Transplanted human iPSC-derived vascular endothelial cells promote functional recovery by recruitment of regulatory T cells to ischemic white matter in the brain.

BACKGROUND: Ischemic stroke in white matter of the brain induces not only demyelination, but also neuroinflammation. Peripheral T lymphocytes, especially regulatory T cells (Tregs), are known to infiltrate into ischemic brain and play a crucial role in modulation of inflammatory response there. We previously reported that transplantation of vascular endothelial cells generated from human induced pluripotent stem cells (iVECs) ameliorated white matter infarct. The aim of this study is to investigate contribution of the immune system, especially Tregs, to the mechanism whereby iVEC transplantation ameliorates white matter infarct. METHODS: iVECs and human Tregs were transplanted into the site of white matter lesion seven days after induction of ischemia. The egress of T lymphocytes from lymph nodes was sequestered by treating the animals with fingolimod (FTY720). The infarct size was evaluated by magnetic resonance imaging. Immunohistochemistry was performed to detect the activated microglia and macrophages, T cells, Tregs, and oligodendrocyte lineage cells. Remyelination was examined by Luxol fast blue staining. RESULTS: iVEC transplantation reduced ED-1+ inflammatory cells and CD4+ T cells, while increased Tregs in the white matter infarct. Treatment of the animals with FTY720 suppressed neuroinflammation and reduced the number of both CD4+ T cells and Tregs in the lesion, suggesting the importance of infiltration of these peripheral immune cells into the lesion in aggravation of neuroinflammation. Suppression of neuroinflammation by FTY720 per se, however, did not promote remyelination in the infarct. FTY720 treatment negated the increase in the number of Tregs by iVEC transplantation in the infarct, and attenuated remyelination promoted by transplanted iVECs, while it did not affect the number of oligodendrocyte lineage cells increased by iVEC transplantation. Transplantation of Tregs together with iVECs into FTY720-treated ischemic white matter did not affect the number of oligodendrocyte lineage cells, while it remarkably promoted myelin regeneration. CONCLUSIONS: iVEC transplantation suppresses neuroinflammation, but suppression of neuroinflammation per se does not promote remyelination. Recruitment of Tregs by transplanted iVECs contributes significantly to promotion of remyelination in the injured white matter.

Severe low back pain with mild leg symptoms due to lumbar spine stenosis.

BACKGROUND: Some patients with lumbar spine stenosis (LSS) have severe low back pain (LBP) with only mild leg symptoms. The effects of decompression surgery for such patients remain unknown. METHODS: Of 818 patients with LSS who underwent surgical treatment in our institution from 2011 to 2019, eight patients had a numeric rating scale (NRS) score of ≥7 for LBP and 3≤ for leg pain. The patients' age, sex, clinical characteristics, preoperative leg symptoms, and level of LSS were investigated. The detailed characteristics of LBP, such as the disease duration, location of LBP, and exacerbating factors, were obtained from each patient. The NRS and Japanese Orthopaedic Association (JOA) scores for LBP were evaluated on admission, at 1 and 3 months postoperatively, and at the final follow-up (>1 year postoperatively). RESULTS: All patients were male with a mean age of 71.5 years (range, 57-82 years). LBP was exacerbated during walking in six patients and during an extension posture in three patients. The median duration of LBP was 2.9 years (range, 0.3-7 years). The stenosis was located at L2/3 in three patients, L3/4 in five patients, and L4/5 in seven patients. The stenosis involved one level in three patients and more than two levels in five patients. Other pathologies, such as sacroiliac joint lesions, facet pain, superior/middle cluneal nerve pain, and discogenic pain, were excluded by diagnostic anesthetic block and detailed physical examination. All patients underwent posterior decompression surgery without fusion. In all eight patients, the NRS score for LBP significantly improved from 7.6 (range, 7-10) to 1.7 (range, 0-3) and the JOA score improved from 13.1 (range, 4-19) to 21.8 (range, 18-27). CONCLUSION: A low proportion of patients showed walking-evoked severe LBP with mild leg symptoms due to lumbar spine stenosis. The patients' pain was improved by decompression surgery with satisfactory results.

Transplantation of iPS-derived vascular endothelial cells improves white matter ischemic damage.

