[Imaging of Sequestered Lumbar Discs]. / 요추 분리추간판의 영상 소견.

Intervertebral disc herniation is frequently encountered in radiological practice. Sequestered disc herniation occurs when the disc material undergoes degeneration and completely loses continuity with the parent nucleus pulposus. Sequestered discs can reside within and outside the spinal canal, exerting a mass effect on adjacent structures, compressing nerve pathways, and eliciting a range of clinical symptoms. In particular, sequestered discs within the dura cannot be identified without durotomy. Therefore, precise preoperative localization is crucial for surgical planning. On MRI, the signal intensity of the sequestered disc may vary due to independent degeneration processes. Additionally, most sequestered disc fragments show varying degrees of peripheral enhancement depending on the degree of angiogenesis and granulation around the isolated tissue. In this article, we review various imaging findings and the location of the sequestered disc to provide patients with an accurate diagnosis and appropriate treatment direction.

Intradural Extramedullary Ependymoma with Hemorrhage: A Case Report.

In adults, spinal ependymomas are usually found in intramedullary locations. However, intradural extramedullary spinal ependymomas are rare. Additionally, spinal ependymomas usually show iso to hypointensity on T1-weighted images without hemorrhage. Herein, we present a rare case of a 43-year-old female with a pathologically confirmed intradural extramedullary ependymoma that showed hyperintensity on T1-weighted imaging accompanied by hemorrhage.

Image quality and lesion detectability of deep learning-accelerated T2-weighted Dixon imaging of the cervical spine.

OBJECTIVES: To validate the subjective image quality and lesion detectability of deep learning-accelerated Dixon (DL-Dixon) imaging of the cervical spine compared with routine Dixon imaging. MATERIALS AND METHODS: A total of 50 patients underwent sagittal routine Dixon and DL-Dixon imaging of the cervical spine. Acquisition parameters were compared and non-uniformity (NU) values were calculated. Two radiologists independently assessed the two imaging methods for subjective image quality and lesion detectability. Interreader and intermethod agreements were estimated with weighted kappa values. RESULTS: Compared with the routine Dixon imaging, the DL-Dixon imaging reduced the acquisition time by 23.76%. The NU value is slightly higher in DL-Dixon imaging (p value: 0.015). DL-Dixon imaging showed superior visibility of all four anatomical structures (spinal cord, disc margin, dorsal root ganglion, and facet joint) for both readers (p value: < 0.001 ~ 0.002). The motion artifact scores were slightly higher in the DL-Dixon images than in routine Dixon images (p value = 0.785). Intermethod agreements were almost perfect for disc herniation, facet osteoarthritis, uncovertebral arthritis, central canal stenosis (κ range: 0.830 ~ 0.980, all p values < 0.001) and substantial to almost perfect for foraminal stenosis (κ = 0.955, 0.705 for each reader). There was an improvement in the interreader agreement of foraminal stenosis by DL-Dixon images, from moderate to substantial agreement. CONCLUSION: The DLR sequence can substantially decrease the acquisition time of the Dixon sequence with subjective image quality at least as good as the conventional sequence. And no significant differences in lesion detectability were observed between the two sequence types.

Comparison of the Clinical Effectiveness Between Infrared Thermography and Electrophysiology Tests in Spinal Intradural Extramedullary Schwannoma.

Objective: Subjective pain is experienced differently by each patient; therefore, modalities that can objectify subjective symptoms are useful. Electrophysiology tests and infrared (IR) thermography can present subjective symptoms in an objective manner. This study aimed to compare the effectiveness of electrophysiology tests and IR thermography in patients with intradural extramedullary (IDEM) schwannoma and statistically analyze the results to verify the positive relationship between the subjective neurologic symptoms and test results. Methods: We retrospectively analyzed the data from 23 patients, pathologically confirmed to have IDEM spinal schwannoma after surgery between January 2012 and December 2020. All patients were preoperatively examined using IR thermography and an electrophysiology test. IR thermography was conducted again week after operation. The IR thermography results were classified as either positive or negative. Results: Radiculopathy symptoms were reported in 16 cases and myelopathy in 7 cases. Among the radiculopathy patients, 9 out of 16 (56.2%) showed positive electrophysiology test results. Among the myelopathy patients, 2 out of 7 (28.5%) showed positive electrophysiology test results. In the radiculopathy group, 15 out of 16 (93.7%) patients showed positive IR thermography results. In the myelopathy group, 2 out of 7 (28.5%) patients showed positive IR thermography results. The correlation between the IR thermography and electrophysiology test was analyzed. In the radiculopathy group, positive electrophysiology test result was obtained in 8 out of 15 (53.5%) patients with positive IR thermography result. Conclusion: In patients with IDEM schwannoma presenting radiculopathy symptoms, IR thermography is a complementary tool to objectify the neurological symptoms.

