Lateral Mass Intrapedicular Screw Fixation for Subaxial Cervical Spines: A Short- to Medium-Term Retrospective Follow-Up Study of 20 Cases.

BACKGROUND: Lateral mass intrapedicular screw(LMIS) fixation was introduced in 2021 as an alternative method for the fixation of subaxial cervical spines for the treatment of various cervical spine disease. The objective of this study is to provide a short- to medium-term result of the 20 patients who underwent cervical spine fixation using LMIS. METHODS: Twenty patients with varying cervical spine pathology who underwent cervical spine fixation using LMIS in a 21-month period were included in the study. Postoperative computed tomography (CT) imaging was used to evaluate the screw placement. RESULTS: A total of 105 screws were used. The average screw size used was 3.5 × 14 mm. The average screw angle in the axial plane was 18 degrees. Five screws had breached the inner cortex of the vertebral canal. None of the patients had any postsurgical neurologic deficit. Fifteen screws did not reach the pedicle. Intraoperative fixation was excellent and no screw showed signs of loosening in the subsequent follow-up imaging. CONCLUSION: LMIS is a good alternative to the commonly used methods for subaxial cervical spine fixation and is worth considering in many patients.

Less Severe Intra-Abdominal Infections in Robotic Surgery for Gastric Cancer Compared with Conventional Laparoscopic Surgery: A Propensity Score-matched Analysis.

BACKGROUND: The impact of robotic gastrectomy (RG) for gastric cancer (GC) on the incidence of postoperative complication is debatable and unclear. METHODS: This study enrolled 200 patients with GC who were surgically treated and consisted of 100 RG and 100 laparoscopic gastrectomy (LG) cases using an ultrasonic scalpel. The short-term outcomes were compared between the two groups. These outcomes were compared using a 1:1 propensity score (PS)-matching analysis. RESULTS: After PS matching, 76 cases in each group were well matched. Mean surgical time was significantly longer in the RG group than in the LG group (393 vs. 342 min, p < 0.005), whereas mean blood loss during surgery was significantly lower in the RG group than in the LG group (30.1 vs. 50.1 mL, p = 0.023). The median number of surgeons who attend the main part of the surgery was significantly less in the RG group than in the LG group (2.0 vs. 3.0, p = 0.01). The rate of severe intra-abdominal infectious complication was significantly lower in the RG group than in the LG group (0% vs. 9.2%, p = 0.014). The duration from surgery to adjuvant chemotherapy was significantly shorter in the RG group than in the LG group (29.6 ± 11.0 vs. 45.2 ± 27.8 days, p = 0.046). CONCLUSIONS: RG using an ultrasonic scalpel may be a viable alternative to LG because of the improvement in the rate of postoperative intra-abdominal infectious complications after curative surgery for GC.

Lateral mass intra-pedicular screw fixation for subaxial cervical spines - An alternative surgical technique.

BACKGROUND: Lateral mass screw (LMS) and transpedicular screw (TPS) techniques are the two major options for performing posterior cervical fusion of the subaxial cervical spine. Although these two techniques can cover the vast majority of patients who require posterior fixation of the cervical spine, they are not without their limitations. OBJECTIVE: The objective of this study is to introduce a novel technique, lateral mass intrapedicular screw (LMIS) fixation, for posterior subaxial cervical spine (C3-C6) fixation. MATERIALS AND METHODS: The starting point of the screw is defined as the midpoint of the lateral mass. In the axial plane, the screw is angled at 20-25 with respect to the midline of the spinous process. In the sagittal plane, the screw is directed toward the rostral quarter (zone 1) of the vertebral body and placed within the pedicle. A preliminary, proof-of-concept experiment was performed using a bone model created with synthetic bone and computed tomography images before performing the operation on a patient. RESULTS: During the preliminary experiment, insignificant breaching of the inner cortex of the pedicle was observed with one of the screws. However, no other screws breached the inner cortex in the same manner during the preliminary experiment or during the operation, and the intraoperative fixation was strong. CONCLUSION: LMIS is a relatively simple and safe technique that can be performed for the fixation of subaxial cervical spines with screws that are longer than those used in LMS. We believe that this technique may join the two existing techniques to become a common alternative technique, particularly for patients with poor bone quality.

