New Grading System for Cervical Paraspinal Soft Tissue Damage After Traumatic Cervical Spinal Cord Injury Without Major Fracture Based on the Short-T1 Inversion Recovery Mid-Sagittal MRI for Prediction of Neurological Improvements: The STIR-MRI Grade.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To develop a grading method for cervical paraspinal soft tissue damage after cervical spinal cord injury (CSCI) without major fracture based on the short T1 inversion recovery (STIR) mid-sagittal magnetic resonance image (MRI) for prediction of neurological improvements. METHODS: This study included 34 patients with CSCI without major fracture, treated conservatively for at least 1 year and graded using the STIR-MRI Grade. This system consists of anterior grades; A0: no high-intensity area (HIA), A1: linear HIA, and A2: fusiform HIA, and posterior grades; P0: no HIA, P1: HIA not exceeding the nuchal ligament, and P2: HIA exceeding the nuchal ligament, within 24 hours postinjury. The American Spinal Injury Association impairment scale (AIS) and the Japanese Orthopedic Association (JOA) scores were examined. RESULTS: Anterior grades were not significantly correlated with the AIS and JOA score. At both injury and final follow-up, the AIS in P2 patients was significantly more severe (P = 0.007, P = 0.015, respectively) than that in P0 patients. At the injury, the AIS in P2 patients was significantly more severe (P = 0.008) than that in P1 patients. Among P2 patients only, the JOA score at the injury (1.4 points) did not improve by the final follow-up (3.9 points). The final follow-up JOA score (3.9 points) in P2 patients was significantly lower than that (13.6 points) in P0 patients (P = 0.016). CONCLUSIONS: Grade P2 led to poor neurological outcomes. The STIR-MRI Grade is a prognostic indicator for neurological improvements past-CSCI.

Prevalence of Cervical Canal Stenosis in Patients with Femoral Fracture: A Retrospective Single-Center Study.

Introduction: Cervical spine surgery reduces falls and subsequent femoral fractures. Nonetheless, current evidence on the prevalence of cervical cord compression (CCC) and increased signal intensity (ISI) in patients with femoral fractures is limited. We aimed to determine the prevalence of CCC and ISI and characterize the physical status and imaging findings using cervical spine magnetic resonance imaging (MRI) and brain computed tomography (CT) in patients with femoral fractures. Methods: This study included 173 patients (140 women, 33 men) with femoral fractures caused by falling, who underwent both cervical spine MRI and brain CT. CCC cases classified as grade 2 (compression of less than one-third of the spinal cord) or higher were investigated. The ISI of the severely affected intervertebral disc level was evaluated using T2-weighted MRI. Hand grip strength and myelopathic signs were also evaluated. Data analysis was performed using the χ2 test, Fisher's exact test, and Student's t-test. Results: Among the 173 patients, 83 (48.0%) had CCC, 29 (16.8%) had ISI, and 68 (39.3%) had abnormal brain CT findings. There was no ISI in patients in the non-CCC group. The patients' average age in the CCC group was significantly higher than that in the non-CCC group. There was no significant difference in the proportion of myelopathic sign and abnormal brain CT findings between the CCC and non-CCC groups or between the ISI and non-ISI groups. Bilateral hand grip strength was significantly negatively correlated with the stenosis rate (right, p=0.047; left, p=0.0018). Conclusions: In conclusion, our study showed that patients with femoral fractures had a high frequency of cervical canal stenosis and intracranial lesions using cervical spine MRI and brain CT.

The effect of disruption of the repaired nuchal ligament on clinical outcomes after posterior cervical spine surgery: A retrospective comparative study.

OBJECTIVE: This study aimed to investigate whether disruption of the repaired nuchal ligament (NL) affects clinical outcomes following posterior cervical spine surgery. METHODS: This retrospective study included 101 patients (65 males, 36 females) who underwent posterior cervical spine surgery, 69 of whom received laminoplasty (LP), and 32 posterior decompression and fusion (PDF). The NL was split during the surgical approach and repaired at the time of wound closure. The frequency and spinal levels of NL disruption at one month, six months, and one year postoperatively were evaluated on mid-sagittal and axial magnetic resonance images. Postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, C2-C7 lordotic angle, and decrease rate of C2-C7 range of motion (ROM) were examined at six months and/or one year postoperatively. Based on the NL disruption levels, the patients were divided into the upper group (C2-C5), lower group (C6-T1), and non-disruption group. RESULTS: Although the lower group contained patients with NL disruption (10%) after LP at final follow-up, all PDF patients belonged to the non-disruption group. For the LP patients, the postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, and C2-C7 lordotic angle did not significantly differ between the lower and non-disruption groups; however, the rate of C2-C7 ROM decrease in the lower group (48%) was considerably larger than that in the non-disruption group (33%) after LP. CONCLUSION: Evidence from this study has shown that postoperative disruption of the repaired NL has no significant effect on postoperative axial symptoms and C2-C7 alignment, but it can affect the rate of decrease in C2-C7 ROM after LP. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Critical points and effectiveness of prophylactic C4/5 foraminotomy to prevent C5 palsy after posterior cervical spine surgery.