White matter infarct induces demyelination and brain dysfunction. We previously reported that transplantation of brain microvascular endothelial cells improved the behavioral outcome and promoted remyelination by increasing the number of oligodendrocyte precursor cells in the rat model of white matter infarct. In this study, we investigated the effects of transplantation of vascular endothelial cells generated from human induced pluripotent stem cells (iPSCs) on the rat model of white matter infarct. Seven days after induction of ischemic demyelinating lesion by injection of endothelin-1 into the internal capsule of a rat brain, iPSC-derived vascular endothelial cells (iVECs) were transplanted into the site of demyelination. The majority of iVECs transplanted into the internal capsule survived for 14 days after transplantation when traced by immunohistochemistry for a human cytoplasmic protein. iVEC transplantation significantly recovered hind limb rotation angle as compared to human iPSC or rat meningeal cell transplantation when evaluated using footprint test. Fourteen days after iVEC transplantation, the infarct area remarkably decreased as compared to that just before the transplantation when evaluated using magnetic resonance imaging or luxol fast blue staining, and remyelination was promoted dramatically in the infarct when assessed using luxol fast blue staining. Transplantation of iVECs increased the number of oligodendrocyte lineage cells and suppressed the inflammatory response and reactive astrocytogenesis. These results suggest that iVEC transplantation may prove useful in treatment for white matter infarct.

Computed tomography findings after head injury preceding chronic subdural hematoma.

OBJECTIVE: Head CT is sometimes performed immediately after minor head injury; however, which cases develop into chronic subdural hematoma (CSDH) remains unclear. Here, the authors retrospectively reviewed the rare cases of CSDH treated surgically in which early head CT had been performed after the initial head trauma. METHODS: A total of 172 patients (133 male and 39 female, median age 76 years) underwent surgery for CSDH at Gunma University Hospital between April 2010 and December 2017. Among these patients were 23 who had visited Gunma University Hospital or a nearby hospital and had undergone head CT within 7 days after the initial head trauma. Characteristics of the initial head CT were examined to identify indicators of subsequent CSDH. RESULTS: Among the 23 CSDH cases (17 male and 6 female, median age 80 years), CT scans were obtained on the day of the initial injury (day 0) in 19 cases (25 sides) and 1-7 days after injury in 12 cases (19 sides); scans were obtained during both periods in 8 cases (12 sides), so that a total of 44 sides were examined. These CT scans were divided into two groups according to when they were obtained; cases in which scans were taken during both periods were included in both groups. Head CT performed on the day of injury showed normal findings in 5 (20%) of 25 sides, thin subdural effusion (SDE) ≤ 6 mm in 16 (64%) of 25 sides, thick SDE > 6 mm in 3 (12%) of 25 sides, and acute subdural hematoma (ASDH) in 1 (4%) of 25 sides. CT from 1-7 days after trauma showed thick SDE in 9 (47%) of 19 sides, thin SDE in 8 (42%) of 19 sides, and ASDH in 2 (11%) of 19 sides. A high-density line in the lateral direction (onion skin-like) was found between the skull and the brain in 9 (35%) of 26 sides with SDE on initial CT 0-7 days after the injury. CONCLUSIONS: ASDH was not a common cause of CSDH. Head CT at the time of trauma that precedes CSDH often showed SDE. Such SDE that precedes CSDH was often close to the detection limit of CT immediately after the injury but became more apparent from the day after the injury.

Microglial Activation Induces Generation of Oligodendrocyte Progenitor Cells from the Subventricular Zone after Focal Demyelination in the Corpus Callosum.

Neuroblasts derived from neural stem cells (NSCs) in the subventricular zone (SVZ) migrate along the rostral migratory stream into the olfactory bulb to generate interneurons under normal physiological conditions. When demyelination occurs, NSCs or neural progenitor cells (NPCs) in the SVZ provide newly formed oligodendrocytes to demyelinated lesions. The plasticity of NSC/NPC lineages may tend to oligodendrogenesis under the influence of demyelinated lesions. The mechanisms, however, still remain unknown. This study revealed that focal demyelination in the corpus callosum caused activation of the microglia, not only at the site of demyelination but also in the SVZ, and dramatically increased the generation of oligodendrocyte progenitor cells (OPCs) in the SVZ. Furthermore, the inhibition of microglial activation by minocycline treatment decreased OPC generation in the SVZ, suggesting that microglial activation in the SVZ, induced by the focal demyelination in the corpus callosum, regulates NSC/NPC lineage plasticity in situ. In contrast to the findings regarding demyelination in the corpus callosum, inducing focal demyelination in the internal capsule did not induce either microglial activation or OPC generation in the SVZ. These results suggest that the mechanism of OPC generation in the SVZ after inducing demyelinating lesions could be different across the demyelinated regions.

