A Novel Staged Revascularization Strategy for Bilateral Severe Internal Carotid Artery Stenosis at High Risk for Hyperperfusion Syndrome.

OBJECTIVE: Since bilateral severe internal carotid artery stenosis often is associated with severely decreased cerebrovascular reactivity (CVR) due to poor collateral blood flow, revascularization carries a high risk for development of hyperperfusion syndrome. In this study, we report a new staged strategy to prevent postoperative hyperperfusion syndrome in such patients. METHODS: Bilateral severe cervical internal carotid artery stenosis patients with decreased CVR to 10% or less on one side were prospectively enrolled in this study. We first performed carotid artery stenting on the side with the milder CVR decrease (lower-risk side), aiming to improve hemodynamics associated with the severe CVR decrease on the greater-risk side. Then, carotid endarterectomy or carotid artery stenting was performed on the contralateral side after an interval of 4-8 weeks. RESULTS: In all 3 cases enrolled in this study, CVR on the greater-risk side improved to 10% or more 1 month after the first treatment. The ratio of regional cerebral blood flow on the contralateral greater-risk side was 114% 1 day after the second treatment, and HPS did not develop in any of the cases. CONCLUSIONS: Our treatment strategy, in which revascularization on the lower-risk side precedes that on the greater-risk side, is effective for the prevention of HPS in bilateral ICA stenosis patients.

Neuronal dysfunction and hemodynamic disturbance due to venous congestion in dural arteriovenous fistula revealed by 123I-iomazenil SPECT.

OBJECTIVE: Retrograde leptomeningeal venous drainage (RLVD) of a dural arteriovenous fistula (dAVF) is associated with neurological morbidity and unfavorable outcomes. However, the direct damage to cortical neurons by dAVF with RLVD has not been elucidated. 123I-iomazenil (123I-IMZ) SPECT can reveal cerebral blood flow and cortical neuronal damage in early and late images, respectively. This study aimed to assess the cerebral venous congestive encephalopathy caused by dAVF using 123I-IMZ SPECT. METHODS: Based on the pre- and posttreatment MRI findings, patients were divided into three groups: a normal group, an edema group, and an infarction group. Radioactive counts in the early and late images of 123I-IMZ SPECT were investigated using the affected-to-contralateral side asymmetry ratio (ACR). RESULTS: None of the patients in the normal group showed any symptoms related to venous congestion. In contrast, all the patients in the edema and infarction groups developed neurological symptoms. The ACR in early images in the edema group was significantly lower than that in the normal group and significantly higher than that in the infarction group. The ACR in the late images of the infarction group was significantly lower than those of the normal and edema groups. After treatment, the neurological signs disappeared in the edema group, but only partial improvement was observed in the infarction group. The ACR in early images significantly improved after treatment in the edema group, but the ACR in late images did not change in any groups. CONCLUSIONS: 123I-IMZ SPECT is useful for evaluating hemodynamic disturbances and neuronal damage in dAVFs. The reduction in early images was correlated with the severity of venous congestive encephalopathy, and the significant reduction in late images is a reliable indicator of irreversible venous infarction caused by RLVD.

Primary Spinal Intradural Extramedullary Mesenchymal Chondrosarcoma.

BACKGROUND: Among chondrosarcomas arising from bones and soft tissues, mesenchymal chondrosarcoma (MCS), especially primary spinal intradural extramedullary MCS, is extremely rare, and only 18 cases have been reported to date. We report an adult case of this rare condition mimicking meningioma. CASE DESCRIPTION: A 42-year-old woman presented with paraplegia and sensory disturbance associated with right-sided Brown-Séquard syndrome following back pain. Magnetic resonance imaging showed an intradural mass in the right dorsal spinal canal with homogeneous enhancement and dural tail sign at the T8 level. Computed tomography demonstrated a calcified portion in the mass. Following T7-8 laminectomies, an intradural extramedullary tumor was completely removed after detaching the tumor from the dura mater. The histopathologic diagnosis was MCS, and positron emission tomography showed no metastatic lesions at other sites. The patient did not receive adjuvant therapy, and magnetic resonance imaging revealed no evidence of recurrence during 2-year follow-up. CONCLUSIONS: Primary spinal intradural extramedullary MCS has been reported to have a better prognosis than MCS occurring in other regions. In a case with early complete surgical resection, adjuvant therapy should be considered at the time of recurrence.

