✓ The authors describe a very rare case of cervical cord compression caused by anomalous bilateral vertebral arteries (VAs). A 65-year-old woman had been suffering from intractable nape pain and torticollis. Magnetic resonance imaging revealed a signal void region in which spinal cord compression was present. Angiography demonstrated anomalous bilateral VAs compressing the spinal cord. Microvascular decompressive surgery was successfully performed. Neuroradiological and intraoperative findings are presented.
Kei Watanabe, Kazuhiro Hasegawa, and Kou Takano
Kei Watanabe, Kazuhiro Hasegawa, Toru Hirano, Naoto Endo, Akiyoshi Yamazaki, and Takao Homma
The mechanism underlying cervical flexion myelopathy (CFM) is unclear. The authors report the results of anterior decompression and fusion (ADF) in terms of neurological status and radiographically documented status in young patients and discuss the pathophysiological mechanism of the entity.
Twelve patients underwent ADF in which autogenous iliac bone graft was placed. The fusion area was one segment in four cases, two segments in seven, and three segments in one. Neurological status, as determined by the Japanese Orthopaedic Association (JOA) score, radiographic findings, and intraoperative findings were evaluated. The mean follow-up period was 63.3 months (range 20–180 months).
Grip strength was significantly improved and sensory disturbances resolved completely. Intrinsic muscle atrophy, however, persisted in all patients at the final follow-up examination. Local kyphosis in the flexed-neck position at the fusion levels was corrected by surgery. Preoperative computerized tomography myelography revealed that the cord compression index, which was calculated by anteroposterior and transverse diameters of the spinal cord, decreased to 33 ± 6.2% in the flexed-neck position from 39.7 ± 9.9% in the extended-neck position. The anterior dura mater—spinal cord distance decreased to 1.9 ± 0.7 mm in the flexed-neck position from 4 ± 1.2 mm in extended-neck position. The posterior dura mater—spinal cord distance increased to 2.5 ± 1.1 mm in the flexed-neck position from 1.3 ± 0.5 mm in the extended-neck position.
Postoperative neurological status was improved in terms of grip strength, sensory disturbance, and JOA score, and local kyphosis in the flexed-neck position at the fusion levels was reduced and stabilized by ADF.
In most cases local kyphosis in the flexed-neck position was demonstrated at the corresponding disc level, as were cervical cord compression and decrease of the anterior wall of the dura mater—spinal cord distance in the flexed-neck position. Therefore, the contact pressure between the spinal cord and anterior structures (intact vertebral bodies and intervertebral discs) in the mobile and kyphotic segments was considered to contribute to the onset of CFM. The ADF-related improvement of the clinical symptoms, preventing kyphotic alignment in flexion and decreasing movement of the cervical spine, supports the idea of a contact pressure mechanism. Furthermore, short ADF performed only at the corresponding segments can preserve more mobile segments compared with posterior fusion. Thus, ADF should be the first choice in the treatment of CFM.
Keiichi Katsumi, Akiyoshi Yamazaki, Kei Watanabe, Toru Hirano, Masayuki Ohashi, and Naoto Endo
Cervical radiculopathy of the C2–4 spinal nerves is a rare condition and is poorly documented in terms of clinical symptoms, hindering its detection during initial patient screening based on imaging diagnostics. The authors describe in detail the clinical symptoms and successful surgical treatment of a patient diagnosed with isolated C-4 radiculopathy. This 41-year-old man suffered from sleep disturbance because of pain behind the right ear, along the right clavicle, and at the back of his neck on the right side. The Jackson and Spurling tests were positive, with pain radiating to the area behind the patient's ear. Unlike in cases of radiculopathy involving the C5–8 spinal nerves, no loss of upper-extremity motor function was seen. Magnetic resonance imaging showed foraminal stenosis at the C3–4 level on the right side, and multiplanar reconstruction CT revealed a beak-type ossification of the posterior longitudinal ligament in the foraminal region at the same level. In the absence of intracranial lesions or spinal cord compressive lesions, the positive Jackson and Spurling tests and the C3–4 foraminal stenosis were indicative of isolated C-4 radiculopathy. Microscopic foraminotomy was performed at the C3–4 vertebral level and the ossified lesion was resected. The patient's symptoms completely resolved immediately after surgery. To the authors' knowledge, this report is the first to describe the symptomatic features of isolated C-4 radiculopathy, in a case in which the diagnosis has been confirmed by both radiological findings and surgical outcome. Based on this case study, the authors conclude that the characteristic symptoms of C-4 radiculopathy are the presence of pain behind the ear and in the clavicular region in the absence of upper-limb involvement.
