脊髄外科 Vol. 31(2017) No. 1

  Prior to the recent development of the time-spatial spin labeling inversion pulse (Time-SLIP) technique, an innovating imaging method, no method allowed direct tracing of cerebrospinal fluid (CSF) dynamics under physiological and pathophysiological conditions, without disturbing the environment of the central nervous system. Time-SLIP allows the direct visualization of CSF motion using magnetic resonance imaging (MRI), permitting CSF dynamics to be depicted during a certain time frame. CSF dynamics, which are visualized using Time-SLIP, have been found to differ markedly from those describing classical CSF circulation theory in medical textbooks. Thus, Time-SLIP has allowed research on CSF dynamics to advance to the next stage, and provides a more accurate understanding of normal spinal CSF physiology and its alterations in pathophysiological states. The observation of CSF dynamics using Time-SLIP should improve diagnostic accuracy, permitting the identification of new etiological factors in a variety of diseases, and promoting the development of new therapeutic approaches.

  Introduction : Spinal cord stimulation (SCS) is an established treatment method for chronic pain syndrome. Percutaneous placement of cylindrical electrodes is the first choice in most cases, whereas surgical electrode placement is performed when paddle electrodes are used or extensive epidural scar tissue interferes with optimal electrode placement. The objective of this study was to examine the effectiveness of surgical electrode placement in SCS.

  Methods : Patients who had undergone surgical electrode placement from December 2009 to January 2016 were included. The reasons for choosing surgical electrode placement, procedures, pain assessments, and complications were analyzed.

  Result : Surgical electrode placements were performed in 10 (6 male and 4 female) of the 91 patients who underwent electrode placement. Surgical electrode placement was chosen owing to extensive epidural scar tissue in 2 procedures, the use of paddle electrodes in 4 procedures, and for both reasons in 3 procedures. The mean age of the patients was 52 years, with a ranging 38-71 years. Surgical placement was performed twice in a case involving surgical site infection. For the procedures, laminectomies were performed in 6 cases ; partial laminectomies, in 3 cases ; laminoplasty, in 1 case ; lamina exposure only, in 1 case. Nine patients showed at least 50% improvement based on a visual analog scale. The complications included 1 case each of an epidural hematoma and surgical site infection.

  Conclusion : We performed surgical electrode placements in cases in which it was extremely difficult to achieve analgesia with standard SCS and percutaneous placement of cylindrical electrodes, and significant analgesia was achieved in most cases. Laminectomies were useful when extensive epidural scar tissue existed, whereas minimally invasive procedures were effective in cases without extensive epidural scar tissue. It is very important to choose the appropriate procedure for each patient.

  Objective : Cervical pedicle screw (CPS) may be the best anchor system for posterior cervical segmental fixation, but may carry high surgery-related risks such as neurovascular injury. The purpose of this study was to evaluate the accuracy of CPS placement by using various techniques such as a free-hand, computer navigation system.

  Methods : Posterior cervical instrumented fixation using a CPS was performed in 156 patients during the period January 2002 to April 2016. The patients were divided into five groups depending on the insertion techniques as follows : group 1 (free-hand technique with fluoroscopy), group 2 (preoperative three-dimensional [3-D] computed tomography [CT] based navigation system), group 3 (intraoperative 3-D CT based navigation system : O-arm), group4 (O-arm plus a cannulated screw), and group 5 (full-time navigation system).

  Results : At the spinal level of C2 through T3, 861 CPSs were placed. The radiological accuracy of the CPS placement was evaluated by using postoperative CT (post-insertion intraoperative CT when using an O-arm). The rate of-CPS misplacement (more than half of the screw) was 14.5% (8/55 screws) with the free-hand technique, 3.1% (14/452 screws) with the preoperative 3-D CT based navigation system, 1.1% (2/178 screws) with an O-arm, 0.8% (1/132 screws) with an O-arm plus a cannulated screw, and 0% with the full-time navigation system. In total, 54 screws (6.2%) were found to perforate the cortex of the pedicle, although no neural or vascular complications closely associated with CPS placement were observed.

  Conclusion : Image-guided CPS placement has been an important advancement to secure the safety of surgery, although whether a CPS is needed should be carefully determined on the basis of the individual pathology and background.

  Reports on the etiology of cervical spinal extradural hematoma secondary to epidural arteriovenous malformation (AVM) are comparatively few. We report here the clinical course and treatment outcome in two such cases.

  Case 1 : 54-year-old man visited an emergency outpatient clinic because of sudden-onset pain around the right scapula and numbness of the right arm with no apparent cause. Electrocardiography revealed an abnormal wave, necessitating urgent cardiovascular examination. No obvious coronary artery abnormality was detected, and acute coronary syndrome seemed doubtful. The next morning, the patient had complete paralysis of the right arm and both legs, and paresis of the left arm. Magnetic resonance imaging (MRI) was not possible because of a previous ophthalmologic surgery. Cervical spinal computed tomography (CT) revealed an epidural hematoma at C3-C7. C3-C6 laminectomy was emergently performed to remove the hematoma and decompress the spinal cord within 24 h after the first appearance of the disease. Histopathological analyses suggested that an abnormal blood vessel in the surrounding net was responsible for the epidural hematoma. The pathological diagnosis was epidural AVM. No obvious abnormalities were observed on postoperative conventional cerebral or cervical angiography. The patient’s neurological symptoms almost completely resolved, and he returned to work.

