Microsurgical results with large vestibular schwannomas with preservation of facial and cochlear nerve function as the primary aim

Summary Objective. To evaluate our microsurgical results in dealing with vestibular schwannomas (VS) greater than or equal to 30 mm when preservation of cranial nerve function was considered more important than total tumour removal.Methods. Sixteen consecutive cases were operated on by the same neurosurgeon according to a prospective protocol using intraoperative neuro-monitoring (IONM) based on electromyographic and brain stem auditory evoked potential recordings. Facial nerve function was evaluated on the House-Brackmann Scale and cochlear nerve function on the Gardner-Robertson Scale. Someone not involved in the clinical management of our patients collected all data.Results. Fifteen patients showed facial nerve (FN) function of House-Brackmann grade (HBG) I or II at one year postoperatively and one kept the HBG IV she had preoperatively. Two patients of four maintained a cochlear nerve function of Gardner-Robertson grade (GRG) II. The tumour excision rates were: total, 68.7%; near total, 6.3%; subtotal, 18.7%, and partial, 6.3%. The average follow-up was 55 months (1–106). Three patients underwent radiotherapy later with growth stabilisation and no additional morbidity.Conclusion. When dealing with VS greater than or equal to 30 mm, microsurgery guided by IONM, with a rate of total or near-total tumour excision of about 75%, can retain socially acceptable facial nerve function (HBG I or II) in all cases and serviceable hearing (GRG I or II) in two cases out of four. Maintaining serviceable cranial nerve function should take precedence over total tumour excision.     

Testing equality of two functions using BARS

This article presents two methods of testing the hypothesis of equality of two functions H(0):f(1)(t)=f(2)(t) for all t, in a generalized non-parametric regression framework using a recently developed generalized non-parametric regression method called Bayesian adaptive regression splines (BARS). Of particular interest is the special case of testing equality of two Poisson process intensity functions lambda(1) (t)=lambda(2) (t), which arises frequently in neurophysiological applications. The first method uses Bayes factors, and the second method uses a modified Hotelling T(2) test. Both methods are applied to the analysis of 347 motor cortical neurons and, for certain choices of test criteria, the two methods lead to the same conclusions for all but 7 neurons. A small simulation study of power indicates that the Bayes factor can be somewhat more powerful in small samples. The T(2)-type test should be useful in screening large number of neurons for condition-related activity, while the Bayes factor will be especially helpful in assessing evidence in favour of H(0).     

Ornithine breath test as a method to evaluate functional liver volume

BACKGROUND: The purpose of this study was to investigate whether the functional liver volume can be measured from changes in expiratory 13CO2 levels after intravenous administration of L-[1, 2-13C] ornithine, using a rat model of hepatectomy. MATERIALS AND METHODS: Under pentobarbital anesthesia, 30%, 70%, or 90% hepatectomy was performed. In the control group, simple laparotomy was performed. Then, 20 mg/kg L-[1, 2-13C] ornithine was administered to rats via the femoral vein. A breath test was conducted 20 min after laparotomy. We examined the correlation of the sum of 13CO2 output (S) or a single point of 13CO2 level (SP) with liver weight/body weight (LW/BW) (%) every 15 min. RESULTS: In all of the groups, the ornithine breath test (OBT) graph reached a plateau level at about 6 min. The correlation coefficient between S15 and LW/BW was highest 0.952 (P <0.0001). The correlation coefficient between SP14 and LW/BW was highest, 0.944 (P <0.0001). The severity of hepatic injury could be evaluated, with significant differences in S5-15 and SP5-15 in all comparisons between groups. CONCLUSION: In the breath test with intravenously administered L-[1, 2-13C] ornithine, functional liver volume could be evaluated accurately in a short period.     

Organization of horizontal axons in the inferior temporal cortex and primary visual cortex of the macaque monkey

We investigated the organization of horizontal connections at two distinct hierarchical levels in the ventral visual cortical pathway of the monkey, the inferior temporal (TE) and primary visual (V1) cortices. After injections of anterograde tracers into layers 2 and 3, clusters of terminals ('patches') of labeled horizontal collaterals in TE appeared at various distances up to 8 mm from the injection site, while in V1 clear patches were distributed only within 2 mm. The size and spacing of these patches in TE were larger and more irregular than those observed in V1. The labeling intensity of patches in V1 declined sharply with distance from the injection site. This tendency was less obvious in TE; a number of densely labeled patches existed at distant sites beyond weakly labeled patches. While injections into both areas resulted in an elongated pattern of patches, the anisotropy was greater in TE than in V1 for injections of a similar size. Dual tracer injections and larger-sized injections further revealed that the adjacent sites in TE had spatially distinct horizontal projections, compared to those in V1. These area-specific characteristics of the horizontal connections may contribute to the differences in visual information processing of TE and V1.     