OBJECTIVE: The aim of this study was to clarify the cut-off values of the spinal canal parameters as risk factors for C5 palsy after posterior cervical spine surgery with and without foraminotomy. METHODS: One hundred three consecutive patients (67 males, 36 females; mean age = 66 years, age range = 27-87 years) with cervical myelopathy who underwent posterior cervical spine surgery at our institution were retrospectively reviewed and included in the study. The first consecutive 69 patients who underwent posterior cervical spine surgery with prophylactic bilateral C4/5 foraminotomy were designated as the F (+) group. The subsequent 34 consecutive patients who underwent posterior cervical spine surgery without prophylactic bilateral C4/5 foraminotomy were designated as the F (-) group. All patients were then divided into four subgroups. In the F (+) group, patients with C5 palsy were designated as the F (+) P (+) subgroup (n = 13), while those without C5 palsy were designated as the F (+) P (-) subgroup (n = 56). In the F (-) group, patients with C5 palsy were designated as the F (-) P (+) subgroup (n = 5), while those without C5 palsy were designated as the F (-)P(-) subgroup (n = 29). Receiver operating characteristic curves were used to investigate the cut-off values of the spinal canal parameters for the development of postoperative C5 palsy. The assessed spinal parameters were the gutter positions (GP), laminar inclination angles (LIA), and postoperative cross-sectional areas (CSA) of the dural sac. The risk ratios (RR) of the spinal canal parameters as risk factors for C5 palsy were evaluated. RESULTS: The incidence of C5 palsy was similar between the F (+) group (18.8%) and the F (-) group (14.7%). The cut-off values for each spinal canal parameter in the F (+) group (GP: 0.82-0.84, LIA: 58.9-62.4°, and CSA: 189.5-200 mm2 ) were similar to those in the F (-) group (0.81-0.89, 61.7-62.5°, and 197.5-199.5 mm2, respectively). In the RR results for C5 palsy, the LIA was highest in both groups. The F (+) P (-) subgroup had significantly larger mean CSA at C4/5 and C5/6 (202.3 mm2 and 200.9 mm2, respectively) than the F (-)P(-) subgroup (177.3 mm2 and 178.9 mm2, respectively) (P = 0.0181 and P = 0.0277, respectively). Prophylactic C4/5 foraminotomy did not specifically prevent postoperative C5 palsy due to foraminal stenosis at C4/5. CONCLUSION: C4/5 foraminotomy should not be recommended for avoidance of C5 palsy. Although the bony spinal parameters were similar between the F (+) and F (-) groups, the CSA in the F (+) group was significantly than that in the F (-) group in the patients without C5 palsy.

Flexional distance index: A new prognostic indicator of neurological outcomes at 4 years after cervical laminoplasty for K-line (+) ossification of the posterior longitudinal ligament.

OBJECTIVE: We aimed to investigate whether K-line in the neck flexion (FK-line), flexion angle (FA), or flexion distance index (FDI) could predict the recovery rate of the Japanese Orthopedic Association score (RR-JOA) at 4 years after cervical laminoplasty (LP) for ossification of the posterior longitudinal ligament (OPLL). METHODS: A new index, i.e., the FDI, which is based on the degree of neck flexion and the OPLL size on a lateral radiograph. "Flexional distance" is the distance from C2 to C7 in neck flexion, and "distance to OPLL" is the maximal distance from the line of the flexional distance to OPLL. FDI was defined as follows: FDI = flexional distance/distance to OPLL. Twenty-three patients with K-line (+) OPLL were evaluated at 4 years after LP (follow-up rate, 92%). We investigated the relationships between preoperative radiological factors, including FK-line, FA, and FDI, and RR-JOA at 4 years postoperatively. RESULTS: Preoperative FK-line and FA were significantly related with the RR-JOA at 1 year postoperatively, but not at 4 years postoperatively. Preoperative FDI was significantly positively correlated with the RR-JOA at 1 year and 4 years postoperatively (P = 0.0132, r = 0.504 and P = 0.0183, r = 0.484, respectively). Preoperative FDI < 2.5 was associated with worsening of the RR-JOA at 4 years postoperatively, with a probability of 80% DISCUSSIONS: FDI could predict the RR-JOA at 4 years after LP for OPLL. Decompression with fusion may be recommended for patients with preoperative FDI < 2.5. LEVEL OF EVIDENCE: 4.