[A Case of a Massive Retropharyngeal Hematoma Associated with Traumatic Cervical Cord Injury].

Retropharyngeal hematomas are uncommon, but they may rarely cause occlusion of the upper airway and threaten life. Retropharyngeal hematomas often occur due to head or neck injury;they rarely occur due to iatrogenic causes such as insertion of a gastric tube or anticoagulant therapy. It has been found that patients receiving anticoagulant therapy are more likely to experience potentially severe retropharyngeal hematomas. We report the case of a patient with retropharyngeal hematoma with cervical cord damage. A 75-year-old man was transferred to our hospital after he sustained a fall and damaged his face. CT showed a massive retropharyngeal hematoma, but he did not complain of any breathing issues. Therefore, we selected conservative therapy. However, after approximately 4 hours, he suddenly complained of breathing problems and suffered from loss of consciousness. We performed intubation and provided sedation. After one week, his condition clearly improved and he was extubated.

Rare Neurologic Disease-Associated Mutations of AIMP1 are Related with Inhibitory Neuronal Differentiation Which is Reversed by Ibuprofen.

BACKGROUND: Hypomyelinating leukodystrophy 3 (HLD3), previously characterized as a congenital diseases associated with oligodendrocyte myelination, is increasingly regarded as primarily affecting neuronal cells. METHODS: We used N1E-115 cells as the neuronal cell model to investigate whether HLD3-associated mutant proteins of cytoplasmic aminoacyl-tRNA synthase complex-interacting multifunctional protein 1 (AIMP1) aggregate in organelles and affect neuronal differentiation. RESULTS: 292CA frame-shift type mutant proteins harboring a two-base (CA) deletion at the 292th nucleotide are mainly localized in the lysosome where they form aggregates. Similar results are observed in mutant proteins harboring the Gln39-to-Ter (Q39X) mutation. Interestingly, the frame-shift mutant-specific peptide specifically interacts with actin to block actin fiber formation. The presence of actin with 292CA mutant proteins, but not with wild type or Q39X ones, in the lysosome is detectable by immunoprecipitation of the lysosome. Furthermore, expression of 292CA or Q39X mutants in cells inhibits neuronal differentiation. Treatment with ibuprofen reverses mutant-mediated inhibitory differentiation as well as the localization in the lysosome. CONCLUSIONS: These results not only explain the cell pathological mechanisms inhibiting phenotype differentiation in cells expressing HLD3-associated mutants but also identify the first chemical that restores such cells in vitro.

[Surgical Technique for Lumbar Spinal Extraforaminal Schwannoma].

INTRODUCTION: Spinal neurinomas are frequently observed in the cauda equina, particularly within the dura mater. However, extraforaminal schwannomas(EFS), which are neither intradural nor dumbbell type, are relatively rare; hence, different surgical procedures have been employed. Here, we report 12 cases of lumbar EFS with total resection that were safely performed. METHODS AND SUBJECTS: This study was comprised of 12 patients with lumbar EFS(excluding those with neurofibromas)who were previously treated at our hospital. Using the Wiltse paraspinal approach, we inserted the microscope until it reached the tumor surface. After confirming the tumor surface, we inserted a scalpel to make an incision in a portion of the outer capsule. Then, we confirmed that the surfaces of the outer capsule and the tumor within the capsule could be dissected. Next, a thread was attached to the outer capsule and pulled upwards so that there was enough space to perform the required procedures within the capsule. Using a CUSA®, we removed the intracapsular tumor. After its removal, the outer capsule was treated carefully to ensure that the origin nerve was not damaged. RESULTS: In all cases, we successfully performed a total removal of the intracapsular tumor;in the mean postoperative observation period of 8 years, no recurrence was observed. Although temporary paralysis was observed in three patients, this improved over time. CONCLUSION: We report our experience with a surgical technique that ensured the safe removal of lumbar EFS. Satisfactory results were achieved, with no recurrences observed during the mean 8-year postoperative observation period.

Idiopathic Spinal Epidural Fat Accumulation Is Associated With Hyperlipidemia.

