Diffusion tensor imaging combined with the dual-echo steady-state (DESS) protocol for the evaluation of the median nerve in the carpal tunnel: A preliminary study.

Background: Carpal tunnel syndrome (CTS) is diagnosed based on neurological, electrophysiology, and radiological findings. Due to the technical development of magnetic resonance imaging (MRI), the median nerve is evaluated with several MRI protocols. However, diffusion tensor imaging (DTI) combined with a dual-echo steady-state (DESS) protocol is not frequently used to evaluate the median nerve of CTS. This study aimed to evaluate the median nerve in the carpal tunnel using DTI combined with a DESS protocol. Methods: Five healthy volunteers and seven patients with CTS were enrolled. The patients underwent MRI for CTS pre- and post-operatively. The median nerve was evaluated using a 3-T MRI scanner. The parameters of the DESS protocol were as follows: Repetition time (TR)/echo time (TE) = 10.83/3.32 ms, slice thickness = 0.45 mm, field of view (FoV) = 350 × 253 × 350 mm, and 3D voxel size = 0.5 × 0.5 ×0.4 mm. The parameters of the DTI sequence were as follows: TR/TE = 4000/86 ms, slice thickness = 3 mm, FoV = 160 × 993 × 90 mm, 3D voxel size = 1.2 × 1.2 ×3.0 mm, and b value = 0.1000 s/mm2. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the median nerve were statistically analyzed. Statistical significance was set at P< 0.05. Results: The FA value of healthy volunteers was 0.576 ± 0.058, while those of the patients were 0.357 ± 0.094 and 0.395 ± 0.062 pre-and post-operatively, respectively. Statistically significant differences were identified between the FA values of healthy volunteers and pre-operative/post-operative patients. The ADC values of healthy volunteers and pre-operative patients were 0.931 ± 0.096 and 1.26 ± 0.282 (10-3 mm2/s), respectively (P< 0.05). Conclusion: This MRI protocol may be useful for evaluating the median nerve in the carpal tunnel.

Primary extranodal marginal zone mucosa-associated lymphoid tissue-type B-cell lymphoma involving the dura: A case report.

Background: Primary extranodal marginal zone mucosa-associated lymphoid tissue-type B-cell lymphoma (EMZMBCL), which presents as a dural mass, is a rare intracranial tumor that mimics a subdural hematoma or meningioma. Case Description: A 49-year-old woman presented to our hospital with transient right upper limb paresis, dysarthria for 10 min, and ongoing right upper-limb numbness. Computed tomography (CT) of the head revealed extra-axial lesions in the left frontal and parietal lobes. Based on the initial CT findings in the emergency room, an acute subdural hematoma was suspected. However, meningiomas and other intracranial tumors were also listed as differential diagnoses because there was no history of head trauma or coagulation abnormalities on blood examination, and further imaging studies were performed. Imaging findings suggested a subdural neoplastic lesion. A partial resection was performed for the lesion. Based on histopathological and immunohistochemical examinations, the patient was diagnosed with EMZMBCL. Whole-brain and intensity-modulated radiation therapies were administered as adjuvant therapies. The patient was discharged without neurological deficits. Conclusion: EMZMBCL is a rare disease that should be considered in the differential diagnosis of subdural lesions, especially when there is no history of trauma or abnormalities in the coagulation system. The patient had a favorable outcome after selecting radiotherapy as the adjuvant therapy.

A Progressive Spontaneous Cervical Compression Fracture Over Years Following Long-Term Corticosteroid Use.

Spontaneous vertebral compression fractures in the cervical region can have a significant impact on a patient's condition even after surgical management. Due to the rarity of spontaneous cervical vertebral compression fractures and the lack of a comprehensive description of this condition, the establishment of a clear understanding of its natural course remains incomplete. In this case study, a 73-year-old woman on long-term corticosteroid therapy underwent combined anterior and posterior fixation for a spontaneous vertebral compression fracture at the C3-C4 level. The vertebral compression fracture gradually worsened over a span of four years. Following the surgery, the patient experienced a temporary improvement in her neurological symptoms. However, seven months after the second operation, an instrumentation failure resulted in the patient becoming bedridden. This highlights the importance of considering the potential long-term implications and monitoring patients closely even after surgical intervention.

Cervical dumbbell-type tumor spontaneously shrinking following an ischemic stroke.