Systemic metabolism and energy consumption after microsurgical clipping and endovascular coiling for aneurysmal subarachnoid hemorrhage.

BACKGROUND: The postoperative metabolic states of subarachnoid hemorrhage (SAH) patients were investigated using indirect calorimetry (IDC) and various nutritional evaluations to establish any difference in perioperative metabolic and nutritional states between microsurgical and endovascular treatment. METHODS: This study included 30 acute aneurysmal SAH patients with ruptured intracranial aneurysms treated by surgical clipping (n = 16) or coil embolization (n = 14) at a single institute. The resting energy expenditure (REE) and respiratory quotient were measured using IDC on days 1, 4, 7, 10, 14, and 17-21 after the operation. Various blood tests, including C-reactive protein (CRP) and prealbumin, were evaluated on the same days. RESULTS: The clipping group showed a significant increase in REE/basal energy expenditure (BEE) compared with the coiling group on days 1 and 4 (p = 0.04 and 0.03, respectively). No significant differences were found on days 7, 10, 14, and 17-21. The mean REE/BEE on days 1-14 and 1-21 showed no significant differences between the groups with repeated measures analysis of variance. The clipping group showed a significant decrease of prealbumin on day 4 and significant increase in CRP on days 1, 4, and 7. CONCLUSIONS: The clipping group was in the hypermetabolic state compared with the coiling group during the very early postoperative period. However, the difference associated with the treatment modality was relatively small compared to the effects of the SAH and of the sequelae.

Intramedullary spinal cord abscess involving Actinomyces and Streptococcus: a case report and literature review.

INTRODUCTION: Intramedullary spinal cord abscesses (ISCA) are rare and caused by central nervous system infections. Although polymicrobial infections are rarely seen in ISCAs, isolation of the causative pathogen is important for treatment. Here, we describe a very rare case of ISCA resulting from a mixed Streptococcus and Actinomyces infection. CASE PRESENTATION: An 82-year-old man presented with acute posterior cervical pain and progressive quadriplegia. Radiological investigations revealed a mass lesion showing marginal enhancement at the level of the C3-4 vertebrae. Microsurgical drainage was performed, and Streptococcus and Actinomyces were identified as causative agents. Subsequent antibiotic treatment was noted to be beneficial to the patient. DISCUSSION: This case suggests that mixed infection can develop into ISCA depending on the causative agents such as Actinomyces. Prompt pathogen-directed antibacterial therapy is required for ISCA treatment.

Prognostic Factors Associated with Poor Treatment Outcomes After Balloon Kyphoplasty in Elderly Patients Aged ≥81 years.

OBJECTIVE: Balloon kyphoplasty (BKP) is an effective procedure for osteoporotic vertebral compression fractures; however, there is limited data regarding its outcomes in patients aged ≥81 years. This study investigated the treatment outcomes and prognostic factors for BKP in this age group. METHODS: A retrospective analysis was conducted on 115 patients with osteoporotic vertebral compression fracture undergoing single-level BKP after failed conservative treatment, classified into the <81 years (n=70) and ≥81 years (n=45) groups. Surgical results were evaluated as good outcomes (independent indoors 1 year postoperatively) and poor outcomes, followed by univariate and multivariate analyses to determine prognostic factors correlating with these outcomes. RESULTS AND CONCLUSION: The majority of patients (<81 years: 85.7%; ≥81 years: 73.3%) had a good degree of independence at 1 year postoperatively, which was comparable in both groups. Further analysis of patients aged ≥81 years showed that longer duration from onset to surgery, more subsequent vertebral fractures, and lower preoperative body mass index were correlated with poorer outcomes postoperatively, and low body mass index, time from onset to surgery, and female sex were independent risk factors for these outcomes (area under the receiver operating characteristics curve: 0.91).

Comparison of Early Postoperative Diffusion Weighted Magnetic Resonance Imaging Findings After Resection of Gliomas and Meningiomas.