Delayed Multiple Intracerebral Hemorrhage After Burr Hole Drainage of Chronic Subdural Hematoma During Failure of Warfarin Resumption in Atrial Fibrillation.

Many elderly people take warfarin due to underlying disease. Warfarin is a risk factor for developing chronic subdural hematomas and other intracranial hematomas. Our patient was on chronic warfarin treatment for longstanding atrial fibrillation and underwent burr hole trephination due to chronic subdural hematoma. Multiple intracerebral hemorrhages developed 7 days after surgery without resumption of warfarin. Here, we report and review this rare case.

Cerebral Venous Thrombosis Caused by Spontaneous Intracranial Hypotension: A Case Report.

This case report presents a rare case of cerebral venous thrombosis (CVT) caused by spontaneous intracranial hypotension (SIH). The cause and prognosis of CVT can vary; CVT caused by SIH is uncommon and difficult to diagnose and treat. In this case, magnetic resonance imaging myelography showed definite cerebrospinal fluid leakage, and the patient's symptoms did not improve after conventional treatment. Furthermore, subdural hematoma occurred, causing mental deterioration; however, it improved dramatically after the blood patch procedure and burr hole drainage, which was performed after early cessation of anticoagulant therapy.

Desmoid Fibromatosis in the Multifidus Muscle Misdiagnosed as Intramuscular Schwannoma by Incisional Biopsy: A Case Report.

Desmoid fibromatosis is a locally aggressive myofibroblastic neoplasm. In this study, we report a case of desmoid fibromatosis in the paraspinal muscle that was misdiagnosed as intramuscular schwannoma through incisional biopsy at another hospital. We performed total excision of the mass lesion with a clear margin. We found that for an accurate diagnosis, magnetic resonance imaging, incisional biopsy and excisional biopsy were required.

Vertebral Artery Dissecting Aneurysm Causing Central Tapia's Syndrome: A Case Report.

The central type of Tapia's syndrome is an extremely rare presentation, characterized by unilateral paralysis of the vagal and hypoglossal nerves, contralateral hemiparesis, or hemihypesthesia. This report describes a case of a middle-aged patient who developed central Tapia's syndrome due to a right vertebral artery dissecting aneurysm (VADA). The patient complained about swallowing difficulty and odynophagia. Right vocal cord paralysis, mild tongue deviation to the right side, left hypesthesia, and decreased temperature sensation with left hemiparesis were observed in neurologic exams. A right VADA and compression of the medulla oblongata due to the VADA were diagnosed on magnetic resonance imaging. Endovascular flow diversion of the right VADA was performed. After 1 year, all neurological symptoms and vocal cord paralysis were nearly resolved, but left hypesthesia remained with decreased nociception. We present and discuss how a VADA caused those symptoms and propose endovascular flow diversion as a treatment option.

Retropharyngeal chordoma extending to the spinal cord, mimicking a neurogenic tumor: a case report and literature review.

Chordomas are rare, locally aggressive bone malignancies with poor prognoses. However, those with minimal or no bone involvement are more easily resectable because of their well-delineated margins and thus have better prognoses. Such extraosseous chordomas of the spine are localized both intradurally and extradurally. Only a few case reports have focused on extraosseous, extradural spinal chordomas. Radiologically, this type of chordoma has a dumbbell shape; however, dumbbell-shaped spinal tumors are traditionally thought to be neurogenic tumors (i.e., schwannomas or neurofibromas). We herein report a unique case involving a woman with a dumbbell-shaped extraosseous chordoma protruding predominantly into the retropharyngeal space. A 44-year-old woman presented for evaluation of a left submandibular mass. A T2-hyperintense, gadolinium-enhancing mass was found in her cervical spinal canal, protruding through the C2/3 neural foramen into the retropharyngeal space with minimal vertebral involvement. The initial diagnosis was a neurogenic tumor, most likely a schwannoma. After subtotal removal, the pathologic diagnosis was a chordoma. Because chordomas and schwannomas have significantly different prognoses, caution is warranted when a dumbbell-shaped tumor is identified in the spine with minimal or no vertebral deterioration on radiology. This report also provides the first thorough review of extraosseous dumbbell-shaped intraspinal-extraspinal chordomas.