STUDY DESIGN: Single-center retrospective analysis of consecutively collected data. OBJECTIVE: To determine the clinical characteristics of idiopathic spinal epidural lipomatosis (SEL). SUMMARY OF BACKGROUND DATA: SEL is associated with the overt accumulation of nonencapsulated adipose tissue in the epidural space, leading to spinal cord or nerve root compression. The etiology of this condition is currently not completely understood. METHODS: Data of 166 male patients who underwent primary surgery for lumbar spinal canal stenosis (LSS) from May 2013 to February 2016 were retrospectively reviewed. Participants were divided into three groups based on the degree of epidural lipomatous lesion. Patient data of age at surgery, body mass index, prevalence of common noncommunicable diseases, blood tests, arteriosclerotic index, and preoperative clinical scores (assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire) were evaluated. Multivariate analysis was performed to assess the potential associated factors for idiopathic SEL. RESULTS: Patients with LSS with severe SEL had a significantly higher body mass index and elevated serum levels of total cholesterol and triglyceride compared with those without SEL. Analysis of preoperative clinical scores revealed that patients with SEL experienced pain more frequently and showed less walking ability than did those without SEL. Multivariate analysis revealed that hyperlipidemia was significantly associated with idiopathic SEL (odds ratio = 3.74, 95% confidence interval = 1.31-10.64). CONCLUSION: Our data suggest that aberrant lipid metabolism is related to the pathogenesis of idiopathic SEL and that patients with LSS with idiopathic SEL have more severe pain than do those without SEL. LEVEL OF EVIDENCE: 3.

Presence of Modic type 1 change increases risk of postoperative pyogenic discitis following decompression surgery for lumbar canal stenosis.

STUDY DESIGN: Multicenter retrospective study. BACKGROUND: Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies do not appear to have investigated pyogenic discitis following lumbar laminectomy without discectomy. This study aimed to identify risk factors for postoperative pyogenic discitis following lumbar decompression surgery. METHODS: We examined data from 2721 patients undergoing lumbar laminectomy without discectomy in five hospitals from April 2007 to March 2012. Patients who developed postoperative discitis following laminectomy (Group D) and a 4:1 matched cohort (Group C) were included. Fisher's exact test was used to determine risk factors, with values of p < 0.05 considered statistically significant. RESULTS: The cumulative incidence of postoperative discitis was 0.29% (8/2721 patients). All patients in Group D were male, with a mean age of 71.6 ± 7.2 years. Postoperative discitis was at L1/2 in 1 patient, at L3/4 in 3 patients, and at L4/5 in 4 patients. Except for 1 patient with discitis at L1/2, every patient developed discitis at the level of decompression. The associated pathogens were methicillin-resistant Staphylococcus aureus (n = 3, 37.5%), methicillin-susceptible Staphylococcus epidermidis (n = 1, 12.5%), methicillin-sensitive S. aureus (n = 1, 12.5%), and unknown (n = 3, 37.5%). In the analysis of risk factors for postoperative discitis, Group D showed a significantly lower ratio of patients who underwent surgery in the winter and a significantly higher ratio of patients who had Modic type 1 in the lumbar vertebrae compared to Group C. CONCLUSIONS: Although further prospective studies, in which other preoperative modalities are used for the evaluation, is needed, our data suggest the presence of Modic type 1 as a risk factor for discitis following laminectomy. Latent pyogenic discitis should be carefully ruled out in patients with Modic type 1. If lumbar laminectomy is performed for such patients, more careful observation is necessary to prevent the development of postoperative discitis.

Onset and remodeling of coronal imbalance after selective posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis (a pilot study).

