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Nobuo Senbokuya, Hideyuki Yoshioka, Takashi Yagi, Yuji Owada and Hiroyuki Kinouchi

OBJECTIVE

Elucidating the mechanisms of neuronal injury is crucial for the development of spinal cord injury (SCI) treatments. Brain-type fatty acid–binding protein 7 (FABP7) is expressed in the adult rodent brain, especially in astrocytes, and has been reported to play a role in astrocyte function in various types of brain damage; however, its role after SCI has not been well studied. In this study, the authors evaluated the expression change of FABP7 after SCI using a mouse spinal cord compression model and observed the effect of FABP7 gene knockout on neuronal damage and functional recovery after SCI.

METHODS

Female FABP7 knockout (KO) mice with a C57BL/6 background and their respective wild-type littermates were subjected to SCI with a vascular clip. The expression of FABP7, neuronal injury, and functional recovery after SCI were analyzed in both groups of mice.

RESULTS

Western blot analysis revealed upregulation of FABP7 in the wild-type mice, which reached its peak 14 days after SCI, with a significant difference in comparison to the control mice. Immunohistochemistry also showed upregulation of FABP7 at the same time points, mainly in proliferative astrocytes. The number of surviving ventral neurons in the FABP7-KO mice at 28 days after SCI was significantly lower than that observed in the wild-type mice. In addition, motor functional recovery in the FABP7-KO mice was significantly worse than that of the wild-type mice.

CONCLUSIONS

The findings of this study indicate that FABP7 could have a neuroprotective role that might be associated with modulation of astrocytes after SCI. FABP7 could potentially be a therapeutic target in the treatment of SCI.

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Koichi Miki, Kenji Yagi, Masani Nonaka, Mitsutoshi Iwaasa, Hiroshi Abe, Takashi Morishita, Hisatomi Arima and Tooru Inoue

OBJECTIVE

In patients with spontaneous intracerebral hemorrhage (sICH), postoperative recurrent hemorrhage (PRH) is one of the most severe complications after endoscopic evacuation of hematoma (EEH). However, no predictors of this complication have been identified. In the present study, the authors retrospectively investigated whether PRH can be preoperatively predicted by the presence of the spot sign on CT scans.

METHODS

In total, 143 patients with sICH were treated by EEH between June 2009 and March 2017, and 127 patients who underwent preoperative CT angiography were included in this study. Significant correlations of PRH with the patients’ baseline, clinical, and radiographic characteristics, including the spot sign, were evaluated using multivariable logistic regression models.

RESULTS

The incidence of and risk factors for PRH were assessed in 127 patients with available data. PRH occurred in 9 (7.1%) patients. Five (21.7%) cases of PRH were observed among 23 patients with the spot sign, whereas only 4 (3.8%) cases of PRH occurred among 104 patients without the spot sign. The spot sign was the only independent predictor of PRH (OR 5.81, 95% CI 1.26–26.88; p = 0.02). The following factors were not independently associated with PRH: age, hypertension, poor consciousness, antihemostatic factors (thrombocytopenia, coagulopathy, and use of antithrombotic drugs), the location and size of the sICH, other radiographic findings (black hole sign and blend sign), surgical duration and procedures, and early surgery.

CONCLUSIONS

The spot sign is likely to be a strong predictor of PRH after EEH among patients with sICH. Complete and careful control of bleeding in the operative field should be ensured when surgically treating such patients. New surgical strategies and procedures might be needed to improve these patients’ outcomes.

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Nobuyasu Takeuchi, Toru Horikoshi, Hiroyuki Kinouchi, Arata Watanabe, Takashi Yagi, Kentaro Mitsuka and Nobuo Senbokuya

Object

The size of the subarachnoid space in the optic nerve sheath (ONS) on MR images is thought to reflect intracranial pressure. The diagnostic value of this space was investigated in patients with spontaneous intracranial hypotension (SIH) syndrome.

Methods

Coronal fat-saturated T2-weighted MRI of the orbit was performed in 15 patients with SIH fulfilling the diagnostic criteria for headache caused by low CSF pressure of the International Classification of Headache Disorders or the criteria for spontaneous spinal CSF leaks and intracranial hypotension. The size of the subarachnoid space in the ONS was measured in 2 slices behind the eyeballs. The images were compared before and after treatment. The CSF pressure was measured by lumbar puncture.

