Delayed surgical intervention in central cord syndrome with cervical stenosis

Study Design Review of the literature. Objective It is generally accepted that surgical treatment is necessary for central cord syndrome (CCS) with an underlying cervical stenosis. However, the surgical timing for decompression is controversial in spondylotic cervical CCS. The purpose of this study is to review the results of early and delayed surgery in patients with spondylotic cervical CCS. Methods MEDLINE was searched for English-language articles on CCS. There were 1,653 articles from 1940 to 2012 regarding CCS, 5 of which dealt with the timing of surgery for spondylotic cervical CCS. Results All five reports regarding the surgical timing of spondylotic cervical CCS were retrospective. Motor improvement, functional independence measures, and walking ability showed similar improvement in early and late surgery groups in the studies with follow-up longer than 1 year. However, greater improvement was seen in the early surgery group in the studies with follow-up shorter than 1 year. The complication rates did not show a difference between the early and late surgery groups. However, there are controversies regarding the length of intensive care unit stay or hospital stay for the two groups. Conclusions There was no difference in motor improvement, functional independence, walking ability, and complication rates between early and late surgery for spondylotic cervical CCS

Spin-wave propagation in the presence of inhomogeneous Dzyaloshinskii-Moriya interactions

We theoretically investigate spin-wave propagation through a magnetic metamaterial with spatially modulated Dzyaloshinskii-Moriya interaction. We establish an effective Schrodinger equation for spin waves and derive boundary conditions for spin waves passing through the boundary between two regions having different Dzyaloshinskii-Moriya interactions. Based on these boundary conditions, we find that the spin wave can be amplified at the boundary and the spin-wave band gap is tunable either by an external magnetic field or the strength of Dzyaloshinskii-Moriya interaction, which offers a spin-wave analog of the field-effect transistor in traditional electronics.112sciescopu

Tau positron emission tomography in tauopathies: A narrative review

Aggregation of misfolded tau in the brain is a major pathological feature common in various neurodegenerative disorders known as tauopathies, including Alzheimer’s disease, progressive supranuclear palsy, corticobasal syndrome, and dementia with Lewy bodies. Tauopathies are collection of diseases with varied overlapping symptoms and complicated manifestations. Consequently, it is crucial to be able to assess tau deposits in vivo. Over the past decade, tau-specific radioligands for positron emission tomography (PET) have been developed and tested, including first-generation compounds (e.g., 18F-THK5317, 18F-THK5351, 18F-AV1451, and 11C-PBB3) and second-generation compounds (18F-MK-6240, 18F-RO-948, and 18F-PI-2620). With the recent advances of tau PET tracers, assessing the pattern of tau deposition in vivo is possible. These methods will allow accurate diagnosis of tauopathies and monitoring of disease progression. In this mini review, we summarize current findings from studies using tau PET tracers regarding neuropathological characteristics, clinical implications, and potential applications of tau PET. We also discuss methodological considerations for appropriate use of these technologies and discuss what has been learned from these findings

Comparison of Surgical Outcomes in Thoracolumbar Fractures Operated with Posterior Constructs Having Varying Fixation Length with Selective Anterior Fusion

PURPOSE: Surgical treatment in the case of thoracolumbar burst fractures is very controversial. Posterior instrumentation is most frequently used, however, but the number of levels to be instrumented still remains a matter of debate. MATERIALS AND METHODS: A total of 94 patients who had a single burst fracture between T11 and L2 were selected and were managed using posterior instrumentation with anterior fusion when necessary. They were divided into three groups as follows; Group I (n = 28) included patients who were operated by intermediate segment fixation, Group II (n = 32) included patients operated by long segment fixation, and Group III (n = 34) included those operated by intermediate segment fixation with a pair of additional screws in the fractured vertebra. The mean follow-up period was twenty one months. The outcomes were analyzed in terms of kyphosis angle (KA), regional kyphosis angle (RA), sagittal index (SI), anterior height compression rate, Frankel classification, and Oswestry Disability Index questionnaire. RESULTS: In Groups II and III, the correction values of KA, RA, and SI were much better than in Group I. At the final follow up, the correction values of KA (6.3 and 12.1, respectively) and SI (6.2 and 12.0, respectively) were in Groups II and III found to be better in the latter. CONCLUSION: The intermediate segment fixation with an additional pair of screws at the fracture level vertebra gives results that are comparable or even better than long segment fixation and gives an advantage of preserving an extra mobile segment.ope

