Project description:PURPOSE:To provide population-based reference values for cervical spinal canal parameters and vertebral body (VB) width and to study their associations with sex, age, body height, body weight and body mass index (BMI) using MRI. METHODS:Cross-sectional analyses included data from 2,453 participants, aged 21-89 years, of the population-based Study of Health in Pomerania (SHIP) who underwent whole-body MRI at 1.5 Tesla between July 2008 and March 2011. A standardised reading was performed for the C2-C7 cervical spine levels at sagittal T2 TSE weighted sequences. RESULTS:Reference intervals for spinal canal parameters were similar in males and females, while VB width was on average 2.1-2.2 mm larger in males. Age effects were only substantial regarding VB width with a 0.5 mm per ten-year age increase. Body height effects were only substantial regarding the osseous spinal canal and VB width. Body weight and BMI effects are mostly not substantial. CONCLUSIONS:Our study provides MRI-based reference values for the cervical spinal canal parameters in an adult Caucasian population. Except for VB width, associations with sex, age and somatometric measures are mostly small and thus have only limited clinical implications. Some available cut-off values may need a revision because they likely overestimate risks.
Project description:Age-related degeneration of the cervical spinal column is the most common cause of spinal cord lesions. T1 mapping has been shown to indicate the grade and site of spinal cord compression in low grade spinal canal stenosis (SCS). Aim of our study was to further investigate the diagnostic potential of a novel T1 mapping method at 0.75 mm resolution and 4 s acquisition time in 31 patients with various grades of degenerative cervical SCS. T1 mapping was performed in axial sections of the stenosis as well as above and below. Included subjects received standard T2-weighted MRI of the cervical spine (including SCS-grading 0-III), electrophysiological, and clinical examination. We found that patients with cervical SCS showed a significant difference in T1 relaxation times within the stenosis (727 ± 66 ms, mean ± standard deviation) in comparison to non-stenotic segments above (854 ± 104 ms, p < 0.001) and below (893 ± 137 ms, p < 0.001). There was no difference in mean T1 in non-stenotic segments in patients (p = 0.232) or between segments in controls (p = 0.272). Mean difference of the T1 relaxation times was significantly higher in grade III stenosis (234 ± 45) vs. in grade II stenosis (176 ± 45, p = 0.037) vs. in grade I stenosis (90 ± 87 ms, p = 0.010). A higher difference in T1 relaxation time was associated with a central efferent conduction deficit. In conclusion, T1 mapping may be useful as a tool for SCS quantification in all grades of SCS, including high-grade stenosis with myelopathy signal in conventional T2-weighted imaging.
Project description:BackgroundDegenerative changes of the cervical spinal column are the most common cause of spinal cord lesions in the elderly. Conventional clinical, electrophysiological and radiological diagnostics of spinal cord compression are often inconsistent.Materials and methodsThe feasibility and diagnostic potential of a novel T1 mapping method at 0.5 mm resolution and 4 s acquisition time was evaluated in 14 patients with degenerative cervical spinal canal stenosis (SCS) and 6 healthy controls. T1 mapping was performed in axial sections of the stenosis as well as above and below. All subjects received standard T2-weighted MRI of the cervical spine (including SCS-grading 0-III), electrophysiological and clinical examinations.ResultsPatients revealed significantly decreased T1 relaxation times of the compressed spinal cord within the SCS (912 ± 53 ms, mean ± standard deviation) in comparison to unaffected segments above (1027 ± 39 ms, p < .001) and below (1056 ± 93 ms, p < .001). There was no difference in mean T1 in unaffected segments in patients (p = .712) or between segments in controls (p = .443). Moreover, T1 values were significantly lower in grade II (881 ± 46 ms, p = .005) than in grade I SCS (954 ± 29 ms). Patients with central conduction deficit tended to have lower T1 values within the SCS than patients without (909 ± 50 ms vs 968 ± 7 ms, p = .069).ConclusionRapid high-resolution T1 mapping is a robust MRI method for quantifying spinal cord compression in patients with cervical SCS. It promises additional diagnostic insights and warrants more extended patient studies.