Background: Asymptomatic cervical dumbbell-type tumors can be incidentally diagnosed. Notably, the chronological changes in the size of these tumors have not been satisfactorily described. Case Description: A 57-year-old man was clinically followed for an asymptomatic cervical dumbbell-type tumor that had the appearance of a schwannoma on magnetic resonance (MR) images obtained over a 7-year period. Notably, the tumor compressed both the spinal cord and the right vertebral artery. At the end of the 7-year period, the patient sustained a cerebral infarction due to atherosclerosis of the right vertebral artery; the angiogram revealed both atherosclerosis and the tumor compressing the right vertebral artery. After the stroke/ischemic event, the tumor progressively shrunk on MR images obtained for the following 4 years, and the spinal cord compression was similarly relieved. Conclusion: Here, we report on a 57-year-old man with cervical MR images revealing that a cervical dumbbell schwannoma was progressively compressing both the spinal cord and the right vertebral artery. However, following a cerebral infarction, the tumor underwent spontaneous shrinkage over the next 4 years, thus relieving the compression.

Bilateral Percutaneous Transpedicular Drainage under Local Anesthesia for Thoracic Tuberculous Spondylitis.

Tuberculous spondylitis is a common spinal infection. If surgical intervention is necessary, anterior debridement and anterior fixation are typically performed. However, a minimally invasive surgical strategy under local anesthesia seems rarely implemented. A 68-year-old man presented with severe pain in the left flank. Whole spinal magnetic resonance imaging revealed abnormal intensity of vertebral bodies from T6-9. A bilateral paravertebral abscess extending from T4-10 was suspected. The T7/T8 intervertebral disc was destroyed, but severe vertebral deformity or spinal cord compression was not observed. Bilateral percutaneous transpedicular drainage under local anesthesia was planned. The patient was set in the prone position. Under the guide of a biplanar angiographic system, the bilateral drainage tubes were placed paravertebrally in the abscess cavity. The left flank pain improved after the procedure. Laboratory culture of the pus specimen confirmed a diagnosis of tuberculosis. A chemotherapy regimen for tuberculosis was soon initiated. The patient was discharged during postoperative week 2, with continuation of chemotherapy for tuberculosis. Percutaneous transpedicular drainage under local anesthesia can be effective in the management of thoracic tuberculous spondylitis without severe vertebral deformity or compression of the spinal cord by an abscess.

A case of anterior arch fracture of the atlas associated with C1 laminectomy.

Background: Spontaneous anterior arch fracture of the atlas after a C1 laminectomy (CIL) is an extremely rare complication. Case Description: A 72-year-old male presented with the sudden onset of neck pain. His prior history included; a CIL for atlantoaxial subluxation, shunt closure for a spinal dural arteriovenous fistula at C3, a cervical laminoplasty from C3 to C6 for stenosis, and a prior anterior C4/5 and C5/6 fusion 14 years ago. Once the computed tomography documented a right C1 anterior arch fracture, and occipital-cervical fusion was performed utilizing C2 laminar screws and C4 pedicle screws with halo-vest placement. Postoperatively, the neck pain resolved and he remained stable. Conclusion: Neurosurgeons should be aware of the risk of anterior arch fractures following a CIL and may alternatively consider a C1 laminoplasty in the future.

Combined cervical laminoplasty and foraminotomy for coexistence of cervical myelopathy and unilateral radiculopathy: case series and preliminary results.

BACKGROUND: The clinical outcomes and radiographic changes of a one-stage procedure combining cervical laminoplasty and unilateral cervical foraminotomy for patients with coexisting cervical myelopathy and unilateral radiculopathy were evaluated. METHODS: Seven patients (two females and five males) with coexisting cervical myelopathy and unilateral cervical radiculopathy were included in this study. The mean age was 58.4 years (range 45-77 years). Cervical laminoplasty and unilateral cervical foraminotomy were performed on the recruited patients in a single stage. The quantitative clinical changes between the preoperative and 6-month postoperative assessment were analyzed using the Japanese Orthopedic Association (JOA) score, the JOA Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), visual analog scale (VAS), and Neck Disability Index (NDI). Moreover, the preoperative and 6-month postoperative radiographic changes were assessed using the C2-7 angle and range of motion (ROM) between flexion and extension angle. RESULTS: There were significant differences in QOL in the JOA-CMEQ between the groups. Furthermore, the postoperative VAS values in the arms and hands generally improved, although not significantly, between the groups. CONCLUSIONS: The aforementioned surgical procedure may be safe and efficient for patients with coexisting cervical myelopathy and radiculopathy.