OBJECTIVE: Glioma and meningioma require vastly different surgical approaches, even if only involving a simple craniotomy procedure. Diffusion weighted imaging (DWI) is useful for the postoperative evaluation of ischemic damage. The present study evaluated the expected but unproven differences in DWI findings. METHODS: A total of 41 patients with meningiomas and 63 with gliomas met the inclusion criteria for adult cases with superficial lesions treated through simple supratentorial craniotomy. Postoperative DWI findings of DWI-positive rate, DWI-positive area type, and relationship with neurological deficits were evaluated. RESULTS: The DWI-positive rate (P = 0.01) and the proportion of rim-type lesions (P < 0.01) were significantly more common in gliomas. Patients with meningiomas and DWI-positive areas presented with higher rates of new neurological deficits (P < 0.01), and patients with meningiomas on the left side were more likely to develop new neurological deficits (P = 0.02). Patients with gliomas tended to develop new deficits with larger DWI-positive area volumes (P = 0.04). CONCLUSIONS: Postoperative early DWI-positive rate and rim-type lesions are more common after glioma resection than meningioma resection. Larger volumes of DWI-positive areas may be associated with postoperative neurological symptoms in gliomas. DWI-positive finding is less common after meningioma than glioma resection but more likely to be associated with new neurological symptoms. These differences are important for adequate postoperative DWI evaluation of common supratentorial brain tumors.

Factors associated with decreasing diffusion-weighted imaging-positive area volume after mechanical thrombectomy in patients with large early ischemic changes.

OBJECTIVES: This study aimed to evaluate the factors associated with decreasing diffusion-weighted imaging (DWI) positive areas in patients with large early ischemic changes after mechanical thrombectomy (MT). MATERIALS AND METHODS: This retrospective single-center clinical study was conducted between January 2013 and December 2022. We included consecutive patients who underwent MT for acute large-vessel occlusion of the anterior circulation with low pretreatment DWI-Alberta Stroke Program Early Computed Tomography Scores (ASPECTS) (0-5), effective recanalization [thrombolysis in cerebral infarction (TICI) 2b or TICI3], and magnetic resonance imaging (MRI) acquired before and after MT. We measured the DWI-positive area volume before and after MT. The primary endpoint was the after/before-MT DWI-positive area-volume ratio. RESULTS: In total, 28 patients were included in this study. Eight patients (29%) had an after/before-MT DWI-positive area-volume ratio of <1. The median mean apparent diffusion coefficient (ADC) levels of the DWI-positive areas in the groups with a ratio of <1 or >1 were 717 × 106 mm2/s and 637 × 106 mm2/s, respectively (p = 0.011). Multivariate logistic regression analysis showed that ADC level (OR, 1.020 [95% confidence intervals (CIs), 1.001-1.040]; p = 0.040) was an independent predictor of a decreased DWI-positive area after MT. There was a negative correlation between the mean ADC level and the after/before-MT DWI-positive area-volume ratio (p < 0.001, |ρ| = 0.650), and the mean pretreatment ADC cutoff level was 649 × 106 mm2/s (area under the curve (AUC) = 0.806) for predicting a volume ratio of <1. CONCLUSIONS: The mean ADC level before-MT correlated with the after/before-MT DWI-positive area-volume ratio. A mean pretreatment ADC cutoff level of 649 × 106 mm2/s predicted a decreased DWI-positive area after MT.

Thoracic Intra and Extramedullary Capillary Hemangioma with Subacute Clinical Course: A Case Report and Literature Review.

Capillary hemangiomas are benign tumors comprising a lobulated proliferation of capillary vessels frequently located in the soft tissues of the neck and head. Spinal intradural capillary hemangiomas are rare, particularly intramedullary lesions. To our knowledge, only 31 cases of spinal intramedullary capillary hemangiomas have been reported. Here, we describe a rare case of a thoracic capillary hemangioma comprising extramedullary and intramedullary components. A 51-year-old male patient presented with bilateral lower extremity numbness and subsequent paraparesis, sensory disturbance, and bladder-bowel dysfunction with a subacute clinical course. Magnetic resonance imaging revealed a mass lesion with intramedullary and intradural extramedullary components at the Th9-10 vertebrae level and widespread spinal cord edema. Contrast-enhanced computed tomography revealed abnormal vessels on the dorsal spinal cord surface. Spinal angiography revealed a light-stained mass lesion fed by the radiculopial artery from the right Th11 intercostal artery. The tumor was resected en bloc, and the histological diagnosis was a capillary hemangioma. Postoperatively, the spinal cord edema diminished, and the patient was discharged from the convalescent rehabilitation ward. Although intramedullary capillary hemangioma is a rare spinal tumor and its preoperative diagnosis is difficult, it should be considered in the differential diagnosis of spinal intramedullary tumors.

