irritating to the skin. These results suggest that urea derivatives have a strong possibility to be developed as a percutaneous absorption enhancer.