Acute Quadriplegia after Lumbar Puncture in a Patient with Misdiagnosed Cervical Myelopathy.

The incidence of quadriplegia following drainage of cerebrospinal fluid by lumbar puncture (LP) below a spinal occupying lesion is rare. We report a case of acute quadriplegia following LP for presumed normal pressure hydrocephalus (NPH) in a 66-year-old man. Acute cervical myelopathy with a herniated cervical disc was subsequently found on magnetic resonance imaging (MRI) at the C5-6 level. After posterior decompression and anterior cervical discectomy and fusion at the C5-6 level with a cervical plate, the patient's motor and sensory functions recovered. Clinicians should be aware that symptoms of NPH and cervical myelopathy may overlap, and that serious complications may occur when performing LP below a spinal lesion. As a safety measure, cervical spine MRI should be performed before LP.

Microsurgical treatment for the recurrent cerebral aneurysm initially treated using coil embolization.

OBJECTIVE: Microsurgical treatment could be a good alternative for the treatment of recurrent cerebral aneurysm after coil embolization. The purpose of this study was to present our experience of microsurgical treatment for recurrent cerebral aneurysm previously treated using coil embolization. METHODS: From June 2012 to May 2019, 34 patients consecutively received microsurgical treatment for a recurrent cerebral aneurysm previously treated using coil embolization after it ruptured. RESULTS: Of the 34 patients with aneurysm, 33 had the aneurysm located in the anterior circulation. The most common location was the anterior communicating artery (13 cases). Immediate radiologic outcome at coil embolization was completed (n=6), residual neck (n=26), and residual sac (n=2). The reason for microsurgical treatment included rebleeding (n=12), persistent residual sac (n=1), and recurrence on follow-up study (n=21). Rebleeding occurred within 10 days after coil embolization in 10 cases, and the other 2 were due to regrowth. In the 20 recurred and saccular aneurysms, coil compaction was present in 11 aneurysms and regrowth in 9 aneurysms. Simple neck clipping (n=29) and clipping with coil mass extraction (n=3) was possible in the saccular aneurysms. The blood blister like aneurysm (n=2) were treated using bypass and endovascular internal carotid artery trapping. In the follow-up study group after microsurgical treatment there were no severe complications due to the treatment. Age, cause of retreatment, and modified Rankin Scale before microsurgery were associated with good outcome (p<0.001). CONCLUSIONS: Microsurgical treatment may be a viable and effective option for treating recurrent aneurysms previously treated by endovascular techniques.

Swallowing Difficulty in Diffuse Idiopathic Skeletal Hyperostosis with Metabolic Syndrome.

Diffuse idiopathic skeletal hyperostosis (DISH) is a disease of unknown etiology developing following ossification of the antero-lateral ligaments of the spine. Mostly, prevailing elderly adult males, it is an uncommon cause of dysphagia and dysphonia. We report three cases of DISH with metabolic syndrome. They were complained of neck movement restriction and dysphagia. At first, They all visited ear, nose, and throat outpatient department. The initial impression was gastroesophageal reflux, and an endoscopy excluded esophageal lesion. Cervical spine radiologic imaging revealed ossification of the cervical anterior longitudinal ligament with large, conspicuous osteophytes from cervical spine lesion, producing compression of pharyngoesophagus and upper airway; these images corresponded to DISH. Cervical osteophyte surgical removal resulted in a complete alleviation from dysphagia for the patient. DISH should be considered in the differential diagnosis of dysphagia.

Advantages and disadvantages of the ENVOY 6F distal access guiding catheter in endovascular coiling for anterior circulation aneurysms.