Emergent surgical evacuation of traumatic intracranial hematoma in patients with preoperative thrombocytopenia: surgical risk and early outcome.

BACKGROUND: Surgical evacuation of intracranial hematoma, including epidural, subdural, intracerebral, and intraventricular hematoma, is recommended in patients with traumatic brain injury (TBI) for prevention of cerebral herniation and possible saving of life. However, preoperative coagulopathy is a major concern for emergent surgery on patients with severe TBI. METHODS: We reviewed 65 consecutive patients with severe TBI who underwent emergency craniotomy for intracranial hematomas. RESULTS: Univariate analysis showed preoperative pupil abnormality, absence of pupil light reflex, respiratory failure, preoperative thrombocytopenia (< 100 × 109/L), increased activated partial thromboplastin time (> 36 s), low fibrinogen (< 150 mg/dL), platelet transfusion, red cell concentrate transfusion, and presence of brain contusion and traumatic subarachnoid hemorrhage (SAH) on computed tomography were correlated with poor outcome (death or vegetative state). Multivariate analysis revealed that pupil abnormality (p = 0.001; odds ratio [OR] 0.064, 95% confidence interval [CI] 0.012-0.344), preoperative thrombocytopenia (p = 0.016; OR 0.101, 95% CI 0.016-0.656), and traumatic SAH (p = 0.021; OR 0.211, 95% CI 0.057-0.791) were significant factors. Investigation of the 14 patients with preoperative thrombocytopenia found the emergency surgery was successful, with no postoperative bleeding during hospitalization. However, half of the patients died, and almost a quarter remained in the vegetative state mainly associated with severe cerebral edema. CONCLUSIONS: Emergent craniotomy for patients with severe TBI who have preoperative thrombocytopenia is often successful, but the prognosis is often poor. Emergency medical care teams and neurosurgeons should be aware of this discrepancy between successful surgery and poor prognosis in these patients. Further study may be needed on the cerebral edema regulator function of platelets.

The Significance of the Intercarotid Distances for Transsphenoidal Pituitary Surgery: A Magnetic Resonance Imaging Study.

OBJECTIVE: We performed magnetic resonance imaging (MRI) to analyze the distance between the left and right internal carotid arteries (ICD) around pituitary tumors for transsphenoidal surgery (TSS). METHODS: Measurements were performed using thin slice T2-weighted MRI, and/or time-of-flight (TOI) MR angiography imaging for 64 nonfunctioning pituitary neuroendocrine tumors (NF-pitNETs), 22 growth hormone-producing pitNETs (GH producing pitNETs), and 46 normal controls. We measured the ICD at 3 anatomic levels: at the distal dural ring (ICD-A); at the most concave point of the C4-C5 bend (ICD-B); and at the most convex point of the C4 bend (ICD-C). Additionally, we measured the sagittal distance between the tuberculum selle and the junction of the sellar floor and clivus on the midsagittal MRI (TS-C). RESULTS: We found that ICD-B was the longest and that ICD-A was the shortest among the 3 distance parameters in all groups (P < 0.001). The comparison of the groups revealed that the NF-pitNET group had longer distances than the normal control group at all ICDs (P < 0.001). The GH producing pitNET group had longer distance than the normal control group at ICD-B (P < 0.001). Tumor volume was correlated with ICD-A and ICD-B in the NF-pitNET, and was correlated with ICD-C in the GH producing pitNET group. CONCLUSIONS: Among the distance parameters, ICD-B is the longest, and was approximately twice the width of the TS-C. The shape of the sella is an ellipse that is widest in the lateral dimension in TSS. A horizontal based dural incision may be more rational than a conventional X-shaped dural incision.

Paraclinoid internal carotid artery aneurysm with delayed stent occlusion after deployment of a flow diverter stent involving the orifice of the anterior cerebral artery: illustrative case.