Tailor-Made Surgical Strategy for Coexistent Cervical Myelopathy and Bilateral Radiculopathy. Combined Laminoplasty, Laminectomy, and Foraminotomy: Report of Two Cases.

Cervical spondylosis is a common and degenerative disease consisting of myelopathy and radiculopathy. Surgical treatment can be considered for patients with cervical spondylosis resulting in severe pain, motor weakness, ambulation difficulty, and urination disorder. As myelopathy and radiculopathy often coexist, two-staged anterior and posterior fixation/decompression surgery can be selected to resolve those two pathologies. However, due to the invasiveness of that management, posterior surgery in a single session seems favorable. In this study, we present two cases of cervical spondylosis. A 67-year-old man was complaining of pain in the neck and right upper extremity. Radiographically, cervical canal stenosis was concurrently diagnosed with the foraminal stenosis of the left C3/4 and right C6/7. Laminoplasty from C3 to C6 (left open; C3 to C5, right open; C6) and foraminotomy of the left C3/4 and right C6/7 were performed in a single session. Another 43-year-old man was bothered by pain in the neck and bilateral upper extremities resulting from cervical canal stenosis and bilateral foraminal stenosis of C6/7. Laminoplasty from C3 to C5, laminectomy of C6, and foraminotomy of bilateral C6/7 were performed in a single session. Preoperative symptoms were remitted in both cases. As described in our cases, a tailor-made combination of laminoplasty, laminectomy, and foraminotomy can effectively resolve cervical spondylosis in a single session.

An interdural spinal cyst in the cervicothoracic spine: a review and proposal for a revised classification of spinal meningeal cysts. Illustrative case.

BACKGROUND: Spinal cysts in the interdural space are extremely rare and are not included in the standard classification of spinal meningeal cysts. OBSERVATIONS: A 60-year-old female presented to our hospital with a spastic gait and numbness in both palms. Magnetic resonance imaging (MRI) revealed a spinal cyst from C4 to T4 compressing the spinal cord. Computed tomography myelography revealed a fistula at C4-5 and C5-6 that connected the cyst along the right C5 and C6 root sleeves. The cyst was located within the dura mater, and communication with the arachnoid space was achieved using a shunt tube. There was partial spastic gait amelioration after the procedure, but the patient experienced a relapse 2 months postoperation. A repeat procedure was performed without a shunt tube to allow greater communication between the cyst and the subarachnoid space. After this, marked improvement in gait function was observed, and MRI showed a significant reduction in cyst volume. LESSONS: Interdural spinal meningeal cysts are rare. When the interdural cyst cannot be removed entirely, surgery may be appropriate for providing a shunt tube or establishing communication between the cyst and arachnoid space to maintain the circulation of cerebrospinal fluid collected in the cyst cavity.

Primary intramedullary spinal cord pilocytic astrocytoma with anaplasia in an adult: illustrative case.

BACKGROUND: Primary intramedullary spinal cord (IMSC) pilocytic astrocytoma (PA) with anaplasia is extremely rare. OBSERVATIONS: A 50-year-old man presented to our hospital with numbness of the left posterior rib region, back, and bilateral lower limbs. Contrast-enhanced T1-weighted magnetic resonance imaging (MRI) revealed an intramedullary lesion at T2-T3 with no contrast enhancement. The patient opted for conservative treatment. Eighteen months after the first consultation, the patient presented with slowly progressive numbness of the bilateral upper limbs, paraparesis, and dysuria, with rapid deterioration over the following 3 months. T1- and T2-weighted MRI revealed expansion of the intramedullary lesion, which extended from C7 to T5, and syringomyelia at C5-C6. Contrast-enhanced T1-weighted MRI revealed an enhancing intramedullary lesion at C7-T5. Open biopsy and C5-T5 laminectomy were performed for diagnosis and decompression. PA with anaplasia was diagnosed based on pathological and immunohistochemical findings. The patient received postoperative radiotherapy and chemotherapy. LESSONS: Rapidly progressive IMSC PA with a change in contrast enhancement is extremely rare in adults. PA may undergo a spontaneous malignant transformation during its natural clinical course. In this case, the change in contrast enhancement may have been associated with the malignant transformation of the PA.