Lumbar Stenosis: A Recent Update by Review of Literature

Degeneration of the intervertebral disc results in initial relative instability, hypermobility, and hypertrophy of the facet joints, particularly at the superior articular process. This finally leads to a reduction of the spinal canal dimensions and compression of the neural elements, which can result in neurogenic intermittent claudication caused by venous congestion and arterial hypertension around nerve roots. Most patients with symptomatic lumbar stenosis had neurogenic intermittent claudication with the risk of a fall. However, although the physical findings and clinical symptoms in lumbar stenosis are not acute, the radiographic findings are comparatively severe. Magnetic resonance imaging is a noninvasive and good method for evaluation of lumbar stenosis. Though there are very few studies pertaining to the natural progression of lumbar spinal stenosis, symptoms of spinal stenosis usually respond favorably to non-operative management. In patients who fail to respond to non-operative management, surgical treatments such as decompression or decompression with spinal fusion are required. Restoration of a normal pelvic tilt after lumbar fusion correlates to a good clinical outcome

Quality of Life in Patients with Osteoporotic Vertebral Fractures

Study DesignA case-control study.PurposeTo examine several dimensions of health-related quality of life (HRQL) in postmenopausal women with osteoporotic vertebral fractures, compared with a control group.Overview of LiteratureOsteoporotic vertebral fractures are a major cause of morbidity among postmenopausal women. There have been many reports of a decrease in the quality of life in patients with osteoporotic vertebral fractures. However,few reports have analyzed which dimensions contribute to the decline in quality of life.MethodsOne thousand five hundred forty-five postmenopausal women aged 50 years and older from 17 study sites in nationwide hospitals were in enrolled in the study (between April 2008 and January 2009). HRQL was measured using the European Quality of Life 5 Domains (EQ-5D), and visual analogue scale (VAS).ResultsThe average VAS of the case group was 57.80, and that of the control group was 64.10 (p=0.001). All domains of the EQ-5D score were significantly worse in the case group (p=0.001). Among the case group, the average VAS of the 559 patients (45%) who were operated on was 56.8, and that of the remaining 680 patients (55%) who were treated conservatively was 58.6 (p=0.135). Among the case group, the averages of each EQ-5D domain of the 559 patients (45%) who were operated on were: 1.87 in mobility, 1.81 in self-care, 1.99 in usual activities, 2.11 in pain, and 1.62 in anxiety or depression. Those of the 680 patients (55%) who were treated conservatively were: 1.72 in mobility, 1.60 in self-care, 1.76 in usual activities, 1.98 in pain, and 1.57 in anxiety or depression. Except for the domain of anxiety or depression, scores for the other domains were all significantly worse in the patients who were operated on (p=0.001).ConclusionsHealth related quality of life in the patients with osteoporotic vertebral fractures was significantly worse in both the EQ-5D domains and VAS. Among the osteoporotic vertebral fracture patients, the patients who were operated on had a worse quality of life in EQ-5D

Dependence of reaction center-type energy-dependent quenching on photosystem II antenna size

AbstractThe effects of photosystem II antenna size on reaction center-type energy-dependent quenching (qE) were examined in rice plants grown under two different light intensities using both wild type and qE-less (OsPsbS knockout) mutant plants. Reaction center-type qE was detected by measuring non-photochemical quenching at 50 μmol photons m−2 s−1 white light intensity. We observed that in low light-grown rice plants, reaction center-type qE was higher than in high light-grown plants, and the amount of reaction center-type qE did not depend on zeaxanthin accumulation. This was confirmed in Arabidopsis npq1–2 mutant plants that lack zeaxanthin due to a mutation in the violaxanthin de-epoxidase enzyme. Although the electron transport rate measured at a light intensity of 50 μmol photons m−2 s−1 was the same in high light- and low light-grown wild type and mutant plants lacking PsbS protein, the generation of energy-dependent quenching was completely impaired only in mutant plants. Analyses of the pigment content, Lhcb proteins and D1 protein of PSII showed that the antenna size was larger in low light-grown plants, and this correlated with the amount of reaction center-type qE. Our results mark the first time that the reaction center-type qE has been shown to depend on photosystem II antenna size and, although it depends on the existence of PsbS protein, the extent of reaction center-type qE does not correlate with the transcript levels of PsbS protein. The presence of reaction center-type energy-dependent quenching, in addition to antenna-type quenching, in higher plants for dissipation of excess light energy demonstrates the complexity and flexibility of the photosynthetic apparatus of higher plants to respond to different environmental conditions