Project description:Semicircular canals have been sensors of angular acceleration for 450 million years. This vertebrate adaptation enhances survival by implementing postural and visual stabilization during motion in a three-dimensional environment. We used an integrated neuroethological approach in larval Xenopus to demonstrate that semicircular canal dimensions, and not the function of other elements, determines the onset of angular acceleration detection. Before angular vestibuloocular function in either the vertical or horizontal planes, at stages 47 and 48, respectively, each individual component of the vestibuloocular system was shown to be operational: extraocular muscles could be activated, central neural pathways were complete, and canal hair cells were capable of evoking graded responses. For Xenopus, a minimum semicircular canal lumen radius of 60 microm was necessary to permit endolymph displacement sufficient for sensor function at peak accelerations of 400 degrees /s(2). An intra-animal comparison demonstrated that this size is reached in the vertical canals earlier in development than in the horizontal canals, corresponding to the earlier onset of vertical canal-activated ocular motor behavior. Because size constitutes a biophysical threshold for canal-evoked behavior in other vertebrates, such as zebrafish, we suggest that the semicircular canal lumen and canal circuit radius are limiting the onset of vestibular function in all small vertebrates. Given that the onset of gravitoinertial acceleration detection precedes angular acceleration detection by up to 10 d in Xenopus, these results question how the known precise spatial patterning of utricular and canal afferents in adults is achieved during development.
Project description:Background and purposeHyperintense fluid-signal anterior median fissure and hyperintense foci resembling the central canal are seen on cervical spine axial T2 MR imaging. They may also be associated with a channel-like T2-hyperintense craniocaudad line on sagittal images. We hypothesized that the hyperintense foci and the sagittal line may represent the base of the anterior median fissure.Materials and methodsIn this exploratory study, 358 cervical MR images were analyzed for recording and comparing the incidence/numbers of hyperintense foci, anterior median fissure, and sagittal line as hyperintense foci, anterior median fissure, and sagittal line per patient when present alone or together, both with and without the sagittal line.ResultsHyperintense foci were identified on 238/358 (66.5%) studies; an anterior median fissure, on 218/358 (60.9%). The hyperintense foci/anterior median fissure ratio was 3.7/2.3 (P = .00001). Anterior median fissures were seen alone less commonly than hyperintense foci were seen alone (P = .045). We identified increased anterior median fissure/patient in a hyperintense foci +anterior median fissure group compared with an anterior median fissure-only group (4.0 versus 3.2, P = .05), with similar hyperintense foci/patient in the hyperintense foci+anterior median fissure and hyperintense foci-only groups (5.5 versus 5.8, P = .35), and proportional distribution of both across the hyperintense foci+anterior median fissure subgroups (hyperintense foci/anterior median fissure ratio, 1.3). The sagittal line in 89 (24.9%) patients was associated with increased hyperintense foci and anterior median fissure/patient. Greater correlation of anterior median fissure/patient to sagittal line presence was seen in sagittal line subgroup analysis.ConclusionsThis exploratory analysis found an increased anterior median fissure per patient in conjunction with hyperintense foci presence, a proportional increase of both across the hyperintense foci+anterior median fissure group, and greater correlation of anterior median fissure per patient with the sagittal line. These findings suggest that anterior median fissure and hyperintense foci are structurally related, that hyperintense foci may commonly be the base of the anterior median fissure, and that the sagittal line is a manifestation primarily of an anterior median fissure, occasionally appearing as channels that may simulate the central canal.
Project description:Enzyme replacement therapy with laronidase (recombinant human alpha-l-iduronidase) is successfully used to treat patients with mucopolysaccharidosis type I (MPS I). However, the intravenously-administered enzyme is not expected to treat or prevent neurological deterioration. As MPS I patients suffer from spinal cord compression due in part to thickened spinal meninges, we undertook a phase I clinical trial of lumbar intrathecal laronidase in MPS I subjects age 8 years and older with symptomatic (primarily cervical) spinal cord compression. The study faced significant challenges, including a heterogeneous patient population, difficulty recruiting subjects despite an international collaborative effort, and an inability to include a placebo-controlled design due to ethical concerns. Nine serious adverse events occurred in the subjects. All subjects reported improvement in symptomatology and showed improved neurological examinations, but objective outcome measures did not demonstrate change. Despite limitations, we demonstrated the safety of this approach to treating neurological disease due to MPS I.