Asymptomatic spinal subdural epiarachnoid hygroma after lumbar laminectomy for lumbar spinal canal stenosis: illustrative case.

BACKGROUND: Spinal subdural epiarachnoid hygroma (SSEH) after lumbar laminectomy is an extremely rare complication. OBSERVATIONS: An 84-year-old man presented to the hospital with lower back pain, radicular pain, and numbness in the lateral aspect of the left leg. Magnetic resonance imaging (MRI) revealed anterior lumbar spondylolisthesis at L3, severe disc herniation at L3-4, and severe lumbar spinal canal stenosis at L3-4 and L4-5. Lumbar laminectomy at L3-4 and L4-5 and discectomy at L3-4 were performed without complications such as cerebrospinal fluid (CSF) leakage and durotomy intraoperatively. Although lower back pain and numbness at the lateral aspect of the left leg were resolved postoperatively, postoperative MRI showed spinal nerve deviation to the ventral side due to SSEH from T12 to S1. Conservative therapy was performed for asymptomatic SSEH, and MRI 1 week postoperatively indicated improved ventral spinal nerve deviation and reduced SSEH. LESSONS: SSEHs after posterior decompression without durotomy are extremely rare. Asymptomatic SSEHs may resolve with conservative treatment. However, surgery should be performed to decompress hygroma in patients with symptomatic SSEH.

Pathological Examination of Radiologically Fused Interbody Tissue Five Years After Anterior Cervical Discectomy and Fusion Using the Titanium Cage System: A Report of Two Cases.

This case report aimed to identify potential relationships between pathological and radiological assessments of bony fusion after anterior cervical discectomy and fusion (ACDF). ACDF can resolve neurological symptoms related to cervical spondylosis, such as myelopathy and radiculopathy. Intervertebral bony fusion is a key outcome for successful ACDF, often assessed on radiography and computed tomography (CT) images. However, the pathological findings of tissues demonstrating bony fusion after ACDF have not been well studied. This report presents the cases of two female patients, aged 62 and 40 years, who underwent additional ACDFs for recurrent cervical radiculopathy. Findings from CT imaging identified intervertebral calcification in the titanium spacers placed in the first ACDF. In both cases, recurrent compression of nerve roots was observed radiologically. Cervical nerve root block identified habitual symptoms related to recurrent radiculopathy. To resolve the clinical symptoms, additional ACDFs were performed in two cases. In the second ACDF, the titanium cases from the prior ACDF were removed. Histopathological examination of the tissues from the removed cages revealed growth of cartilage tissue. This is the first report concerning the histopathological evaluation of the tissue in titanium spacers placed in ACDF. Completion of intervertebral calcification in titanium spacers placed in ACDF may not signify completion of intervertebral bony fusion after ACDF.

Embolization of a vertebral artery encased in a regrowth cervical meningioma before resection.

Background: Managing intraoperative bleeding may be challenging when a cervical tumor encases the vertebral artery (VA). Here, a patient with a recurrent cervical meningioma between the C1/2 and C3/4 levels and encasement of the right VA injury developed intraoperative bleeding that was endovascularly embolized postoperatively. Case Description: A 30-year-old female presented with a progressive quadriparesis, most markedly involving the right upper extremity. Six years ago, she had a cervical meningioma resected at the C2/3 level. The new MR revealed regrowth of intraspinal tumor between the C1/2 to C4/5 levels accompanied by extradural encasement of the right VA within the C2/3 and C3/4 foramina. Before the first surgery, the right VA was embolized (i.e., after a balloon occlusion test proved negative). During the attempted resection of the intradural/extradural tumor, bleeding from the right VA was encountered; it was temporarily controlled. After complete occlusion of the right VA was angiographically confirmed, a second-stage procedure to fully resect the extradural remanent of the tumor was undertaken. Conclusion: Endovascular embolization of the right VA before the attempted resection of a recurrent intraspinal/extraspinal cervical meningioma failed to occlude the vessel entirely. The VA bleeding encountered intraoperatively was temporarily controlled. Delayed total VA occlusion was angiographically observed before full tumor resection could be completed.