Takanori Nozawa, Kouichirou Okamoto, Shinji Nakazato, Kunio Motohashi, Tomoaki Suzuki, Kotaro Morita, Hideki Tashi, Kei Watanabe, Hitoshi Hasegawa, Masato Watanabe, Hiroyuki Kawashima, and Yukihiko Fujii
Bow hunter’s syndrome or stroke (BHS) is characterized by rotational vertebrobasilar insufficiency elicited by rotation of the neck. It is caused by dynamic and reversible occlusion of the vertebral artery (VA). Reversible symptoms of rotational vertebrobasilar insufficiency are described as bow hunter’s syndrome, although brain infarction is rarely reported as bow hunter’s stroke.
A 70-year-old man experienced repeated cerebellar infarctions three times in the posterior inferior cerebellar artery (PICA) distribution of the nondominant right VA connecting the basilar artery. The onset of symptoms indicating cerebellar infarcts and the patient’s head position changes were unrelated. Dynamic digital angiography (DA) revealed that the nondominant right VA was occluded by an osteophyte from the C4 vertebral body, and the right PICA branches were shown to be passing through the distal right VA from the left VA. These findings were observed when the patient’s head was tilted to the right. An arterio-arterial embolic mechanism was suggested as the cause of repeated cerebellar infarctions.
Transient nondominant VA occlusion has been rarely reported as a cause of BHS when the head is tilted. To confirm the diagnosis of BHS, additional head tilt is recommended when performing dynamic DA in patients with a cervical osteophyte.
Kimihiko Sawakami, Kei Watanabe, Kazuhiro Hasegawa, Noriaki Yamamoto, Taketoshi Shimakura, Masayuki Ohashi, Hirokazu Shoji, Tatsuki Mizouchi, Yuki Tanaka, Hiroyuki Segawa, Seiichi Ishikawa, Toru Hirano, Hiroyuki Kawashima, Naoto Endo, and Hideaki E. Takahashi
Teriparatide (TPTD) is a potent promoter of early-stage osteogenesis and may be a useful adjuvant therapy to reduce complications related to bone fragility in spinal surgery patients with osteoporosis. However, effective neoadjuvant TPTD therapy regimens remain poorly understood. This study aimed to examine the effect of preoperative TPTD administration on cancellous bone with bone histomorphometry and to clarify the timing of preoperative TPTD administration for patients with spinal fusion and osteoporosis.
In this longitudinal multicenter study, 57 patients with spinal fusion and osteoporosis, who consented to undergo iliac biopsy, were allocated to the following treatment groups: neoadjuvant TPTD therapy group (n = 42) and no neoadjuvant therapy (NTC) group (n = 15). Patients in the TPTD group were categorized into subgroups on the basis of duration of preoperative TPTD administration, as follows: 1 month (n = 9), 2 months (n = 8), 3 months (n = 9), 4 months (n = 7), and 6 months (n = 9). All patient samples were preoperatively double labeled with tetracycline, and iliac biopsies were performed during spinal fusion surgery. Histomorphometric analyses were performed on nondecalcified, thin-sliced specimens. Specimens were classified on the basis of TPTD administration duration and subsequently compared with those of the NTC group. Postoperative complications and Oswestry Disability Index scores were evaluated at 1 and 2 years after surgery.
There were no demographic differences between groups. Mineralizing surface/bone surface, a key parameter of dynamic bone formation, started to increase after 1 month of TPTD administration; this increase became significant after 3 months of administration and peaked at 4 months, with a 6-fold increase relative to that of the NTC group. The patients who received preoperative TPTD for 3 months or more had superior clinical results in terms of the osteoporotic complication rate and Oswestry Disability Index scores, except for bisphosphonate-pretreated patients.
When considering neoadjuvant TPTD therapy, the authors recommend at least 3 months of preoperative administration to provide a more substantial anabolic effect from the early postoperative stage.
Keisuke Takai, Toshiki Endo, Takao Yasuhara, Toshitaka Seki, Kei Watanabe, Yuki Tanaka, Ryu Kurokawa, Hideaki Kanaya, Fumiaki Honda, Takashi Itabashi, Osamu Ishikawa, Hidetoshi Murata, Takahiro Tanaka, Yusuke Nishimura, Kaoru Eguchi, Toshihiro Takami, Yusuke Watanabe, Takeo Nishida, Masafumi Hiramatsu, Tatsuya Ohtonari, Satoshi Yamaguchi, Takafumi Mitsuhara, Seishi Matsui, Hisaaki Uchikado, Gohsuke Hattori, Nobutaka Horie, Hitoshi Yamahata, and Makoto Taniguchi
Spinal arteriovenous shunts are rare vascular lesions and are classified into 4 types (types I–IV). Due to rapid advances in neuroimaging, spinal epidural AVFs (edAVFs), which are similar to type I spinal dural AVFs (dAVFs), have recently been increasingly reported. These 2 entities have several important differences that influence the treatment strategy selected. The purposes of the present study were to compare angiographic and clinical differences between edAVFs and dAVFs and to provide treatment strategies for edAVFs based on a multicenter cohort.