BACKGROUND: In-stent thrombotic occlusion is a serious ischemic complication that can also result in ischemia in the distal perfusion territory and the territory of side branches for the artery in which the flow diverter (FD) stent is deployed. OBSERVATIONS: A 49-year-old female with a large paraclinoid internal carotid artery (ICA) aneurysm was treated with an FD involving the orifice of the anterior cerebral artery (ACA). The antiplatelet dose was reduced because of an increased clopidogrel response postintervention. The patient developed aphasia 2 months later. Emergency magnetic resonance imaging and digital subtraction angiography of the brain indicated FD stent occlusion and a small infarct in the distal vascular territory of the ipsilateral ICA, but the anterior choroidal artery (AChoA) territory was preserved by collateral flow. Emergency superficial temporal artery to middle cerebral artery anastomosis was performed, and she was discharged without neurological deficit 2 weeks after the second operation. LESSONS: In-stent occlusion after FD deployment involving the orifice of the ACA can cause severe cerebral ischemia that requires an adequate antiplatelet effect and careful follow-up. The AChoA territory can be preserved by collateral blood flow even in cases of in-stent occlusion.

Management of Cervical Internal Carotid Artery Stenosis or Occlusion in Tandem Lesion with Acute Ischemic Stroke: Which Is More Appropriate Percutaneous Transluminal Angioplasty or Stent?

OBJECTIVE: Carotid artery stenting (CAS) is the established treatment strategy of the cervical internal carotid artery (cICA) stenosis, but its use for acute tandem lesions remains controversial. We investigated the clinical and procedural outcomes of management of cICA lesions and evaluated the risk factors for complications. METHODS: Fifty patients who underwent acute mechanical thrombectomy for tandem lesion between January 2014 and June 2022 were included. Treatment of the cICA lesion was classified into the CAS group or the non-CAS group. The risk factors for postoperative ischemic events or symptomatic intracranial hemorrhage (sICH) were analyzed. RESULTS: The CAS group included 36 patients (72%) and the non-CAS group 14 (28%). Postoperative complications were observed in 9 patients (18%). Thromboembolic complications occurred in 4 patients (29%) of the non-CAS group but in 1 patient (3%) of the CAS group. Severe calcification of the cICA (P = 0.04), non-CAS (P = 0.018), and more than 60% residual stenosis (P = 0.016) were significant risk factors associated with thromboembolic complications. sICH occurred in 4 patients (11%) of the CAS group but in none of the non-CAS group. More than 80% stenosis improvement was significantly associated with sICH (P = 0.049). Twenty-nine patients (58%) had a good clinical outcome at 90 days after onset. CONCLUSIONS: Acute CAS is effective for the management for cICA tandem lesions during mechanical thrombectomy, but care not to overextend may be important to reduce the risk of sICH. Severe calcification of the cICA may increase the risk of postoperative thromboembolic complications using non-CAS treatment.

Severe constipation due to sacral perineural cysts in a pediatrics patient: A case report.

Background: Symptomatic perineural cysts are rare in pediatric patients. Severe bowel dysfunction caused by the perineural cysts at the sacral level is particularly rare in children. Moreover, the long-term outcome of surgery for the perineural cysts in pediatric patients is uncertain. Here, we describe a rare case of perineural cysts originating in the S3 roots in a pediatric patient that manifested as severe constipation. Case Description: The case was a 13-year-old girl who presented with intractable vomiting and constipation. She also had low back and buttock pain, urinary incontinence, and periproctal sensory disturbance. Radiological studies revealed bilateral perineural cysts originating from the S3 nerve roots, which were considered to be the cause of her symptoms. Microsurgical decompression of the cysts relieved her intractable bowel dysfunction. There has been no recurrence in the 5 years since surgery. Conclusion: This case suggests that microsurgery for severe bowel dysfunction due to symptomatic perineural cysts could have a satisfactory long-term outcome in pediatric patients.

Lumbar Canal Stenosis Caused by Marked Bone Overgrowth after Decompression Surgery.

Narrowing of the lumbar canal due to bone regrowth after lumbar decompression surgery generally occurs at the facet joint; it is exceedingly rare for this phenomenon to occur at the laminar arch. Herein, we describe a case of restenosis caused by marked bone overgrowth at the facet joints and laminar arch after lumbar decompression surgery. A 64-year-old man underwent partial hemilaminectomy for lumbar canal stenosis at the L3/L4 level 12 years ago. His symptoms recurred 7 years after the first surgery. Overgrowth of the laminar arch and facet joints was observed at the decompression site. Thus, partial laminectomy of L3 and L4 was performed as a second surgery. Four years after the second surgery, a laminectomy of L3-L4 was performed for bone restenosis and disc herniation. The underlying mechanism of the remarkable overgrowth of the removed lamina remains unclear. Endochondral ossification signals and mechanosignals should be comprehensively examined.