BACKGROUND: Postoperative coronal imbalance is a significant problem after selective thoracic fusion for primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). However, longitudinal studies on postoperative behavior of coronal balance are lacking. This multicenter retrospective study was conducted to analyze factors related to onset and remodeling of postoperative coronal imbalance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-one Lenke 1C or 2C AIS patients, who underwent posterior thoracic fusion ending at L3 or above, were included with a minimum 2-year follow-up. The mean patients' age was 15.1 years at the time of surgery. Radiographic measurements were performed on Cobb angles of the main thoracic (MT) and thoracolumbar/lumbar (TLL) curves and coronal balance. Factors related to the onset of immediately postoperative coronal decompensation (IPCD) and postoperative coronal balance remodeling (PCBR), defined as an improvement of coronal balance during postoperative follow-up, were investigated using comparative and correlation analyses. RESULTS: Mean Cobb angles for the MT and TLL curves were 57.3° and 42.3° preoperatively and were corrected to 22.8° and 22.5° at final follow-up, respectively. Mean preoperative coronal balance of -3.8 mm got worse to -21.2 mm postoperatively, and regained to -12.0 mm at final follow-up. Coronal decompensation was observed in two patients preoperatively, in ten patients immediately postoperatively, and in three patients at final follow-up. The preoperative coronal balance and lowest instrumented vertebra (LIV) selection relative to stable vertebra (SV) were significantly different between patients with IPCD and those without. PCBR had significantly negative correlation with immediately postoperative coronal balance. CONCLUSIONS: IPCD after posterior thoracic fusion for Lenke 1C and 2C AIS was frequent and associated with preoperative coronal balance and LIV selection. However, most patients with IPCD regained coronal balance through PCBR, which was significantly associated with immediately postoperative coronal balance. A fixation more distal to SV shifted the coronal balance further to the left postoperatively.

Modified Goel's Methods for Basilar Impression: A Case Report with Literature.

We report the case of a 57-year-old woman who had basilar impression manifesting as severe myelopathy and occipital neuralgia and was treated by distraction and fixation performed using a modification of Goel's method. Magnetic resonance imaging (MRI) and computed tomography (CT) scans showed severe myelocompression by the dens of the axis from the ventral side and occipitalization of the atlas. After traction using a Halo vest, C1-2 facet distraction and fixation was performed in one stage using a modified Goel's method. Although Goel et al. used a custom-made spacer to distract the facet joints, we used a threaded titanium cylindrical cage that was inserted into the joint to fix the C1-2 facet joint with posterior fixation from occipital bone to C5. Postoperatively, gradual symptomatic and neurological amelioration were observed. The atlantoaxial joints were bone-fused at 3 years post-operation. Distraction and fixation performed using this modified version of Goel's method was effective for treating basilar invagination. The threaded titanium cylindrical cage provided adequate C1-2 space and strong initial fixation.

Cortical bone trajectory and traditional trajectory--a radiological evaluation of screw-bone contact.

BACKGROUND: Cortical bone trajectory (CBT), a relatively new technique for pedicle screw insertion in the lumbar spine, is believed to have equivalent pullout and toggle characteristics compared with the traditional trajectory (TT). It has been hypothesized that the new trajectory offers higher cortical bone contact with the pedicle screws and therefore has an improved anchoring property over the traditional trajectory where the screws are inserted into the vertebral body trabecular space. The aim of this study is to evaluate the pedicle screw-cortical bone contact between the two trajectories from a radiological standpoint. METHODS: Two hundred twenty-two patients with degenerative lumbar spine disease underwent computed tomography scanning. For each patient, axial slices of the L4 and L5 vertebra were cut in two planes, one horizontal to the pedicle representing the plane at which pedicle screws are inserted using the TT and another in a more caudo-cranial plane representing the plane at which pedicle screws are inserted using CBT. For each trajectory, a region of interest (ROI) was selected within the area in which the screws are inserted. A CT number (Hounsfield scale) was then calculated within each ROI to compare the bone density. RESULTS: The CT numbers within the ROI for CBT were constantly almost over four times higher than that for the TT, and there was a significant difference between the values (p < 0.0001). CONCLUSIONS: This study has demonstrated that, with the cortical bone trajectory, the pedicle screws penetrate a region that is richer in cortical bone compared to when using the traditional trajectory. This is in keeping with previous hypotheses that the new trajectory offers higher cortical bone contact.

Postoperative behavior of thoracolumbar/lumbar curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis.