Results

Before treatment, the diameter of the ONS subarachnoid space ranged from 2.58 to 4.21 mm (mean 3.34 mm) and the thickness from 0 to 0.48 mm (mean 0.15 mm). Both measurements showed significant correlations with CSF opening pressure, and 8 patients had no CSF space before treatment. The size of CSF space increased in many patients after effective treatment.

Conclusions

Disappearance of the CSF space in the ONS was frequently observed in patients with SIH. This characteristic finding may be useful in the diagnosis of SIH as well as in the evaluation of treatment effectiveness.

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Koichi Miki, Hiroshi Abe, Takashi Morishita, Shuji Hayashi, Kenji Yagi, Hisatomi Arima and Tooru Inoue

OBJECTIVE

Subdural hygroma has been reported as a causative factor in the development of a chronic subdural hematoma (CSDH) following a head trauma and/or neurosurgical procedure. In some CSDH cases, the presence of a 2-layered space delineated by the same or similar density of CSF surrounded by a superficial, residual hematoma is seen on CT imaging after evacuation of the hematoma. The aims of the present study were to test the hypothesis that the double-crescent sign (DCS), a unique imaging finding described here, is associated with the postoperative recurrence of CSDH, and to investigate other factors that are related to CSDH recurrence.

METHODS

The authors retrospectively analyzed data from 278 consecutive patients who underwent single burr-hole surgery for CSDH between April 2012 and March 2017. The DCS was defined as a postoperative CT finding, characterized by the following 2 layers: a superficial layer demonstrating residual hematoma after evacuation of the CSDH, and a deep layer between the brain’s surface and the residual hematoma, depicted as a low-density space. Correlation of the recurrence of CSDH with the DCS was evaluated by multivariate logistic regression modeling. The authors also investigated other classic predictive factors including age, sex, past history of head injury, hematoma laterality, anticoagulant and antiplatelet therapy administration, preoperative hematoma volume, postoperative residual hematoma volume, and postoperative brain reexpansion rate.

RESULTS

A total of 277 patients (320 hemispheres) were reviewed. Fifty (18.1%) of the 277 patients experienced recurrence of CSDH within 3 months of surgery. CSDH recurred within 3 months of surgery in 32 of the 104 hemispheres with a positive DCS. Multivariate logistic analyses revealed that the presence of the DCS (OR 3.36, 95% CI 1.72–6.57, p < 0.001), large postoperative residual hematoma volume (OR 2.88, 95% CI 1.24–6.71, p = 0.014), anticoagulant therapy (OR 3.03, 95% CI 1.02–9.01, p = 0.046), and bilateral hematoma (OR 3.57, 95% CI 1.79–7.13, p < 0.001) were significant, independent predictors of CSDH recurrence.

CONCLUSIONS

In this study, the authors report that detection of the DCS within 7 days of surgery is an independent predictive factor for CSDH recurrence. They therefore advocate that clinicians should carefully monitor patients for postoperative DCS and subsequent CSDH recurrence.

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Kazuya Kanemaru, Hiroyuki Kinouchi, Hideyuki Yoshioka, Takashi Yagi, Takuma Wakai, Koji Hashimoto, Yuichiro Fukumoto, Takako Umeda, Hiroshi Onishi, Yoshihisa Nishiyama and Toru Horikoshi

OBJECT

The severity of cerebral hemodynamic disturbance caused by retrograde leptomeningeal venous drainage (RLVD) of a dural arteriovenous fistula (dAVF) is related to neurological morbidity and unfavorable outcome. However, the cerebral hemodynamics of this disorder have not been elucidated well. The aim of this study was to assess the relationship between the cerebral venous congestive encephalopathy represented as a high-intensity area (HIA) on T2-weighted MR images and the cerebral hemodynamics examined by 123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), as well as the predictive value of 123I-IMP SPECT for the development and reversibility of venous congestion encephalopathy.

METHODS

Based on the pre- and posttreatment T2 HIAs associated with venous congestion encephalopathy, patients were divided into 3 groups: a normal group, an edema group, and an infarction group. The regional cerebral blood flow (rCBF) at the region with RLVD was analyzed by 123I-IMP SPECT, and the results were compared among the groups.

RESULTS

There were 11, 6, and 3 patients in the normal, edema, and infarction groups, respectively. No patients in the normal group showed any symptoms related to venous congestion. In contrast, all patients in the edema and infarction groups developed neurological symptoms. The rCBF in the edema group was significantly lower than that in the normal group, and significantly higher than that in the infarction group. The cerebral vascular reactivity (CVR) of the infarction group was significantly lower than that of the normal and edema groups. After treatment, the neurological signs disappeared in the edema group, but only partial improvement was seen in the infarction group. The rCBF also significantly increased in the normal and edema groups, but not in the infarction group.