Project description:The aim of the present study was to evaluate the concurrent effect of root canal preparation size and intra coronal bleaching on dentin microhardness.Seventy-two intact anterior teeth were root canal treated and randomly divided into two groups (n=36) according to the size of coronal root canal preparation. The coronal portions of the canals were then enlarged with #2 and 4 Peeso reamers, respectively. Following root canal obturation, teeth were assigned into three groups (n=12) to be treated with bleaching agents containing 35% hydrogen peroxide (HP), sodium perborate (SP) and distilled water as control group. The teeth were stored at 37ºC and 100% humidity for 7 days. Dentinal blocks with 3 mm thickness were obtained from the cervical region and Vickers microhardness number (VHN) were measured for outer and inner dentin in each tooth sample. Data were analyzed using two-way ANOVA and Tukey's HSD tests.In the outer dentin, the mean VHN in the HP and control groups showed statistically significant differences (P=0.047). The mean VHN of inner dentin for the large preparation size was statistically higher in comparison to the small preparation size (P=0.042). There was a statistically significant difference in the mean VHN of inner dentin with small preparation size between HP and SP groups (P=0.029) and HP and control groups (P=0.021).Intra coronal bleaching with 35% hydrogen peroxide, affects the inner and outer dentin significantly. Excessive removal of cervical dentin, following root canal preparation, alongside the adverse effect of bleaching materials on dentin could result in the tooth fracture.
Project description:Vaginal and cervical canal bacteria are associated with women's health and pregnancy outcomes. Here, we compared their composition and characteristics in 37 reproductive-aged Chinese women including 24 pregnant women with cervical incompetence (vaginal and cervical canal bacteria formed Groups A and B, respectively) and 13 healthy pregnant women (vaginal and cervical canal bacteria formed Groups C and D, respectively) using high-throughput sequencing of the V4 region of 16S rRNA gene. The results of alpha and beta diversity analysis, respectively, indicated no statistical differences between Groups A and B (p = 0.32, 0.06), nor Groups B and D (p = 0.69, 0.74); however, differences were found between Groups C and D (p = 0.02, 0.01) and between Groups A and C (p = 0.04, 0.02). PLS-DA analysis showed that the individuals from each group were irregularly distributed according to their clade. Lactobacillus, Bifidobacterium and Ureaplasma were the dominant genera in all groups. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSts) analysis identified 31 Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs associated with the bacterial communities from the four groups, including membrane transport, folding, sorting and degradation, xenobiotics biodegradation and metabolism, and nucleotide metabolism. We further determined relationships between pregnancy outcomes (Apgar scores) and certain bacterial species. A significant positive correlation was found between Apgar scores and Actinomyces neuii and Anoxybacillus flavithermus in the vagina and cervical canal of pregnant women with cervical incompetence while Bacteroides plebeius, Bifidobacterium pseudopodium and Staphylococcus petrasii in the cervical canal displayed negative correlations with Apgar scores. Moreover, Clostridium fimetarium, Methanobacterium congolense, Pseudomonas chlororaphis, and Psychrobacter nivimaris in the vagina were negatively correlated with Apgar scores. These bacteria may serve as potential biomarkers, however, additional research is warranted to verify their role in clinical outcomes.
Project description:The in vivo intervertebral range of motion (ROM) is an important predictor for spinal disorders. While the subaxial cervical spine has been extensively studied, the motion characteristics of the occipito-atlantal (C0-1) and atlanto-axial (C1-2) cervical segments were less reported due to technical difficulties in accurate imaging of these two segments. In this study, we investigated the intervertebral ROMs of the entire cervical spine (C0-T1) during in vivo functional neck motions of asymptomatic human subjects, including maximal flexion-extension, left-right lateral bending, and left-right axial torsion, using previously validated dual fluoroscopic imaging and model registration techniques. During all neck motions, C0-1, similar to C7-T1, was substantially less mobile than other segments and always contributed less than 10% of the cervical rotations. During the axial rotation of the neck, C1-2 contributed 73.2 ± 17.3% of the cervical rotation, but each of other segments contributed less than 10% of the cervical rotation. During both lateral bending and axial torsion neck motions, regardless of primary or coupled motions, the axial torsion ROM of C1-2 was significantly greater than its lateral bending ROM (p < 0.001), whereas the opposite differences were consistently observed at subaxial segments. This study reveals that there are distinct motion patterns at upper and lower cervical segments during in vivo neck motions. The reported data could be useful for the development of new diagnosis methods of cervical pathologies and new surgical techniques that aim to restore normal cervical segmental motion.