Multimodal intraoperative neuromonitoring in corrective surgery for adolescent idiopathic scoliosis: Evaluation of 354 consecutive cases

Background:

Multimodal intraoperative neuromonitoring is recommended during corrective spinal surgery, and has been widely used in surgery for spinal deformity with successful outcomes. Despite successful outcomes of corrective surgery due to increased safety of the patients with the usage of spinal cord monitoring in many large spine centers, this modality has not yet achieved widespread popularity. We report the analysis of prospectively collected intraoperative neurophysiological monitoring data of 354 consecutive patients undergoing corrective surgery for adolescent idiopathic scoliosis (AIS) to establish the efficacy of multimodal neuromonitoring and to evaluate comparative sensitivity and specificity.

Materials and Methods:

The study group consisted of 354 (female = 309; male = 45) patients undergoing spinal deformity corrective surgery between 2004 and 2008. Patients were monitored using electrophysiological methods including somatosensory-evoked potentials and motor-evoked potentials simultaneously.

Results:

Mean age of patients was 13.6 years (±2.3 years). The operative procedures involved were instrumented fusion of the thoracic/lumbar/both curves, Baseline somatosensory-evoked potentials (SSEP) and neurogenic motor-evoked potentials (NMEP) were recorded successfully in all cases. Thirteen cases expressed significant alert to prompt reversal of intervention. All these 13 cases with significant alert had detectable NMEP alerts, whereas significant SSEP alert was detected in 8 cases. Two patients awoke with new neurological deficit (0.56%) and had significant intraoperative SSEP + NMEP alerts. There were no false positives with SSEP (high specificity) but 5 patients with false negatives with SSEP (38%) reduced its sensitivity. There was no false negative with NMEP but 2 of 13 cases were false positive with NMEP (15%). The specificity of SSEP (100%) is higher than NMEP (96%); however, the sensitivity of NMEP (100%) is far better than SSEP (51%). Due to these results, the overall sensitivity, specificity and positive predictive value of combined multimodality neuromonitoring in this adult deformity series was 100, 98.5 and 85%, respectively.

Conclusion:

Neurogenic motor-evoked potential (NMEP) monitoring appears to be superior to conventional SSEP monitoring for identifying evolving spinal cord injury. Used in conjunction, the sensitivity and specificity of combined neuromonitoring may reach up to 100%. Multimodality monitoring with SSEP + NMEP should be the standard of care.     

Risks of rapid decline renal function in patients with type 2 diabetes

Progressive rising population of diabetes and related nephropathy, namely, diabetic kidney disease and associated end stage renal disease has become a major global public health issue. Results of observational studies indicate that most diabetic kidney disease progresses over decades; however, certain diabetes patients display a rapid decline in renal function, which may lead to renal failure within months. Although the definition of rapid renal function decline remained speculative, in general, it is defined by the decrease of estimated glomerular filtration rate (eGFR) in absolute rate of loss or percent change. Based on the Kidney Disease: Improving Global Outcomes 2012 clinical practice guidelines, a rapid decline in renal function is defined as a sustained decline in eGFR of > 5 mL/min per 1.73 m² per year. It has been reported that potential factors contributing to a rapid decline in renal function include ethnic/genetic and demographic causes, smoking habits, increased glycated hemoglobin levels, obesity, albuminuria, anemia, low serum magnesium levels, high serum phosphate levels, vitamin D deficiency, elevated systolic blood pressure, pulse pressure, brachial-ankle pulse wave velocity values, retinopathy, and cardiac autonomic neuropathy. This article reviews current literatures in this area and provides insight on the early detection of diabetic subjects who are at risk of a rapid decline in renal function in order to develop a more aggressive approach to renal and cardiovascular protection.     

前房角切开术治疗青少年型开角型青光眼

小梁切除术联合丝裂霉素C是治疗青少年型开角型青光眼(junior open-angle glaucoma,JOAG)较常用的术式,缺点是存在低眼压性黄斑病变、滤过泡渗漏等潜在并发症的可能.前房角切开术是治疗原发性婴幼儿型青光眼较常用的术式.作者报告了波士顿市马萨诸塞眼耳医院采用前房角切开这一轻度侵人性手术治疗青少年型开角型青光眼的结果.     

Long-term effects of losartan on structure and function of the thoracic aorta in a mouse model of Marfan syndrome

Background and purpose:

During development of thoracic aortic aneurysms in a mouse model of Marfan syndrome, upregulation of matrix metalloproteinase (MMP)-2 and -9 was accompanied by compromised aortic constriction and endothelium-dependent relaxation. Losartan has been proposed for the prevention of thoracic aortic aneurysm. We hypothesized that losartan would suppress MMP-2/-9 activation and improve aortic vasomotor function in this model.

Experimental approach:

A well-characterized mouse model of Marfan syndrome (Fbn1^C1039G/+) was used. Starting at 6 weeks old, Marfan mice were untreated or given losartan (0.6 g·L⁻¹ in drinking water, n= 30). The littermate Fbn1^+/+ mice served as control. Thoracic aortas were studied at 3, 6 and 9 months by histology and by contractility assays in isolated segments in vitro.

Key results:

Losartan improved elastic fibre organization and increased aortic breaking stress. Losartan reduced the activity and protein expression of MMP-2 and MMP-9 at all ages. Aortic constriction in response to membrane depolarization or phenylephrine was increased by losartan at 3 and 9 months by 100–200%. Active force of aortic smooth muscle was also increased at 6 and 9 months. Acetylcholine-induced endothelium-dependent relaxation was improved by 30% after 3 months of losartan treatment, but such improvement disappeared with longer duration of treatment, accompanied by reduced phosphorylation of endothelial nitric oxide (NO) synthase^Ser1177, Akt^Thr308 and Akt^Ser473, compared with the control.

Conclusions and implications:

Losartan improved the contractile function of aorta and reduced MMP activation. However, the endothelial NO pathway remained suppressed in the thoracic aorta during losartan treatment, which might limit its long-term benefits in Marfan syndrome.     

Efficacy of chlorine disinfection of soft contact lenses.

We evaluated the chlorine system SOFTAB (Alcon) for the disinfection of soft contact lenses. The results indicate that a 1000-fold reduction in microorganisms was achieved within 6 h. Even with the slight interference of residual cleaner and the more significant interference of organic matter disinfection was still achieved.     

A job well done--a short history of Dr James Moroka.

James Moroka was one of the first Black South Africans and definitely the first Tswana national to obtain a medical degree. After graduating from Edinburgh University he practised for 58 years as a general practitioner in Thaba 'Nchu. He also played a leading role in the sociopolitical history of his people.     

Idiopathic pulmonary ossification

Idiopathic pulmonary ossification is an uncommon and asymptomatic disorder of unknown etiology in which trabeculated bone is found in the lung. It is usually mistaken for more serious entities radiographically, most commonly appearing as branching linear shadows of calcific density involving a limited area of the lung and exhibiting very slow progression; however, the shadows may be round or irregular and bulky. Sometimes the trabeculae are recognizable, and occasionally the lungs demonstrate widespread involvement. The authors describe 8 proven cases, including one in which a bone scan revealed uptake by heterotopic bone in the lung.     

Fosphenytoin in infants of extremely low birth weight

Fosphenytoin, a phosphorylated prodrug of phenytoin, is useful for acute seizures, is given by parenteral administration, and has few cardiac and local irritation adverse effects. There is limited experience in the administration of this new agent to newborns, and concern has been raised regarding the conversion of the prodrug to phenytoin. In two low--birth-weight infants, it was observed that fosphenytoin was converted adequately with varying effects on seizure control.