Early postoperative sacral fracture after short-segment posterior lumbar interbody fusion for L5/S1 isthmic spondylolisthesis: A case report.

Background: Early postoperative sacral fractures are extremely rare complications of single-level posterior lumbar interbody fusions (PLIFs). Case Description: A 71-year-old female presented with lower back pain and right S1 radiculopathy attributed to MR-documented L5/S1 isthmic spondylolisthesis. Following a L5 laminectomy and bilateral L5/S1 PLIF, she experienced sacral pain while sitting. When the MR showed a sacral insufficiency fracture with anterolisthesis at L5/S1, a secondary posterior fusion was extended to the pelvis, utilizing bilateral iliac screws. Following this reoperation, the patient did well and went on to achieve arthrodesis. Conclusion: Early postoperative sacral fractures that occur following single-segment L5/S1 PLIF for isthmic spondylolisthesis warrant fusion to the pelvis with bilateral iliac screws.

Cauda equina syndrome after L5-S1 posterior decompression surgery showing a "convexity sign" caused by engorgement of the ventral epidural venous plexus: A case series.

Background: Cauda equina syndrome (CES) following posterior lumbar decompression is rare. Here, we present four postoperative cases of L5S1 surgery resulting in CES attributed to engorged ventral epidural veins that decreased spontaneously in three cases, while the fourth warranted a laminoplasty. Case Description: Four patients underwent posterior lumbar decompressions at the L5-S1 level, but developed postoperative symptoms/signs of CES. Interestingly, in all four cases, cauda equina compression was attributed to engorgement of the ventral epidural venous plexus documented on magnetic resonance images (MRI) by the "convexity sign." Postoperatively, three patients' CES compression decreased spontaneously, but one required a laminoplasty. Conclusion: Postoperative CES occurred in four patients undergoing L5-S1 lumbar surgery. This deficit was attributed to marked engorgement of the ventral epidural plexus (i.e., yielding the "convexity sign" on MRI) that resolved spontaneously in three patients, but warranted a laminoplasty in the fourth.

Management of two patients with dropped head syndrome utilizing anterior-posterior cervical surgery.

BACKGROUND: Two elderly patients with dropped head syndromes (DHS) were successfully treated with circumferential cervical surgery. CASE DESCRIPTION: The two patients, respectively, 72 and 53 years of age, both underwent two-staged surgical procedures. The first surgery included the posterior placement of bilateral pedicle screws with multilevel facetectomies, followed by multilevel anterior cervical discectomy/fusion and posterior rod fixation. CONCLUSION: Circumferential decompression/fusion successfully addressed chin on chest deformity in two older patients.

Intractable hiccups and neck pain due to left C4 radiculopathy decreased with posterior foraminotomy.

BACKGROUND: Intractable hiccups can last for more than 1-2 months and can occur, as shown in this case study, due to cervical nerve root compression. CASE DESCRIPTION: A 76-year-old male presented with intractable hiccups and neck pain of 7 months' duration. The patient underwent magnetic resonance imaging studies of the entire neuraxis. The only abnormality found was on the cervical magnetic resonance images that demonstrated left C4 nerve root compression due to the C3- C4 lateral/foraminal osteophyte. Following a left-sided C3-C4 laminoforaminotomy, the hiccups and the neck pain improved. CONCLUSION: A 76-year-old male presented with intractable hiccups and neck pain attributed to a left C3/C4 lateral/foraminal spondylotic ridge. Following a left C3-C4 laminoforaminotomy, the frequency of hiccup attacks remained the same, but their duration was markedly shortened to 30 s, while the neck pain improved.

Spinal Intradural Extramedullary Capillary Hemangioma with Coexistent Spinal Edema and Syringomyelia Successfully Treated by Tumor Removal and Cervical Laminoplasty.