OBJECTIVE: Selecting an appropriate guiding catheter to provide both sufficient supportability for working devices and sufficient distal navigability is essential for ensuring the success of a procedure. This study aimed to evaluate the advantages and disadvantages of using the ENVOY 6F distal access (DA) guiding catheter in coil embolization of anterior circulation cerebral aneurysms. METHODS: We included 98 patients (72 [73.5%] women, median age: 63 [range: 25-84] years) who underwent endovascular coiling with the ENVOY 6F DA guiding catheter from May to November 2016. We analyzed data on patient demographics and the number of co-axial techniques to position the guiding catheter, initial and final location of the catheter, and complications related to the catheter. RESULTS: The co-axial technique was used to position the ENVOY 6F DA guiding catheter in the internal carotid artery (ICA) in 20 cases (20.41%). The initial position of the ENVOY 6F DA guiding catheter involved the cervical ICA (79.6%), horizontal petrous ICA (17.3%), and vertical petrous ICA (3.1%). Final control angiograms after endovascular coiling showed proximal change in the final, compared to the initial, position of the ENVOY 6F DA guiding catheter in 25 cases (25.51%). Procedure-related complications were observed in nine patients (9.18%), involving vasospasm in all cases; however, there was no symptomatic case. CONCLUSION: The ENVOY 6F DA guiding catheter had relatively sufficient distal navigability without symptomatic procedural complications. However, the change in the catheter position after endovascular coiling denoted insufficient supportability.

Burr Hole Drainage versus Small Craniotomy of Chronic Subdural Hematomas.

OBJECTIVE: Chronic subdural hematoma drainage is one of the most common procedures performed in neurosurgical practice. Not only burr hole drainage but also small craniotomy (diameter 3-5 cm) is frequently used neurosurgical treatment of chronic subdural hematomas. We assessed to compare the postoperative recurrence rates between burr hole drainage versus small craniotomy with closed-system drainage for chronic subdural hematomas. METHODS: From January 2016 to December 2018, 75 patients who were treated with burr hole drainage and small craniotomy with closed system drainage for the symptomatic chronic subdural hematoma were enrolled. Pre and postoperative computed tomography (CT) were used for radiologic evaluation. The choice of procedure was decided by preoperative CT images. RESULTS: 60 patients out of 75 patients underwent burr hole drainage, whereas 15 patients underwent small craniotomy. The overall postoperative recurrence rate was 16%. The recurrence occurred in 8 patients out of 60 patients in burr hole drainage group (13.3%) and 7 patients out of 15 patients in small craniotomy group (46.7%). The number of days of hospitalization was 10.3 days in burr hole drainage group and 15.7 days in small craniotomy group. CONCLUSION: Burr hole drainage would be sufficient to evacuate chronic subdural hematoma with lower recurrence rate, but small craniotomy was also needed in some cases such as hematoma has solid portion or multiple septum.

Trigeminal Neuralgia Resulting from Delayed Cervical Cord Compression after Acute Traumatic Fracture of Odontoid Process.

Trigeminal neuralgia is caused by compression of trigeminal nerve root and it leads to demyelination gradually. It was almost idiopathic and occurred unexpected. The upper cervical spinal cord contains the spinal trigeminal tract and nucleus. Fibers with cell bodies in the trigeminal ganglion enter in the upper pons and descend caudally to C2 level. We experienced a rare patient with facial pain, which was paroxysmal attack with severe pain after a clear event, cervical spinal injury (C2). So, this case reminds us of a possible cause of trigeminal neuralgia after a trauma of the head and neck.

Cervicothoracic Junction Approach using Modified Anterior Approach: J-type Manubriotomy and Low Cervical Incision.

Spinal surgery of the anterior aspect of the cervicothoracic junction is difficult and has technological challenges because of the kyphotic alignment of the upper thoracic spine. This approach requires knowledge of the cervicothoracic regional anatomy. Surgery in this region is rare because of its indications; despite this rarity, surgeons must be prepared to expose this region. In addition, surgery in this region demands extensive opening of the surgical field and results in severe postoperative pain. Therefore, a less invasive procedure must be considered. Six cases of cervicothoracic lesion operation have been reported. The patients were successfully treated using an anterior modified approach (J-type manubriotomy). Anterior reconstruction and instrumentation of the cervicothoracic junction offers a distinct advantage of a stable anterior implant bone construction while preserving the posterior osseo-ligamentous tension band. Moreover, the modified anterior approach (J-type manubriotomy) provides the same exposure of the cervicothoracic junction without a full median sternotomy and avoids injury to subclavian vessels during resection of the clavicle or sternoclavicular junction. Therefore, the anterior cervical approach combined with J-type manubriotomy allows extensive exposure of the cervicothoracic junction and causes less complications. We performed preoperative radiological evaluation to identify the cases in which J-type manubriotomy was necessary.

