Background : Superficial siderosis (SS) is an intractable disease characterized by hemosiderin deposition in the subpial layers of the brain, typically the brainstem, cerebellum, and spinal cord. Patients with SS usually exhibit slow cerebellar ataxia and sensorineural hearing disturbances. It was recently reported that spinal magnetic resonance imaging (MRI) revealed an epidural cerebrospinal fluid (CSF) leak with spinal dural defects in patients with SS. However, there is currently no effective treatment that can improve the symptoms of SS. These characteristic findings are sometimes observed in patients with spontaneous intracranial hypotension (SIH).

  Materials and Methods : We summarized the clinical and radiological findings of 8 SS patients over 7 years treated at our hospital since January 2014. We examined epidural CSF leakage and spinal dural defects using conventional MRI plus fluid-attenuated inversion recovery (FLAIR) and/or coherent oscillatory state acquisition for the manipulation of image contrast (COSMIC) sequencing, selective dynamic CT myelography (CTM), and/or spinal endoscopy. Each patient with SS provided informed consent prior to undergoing dural closure.

  Results : Most patients complained of hearing and/or gait disturbances, whereas none experienced bleeding in the central nervous system. Six patients reported chronic slight headaches. Three patients had a history of SIH, while all had longitudinal epidural fluid collection ventral to the spinal cord, mainly at the thoracic spine. We examined the dural defects and surgically closed them in all 6 patients with chronic headache. MRI with COSMIC sequencing detected dural defects in 4 cases. Selective dynamic CTM was used in all 6 cases. Spinal endoscopy was used in 2 cases. Six patients underwent dural closure using sutures or a muscle patch. Although the headaches reported improved after surgery, the chief complaints of hearing and gait disturbance did not improve.

  Conclusion : The use of spinal MRI should be considered in patients with SS to detect epidural CSF leaks with spinal dural defects. However, selective dynamic CTM may be also useful for detecting dural spinal defects. Dural closure may be effective for SS patients with chronic headache; however, their neurological deficits may not resolve. Early diagnosis and treatment may be important for preventing neurological deficits in SS.

  Two patients underwent an antero-lateral partial vertebrectomy (ALPV) as decompression for their progressively deteriorating thoracic myelopathy. The first patient suffered from ossification of the posterior longitudinal ligament (OPLL), located between T1 and T2. Meanwhile, the second patient suffered from a herniated disc at T1-2. In both patients, a linear skin incision, approximately 5 cm long, was made along the medial border of the sternocleidomastoid muscle, on the patients’ right side. The longus colli muscles were dissected at the levels between T1 and T2. The ALPVs were done using a high-speed drill under the operating microscope and the OPLL extending partially to and through the dura. Once the OPLLs were excised, a pulsating movement of the dura was observed. ALPVs done between T1 and T2 allowed partial discectomy and an 18-mm excision of the posterior longitudinal ligament. No fusion technique was used in either patient. This study highlights that anterior compression of the upper thoracic spine can be excised at the level between T1 and T2 using an ALPV.

  We present a case of an intradural arachnoid cyst that was successfully diagnosed via ultrasonography. It is challenging to distinguish between spinal arachnoid cysts and spinal cord herniations on preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Additionally, these diseases have been reported to coexist. Therefore, a definitive diagnosis is not provided until intraoperative findings sufficiently exclude spinal cord herniation. Differentiating these two entities is vital from a surgical perspective. The treatment of spinal cord herniation requires the division of the dentate ligaments to allow rotation of the spinal cord for adequate inspection of the ventral cord and dura. To exclude spinal cord herniation, adequate exposure should be provided for arachnoid cysts. We experienced a case of an intradural arachnoid cyst that was successfully diagnosed via intraoperative ultrasonography. Making the correct diagnosis minimizes unnecessary surgical invasion by omitting the manipulation required to adequately visualize the ventral spinal cord for the exclusion of a spinal cord herniation.

  A 54-year-old woman presented with numbness in her lower extremities. Thoracic MRI revealed spinal cord herniation. CT myelography revealed a T6-8 intradural arachnoid cyst. However, there was no finding sufficient to exclude the presence of an arachnoid cyst in her imaging results. To exclude spinal cord herniation, it is necessary not only to remove the arachnoid cyst, but also to perform an invasive surgery for direct observation of the ventral spinal cord. Intraoperative ultrasonography before the cyst resection showed no ventral cord arachnoid space. Ultrasonography performed after the cyst removal showed preservation of the ventral arachnoid space. He was given a definitive diagnosis of an arachnoid cyst, without spinal cord herniation. This study highlights that intraoperative echocardiography is useful in differentiating spinal arachnoid cysts from spinal cord herniations.