Capillary hemangioma (CH) is usually found in pediatric patients and is located in soft tissue of the neck or head. As uncommon location of CH, spinal intradural extramedullary space has been reported; however, coexistent spinal edema or syringomyelia with spinal intradural extramedullary CH seems rare manifestations on preoperative magnetic resonance imaging. Laminectomy and tumor resection have been often performed for spinal intradural extramedullary CH. An 83-year-old man was referred to our hospital, complaining of nocturia and motor weakness of the lower extremities. Magnetic resonance imaging revealed a mass at the level of T1, which was homogeneously enhanced on gadolinium-enhanced T1-weighted images. The lesion was accompanied by spinal edema and syringomyelia. An intradural extramedullary tumor was first considered. We thought that the coexistent spinal edema and syringomyelia could have been caused by spinal stenosis. Preoperative angiography revealed that the mass was fed by the radicular artery of C5-C6. To improve the clinical symptoms of the patient, tumor removal and cervical laminoplasty were performed. The spinal edema and syringomyelia regressed postoperatively. The histopathological diagnosis was CH. This is the first reported case of cervical intradural extramedullary CH with spinal edema and syringomyelia successfully treated by cervical laminoplasty and tumor removal.

Neurological Disturbance of the Upper Extremities After Cervical Laminoplasty: A Morphological Assessment Focused on the Intervertebral Foramen.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to explore the relationship between postoperative neurological disturbance of the upper extremities (NDUE) after cervical laminoplasty and intervertebral foraminal stenosis. SUMMARY OF BACKGROUND DATA: The relationship between foraminal stenosis and neurological disturbance in the C5 segment (C5 palsy) has been reported, but the relationship at other levels has not been examined before. We evaluated foraminal stenosis morphologically using three-dimensional computed tomography (3D-CT), alongside other risk factors for NDUE. METHODS: We retrospectively reviewed patients treated by open-door laminoplasty at the authors' institution between January and June 2016. NDUE was defined as postoperative motor deterioration and/or newly emerged sensory disturbance within 2 weeks of surgery. Radiological measurements were performed in bilateral intervertebral foramina from C5 to C8, using 3D-CT. Investigation using magnetic resonance imaging (MRI) was also performed. RESULTS: Thirty-one patients were reviewed, and 10 (32.3%) developed NDUE. Nineteen NDUE were observed: seven were in the C5 segment, five in the C6 segment, three in the C7 segment, and four in the C8 segment. Four patients (40%) had NDUE from multiple segments. The mean width of the foramen was 2.60 ±â€Š1.26 mm and 3.66 ±â€Š1.66 mm (P = 0.007), and cross-sectional area was 32.8 ±â€Š10.8 mm and 41.6 ±â€Š12.4 mm (P = 0.003), in symptomatic (n = 19) and nonsymptomatic (n = 187) foramina, respectively. The mean transverse diameter of bony spurs and the maximum shift of the spinal cord on MRI was significantly larger in the NDUE group. The odds ratio of having a foraminal cross-sectional area under 28.0 mm in combination with a maximum spinal shift over 3.10 mm was 14.6 (P < 0.001). CONCLUSION: Stenosis of the intervertebral foramen could be a risk factor for NDUE after cervical laminoplasty, and could be aggravated by excessive posterior spinal cord shift. LEVEL OF EVIDENCE: 3.

Cauda Equina Syndrome Due To Dural Sac Shift with Engorgement of the Epidural Venous Plexus: Rare Complication After Lumbar Microdiscectomy.

BACKGROUND: Several postoperative complications related to lumbar microdiscectomy have been reported, including cauda equina syndrome. However, to the best of our knowledge, postoperative cauda equina syndrome resulting from dural sac shift with engorgement of the epidural venous plexus is yet to be reported. CASE DESCRIPTION: A 71-year-old male patient was referred to our hospital with a chief complaint of pain and sensory disturbance due to the lumbar disc herniation of L5-S1. Microdiscectomy was performed to treat the lumbar disc herniation, and his sensory disturbance improved. However, from postoperative day 2, he started to complain of motor weakness, sensory disturbance of S2, and difficulty in urination. Magnetic resonance imaging showed the dural sac shifted to the bone window of L5-S1 with engorgement of the ventral epidural venous plexus. The dural sac shift was thought to be the cause of postoperative cauda equina syndrome, and laminoplasty was chosen to return the dural sac shift into the spinal canal. Cauda equina syndrome completely resolved after laminoplasty. Postoperative magnetic resonance imaging showed the reduction of the dural sac into the spinal canal. The patient was discharged from the hospital without any residual clinical symptoms. CONCLUSION: We report a rare case of postoperative cauda equina syndrome due to dural sac shift and discuss the nascent mechanism of the dural sac shift focusing on anatomic features of the dural sac. We also propose laminoplasty as an option to treat dural sac shift with engorgement of the epidural venous plexus.