Detection of Transient Increase of Cerebral Blood Flow and Reversible Neuronal Dysfunction by Iodine-123-Iomazenil Single Photon Emission Computed Tomography After Cerebral Hyperperfusion Syndrome After Revascularization Surgery for Moyamoya Disease.

BACKGROUND: Early and late images of single photon emission computed tomography (SPECT) using 123I-iomazenil (123I-IMZ) can demonstrate cerebral blood flow and cortical neuronal viability. Hyperperfusion syndrome is one of the serious complications after revascularization surgery for moyamoya disease; therefore, the real-time observation of the hemodynamics and neuronal viability is important for the treatment after the revascularization. Here we report, a case of moyamoya disease where 123I-IMZ SPECT had a significant efficacy to delineate the hemodynamics and transient neuronal dysfunction in hyperperfusion state after revascularization. CASE DESCRIPTION: A 47-year-old woman presented with motor aphasia 3 days after superficial temporal artery-middle cerebral artery anastomosis with indirect revascularization. Magnetic resonance imaging (MRI) on the same day showed no new ischemic changes but high intensities along the left frontal sulci observed on fluid-attenuated inversion recovery images, and 123I-IMZ SPECT demonstrated the increased uptake on the early images and the decreased uptake on the late images around the anastomosis site. The patient was completely recovered 1 month after surgery, and abnormal changes on MRI and 123I-IMZ SPECT returned to normal along with the symptom withdrawal. CONCLUSIONS: These findings indicate that 123I-IMZ SPECT could be the index for the treatment of revascularization for obstructive vascular diseases such as moyamoya disease.

Anterior Approach Combined with Endoscopic Fluorescence Video Angiography for a Cervical Perimedullary Arteriovenous Fistula.

BACKGROUND: Perimedullary arteriovenous fistulas (pAVFs) of the anterior cervical spinal cord are rare and difficult to eradicate by surgery because of the limitations of the approach routes. Because of the anatomic relationships, an anterior approach with corpectomy can provide direct observation. However, a narrow corridor to the lesion is the drawback of this approach. Therefore, to overcome this limitation, we introduced angled endoscopes integrated with fluorescence video angiography to observe the real-time blood flow. CASE DESCRIPTION: A 47-year-old woman was incidentally found to have a pAVF fed by multiple radicular arteries, and she underwent direct surgery via the anterior approach. Although observation of the entire lesion was difficult with the microscope alone, the introduction of the angled endoscope made it possible to observe the lateral portion of the spinal cord hidden behind the dura mater. Furthermore, endoscopic fluorescein video angiography visualized residual fine feeding arteries that were then electrocoagulated, which contributed to complete obliteration of the shunt. CONCLUSIONS: The anterior approach with endoscopic assistance is a reasonable strategy for the treatment of ventrally located cervical pAVFs. Furthermore, integration of a fluorescence video angiography system with the endoscope enables confirmation of the complicated real-time hemodynamics of the pAVFs, contributing to reliable treatment.

Effects of FABP7 on functional recovery after spinal cord injury in adult mice.

OBJECTIVEElucidating 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.METHODSFemale 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.RESULTSWestern 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.CONCLUSIONSThe 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.

Embolization of a peripheral cerebral aneurysm associated with intracranial major artery occlusion through a transdural anastomotic artery: Case report.

A peripheral cerebral aneurysm is known to develop at collateral vessels as a result of hemodynamic stress by the occlusion of the intracranial major arteries. We report a case of successful embolization of a ruptured aneurysm through a transdural anastomotic artery. The aneurysm formed at the developed collateral vessel from the meningeal branch of the occipital artery (OA) to the posterior pericallosal artery. A 59-year-old man presented with acute-onset headache, and computed tomography revealed subarachnoid hemorrhage and intracerebral hemorrhage at the splenium of the corpus callosum with intraventricular hemorrhage. Digital subtraction angiography demonstrated a ruptured aneurysm located at a transdural anastomotic artery from the right OA to the posterior pericallosal artery. The patient underwent endovascular treatment for the aneurysm through the transdural anastomotic artery with a coil and n-butyl-2-cyanoacrylate. Because it was impossible to navigate a microcatheter to the aneurysm through the right anterior cerebral artery because of the occlusion of its proximal portion, it was advanced through the transdural anastomosis from the right OA. The aneurysm was completely occluded without complications. Endovascular embolization is a useful treatment option for a peripheral cerebral aneurysm developed at a collateral vessel with intracranial major artery occlusion.