Modified K-Line in Neck Extension Is a Prognostic Indicator of the Surgical Outcome at 5 Years After Cervical Laminoplasty for Cervical Spondylotic Myelopathy.

STUDY DESIGN: A retrospective comparison of the surgical outcome after cervical laminoplasty for cervical spondylotic myelopathy (CSM) using a modified K-line based on lordosis in neck extension as a predictor: in K-line Back CSM (KB group), the K-line crosses the ventral edge of any of the spinous processes, whereas in K-line Front CSM (KF group), the K-line does not. OBJECTIVE: To investigate the neurological and radiological outcomes 5 years after surgery and the contact between the spinal cord and posterior elements after laminoplasty for CSM using the modified K-line. SUMMARY OF BACKGROUND DATA: No indicators on a lateral radiograph can predict the neurological outcome after laminoplasty for CSM. METHODS: Patients with CSM were divided into KB (n = 20) and KF groups (n = 13). We compared the postoperative Japanese Orthopedic Association (JOA) score, recovery rate, grip-and-release and foot-tapping test results, alignment, and contact between the spinal cord and posterior elements between the two groups. RESULTS: The postoperative JOA score and its recovery rate were significantly lower in the KB group (12.4 points and 34.1%, respectively) than in the KF group (14.1 points and 59.0%, respectively) at final follow-up (P = 0.0415 and 0.0458). The grip-and-release and foot-tapping test results improved significantly in the KF group but not in the KB group. In the KB group, a larger lordotic angle in extension at 1 year postoperatively continued until final follow-up. The rate of recovery of the JOA score in patients with contacts at both C4/5 and C5/6 and any contact in the KB group (-1.5% and 31.9%, respectively) were lower (P = 0.0013 and 0.0534, respectively) than those in the KF group (58.6% and 60.7%, respectively). CONCLUSION: The K-line Back predicts a poor neurological outcome after laminoplasty for CSM. Decompression with fusion may be recommended for these patients.Level of Evidence: 4.

Comparison of Short-Term Clinical Results and Radiologic Changes Between Two Different Minimally Invasive Decompressive Surgical Methods for Lumbar Canal Stenosis: Lumbar Spinous Process Splitting Laminectomy and Trans-Interspinous Lumbar Decompression.

STUDY DESIGN: A multicenter, retrospective study. OBJECTIVE: To clarify the clinical and radiological effects of removing interspinous contextures in lumbar decompression surgery for patients with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: There have seldom been reports that have compared both clinical results and radiological changes among minimally invasive decompression methods. METHODS: Consecutive 52 patients underwent lumbar spinous process-splitting laminectomy (LSPSL), following which 50 patients underwent trans-interspinous lumbar decompression (TISLD). All patients presented with cauda equina type of lumbar spinal stenosis and underwent a minimum 1-year follow-up. The Japanese Orthopaedic Association (JOA) score and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score were evaluated to determine the extent of daily living activities. Propensity score (PS)-matched analysis was used to match patients' age and preoperative JOA scores between the two groups. Lumbar lordosis (LL), disc height (DH), segmental range of motion (ROM), and vertebral anterior translation were measured by functional lumbar lateral x-ray, and changes between preoperative and 1-year postoperative values were evaluated. RESULTS: Twenty-nine pairs of patients were selected by PS-matching. Mean JOA scores increased from 14.4 to 23.5 (mean recovery rate was 62.3%) in the LSPSL group and from 14.0 to 23.2 (61.3%) in the TISLD group at preoperative and 1-year follow-up, respectively. There were no significant differences in clinical results and changes in LL, ROM, and vertebral anterior translation in each group. The DH at L4/5 level at 1-year after surgery revealed significant decrease in the TISLD group compared with the LSPSL group. There was a correlation between preoperative DH and DH decrease in the LSPSL group, but not in TISLD group. CONCLUSION: Removal of interspinous contextures did not influence clinical outcomes at 1 year after surgery, but it may be likely to cause disc height loss when it applied at the L4/5 level.Level of Evidence: 3.