BACKGROUND: Controversy still exists around surgical strategies for Lenke type 1C and 2C curves with primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). The benefit of selective thoracic fusion (STF) for these curve types is spontaneous lumbar curve correction while saving more mobile lumbar segments. However, a risk of postoperative coronal decompensation after STF has also been reported. This multicenter retrospective study was conducted to evaluate postoperative behavior of thoracolumbar/lumbar (TLL) curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-four Lenke 1C and 2C AIS patients who underwent posterior thoracic fusion were included. The mean age of patients was 15.7 years old at time of surgery. Constructs used for surgery in all cases were pedicle screw constructs ending at L3 or above. Radiographic measurements were performed on Cobb angles of the main thoracic and TLL curves and coronal balance. Factors related to final Cobb angle of TLL curve and postoperative change of coronal balance were investigated. RESULTS: Mean Cobb angles for main thoracic and TLL curves were 59.0° and 43.9° preoperatively, and were corrected to 21.5° and 22.0° at final follow-up, respectively. Mean coronal balance was -5.6 mm preoperatively and was corrected to -14.6 mm at final follow-up. Final Cobb angle of TLL curve was significantly correlated with immediate postoperative Cobb angle of main thoracic curve and tilt of lowest instrumented vertebra (LIV). Postoperative change of coronal balance was significantly correlated with selection of LIV relative to stable vertebra. CONCLUSION: Spontaneous correction of TLL curve occurred consistently by correcting the main thoracic curve and making the LIV more horizontal after posterior thoracic fusion for Lenke 1C and 2C AIS. The more distal fixation to stable vertebra resulted in coronal balance shifting more to the left postoperatively.

Diagnosis and surgical strategy for sacral meningeal cysts with check-valve mechanism: technical note.

OBJECTIVE: There is agreement that symptomatic sacral meningeal cysts with a check-valve mechanism and/or large cysts representing space-occupying lesions should be treated surgically. This study investigated factors indicating a need for surgical intervention and surgical techniques for sacral meningeal cysts with a check-valve mechanism. METHODS: In ten patients presenting with sciatica and neurological deficits, myelography, computed tomography (CT) myelography, and magnetic resonance imaging (MR imaging) detected sacral meningeal cysts with a check-valve mechanism. One patient had two primary cysts. Ten cysts were type 2 and one cyst was type 1. Nine of the ten patients had not undergone previous surgery, while the remaining case involved recurrent cyst. For the seven patients with normal (i.e., not huge or recurrent) type 2 cysts and no previous surgery (eight cysts), suture after collapse of the cyst wall was performed. For the recurrent type 2 cyst, duraplasty and suture with collapse of the cyst wall were performed to eliminate the check-valve mechanism. For the remaining type 2 cyst, a primary root was sacrificed because of the huge size of the cyst. For the type 1 cyst, the neck of the cyst was ligated. RESULTS: In all cases, chief complaints disappeared immediately postoperatively and no deterioration of clinical symptoms has been seen after a mean follow-up of 27 months. CONCLUSIONS: The presence or absence of a check-valve mechanism is very important in determining the need for surgical intervention for sacral meningeal cysts.

Adenomatous polyposis coli heterozygous knockout mice display hypoactivity and age-dependent working memory deficits.

A tumor suppressor gene, Adenomatous polyposis coli (Apc), is expressed in the nervous system from embryonic to adulthood stages, and transmits the Wnt signaling pathway in which schizophrenia susceptibility genes, including T-cell factor 4 (TCF4) and calcineurin (CN), are involved. However, the functions of Apc in the nervous system are largely unknown. In this study, as the first evaluation of Apc function in the nervous system, we have investigated the behavioral significance of the Apc gene, applying a battery of behavioral tests to Apc heterozygous knockout (Apc(+/-)) mice. Apc(+/-) mice showed no significant impairment in neurological reflexes or sensory and motor abilities. In various tests, including light/dark transition, open-field, social interaction, eight-arm radial maze, and fear conditioning tests, Apc(+/-) mice exhibited hypoactivity. In the eight-arm radial maze, Apc(+/-) mice 6-7 weeks of age displayed almost normal performance, whereas those 11-12 weeks of age showed a severe performance deficit in working memory, suggesting that Apc is involved in working memory performance in an age-dependent manner. The possibility that anemia, which Apc(+/-) mice develop by 17 weeks of age, impairs working memory performance, however, cannot be excluded. Our results suggest that Apc plays a role in the regulation of locomotor activity and presumably working memory performance.

Medial patellofemoral ligament reconstruction with hanger lifting procedure.