Distribution Patterns of Spinal Epidural Fluid in Patients with Spontaneous Intracranial Hypotension Syndrome.

The aim of this study is to clarify the details of distribution patterns of spinal epidural fluid and to establish it as measure of spontaneous intracranial hypotension (SIH) syndrome diagnosis. Magnetic resonance imaging findings of the spine were analyzed in 37 patients, 24 women and 13 men (mean age 46.3 years), with SIH. Detection rate, thickness and patterns of the fluid collection were evaluated at every vertebral level. Follow-up spinal MRI findings were also analyzed for changes in epidural fluid collection and association with clinical symptoms. The MR images of the cervical spine were obtained in 30 patients, the thoracic spine in 36, and the lumbar spine in 17 patients. Epidural fluid collection was detected totally in 36 patients (97%) and was predominantly found at the mid-thoracic vertebrae. The fluid tended to locate dorsal to the dural sac at the thoracic spine and ventral at the cervical and lumbar spine. Patients with shorter duration of illness tended to have thicker fluid in the thoracic spine. In follow-up MRI, the findings of epidural fluid collection has disappeared in 32/36 cases within 3 months after treatment. Although residual fluid collection was found at the thoracic level in 4 cases, clinical symptoms were improved in all patients. This study suggested that the mid-thoracic spine should be chosen as the target of MRI in screening of SIH, and enlarged dorsal epidural space is strongly indicative of SIH.

Effects of cilostazol on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a multicenter prospective, randomized, open-label blinded end point trial.

OBJECT: Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of subsequent morbidity and mortality. Cilostazol, a selective inhibitor of phosphodiesterase 3, may attenuate cerebral vasospasm because of its antiplatelet and vasodilatory effects. A multicenter prospective randomized trial was conducted to investigate the effect of cilostazol on cerebral vasospasm. METHODS: Patients admitted with SAH caused by a ruptured anterior circulation aneurysm who were in Hunt and Kosnik Grades I to IV and were treated by clipping within 72 hours of SAH onset were enrolled at 7 neurosurgical sites in Japan. These patients were assigned to one of 2 groups: the usual therapy group (control group) or the add-on 100 mg cilostazol twice daily group (cilostazol group). The group assignments were done by a computer-generated randomization sequence. The primary study end point was the onset of symptomatic vasospasm. Secondary end points were the onset of angiographic vasospasm and new cerebral infarctions related to cerebral vasospasm, clinical outcome as assessed by the modified Rankin scale, and length of hospitalization. All end points were assessed for the intention-to-treat population. RESULTS: Between November 2009 and December 2010, 114 patients with SAH were treated by clipping within 72 hours from the onset of SAH and were screened. Five patients were excluded because no consent was given. Thus, 109 patients were randomly assigned to the cilostazol group (n = 54) or the control group (n = 55). Symptomatic vasospasm occurred in 13% (n = 7) of the cilostazol group and in 40% (n = 22) of the control group (p = 0.0021, Fisher exact test). The incidence of angiographic vasospasm was significantly lower in the cilostazol group than in the control group (50% vs 77%; p = 0.0055, Fisher exact test). Multiple logistic analyses demonstrated that nonuse of cilostazol is an independent factor for symptomatic and angiographic vasospasm. The incidence of new cerebral infarctions was also significantly lower in the cilostazol group than in the control group (11% vs 29%; p = 0.0304, Fisher exact test). Clinical outcomes at 1, 3, and 6 months after SAH in the cilostazol group were better than those in the control group, although a significant difference was not shown. There was also no significant difference in the length of hospitalization between the groups. No severe adverse event occurred during the study period. CONCLUSIONS: Oral administration of cilostazol is effective in preventing cerebral vasospasm with a low risk of severe adverse events. Clinical trial registration no. UMIN000004347, University Hospital Medical Information Network Clinical Trials Registry.

Diagnostic value of the optic nerve sheath subarachnoid space in patients with intracranial hypotension syndrome.

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.

Endoscopic indocyanine green video angiography in aneurysm surgery: an innovative method for intraoperative assessment of blood flow in vasculature hidden from microscopic view.