Ten-Year Long-term Results of Modified Cervical Double-door Laminoplasty With C3 Laminectomy Preserving the Semispinalis Cervicis Inserted Into the Axis Compared With Those of Conventional Cervical Laminoplasty.

STUDY DESIGN: A retrospective study. OBJECTIVE: To compare long-term clinical and radiologic outcomes between conventional double-door laminoplasty (LP) (group A) and cervical LP with C3 laminectomy (group B). SUMMARY OF BACKGROUND DATA: Cervical LP with C3 laminectomy preserving the semispinalis cervicis inserted into the axis decreased the patients' postoperative axial pain and muscle atrophy, prevented interlaminar bony fusion, decreased limitations of daily living activity, including reduced postoperative neck mobility, and maintained the cervical range of motion (ROM) more effectively than conventional cervical LP reattaching the semispinalis cervicis in the short-term. MATERIALS AND METHODS: Group A included 14 patients with an average age of 56.6 years at the time of surgery (follow-up rate 58.1%), and group B included 21 patients with an average age of 56.3 years at the time of surgery (follow-up rate 29.1%). We evaluated the clinical results, which included the Japanese Orthopaedic Association (JOA) score, JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and radiologic results, including C2-C7 ROM, number of interlaminar bony fusions and presence of new spondylolisthesis at C3. RESULTS: There were no significant differences in preoperative and postoperative JOA scores, recovery rate of JOA score, and JOACMEQ. Significantly fewer patients in group B experienced interlaminar bony fusion at C2-C3 compared with those in group A. There was no significant difference in the presence of new spondylolisthesis at C3. In patients with cervical spondylotic myelopathy, the rate of decrease of C2-C7 ROM was significantly less in group B than in group A. In patients with ossification of the posterior longitudinal ligament, there was no significant difference in the rate of decrease of C2-C7 ROM between the groups. CONCLUSIONS: C3 laminectomy prevented interlaminar bony fusion at C2-C3. C3 laminectomy maintained cervical ROM in patients with cervical spondylotic myelopathy. There were no adverse events due to C3 laminectomy at 10 years postsurgery.

Can prophylactic C4/5 foraminotomy prevent C5 palsy after cervical laminoplasty with and without posterior instrumented fusion with maximal expansion?

OBJECTIVE: To prospectively examine whether laminoplasty with maximal expansion induces C5 palsy, even with prophylactic bilateral C4/5 foraminotomy. METHODS: Thirty-five consecutive patients with cervical myelopathy underwent laminoplasty (n = 19: LP group) or posterior decompression and fusion (n = 16: PDF group) with maximal expansion. Prophylactic bilateral C4/5 foraminotomy was performed alternately in consecutive five patients undergoing each type of surgery. In each type of surgery, the first and third consecutive five patients did not undergo foraminotomy (NF subgroup: 20 patients), while the second and fourth consecutive five patients underwent foraminotomy (F subgroup: 15 patients). The widths between the gutters was equivalent to the diameter of the spinal canal, and an inclination angle of the lamina of approximately 90° was created during laminoplasty. The incidence and severity of postoperative C5 palsy were investigated. Patients with a manual muscle testing score for the deltoid muscle and/or biceps brachii muscle of ≤ 2 were diagnosed with severe palsy. RESULTS: The respective incidences of C5 palsy in the F and NF subgroups were 33% and 20% in the LP group and 50% and 20% in the PDF group. Severe palsy occurred in 67% and 0% of patients who had developed palsy in F and NF subgroups, respectively, in the LP group, and in 100% of patients in the PDF group. Furthermore, 40% of the patients with severe palsy took more than 6 months to recover. CONCLUSIONS: Laminoplasty with maximal expansion induced C5 palsy in both the LP and PDF groups, even with the addition of prophylactic bilateral C4/5 foraminotomy.

Osmotic perception of GABAergic synaptic transmission in the supraoptic nucleus of rats.