Medial patellofemoral ligament (MPFL) reconstruction has become a common surgical procedure in the treatment of recurrent dislocation of the patella. A technique of MPFL reconstruction with the "hanger lifting procedure" using extra-articular arthroscopy is presented. After conventional intra-articular arthroscopy, an incision about 1 cm long is made at the superomedial edge of the patella. A bone tunnel is created with a guide pin and overdrilling method, from this portal to the subcutaneous surface of the patella. Using a semi-loop-shaped hanger, the harvested Gracillis tendon is passed through the bone tunnel using a passing pin. Under extra-articular arthroscopy with the "hanger lifting procedure", this tendon is then led back to the superomedial portal. Both ends of the Gracillis tendon are then led to the femoral fixation site posterosuperior to the medial epicondyle with a tendon passer, and fixed by an absorbable interference screw. This procedure can be performed under a minimum incision using a hanger, but control radiographs should be taken to confirm appropriate placement of bone tunnels.

Hanger-lifting procedure in knee arthroscopy.

We propose a unique arthroscopic technique, the "hanger-lifting procedure." Unlike conventional arthroscopy, the space in which the arthroscope is placed is not a joint space filled with water but a subcutaneous space filled with air. The space is kept lifted by a semi-loop-shaped hanger and a retraction system by use of a wire. In general, arthroscopes are unable to be applied outside the joint because of the lack of a cavity. However, this method can provide extra-articular visualization of the knee in addition to standard intra-articular visualization. This approach is useful for lateral release of the knee extensor and bipartite patellae, allowing direct vision from both outside and inside the joint. One possible complication is subcutaneous effusion or interstitial edema. Compressive dressings should be applied to prevent subcutaneous effusion after surgery. However, the combination of conventional arthroscopy by use of saline solution and the hanger-lifting technique by use of air arthroscopy can provide an excellent view inside and outside the joint. This technique may continue to evolve, and although some points in the technique can be improved, this method is useful in joint surgeries.

Time course of systolic and diastolic blood pressure decreases during the preintubation period of anesthesia induction: modeling with a logistic function.

STUDY OBJECTIVE: To investigate whether systolic (SBP) and diastolic blood pressure (DBP) decreases during the preintubation period could be expressed as 4-parameter logistic and cubic functions giving S-shaped curves. DESIGN: Prospective, clinical study. SETTING: Operating room of a metropolitan general hospital. PATIENTS: Seven ASA physical status I and II patients scheduled for elective spinal surgery during general anesthesia. INTERVENTIONS: Anesthesia was induced with fentanyl, propofol, and vecuronium injection followed by inhalation of sevoflurane. MEASUREMENTS: The SBP and DBP data were recorded at all beats from fentanyl injection to direct laryngoscopy. The respective changes were analyzed using a logistic function: P(t) = p(L) + (q(L) - p(L))/(1 + exp{[4 m(L)/(q(L) - p(L))][k(L) - t]}) and a cubic function: P(t) = at(3) + bt(2) + ct + d, where parameter p(L) is the upper asymptote, q(L) is the lower asymptote, m(L) is the slope at the inflection point, and k(L) is the time to the inflection point and where a, b, and c are coefficients, and d are constants. Goodness of fit of the two functions was compared using a correlation coefficient and residual mean squares. Each parameter was compared with the corresponding observed data. MAIN RESULTS: Logistic correlation coefficient values for SBP and DBP decreases were larger than the cubic correlation coefficient values (0.990 [Z transformation: 2.64 +/- 0.32] vs 0.981 [Z: 2.32 +/- 0.37] and 0.977 [Z: 2.22 +/- 0.33] vs 0.967 [Z: 2.05 +/- 0.34], respectively; P < 0.05). Logistic residual mean squares values for SBP and DBP decreases were smaller than cubic residual mean squares values (20.6 vs 41.0 and 9.2 vs 13.7 mmHg(2), respectively; P < 0.05). There were significant correlations between p(L) and SBP or DBP after anesthesia induction, between q(L) and SBP or DBP before endotracheal intubation, and between k(L) and time to maximal rate of the SBP or DBP decrease (dP/dt(min)), but no significant correlation between m(L) and dP/dt(min) for SBP or DBP. CONCLUSIONS: Time courses of SBP and DBP decreases during the preintubation period of anesthesia induction are modeled effectively by a logistic function.

Genetic ablation of NMDA receptor subunit NR3B in mouse reveals motoneuronal and nonmotoneuronal phenotypes.