Assessment of Functional Capacity of the Musculoskeletal System in the Context of Work,Daily Living,and Sport: A Systematic Review

The aim of this systematic review was to survey methods to assess the functional capacity of the musculoskeletal system within the context of work, daily activities, and sport. The following key words and synonyms were used: functional physical assessment, healthy/disabled subjects, and instruments. After applying the inclusion criteria on 697 potential studies and a methodological quality appraisal, 34 studies were included. A level of reliability > 0.80 and of > 0.60 resp 0.75 and 0.90, dependent of type of validity, was considered high. Four questionnaires (the Oswestry Disability Index, the Pain Disability Index, the Roland–Morris Disability Questionnaire, and the Upper Extremity Functional Scale) have high levels on both validity and reliability. None of the functional tests had a high level of both reliability and validity. A combination of a questionnaire and a functional test would seem to be the best instrument to assess functional capacity of the musculoskeletal system, but need further examined.     

Are Gender,Marital Status or Parenthood Risk Factors for Outcome of Treatment for Chronic Disabling Spinal Disorders?

Recent clinical research has suggested that single working mothers may differ in their response to health treatment and outcomes, relative to their married female or male counterparts. The present study explored, on an a priori basis, the existence and extent of differences in chronic pain rehabilitation outcomes of pain report, return-to-work and future health utilization for single working mothers, relative to other patients. A cohort of 1,679 consecutive chronically disabled work related spinal disorder (CDWRSD) patients were placed into one of eight groups as a function of gender, marital status (single/married), and parenthood (with/without children). All patients completed an assessment battery measuring psychosocial variables at pre- and post-treatment, and a structured clinical interview evaluating socioeconomic outcomes at 1 year following completion of a 5–7 week functional restoration program. Results revealed that single females with children differed from all other groups in racial representation, with 57.1% of these individuals being African American, widely disparate from the prevailing local ethnicity. Single females and males with children were represented by a higher incidence of cervical injuries (25.0% and 26.7%, respectively) than all other groups (5.4–16.6%, p < .001). Contrary to expectation, the 8 groups did not differ significantly in program completion rate, work return, work retention, health utilization, recurrent injury or case settlement rates at one-year follow-up. The single females with children group did display greater levels of depression pre-treatment compared to the other groups. However, at post-treatment, these differences no longer existed. This investigation is one of the first to examine if the combination of gender and parenthood distinguishes significantly among CDWRSD patients. Overall, contrary to expectation, the single mothers did not show any significant differences in CDWRSD outcome at one-year post-rehab follow-up, and the single mothers and fathers showed no differences in depression or pain severity post-treatment. Thus, in spite of the societal belief to the contrary, it seems that single parent patients can show similar chronic pain rehabilitation outcomes, relative to other CDWRSD patients, after a prescribed course of tertiary functional restoration rehabilitation.     

Safety Issues in Functional Capacity Evaluation: Findings From a Trial of a New Approach for Evaluating Clients With Chronic Back Pain

Although safety is recognized as a critical issue in functional capacity evaluations (FCEs), it has rarely been investigated. This paper reports on the findings of a study which examined safety aspects of a new approach to FCE. Fourteen rehabilitation clients with chronic back pain participated in the study. Aspects examined included the pre-FCE screening procedures, the monitoring of performance and safety during the FCE, and the end of FCE measures and follow-up procedures. Support was found for the screening procedures of the approach, particularly blood pressure measurement, and for the combined approach to monitoring of the persons performance from biomechanical, physiological and psychophysical perspectives. Issues for FCE safety in general are identified and discussed, including the importance of screening procedures to determine readiness for FCEs and the issue of load handling in FCEs, especially in relation to clients with chronic back pain.     

Histologic and histomorphometric analysis of three types of dental implants following 18 months of occlusal loading: a preliminary study in baboons