  The aim of this study was to describe a rare case of gait disturbance resulting from lumbosacral transitional vertebrae (LSTV) in a patient who underwent decompression of the anterior exit zone through the posterior approach. More importantly, the effectiveness of surgical decompression was confirmed by intraoperative motor-evoked potential (MEP) monitoring. The pathogenesis of LSTV is involves the appearance of back pain with L5 radiculopathy, also known as “far out syndrome,” which is caused by morphological anomalies related to anatomical characteristics. Notably, a treatment strategy for L5 radiculopathy caused by LSTV has not yet been established. An 80-year-old woman presented with a five-year history of gait disturbance resulting from a right drop foot. A neurological examination revealed grade 4 motor weakness of the right extensor hallucis longus and sensory disturbance in the right L5 dermatome. Magnetic resonance imaging and computed tomography revealed an extraforaminal stenosis that resulted right L5 nerve root compression caused by the LSTV. The diagnosis was confirmed by selective radiculography. Selective L5 nerve root decompression at the anterior exit zone through the posterior approach was performed. Thereafter, the MEP amplitude significantly increased intraoperatively, and the patient’s gait disturbance improved postoperatively. According to previous studies, nerve compression is released via the anterior approach when motor weakness is evident, because the anterior exit zone can be visualized directly. However, the nerve root should not be retracted vigorously during the procedure in order to avoid injury or postoperative neurological deficits.

  Recently, the posterior approach has been found to provide several advantages in the treatment of radicular pain caused by LSTV. First, spinal surgeons are more familiar with the posterior approach than the anterior approach. Second, it is unnecessary to retract the nerve roots during the procedure. As described in this article, functional recovery following adequate decompression was confirmed by intraoperative MEP monitoring, even in patients with motor weakness. Therefore, decompression of the L5 nerve root via the posterior route may provide a safe and useful treatment option for LSTV.

  Background : Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism that leads to the accumulation of copper in the liver, brain, cornea, and kidneys. Little is known about spinal deformities associated with this syndrome. We report two cases of spinal deformity in adults with WD who underwent surgical treatment.

  Case presentation : 【Case 1】A 54-year-old man was diagnosed with WD at the age of 16. At the age of 43, he developed lumbar canal stenosis (LCS) with lower-extremity pain (LEP) and underwent lumbar laminectomy (L4/5). The postoperative course was good, however, at the age of 44, he developed lower back pain (LBP) and LEP, and progressive degenerative slippage of the L5/S1, and underwent posterior lumbar fusion in the same area. Thereafter, at the age of 49, with the progression of dystonia and worsening of T7-L3 degenerative scoliosis, posterior fusion from T8 to the iliac bone was performed.

  【Case 2】A 38-year-old man was diagnosed with WD at the age of 18. At the age of 36, he developed LBP after aerobics and was diagnosed with T11 compression fracture. Thereafter, he developed a series of T8-10 compression fractures, and the kyphotic deformity progressed. At 37 years of age, he underwent thoracolumbar posterior fusion of T6-L2 to correct kyphosis (T10-12 : kyphosis, 21°). Subsequently, owing to the gradual progression of kyphosis, posterior fixation was extended (T6-iliac bone), and pedicle subtraction osteotomy was performed (T9 and L2).

  Conclusion : We report the experience of two cases of spinal deformity in adults with WD who underwent surgical treatment. Surgical planning should take a long-term perspective, keeping in mind that spinal deformities may progress rapidly and severely in patients with WD.

  We report a rare case of syringomyelia and isolated fourth ventricle (IVF) caused by adhesive arachnoiditis at the foramen magnum. A 56-year-old woman was diagnosed with idiopathic syringomyelia and isolated fourth ventricle 44 years after an operation for foramen magnum meningioma. She was treated successfully using syringo-subarachnoid and fourth ventriculoperitoneal shunts, expansive dural plasty, and subarachnoid reconstruction. After the operation, the syrinx collapsed immediately and no neurological deficit was observed. In addition, we recommend that a follow-up serial magnetic resonance imaging (MRI) be done for patients who have adhesive arachnoiditis in order to detect syringomyelia as early as possible.

  Intraosseous schwannomas are rare, accounting for only 0.2% of primary bone tumors, of which schwannomas located in the cervical, thoracic, and lumbar spine are even more uncommon. Schwannomas are rarely located in the posterior column of the mobile spine. To the best of our knowledge, only one case of intraosseous schwannoma of the posterior column of the mobile spine has been reported.

  We reported a rare case of intraosseous schwannoma originating from the posterior column of the thoracic spine, with schwannomatosis. A 56-year-old man presented with anarthria. Magnetic resonance imaging (MRI) revealed a tumor in the craniocervical junction. According to the patient’s operative and pathological findings, he was diagnosed with a schwannoma originating from the C1 nerve. Swelling in his back was observed postoperatively. Computed tomography (CT) and MRI revealed a mass lesion occupying the posterior column and lamina of the 10th thoracic vertebra. In addition, a few small intradural masses at the level of T8 and the lumbar spine. The tumor arising from the 10th thoracic lamina showed a large mass extending into the paravertebral muscle and spinal canal. The tumor severely compressed the spinal cord.

  The patient underwent tumor excision without facetectomy or instrumentation. No nerve involvement of the tumor was identified intraoperatively. The histological diagnosis was a schwannoma. The tumor was successfully removed with no postoperative complications. A follow-up MRI done 3 years postoperatively showed no recurrence and instability.

  Though intraosseous schwannomas are extremely rare, these tumors should be considered in patients presenting with a mass in the thoracic lamina.