NR3B is a modulatory subunit of the NMDA receptor, abundantly expressed in both cranial and spinal somatic motoneurons and at lower levels in other regions of the brain as well. Recently, we found the human NR3B gene (GRIN3B) to be highly genetically heterogeneous, and that approximately 10% of the normal European-American population lacks NR3B due to homozygous occurrence of a null allele in the gene. Therefore, it is especially important to understand the phenotypic consequences of the genetic loss of NR3B in both humans and animal models. We here provide results of behavioral analysis of mice genetically lacking NR3B, which is an ideal animal model due to homogeneity in genetic and environmental background. The NR3B(-/-) mice are viable and fertile. Consistent with the expression of NR3B in somatic motoneurons, the NR3B(-/-) mice showed a moderate but significant impairment in motor learning or coordination, and decreased activity in their home cages. Remarkably, the NR3B(-/-) mice showed a highly increased social interaction with their familiar cage mates in their home cage but moderately increased anxiety-like behaviour and decreased social interaction in a novel environment, consistent with the inhibitory role of NR3B on the functions of NMDA receptors. This work is the first reporting of the functional significance of NR3B in vivo and may give insight into the contribution of genetic variability of NR3B in the phenotypic heterogeneity among human population.

Open-door laminoplasty for cervical myelopathy resulting from adjacent-segment disease in patients with previous anterior cervical decompression and fusion.

STUDY DESIGN: This is a retrospective study of patients with cervical myelopathy resulting from adjacent-segment disease who were treated by open-door expansive laminoplasty. OBJECTIVES: The purpose of this study was to evaluate the effectiveness of laminoplasty for cervical myelopathy resulting from adjacent-segment disease. SUMMARY OF BACKGROUND DATA: Adjacent-segment disease is one of the problems associated with anterior cervical decompression and fusion. However, the optimal surgical management strategy is still controversial. METHODS: Thirty-one patients who underwent open-door expansive laminoplasty for cervical myelopathy resulting from adjacent-segment disease and age- and sex-matched 31 patients with myelopathy who underwent laminoplasty as the initial surgery were enrolled in the study. The pre- and postoperative Japanese Orthopedic Association scores (JOA scores) and the recovery rate were compared between the two groups. RESULTS: The average JOA scores in the patients with adjacent-segment disease and the controls were 9.2 +/- 2.6 and 9.4 +/- 2.3 before the expansive laminoplasty and 11.9 +/- 2.8 and 13.3 +/- 1.7 at the follow-up examination, respectively; the average recovery rates in the two groups were 37.1 +/- 22.4% and 50.0 +/- 21.3%, respectively (P = 0.04). The mean number of segments covered by the high-intensity lesions on the T2-weighted magnetic resonance images was 1.87 and 0.9, respectively (P = 0.001). CONCLUSIONS: Moderate neurologic recovery was obtained after open-door laminoplasty in patients with cervical myelopathy resulting from adjacent-segment disc disease, although the results were not as satisfactory as those in the control group. This may be attributed to the irreversible damage of the spinal cord caused by persistent compression at the adjacent segments.

Spinal chronic subdural hematoma in association with anticoagulant therapy: a case report and literature review.

STUDY DESIGN: A case of spinal chronic subdural hematoma (SCSDH) in association with anticoagulant therapy was treated surgically. OBJECTIVE: To clarify the etiopathogenesis, clinical presentation, and surgical outcomes of SCSDH. SUMMARY OF BACKGROUND DATA: Intracranial chronic subdural hematoma is a well-recognized complication of anticoagulant therapy. However, SCSDH is very rare and its etiopathogenesis is uncertain. METHODS: A 72-year-old man with SCSDH who had received anticoagulant therapy for atrial fibrillation complained of bilateral lower extremity pain, cramps, and gait disturbance. The patient underwent an operation for evacuation of the hematoma. RESULTS: Lower-extremity pain, cramps, and gait disturbance improved, and the patient was discharged 10 days after surgery. CONCLUSION: SCSDH should be included in the differential diagnosis of progressive spinal cord and nerve root compression in patients receiving anticoagulant therapy. Prompt diagnosis and early surgical decompression lead to a good outcome.