Extracellular osmolality plays a crucial role in controlling the activation of neurons. Hypertonic stimulation modulates glutamatergic inputs to the supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs) putative vasopressin (VP) neurons through capsaicin-insensitive transient receptor potential vanilloid (TRPV) 1 channels on the presynaptic terminals. However, it remains unclear whether osmotic stimulation modulates GABAergic inputs to VP-secreting neurons within punched-out slices containing only the SON and the perinuclear zone. To answer this question, we studied the effects of various osmotic conditions on the miniature GABAergic postsynaptic currents (mGPSCs) using the whole-cell patch-clamp technique on rat SON putative VP-secreting neurons in small slice preparations. We revealed that incubation in hypertonic solution for 2 h reduced both the frequency and amplitude of the mGPSCs to the SON putative VP neurons, whereas the mGPSCs were unaffected when the external osmolality was changed from isotonic to hypotonic. Of interest, we found that changing from a hypertonic to hypotonic environment increased the frequency of the mGPSCs. This effect was independent of TRPV4. We hypothesize that two coordinated mechanisms may play an important role in the regulation of a wide range of physiological functions of VP.: 1) the modulation of GABAA receptor properties by brain-derived neurotrophic factor (BDNF)-induced tyrosine kinase B receptor-mediated signaling under hypertonic conditions, and 2) cell swelling-induced activation of whole-cell anion currents under hypotonic conditions.

A novel method for evaluating activity of transient receptor potential channels using a cellular dielectric spectroscopy.

Cellular dielectric spectroscopy (CDS) is a novel technology enabling pharmacological evaluation of multiple receptor types with a label-free cell-based assay. We evaluated activities of a family of ligand-gated channels, transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) channels by an electrical impedance-based biosensor (CellKey™ system) using CDS. Measures of both potency (EC50) and efficacy (Emax) of these agonists with CellKey™ were almost identical to those made using the traditional Ca2+ influx assay in TRPV1- or TRPA1-expressing cells, suggesting that CellKey™ is a simpler and easier means of evaluating TRP activities.

Improvement in the results of the simple-foot-tapping test and cross-sectional area of the dural sac in patients with C5 palsy after posterior cervical spine surgery.

INTRODUCTION: The smaller cross-sectional areas of the dural sacs in patients without C5 palsy after posterior cervical spine surgery may lead to less neurological improvement. OBJECTIVES: The aim of this retrospective study was to clarify the differences in the cross-sectional area of the dural sac in the cervical spine and neurological improvement in patients with and without C5 palsy after posterior cervical spinal surgery. METHODS: We retrospectively evaluated the postoperative cross-sectional areas of the dural sacs and neurological outcomes in patients with and without C5 palsy after posterior cervical spine surgery. We compared the postoperative cross-sectional areas of the dural sac at C4/5 and C5/6 on magnetic resonance images between the C5 palsy group (n = 19) and the no-C5 palsy group (n = 84) after posterior cervical spinal surgery 1 year postoperatively. Performance tests, namely, the 10-s grip-and-release test and the 10-s single-foot-tapping (FT) test, were compared between the two groups. RESULTS: Postoperative cross-sectional areas of the dural sac at C4/5 and C5/6 (233.3 mm2 and 226.6 mm2, respectively) in the C5 palsy group were significantly larger (P = 0.0036 and P = 0.0039, respectively) than those (195.0 mm2 and 193.8 mm2, respectively) in the no-C5 palsy group. Postoperative gain in the grip-and-release test was similar between the two groups. Postoperative gain in the FT test (4.9 times) in the C5 palsy group was significantly larger (P = 0.0060) than that (1.8 times) in the no-C5 palsy group. CONCLUSIONS: In the C5 palsy group 1 year after posterior cervical spine surgery, the cross-sectional areas of the dural sac were larger, and the 10-s single FT test improved noticeably.

Accuracy of the Gutter Position in Cervical Double-door Laminoplasty Using Intraoperative Computed Tomography Navigation and the Factors Associated With C5 Palsy.