A total of 280 consecutive patients with thoracic and lumbosacral spinal dural arteriovenous fistulas (dAVFs) and edAVFs with intradural venous drainage were collected from 19 centers. After angiographic and clinical comparisons, the treatment failure rate by procedure, risk factors for treatment failure, and neurological outcomes were statistically analyzed in edAVF cases.
Final diagnoses after an angiographic review included 199 dAVFs and 81 edAVFs. At individual centers, 29 patients (36%) with edAVFs were misdiagnosed with dAVFs. Spinal edAVFs were commonly fed by multiple feeding arteries (54%) shunted into a single or multiple intradural vein(s) (91% and 9%) through a dilated epidural venous plexus. Preoperative modified Rankin Scale (mRS) and Aminoff-Logue gait and micturition grades were worse in patients with edAVFs than in those with dAVFs. Among the microsurgical (n = 42), endovascular (n = 36), and combined (n = 3) treatment groups of edAVFs, the treatment failure rate was significantly higher in the index endovascular treatment group (7.5%, 31%, and 0%, respectively). Endovascular treatment was found to be associated with significantly higher odds of initial treatment failure (OR 5.72, 95% CI 1.45–22.6). In edAVFs, the independent risk factor for treatment failure after microsurgery was the number of intradural draining veins (OR 17.9, 95% CI 1.56–207), while that for treatment failure after the endovascular treatment was the number of feeders (OR 4.11, 95% CI 1.23–13.8). Postoperatively, mRS score and Aminoff-Logue gait and micturition grades significantly improved in edAVFs with a median follow-up of 31 months.
Spinal epidural AVFs with intradural venous drainage are a distinct entity and may be classified as type V spinal vascular malformations. Based on the largest multicenter cohort, this study showed that primary microsurgery was superior to endovascular treatment for initial treatment success in patients with spinal edAVFs.
Keisuke Takai, Toshiki Endo, Takao Yasuhara, Toshitaka Seki, Kei Watanabe, Yuki Tanaka, Ryu Kurokawa, Hideaki Kanaya, Fumiaki Honda, Takashi Itabashi, Osamu Ishikawa, Hidetoshi Murata, Takahiro Tanaka, Yusuke Nishimura, Kaoru Eguchi, Toshihiro Takami, Yusuke Watanabe, Takeo Nishida, Masafumi Hiramatsu, Tatsuya Ohtonari, Satoshi Yamaguchi, Takafumi Mitsuhara, Seishi Matsui, Hisaaki Uchikado, Gohsuke Hattori, Hitoshi Yamahata, and Makoto Taniguchi
The purpose of the present study was to compare the treatment success rates of primary neurosurgical and endovascular treatments in patients with spinal dural arteriovenous fistulas (dAVFs).
Data from 199 consecutive patients with thoracic and lumbosacral spinal dAVFs were collected from 18 centers. Angiographic and clinical findings, the rate of initial treatment failure or recurrence by procedures, risk factors for treatment failure, complications, and neurological outcomes were statistically analyzed.
Spinal dAVFs were frequently detected in the thoracic region (81%), fed by a single feeder (86%), and shunted into an intradural vein via the dura mater. The fistulous connection between the feeder(s) and intradural vein was located at a single spinal level in 195 patients (98%) and at 2 independent levels in 4 patients (2%). Among the neurosurgical (n = 145), and endovascular (n = 50) treatment groups of single dAVFs (n = 195), the rate of initial treatment failure or recurrence was significantly higher in the index endovascular treatment group (0.68% and 36%). A multivariate analysis identified endovascular treatment as an independent risk factor with significantly higher odds of initial treatment failure or recurrence (OR 69; 95% CI 8.7–546). The rate of complications did not significantly differ between the two treatment groups (4.1% for neurosurgical vs 4.0% for endovascular treatment). With a median follow-up of 26 months, improvements of ≥ 1 point in the modified Rankin Scale (mRS) score and Aminoff-Logue gait and Aminoff-Logue micturition grades were observed in 111 (56%), 121 (61%), and 79 (40%) patients, respectively. Independent risk factors for lack of improvement in the Aminoff-Logue gait grades were multiple treatments due to initial treatment failure or recurrence (OR 3.1) and symptom duration (OR 1.02).
Based on data obtained from the largest and most recently assessed multicenter cohort, the present study shows that primary neurosurgery is superior to endovascular treatment for the complete obliteration of spinal dAVFs by a single procedure.