  Case 2 : A 41-year-old man was awakened by sudden chest and back pain. The pain in the cervical region steadily worsened, and motor paralysis in both legs progressed. When he experienced numbness below the navel and was unable to move, he was transported by ambulance to the hospital. No obvious paralysis was found in the arms, but he complained of bilateral pain in the C5 region. The anal sphincter and bulbocavernous reflex were absent. A cervical spinal epidural hematoma was identified on cervical CT and was confirmed to involve C3-C7 on MRI. No abnormal blood vessels were detected on three-dimensional CT angiography. C3-C6 laminectomy and partial C7 laminectomy were emergently performed, and the hematoma was removed within approximately 6 h after presentation. Histopathological examination revealed the same diagnosis as in Case 1. The patient in Case 2 was able to return to work.

  Emergency surgery is frequently required in patients with exacerbated neurological symptoms due to acute spinal epidural hematoma. Physicians should be cognizant of the possibility of vascular malformation such as AVM, despite its relatively low incidence, in such cases.

  Stage IV symptomatic cervical metastasis is accompanied by progressing neurologic symptoms and neck pain. Typically, the goal of the treatment of this type of cancer is to improve the quality of life (QOL) of the patient. Indeed, function recovery is achieved by timely surgical treatment and radiosurgery that delivers high doses of radiation with very high accuracy. Here, we describe a case of symptomatic cervical metastasis that was treated by our multidisciplinary approach, which is imperative to restore the activities of daily living (ADL) of patients and improve their QOL.

  A 72-year-old man presented with paralysis of the left arm and neck pain that were caused by cervical metastasis of hepatocellular cancer. The patient was treated with an emergency tumor resection that was followed by posterior cervical spinal fusion. Beginning the next day, acute rehabilitation was provided, and the patient was able to perform ADLs. After three postoperative weeks, he returned home from the hospital. Fractionated radiation using Cyberknife was then administered for 4 days as adjuvant stereotactic radiosurgery. Three months after the first round of radiation treatment, cervical metastasis with muscular weakness of the right arm and pain emerged outside the irradiated field. Thus, fractionated radiosurgery was administered for 4 more days. After 13 months, thoracic spinal metastasis was identified, and the pain was treated with standard external-beam radiotherapy. These treatments resolved the symptoms and pain, and the patient has been able to perform ADLs at his home for more than 18 months.

  Restoration of daily activity that was decreased by symptomatic cervical metastasis was essential for improving the QOL of the patient. Considering the poor prognosis of the patient due to the disease progression, it was critical to perform prompt diagnosis, ensure appropriate treatment, and reduce the duration of therapy. Therefore, the results of this report suggest the importance of multidisciplinary team-oriented medicine, including emergency surgery, high-dose radiation with extreme accuracy, focused rehabilitation, coordinated home care, and comprehensive postoperative consultation.

  Cervical angina is a pathological condition characterized by angina-like paroxysmal precordial pain caused by a lesion in the proximity of the cervical spine without cardiovascular abnormality. The symptom cannot be alleviated even with nitroglycerin administration. Although various reports have suggested possible causes, no report has identified the definite etiology of the disease. We report a rare case with frequent chest pain attacks, which completely disappeared after anterior cervical decompression and fusion and cervical calcified disc herniation. In addition, we compared the present case with previously reported cases.

  The patient was a 78-year-old woman who complained of pain in the left chest and back area. Her symptoms worsened in August 2007. She was then hospitalized after undergoing medical examination in the emergency department, with the following results: ST segment depression (+), horizontal down-sloping V4-V6 on electrocardiography, and troponin (−). On the basis of these results, she was diagnosed as having unstable angina. Later, we conducted a cardiac catheter test and found 99-100% stenosis for #6 and 99% stenosis for #13 periphery. Percutaneous coronary intervention (PCI) for #6 was performed with a favorable collateral circulation. The patient did not have any symptoms during treadmill exercise and was discharged from the hospital. Although she repeatedly visited the emergency department every 2 or 3 months because of the pain in her left chest and back area, ischemia findings at the time of electrocardiography and blood test results were always negative. In March 2012, the symptom persisted even with PCI for #13. In June 2014, an acetylcholine prorocation test was conducted for suspected vasospastic angina, but the result was negative. As the patient occasionally had numbness and pain in both upper extremities, which worsened, she underwent a medical examination in our clinic in February 2015. Midline calcified hernia at C3/C4 and spur at C4/C5 were found on magnetic resonance imaging and computed tomographic myelography. Anterior decompression and fusion (C3/C4 and C4/C5) were conducted with a cylindrical cage in June 2015, and the postsurgical pain in the chest and back area completely resolved. A philological study showed that the affected segment often indicated symptoms associated with radiculopathy at the C6 or C7 myotome areas, but our case was considered a spinal segment disorder or sympathetic involvement.