STUDY DESIGN: This was a prospective study. OBJECTIVE: This study aimed to investigate the accuracy of the gutter position after cervical double-door laminoplasty (LP) using intraoperative computed tomography (CT) navigation and the factors associated with C5 palsy. SUMMARY OF BACKGROUND DATA: There were some reports in which the gutter position and the width of decompression in cervical LP were associated with C5 palsy; however, there were few reports about the accuracy of the gutter position. MATERIALS AND METHODS: Thirty-three patients treated with cervical LP were enrolled. We marked our targeted gutter position on the lamina with a high-speed drill using intraoperative CT navigation and performed the LP procedure. The accuracy of the gutter position was evaluated with a postoperative CT scan. We measured the angle of the opened lamina (AOL), the proportion of the distance between the gutters and the distance of transverse diameter of spinal canal (PGSC) with a postoperative CT scan and spinal cord posterior shifting (SCPS) with preoperative and postoperative magnetic resonance imaging scans. We investigated the incidence of C5 palsy and analyzed AOL, PGSC, and SCPS between the C5 palsy (+) and (-) groups. RESULTS: The accuracy of all gutter positions was 78.4% (182/232). The accuracy of the gutter position at the right C4 and right C7 was lower than that at the other levels. The AOL in all cases was ~60 degrees. The PGSC was 90.1%-97.2%. The SCPS at C5 was the largest with 2.2 mm. C5 palsy occurred in 3 of 33 patients (9.1%). There were no significant differences in the AOL, PGSC, or SCPS between the 2 groups. CONCLUSIONS: The accuracy of the gutter position using intraoperative CT navigation was good. The incidence of C5 palsy was higher in this study than in the previous reports.

A New Grading of Epidural Hematoma or Scar Formation after Posterior Cervical Spine Surgery: Evaluation of Perioperative Related Factors, Distributions, and Clinical Outcomes after Surgery.

INTRODUCTION: The purpose of this study was to evaluate surgical outcomes using a new grading of postoperative epidural hematoma (EH) or epidural scar formation after posterior cervical spine surgery. METHODS: Postoperative EH or epidural scar formation after cervical laminoplasty (LP) or posterior decompression and fusion (PDF) were graded into Grades 1-5 by magnetic resonance imaging at 24 hours, 2 weeks, 6 months, and one year after surgery. The patients were divided into the Mild group (Grades 1-3) and the Severe group (Grades 4, 5). Perioperative factors were compared between the two groups at 24 hours after surgery. Distribution of EH or scar formation was investigated according to two surgeries. The recovery rate of Japanese Orthopedic Association (JOA) scores and the improvements of neck disability index (NDI) were compared between the two groups at one year postoperatively. RESULTS: Of the postoperative factors, posterior shift of the cervical spinal cord at C4 and C7 significantly differed between the two groups. Patients in the Severe group at 24 hours after surgery (17%) increased to 41% at 2 weeks and subsequently decreased to 16% at 6 months after LP. After PDF, 3% in the Severe group at 24 hours after surgery increased to 15% at 2 weeks and then decreased to 3% at 6 months postoperatively. Only one (3%) patient remained in the Severe group at 1 year after PDF. The recovery rate of JOA score (47.5%) of the patients in the Mild group showed trend larger than that of the Severe group (34.7%) after LP. Preoperative NDI (15.6 points) significantly improved postoperatively to 12.1 points in only the Mild group after LP. CONCLUSIONS: The patterns of distribution of EH or scar formation did not differ between the two surgical methods. The severity of postoperative scar formation related to surgical outcomes after LP.

Short Monocortical Screws at C4-C6 Lateral Masses as Novel Mid-cervical Anchor in Cervical Laminoplasty with Instrumented Fusion: Surgical Outcomes Compared with C5 Pedicle Screws as Mid-cervical Anchor.

INTRODUCTION: This retrospective study compared rates of bony fusion and screw loosening after multilevel posterior decompression and fusion (PDF) with short monocortical screws (SMS) as a novel mid-cervical anchor versus C5 pedicle screws (PS) as a mid-cervical anchor. METHODS: We analyzed 15 consecutive patients who underwent C2-T1 PDF with C5 PS as mid-cervical anchor (PS group) and 18 consecutive patients who underwent the procedure with SMS at C4-C6 as mid-cervical anchor (SMS group). Radiological outcomes, including rates of bony fusion at each level and screw loosening, and clinical outcomes, including Japanese Orthopedic Association (JOA) score, neck pain, neck disability index (NDI), and EuroQol 5 Dimension (EQ-5D), were compared between groups. In the SMS group, screw perforation types and appropriate screw insertion procedure were also investigated. RESULTS: The fusion rate at C2/3 in the SMS group (56%) was significantly higher than that in PS group (13%; P = 0.0272). None of the patients had SMS loosening postoperatively. Clinical outcomes, including JOA score, neck pain, NDI, and EQ-5D, did not differ between the groups. In the SMS group, facet perforation was the most common type of perforation. The recommended direction for SMS insertion at C4-C6 was 35°-37° in the cranial direction and 25°-30° in the medial direction; the recommended screw length was 10 mm. CONCLUSIONS: SMS at C4-C6 was as effective as C5 PS as a mid-cervical anchor in PDF, according to clinical and radiological outcomes. The fusion rate at C2/3 in the SMS group was significantly higher than that in the PS group. There was no postoperative loosening of the C5 PS or C4-C6 SMS in either group.