Recently, intraoperative fluorescence video angiography using indocyanine green (ICG) has been widely used in aneurysm surgery. This is a simple and useful method to confirm complete occlusion of the aneurysm lumen and preservation of blood flow in the arteries around the aneurysm. However, the observation field of ICG video angiography is limited under a microscope, making it difficult to confirm the flow in the arteries behind the parent arteries or aneurysm. The authors developed a new technique of intraoperative endoscopic ICG video angiography to assess the blood flow in perforating arteries hidden by the parent arteries or aneurysm. The endoscope emits excitation light with a wavelength of approximately 800 nm, and video images were obtained through a cut filter. The authors used this ICG fluorescence endoscope in treating 3 patients with unruptured cerebral aneurysms. During clip placement, the endoscope was inserted to confirm aneurysm occlusion. Then, ICG was intravenously administered, and the fluorescence in the vessels was observed via the endoscope as well as under the microscope. The blood flow in the perforating arteries was clearly identified, and no procedural complication occurred. The authors conclude that the technique is very useful and facilitates intraoperative real-time assessment of the patency of perforating arteries behind parent arteries or aneurysms.

Giant serpentine aneurysm of the distal anterior cerebral artery.

We report a case of a 38-year-old man with a giant serpentine aneurysm arising from the distal anterior cerebral artery. This aneurysm grew from a fusiform aneurysm to a huge aneurysm within 5 months before manifesting as a mass lesion. The aneurysm was largely filled with thrombus, and 4 distal branches arose from the aneurysm dome. Selective balloon test occlusion of the distal anterior cerebral artery using an intravascular technique was performed to confirm the tolerance of the brain tissue. The balloon test occlusion elicited adequate leptomeningeal collateral circulation and no neurologic symptoms; thus, the aneurysm was treated with trapping and resection. The patient had no ischemic complications after the surgery and returned to his job 1 month later. No ischemia developed in the 2 years after surgery. Selective balloon test occlusion of the distal cerebral artery using an intravascular technique can be a very useful tool in planning the therapeutic strategy for a complicated distal cerebral aneurysm.

Indocyanine green videoangiography to detect aneurysm and related vascular structures buried in subarachnoid clots.

This 44-year-old woman presented with a ruptured anterior communicating artery aneurysm. Intraoperative indocyanine green (ICG) videoangiography demonstrated the aneurysm neck and dome, which were buried in subarachnoid clots. Dissection and aspiration of the clots around the neck were safely performed without touching the ruptured points. The aneurysm was successfully clipped. The patient's postoperative course was excellent. This case illustrates the use of intraoperative ICG videoangiography to provide information about the anatomical location of the aneurysm neck and dome despite their being completely obscured by subarachnoid clots. Intraoperative ICG videoangiography allowed safer dissection of the ruptured aneurysm from the blood clots.

[Refractory chronic subdural hematoma due to spontaneous intracranial hypotension].

Spontaneous intracranial hypotension (SIH) is reported to cause chronic subdurai hematoma (SDH), however diagnosis of SIH in patients with SDH is not always easy. We report a case of chronic SDH refractory to repeated drainage, which was attributed to SIH. A forty-five-year-old man who had been suffering from orthostatic headache for one month was admitted to our hospital presenting with unconsciousness and hemiparesis. CT on admission revealed a chronic subdural hematoma, which was successfully treated once with subdural drainage. However, the patient fell into unconscious again with recurrence of the hematoma within several days. After two more sessions of drainage, SIH due to cerebrospinal fluid leakage was diagnosed with spinal magnetic resonance imaging (MRI) and radionuclide cisternography. Spinal MRI demonstrated abnormal fluid accumulation in the thoracic epidural space, and the radionuclide cisternogram showed early excretion of tracer into urine as well as absence of intracranial tracer filling. After treatment with epidural blood patching, the hematoma rapidly disappeared and he was discharged without symptoms. In the treatment of chronic SDH, especially in young to middle aged patient without preceding trauma or hematological disorders, physicians should pay attention to underlying SIH to avoid multiple surgery. MRI of the spine as well as radionuclide cisternography is useful in evaluation of this condition.

Atypical meningioma with large cyst. Case report.

A 29-year-old male presented with loss of consciousness and generalized seizure, followed by right hemiparesis and speech disturbance. Computed tomography and magnetic resonance imaging showed a solid, enhanced tumor with a cyst in the left frontal area with surrounding edema and mild mass effect. The cyst wall was also enhanced. The preoperative diagnosis was cystic falx meningioma. The tumor was totally resected, but most of the cyst wall adhered tightly to the surrounding brain and could not be removed. Histological examination revealed atypical meningioma and tumor cells in the cyst wall. The patient received local radiotherapy to the residual cyst wall with a total dose of 50 Gy.