What Causes Severe Myelopathy Resulting in Acute Quadriplegia after a Surgery for Atlantoaxial Subluxation due to Os Odontoideum? A Case Report.

A case of acute quadriplegia resulting from reduction of atlantoaxial subluxation due to os odontoideum is rare. Patient with os odontoideum are at a greater risk for atlantoaxial instability and resultant spinal cord compression. In our case, the patient exhibited mild myelopathic symptoms before the onset of acute quadriplegia. Owing to the clinical presentations, the spinal cord not only seemed to suffer a mechanical compression but also an insufficiency of blood supply to the spinal artery and its branches. No other report has described the findings from magnetic resonance imaging before and after the onset of acute myelopathy after surgery. The aim of our case report is to highlight the pathophysiology and appropriate management strategy of a patient with severe progressive spinal cord myelopathy after surgery, secondary to chronic atlantoaxial subluxation due to os odontoideum. This case depicts the presence of this rare yet possible complication, and emphasizes the importance of preoperative evaluation in cases with chronic progressive myelopathy. Moreover, urgent postoperative treatment and rehabilitation are important for the recovery of neurological symptoms.

Stimulation in Supplementary Motor Area Versus Motor Cortex for Freezing of Gait in Parkinson's Disease.

BACKGROUND AND PURPOSE: Freezing of gait (FOG) is a frustrating problem in Parkinson's disease (PD) for which there is no effective treatment. Our aim was to find brain stimulation areas showing greater responses for reducing FOG. METHODS: Twelve PD patients with FOG were selected for inclusion. We explored the therapeutic effect of repetitive transcranial magnetic stimulation (rTMS) in the supplementary motor area (SMA) and the motor cortex (MC). We measured the number of steps, completion time, and freezing episodes during the stand-walk-sit test before and after rTMS treatment. We also tested freezing episodes in two FOG-provoking tasks. RESULTS: There was a trend for a greater reduction in freezing episodes with SMA stimulation than MC stimulation (p=0.071). FOG was significantly improved after SMA stimulation (p<0.05) but not after MC stimulation. CONCLUSIONS: Our study suggests that the SMA is a more-appropriate target for brain stimulation when treating PD patients with FOG. This study provides evidence that stimulating the SMA using rTMS is beneficial to FOG, which might be useful for future developments of therapeutic strategies.

Thoracolumbar Paraspinal Myonecrosis after Aortic Dissection.

Thoracolumbar paraspinal myonecrosis can be developed with various etiologies. It can induce compartment syndrome of spinal muscles and cause elevated pressure on back muscles, resulting in severe back pain. Thoracolumbar paraspinal myonecrosis is a very rare disease. There are only a few studies about paraspinal myonecrosis. Here we report a case of a spontaneous thoracolumbar paraspinal myonecrosis in a patient who had asymptomatic abdominal aortic dissection. Through this case, etiologies, clinical features, radiologic findings, and treatment options for thoracolumbar paraspinal myonecrosis are discussed.

Superficial Temporal Artery-Sparing Mini-Pterional Approach for Cerebral Aneurysm Surgery.

OBJECTIVE: The purposes of this study were to introduce a superficial temporal artery (STA)-sparing mini-pterional approach for the treatment of cerebral aneurysms and review the surgical results of this approach. METHODS: Between June 2010 and December 2015, we performed the STA-sparing mini-pterional approach for 117 patients with 141 unruptured intracranial aneurysms. We analyzed demographic, radiologic, and clinical variables including age, sex, craniotomy size, aneurysm location, height of STA bifurcation, and postoperative complications. RESULTS: The mean age of patients was 58.4 years. The height of STA bifurcation from the superior border of the zygomatic arch was 20.5 mm±10.0 (standard deviation [SD]). The craniotomy size was 1051.6 mm2±206.5 (SD). Aneurysm neck clipping was possible in all cases. Intradural anterior clinoidectomy was performed in four cases. Contralateral approaches to aneurysms were adopted for four cases. Surgery-related complications occurred in two cases. Permanent morbidity occurred in one case. CONCLUSION: Our STA-sparing mini-pterional approach for surgical treatment of cerebral aneurysms is easy to learn and has the advantages of small incision, STA sparing, and a relatively wide surgical field. It may be a good alternative to the conventional pterional approach for treating cerebral aneurysms.