Relationship between Enlargement of the Cross-Sectional Area of the Dural Sac and Neurological Improvements after Cervical Laminoplasty: Differences between Cervical Spondylotic Myelopathy and Ossification of the Posterior Longitudinal Ligament.

INTRODUCTION: The purpose of this study was to investigate the relationship between postoperative enlargement of the dural sac cross-sectional area at the symptomatic level and neurological improvements after laminoplasty. METHODS: The cross-sectional areas of the dural sac at the symptomatic level before and after laminoplasty and the expansion ratio (post-/preoperative cross-sectional area) were measured using magnetic resonance imaging in patients with ossification of the posterior longitudinal ligament (OPLL) (n = 25) and patients with cervical spondylotic myelopathy (CSM) (n = 49). The relationships between the expansion ratio and the Japanese Orthopedic Association (JOA) score, JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and postoperative laminae morphology were investigated. RESULTS: In the OPLL group, the expansion ratio was significantly positively correlated with the postoperative JOA score (P = 0.025), recovery rate of the JOA score (P = 0.026), and postoperative change in lower extremity sensory function according to the JOA score (P = 0.0375); furthermore, patients whose JOACMEQ responses indicated positive outcomes for lower extremity function had a significantly larger expansion ratio than patients with negative results (P = 0.027). In the CSM group, the expansion ratio showed no correlation with the JOA and JOACMEQ scores. The expansion ratio was significantly positively correlated with the width between bilateral gutters in both CSM (P = 0.025) and OPLL (P = 0.0451). In the OPLL group, the expansion ratio in those with a gutter position of less than 0.8 was significantly smaller than that those with a gutter position of more than 0.8 (P = 0.0156). However, there was no correlation between the gutter position and the recovery rate of the JOA score. CONCLUSIONS: In OPLL, insufficient enlargement of the cross-sectional area of the dural sac at the symptomatic level leads to poor neurological improvements after laminoplasty.

Carboplatin Enhances the Activity of Human Transient Receptor Potential Ankyrin 1 through the Cyclic AMP-Protein Kinase A-A-Kinase Anchoring Protein (AKAP) Pathways.

Carboplatin, an anticancer drug, often causes chemotherapy-induced peripheral neuropathy (PN). Transient receptor potential ankyrin 1 (TRPA1), a non-selective cation channel, is a polymodal nociceptor expressed in sensory neurons. TRPA1 is not only involved in pain transmission, but also in allodynia or hyperalgesia development. However, the effects of TRPA1 on carboplatin-induced PN is unclear. We revealed that carboplatin induced mechanical allodynia and cold hyperalgesia, and the pains observed in carboplatin-induced PN models were significantly suppressed by the TRPA1 antagonist HC-030031 without a change in the level of TRPA1 protein. In cells expressing human TRPA, carboplatin had no effects on changes in intracellular Ca2+ concentration ([Ca2+]i); however, carboplatin pretreatment enhanced the increase in [Ca2+]i induced by the TRPA1 agonist, allyl isothiocyanate (AITC). These effects were suppressed by an inhibitor of protein kinase A (PKA). The PKA activator forskolin enhanced AITC-induced increase in [Ca2+]i and carboplatin itself increased intracellular cyclic adenosine monophosphate (cAMP) levels. Moreover, inhibition of A-kinase anchoring protein (AKAP) significantly decreased the carboplatin-induced enhancement of [Ca2+]i induced by AITC and improved carboplatin-induced mechanical allodynia and cold hyperalgesia. These results suggested that carboplatin induced mechanical allodynia and cold hyperalgesia by increasing sensitivity to TRPA1 via the cAMP-PKA-AKAP pathway.

Comparison of Axial Symptoms and Limitations of Activities of Daily Living Accompanying Reduced Neck Mobility After Cervical Laminoplasty Preserving C2 Muscle Attachments With and Without C2 to T1 Instrumented Fusion.