Morphological changes in nerve rootlets in patients with cervical radiculopathy assessed using computed tomography myelogram.

Background: There are only a few reports that utilize computed tomography myelogram (CTM) to define cervical nerve rootlet compromise in patients with radiculopathy. Here, we assessed the characteristic morphological changes in nerve rootlets in 32 cases with cervical radiculopathy by analyzing CTMs warranting anterior foraminotomy. Methods: CTMs were analyzed to elucidate morphological changes in nerve rootlets in 31 patients/32 cases with cervical radiculopathy. Notably, three of the four neurosurgeons evaluating these CTM had to agree on the presence of "significant" changes consisting of contrast-enhanced defects near the entrance of the intervertebral foramen on axial sections. Results: Our findings included; posterior deviation of the ventral rootlet on the sagittal section (63%), ventral rootlet meandering or horizontalization (52%), and dorsal rootlet meandering (39%) on the coronal section. Furthermore, 16% of cervical nerve rootlets may exhibit an abnormal course proximal to the compression site (i.e., the definition of the "rootlet stagnation sign"). Conclusion: CTM better defines the anatomy, pathology, and radiology impacting the anterior or posterior cervical roots in patients presenting with cervical radiculopathy.

Postoperative spinal deformity and instability after cervical spinal cord tumor resection in adults: A systematic review and meta-analysis.

OBJECTIVE: To investigate the incidence of cervical spine deformity and instability after posterior cervical spinal cord tumor (CSCT) resection without fusion or fixation in adults and examine relevant risk factors by reviewing and summarizing previously reported studies. METHODS: We selected peer reviewed articles published between January 1990 and December 2020 from the MEDLINE and Cochrane Library databases using relevant key words. Articles in which the authors mainly described spinal cord tumor resection through posterior surgery without fusion or fixation in adults were selected for analysis. Patient's data including age, sex, extensive number of laminectomy levels, laminectomy at C2, C3, or C7, multilevel facetectomy, facet destruction, preoperative cervical kyphosis, and preoperative motor deficit were documented. Comparable factors were assessed using the odds ratio (OR) and weighted mean difference (WMD) of 95% confidence intervals (CI). RESULTS: Among 133 articles identified, 18 met selection criteria. Overall incidence of deformity and instability after CSCT surgery was 0%-41.7% and 0%-20.5%, respectively. Younger age (WMD, -5.5; 95% CI, -10.52 âˆ¼ -0.49; P = 0.03), C2 laminectomy (OR, 5.33; 95% CI, 2.39 âˆ¼ 11.91; P < 0.0001), more laminectomy level (WMD, 2.77; 95% CI, 1.78 âˆ¼ 3.76; P < 0.00001) were identified as risk factors for deformity and instability after CSCT surgery. CONCLUSION: Patients undergoing CSCT resection should receive careful follow-up for postoperative spinal deformity and instability. Younger age, C2 laminectomy, and more laminectomy level were significantly associated with occurrence of deformity and instability after CSCT surgery. Upfront spinal fixation at the time of resection should be considered in selected patients.

Small L4 ventral root schwannoma with acute onset of radicular pain: A case report.

BACKGROUND: Patients with cauda equina schwannomas usually present with slowly progressive radiculopathy. Herein, we describe a 34-year-old male who presented with acute radiculopathy attributed to a small L4 ventral root schwannoma. CASE DESCRIPTION: A 34-year-old male suddenly developed left leg pain. Magnetic resonance imaging (with/without contrast) revealed a small intradural mass lesion involving the L4 nerve root that was enhanced with contrast (size: 9 × 12 × 12 mm). The computed tomography myelogram revealed that the tumor had originated from the L4 ventral root and compressed the dorsal root in the lateral recess. Following a decompressive laminectomy for tumor removal, the patient's radicular pain improved. The histological diagnosis was consistent with a schwannoma. CONCLUSION: Small cauda equina schwannomas involving ventral nerve roots can cause acute radiculopathy readily relieved with decompressive laminectomies for tumor excision.