The purpose of this study was to determine the percentage of 'bone area' (BA) and 'bone-to-implant contact' (BIC) of dental implants with different designs and surface modifications after functional loading. Three types of dental implants with fixed partial dentures were placed in the posterior jaws of adult baboons (commercially pure titanium (CpTi) screws, grit-blasted acid-etched (GBAE) screws, and titanium plasma-sprayed (TPS) cylinders), three of the same design per quadrant. After 18 months of functional loading, all implants investigated were successfully integrated in the jawbone and histologic and histomorphometric analyses were carried out. Statistical evaluation was performed with a mixed model with data given as least-square means and standard errors of the mean (SEM). Histologically, direct BIC without connective tissue interposed between implant surfaces and peri-implant bone was seen. Analysis of BA within 1 mm around implants showed significant differences between CpTi (50.5%) and TPS (39.7%) (+/-2.72 SEM; P<0.01) in the maxilla. To account for the different implant designs, absolute BIC was calculated. Significant differences were found between CpTi (23.9 mm) and TPS (15.1 mm) and between GBAE (27.2 mm) and TPS (15.1 mm) (+/-1.05 SEM; P<0.01) in the maxilla and between GBAE (26.5 mm) and TPS (19.6 mm) (+/-1.42 SEM; P<0.01) in the mandible. Overall, the data indicate that, in the maxilla, screw-shaped implants showed more absolute BIC than cylindrical implants, which had less maxillary than mandibular absolute BIC after 18 months of functional loading.     

Rizatriptan 10-mg wafer versus usual nontriptan therapy for migraine: analysis of return to function and patient preference

BACKGROUND: More than half of patients with migraine suffer moderate to severe functional disability during migraine attacks. OBJECTIVE: To compare effects on functional disability at 2 hours after treating a migraine with rizatriptan 10-mg wafer versus usual nontriptan therapy for triptan-na?ve patients with migraine. DESIGN: Open-label, prospective, two-attack study conducted at 111 neurology clinics. METHODS: Adult patients with migraine treated two migraine attacks, the first with their usual nontriptan therapy (nonsteroidal anti-inflammatory drugs, 57%; analgesics, 27%; or ergot derivatives, 16%) and the second with rizatriptan 10-mg wafer. Patients recorded pain intensity and functional disability at the start, and functional disability at 2 hours, as well as the time of return to normal function. RESULTS: A total of 1353 patients, 76% of them female, completed the study and were considered evaluable. During first and second migraine attacks, 55% and 63% of patients, respectively, reported severe disability or requiring bed rest. At 2 hours after treatment, the likelihood of experiencing any disability was more than five times greater after usual nontriptan therapy than after rizatriptan (odds ratio, 5.68; 95% confidence interval (CI), 4.66 to 6.94; P < .001). Rizatriptan was twice as likely to return patients to normal function than usual nontriptan therapy after adjusting for confounding factors (adjusted hazard ratio, 2.08; 95% CI, 1.92 to 2.25; P < .001). Assessed over all time points up to 6 hours, the speed of return to normal function was 52% faster after rizatriptan therapy (P < .001). Significantly more patients preferred rizatriptan than usual nontriptan therapy (78.8% vs. 21.2%; P < .001). The most common reasons cited for preference for rizatriptan were faster relief of headache pain and faster return to normal function. CONCLUSIONS: Patients in this study were more likely to experience a return to normal function at 2 hours after receiving rizatriptan than after their usual nontriptan therapy for migraine. The results of this study, using patient-oriented, clinically relevant endpoints such as functional disability and preference, will help to guide practitioners in making recommendations for acute migraine treatment.     

Functional hyperemia is reduced in skeletal muscle of aged rats

OBJECTIVE: To test the hypothesis that active hyperemia is reduced in skeletal muscle of old rats due to a decreased bioavailability of prostanoids, which in turn is due to increased oxidative stress. METHODS: The microvasculature of the spinotrapezius muscle of 3-, 12-, and 24-month male Sprague-Dawley rats was examined using in vivo videomicroscopy. Arteriolar diameter and centerline red cell velocity were measured in resting and contracting muscle. The effect of prostanoids was examined using indomethacin (10 microM), and passive resting arteriolar diameters were determined using adenosine (100 microM). Lipid peroxidation was assessed ex vivo by measuring tissue levels of malondialdehyde. RESULTS: Arteriolar diameters and blood flow in resting muscle did not differ among the age groups, but increases in diameter and flow during muscle contraction in young rats were greater than in the two older age groups. Indomethacin did not affect resting arteriolar diameters and blood flow in 3- and 12-month rats, but significantly decreased both parameters in 24-month rats. Indomethacin had no effect on arteriolar diameter and blood flow responses during muscle contraction in any age group. Passive resting diameters of arterioles were significantly smaller in 12- and 24-month rats than in 3-month rats. Tissue levels of TBARS were not different among the three age groups. CONCLUSIONS: Arteriolar tone and blood flow in resting skeletal muscle of rats is not altered with age, whereas the increases in these variables that normally accompany muscle contraction are markedly impaired during aging. Neither cyclooxygenase metabolites nor lipid peroxidation appear to be involved in this impairment.