CONCLUSIONS

Quantitative rCBF measurement is useful for evaluating hemodynamic disturbance in dAVF with RLVD. The reduction of rCBF was strongly correlated with the severity of venous congestive encephalopathy, and loss of CVR is a reliable indicator of irreversible venous infarction caused by RLVD.

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Eiji Ito, Kiyoshi Saito, Tetsuya Nagatani, Masaaki Teranishi, Yuzuru Kamei, Shunjiro Yagi, Takashi Kawabe, Norihiro Niimi and Jun Yoshida

Lymphangioma localized to the bones of the skull base is rare. The authors report herein the case of a 5-year-old boy who presented with lymphangioma of the bone, localized to the skull base and leading to cerebrospinal fluid (CSF) rhinorrhea with meningitis. Neuroimaging demonstrated lytic destruction with a cyst in the right middle skull base. The patient was successfully treated with resection of the tumor and prevention of CSF leakage. Histopathological examination revealed a lymphangioma. An enlarging lymphangioma can lead to bone destruction. A differential diagnosis of a lytic lesion for a cyst at the skull base is important for proper case management.

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Sanjeev Ariyandath Sreenivasan, Kanwaljeet Garg, Manmohan Singh and Poodipedi Sarat Chandra

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Satoshi Nori, Akio Iwanami, Akimasa Yasuda, Narihito Nagoshi, Nobuyuki Fujita, Tomohiro Hikata, Mitsuru Yagi, Takashi Tsuji, Kota Watanabe, Suketaka Momoshima, Morio Matsumoto, Masaya Nakamura and Ken Ishii

OBJECTIVE

A number of studies have reported that surgery for cervical intramedullary tumors via the posterior approach can result in postoperative sagittal malalignment of the cervical spine; however, the risk factors remain unclear. The purpose of this study was to investigate the changes in cervical spinal alignment after surgery for cervical intramedullary tumors in adults and to elucidate the risk factors for cervical spinal sagittal misalignment.

METHODS

Data for the period from April 2001 to December 2011 for all adults who had undergone surgery for cervical intramedullary spinal cord tumors at a single institution were retrospectively analyzed to determine the postoperative changes in cervical spine alignment. Patients younger than 20 years of age and those who required postoperative radiotherapy were excluded from the study. Patients were divided into 2 groups according to tumor location: upper tumor (U) group, in which the central region of the tumor was above the C-5 level; and lower tumor (L) group, in which the central region of the tumor was at or below the C-5 level. Changes in alignment of the cervical spine were measured on plain lateral radiographs. Data on atrophy of the deep extensor muscles (DEMs), tumor location, detachment of the DEMs from the C-2 spinous process, the C2–7 angle before surgery, patient age at surgery, tumor histology, patient sex, tumor size, and number of laminae affected were reviewed for each patient, and the correlation of each of these factors with cervical spinal malalignment was evaluated using statistical analysis.

RESULTS

The 54 adults eligible for analysis had a mean age of 49.1 years. Ependymoma was the most common cervical intramedullary tumor (63.0%) in this series. In the tumor location U group, the kyphotic angle of the C2–7 spinal segments increased after surgery (−5.8° ± 2.8°). In contrast, in the L group, the C2–7 lordotic angle increased after surgery (6.4° ± 2.6°). In the univariate analysis, atrophy of the DEMs, detachment of the DEMs from the C-2 spinous process, and an upper cervical location of the tumor were identified as factors significantly correlated with the development of cervical spinal kyphosis after surgery. Multiple linear regression analysis revealed the following as risk factors for kyphotic change of the cervical spine after surgery: 1) atrophy of the DEMs after surgery (β = −0.54, p < 0.01), and 2) detachment of the DEMs from the C-2 spinous process (β = −0.37, p < 0.01).

CONCLUSIONS

Atrophy of the DEMs after surgery and detachment of the DEMs from the C-2 spinous process are directly related to the risk of cervical spinal kyphosis after surgery for cervical intramedullary tumors in adults. Therefore, preservation of the DEMs, especially those attached to the C-2 spinous process, is important for the prevention of kyphotic malalignment of the cervical spine after surgery for intramedullary tumors.