OBJECTIVE: Muscles are usually detached from C2 to facilitate C2 pedicle screw insertion. The aim of this study was to compare 1-year postoperative axial symptoms and limitations in activities of daily livings (ADLs) accompanying reduced neck mobility between 2 procedures in which all C2 muscle attachments are preserved: laminoplasty and C2 to T1 fusion (LPF group: n=15) and laminoplasty alone (LP group: n=26). METHODS: We examined axial symptoms and limitations in ADLs using the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire. We also examined related factors, including the occiput (O)-C7 angle in extension and flexion, and the rotational and O-C2 ranges of motion (ROM). RESULTS: The postoperative decreases in the O-C7 angle in flexion (27.8° vs. 9.4°) and rotational ROM (40° vs. 15°), as well as the compensating postoperative increase in the O-C2 ROM (11.7° vs. 2.3°), were significantly greater in the LPF group. Most of the axial symptoms were similar between groups. The ability to perform ADLs tended to worsen more frequently in the LPF group, but the difference did not achieve significance. CONCLUSION: Postoperative changes in axial symptoms and loss of ROM were not obstacles affecting patients' ability to perform ADLs after laminoplasty with muscle-sparing C2 to T1 fusion.

Severe C8 or T1 Symptoms after Cervical Laminoplasty and Related Factors: Are Tere Any Differences between C3-C6 Laminoplasty and C3-C7 Laminoplasty?

Study Design: Retrospective study. Purpose: We experienced the situation wherein some patients had new-onset pain or dysesthesia around the ring and little fingers (C8 symptom) or ulnar aspect of the forearm (T1 symptom) after cervical laminoplasty (LP). We investigated the incidence and the cause of new C8 or T1 symptoms and the clinical outcomes after C3-C6 LP or C3-C7 LP. Overview of Literature: There were some reports regarding complications after cervical LP. However, there was no report regarding C8 or T1 symptoms after cervical LP. Methods: Among the 33 patients enrolled in this study, 11 and 22 patients were treated with C3-C6 LP and C3-C7 LP, respectively. We prospectively evaluated C8 or T1 symptoms daily postoperatively for 1 week. The distance of the posterior spinal cord shifting and posterior subarachnoid space from C2 to T1 was measured by T2-weighted midsagittal magnetic resonance imaging (MRI). We evaluated pre- and postoperative axial neck pain, Japanese Orthopaedic Association (JOA) score, and JOA score improvement rate. Results: C8 or T1 symptoms occurred in five and three patients with C3-C6 LP (45.5%) and C3-C7 LP (13.6%), respectively. The distance of the posterior subarachnoid space in C3-C6 LP at C7 was significantly shorter than that in C3-C7 LP at T1 on MRI 24 hours postoperatively (p=0.0448). Postoperative axial neck pain, pre- and postoperative JOA scores, and JOA score improvement rate were not significantly different. Conclusions: The incidence of C8 or T1 symptoms in C3-C6 LP was higher than that in C3-C7 LP. C8 or T1 symptoms would be caused by the posterior fila radicularia and spinal cord impingement on the intact lower end of the lamina.

Modulation of synaptic inputs in magnocellular neurones in a rat model of cancer cachexia.

In cancer cachexia, abnormal metabolism and neuroendocrine dysfunction cause anorexia, tissue damage and atrophy, which can in turn alter body fluid balance. Arginine vasopressin, which regulates fluid homeostasis, is secreted by magnocellular neurosecretory cells (MNCs) of the hypothalamic supraoptic nucleus. Arginine vasopressin secretion by MNCs is regulated by both excitatory and inhibitory synaptic activity, alterations in plasma osmolarity and various peptides, including angiotensin II. In the present study, we used whole-cell patch-clamp recordings of brain slices to determine whether hyperosmotic stimulation and/or angiotensin II potentiate excitatory synaptic input in a rat model of cancer cachexia, similar to their effects in normal (control) rats. Hyperosmotic (15 and 60 mmol L-1   mannitol) stimulation and angiotensin II (0.1 µmol L-1 ) increased the frequency, but not the amplitude, of miniature excitatory postsynaptic currents in normal rats; in model rats, both effects were significantly attenuated. These results suggest that cancer cachexia alters supraoptic MNC sensitivity to osmotic and angiotensin II stimulation.