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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.

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.

Neck clipping of a large middle cerebral artery aneurysm was performed using a newly developed surgical microscope integrated with modules for both indocyanine green (ICG) and fluorescein videoangiography. During surgery, ICG and fluorescein videoangiography by intra-arterial or intravenous injection were safely carried out without interrupting the surgical procedure. Based on the findings obtained from the case, we evaluated the differences between the dyes and the injection routes. With intra-arterial injection, fluorescein offered sharper contrast images and was better at depicting fine arteries than ICG. Patchy staining of vessel walls was observed in intravenous fluorescein videoangiography, while it was not evident in ICG. Intra-arterial injection method had a great advantage in the rapid clearance of the dyes, which allowed us to perform repeated videoangiography within a short period, and was useful in detecting incomplete clipping in this case; however, catheter insertion requires additional work and carries a potential risk. Use of a microscope integrated for both ICG and fluorescein videoangiography would be another method for repeated evaluation. Namely, alternate use of the dyes enables us to perform videoangiography in a short time even via intravenous injection.

In-stent thrombosis (IST) after carotid artery stenting (CAS) is a rare but potentially devastating complication. We present a case of early IST after CAS despite sufficient antiplatelet therapy in a patient with bladder cancer. A 77-year-old man under preventive triple antiplatelet therapy underwent CAS without any intra- or periprocedural complications. However, the patient developed a large asymptomatic IST 6 days after CAS. Anticoagulant therapy with argatroban was reintroduced to treat IST concomitant with antiplatelet agents. Subsequently, the IST shrank and disappeared without any thrombotic symptoms. Malignancy is regarded as an acquired thrombophilic condition associated with a significant risk of thrombosis. In the field of coronary stents, cancer is associated with a significant increasing risk of IST. The cause of IST in our case was possibly related in hypercoagulable state because of the patient's cancer. Attention for IST should be paid in CAS cases with these risk factors, and repeated examination is recommended.

BACKGROUND : Indoleamine 2,3-dioxygenase (IDO) is a tryptophan catabolic enzyme involved in immune tolerance and tumor immune escape processes. Recently, IDO expression has been found to correlate with the prognosis of malignant tumors, but the implication of IDO in glioma progression remains unknown. OBJECTIVE : To investigate the relationship between IDO expression and histological malignancy in gliomas. METHODS : IDO expression was examined in a total of 75 surgical specimens obtained from 68 patients with glioma using immunohistochemical staining. The 75 specimens included 15 diffuse astrocytomas, 21 anaplastic astrocytomas, and 39 glioblastomas. Six of 39 glioblastomas were secondary glioblastomas, transforming from grade II or III gliomas that had been determined at the first surgery. IDO expression rate was compared in each histological grade, and patient survival was analyzed. RESULTS : Expression of IDO was found in 72 of 75 gliomas at varying intensities. Stronger expression of IDO was more likely to be observed in malignant gliomas compared with low-grade gliomas. IDO expression in the 6 cases of secondary glioblastoma was stronger than in the initial low-grade glioma. Survival analysis using the Kaplan-Meier method revealed that grade IV patients with strong IDO expression had significantly worse overall survival rates (P = .04) than patients with weak IDO expression. CONCLUSION : IDO is expressed more strongly in both primary and secondary glioblastoma tissue than low-grade glioma and may affect clinical outcome. If IDO promotes glioma cells to escape from the immune system, IDO may be a crucial therapeutic target for malignant gliomas.

To elucidate the precise recovery process and prognosis of language functions in aphasic patients with left putaminal hemorrhage, we investigated 48 aphasic patients classified into 4 groups according to the location and extent of hematoma. The hematoma extended to the corona radiata in all patients, extracapsular in type I (12 cases), to the anterior limb in type II (10 cases), to the posterior limb in type III (12 cases), and to both limbs in type IV (14 cases). The Standard Language Test for Aphasia was performed at 1 month, 3 months, and 6 months after the attack. The type II, III, and IV patients were divided into 2 groups, with and without ventricular rupture of the hemorrhage. At 3 and 6 months after the attack, the type I, II, and III patients showed significant improvement (P.05) in all language modalities compared with the type IV patients. Most improvement in language modalities occurred in the first 3 months. The evaluation of patients with ventricular rupture after 6 months revealed poor recovery (P.05) in oral commands, visual commands, confrontation naming, sentence repetition, narratives, verbal fluency, and writing in type II and III patients. In type IV patients, this evaluation showed poor recovery (P.05) only in oral and written naming (kanji words). No significant difference in prognostic outcome was observed between the surgical treatment group and the nonsurgical treatment group. The classification of hemorrhage may be useful in predicting the outcome of aphasia with putaminal hemorrhage and in guiding clinicians in providing effective instructions to patients and their relatives.

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.

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.

The signal transducers and activators of transcription 3 (STAT3) has been suggested to have neuroprotective roles. However, its role in ischemic preconditioning (PC) is still obscure. In this study, we examined the phosphorylation status of ser727-STAT3, which is necessary for activation of STAT3, and its roles in a rat global ischemia model with or without PC. PC was induced by 3 min of nonlethal ischemia 48 h before 5 min of lethal ischemia. Western blot analysis showed that phospho-ser727-STAT3 significantly increased from 8 to 48 h after nonlethal ischemia, while it increased only for 1h after lethal ischemia and returned to the baseline within 24h. In the preconditioned brains, phospho-ser727-STAT3 was induced at 1 to 4h after lethal ischemia, and decrease of its levels delayed compared to the nonconditioned brains. Immunohistochemistry revealed that phospho-ser727-STAT3 was expressed mainly in CA1 neurons after nonlethal ischemia. Additionally, STAT3 inhibitor peptide treatment prevented PC induced-neuroprotection. These results indicate that phosphorylation of ser727-STAT3 plays an important role in PC induced- neuroptotection.

In this report, a rare case of dysembryoplastic neuroepithelial tumor (DNET) initially presented as a small white matter lesion with calcification adjacent to the lateral ventricle and extending to the frontal cortex after 7 years. This 1-year-old boy initially suffered from partial seizures. Initial CT revealed a small, low-density area surrounding a tiny calcified mass in the deep white matter of the left frontal lobe. Seven years later, his seizures had become intractable to antiepileptic agents, and MR imaging demonstrated a relatively large mass extending from the calcified lesion up to the adjacent cortical surface. He underwent surgery and the tumor was subtotally removed. Histological examination of the tumor verified it as a DNET consisting of clusters of small oligodendrocytes with floating neurons in the mucoid background. The pattern of the tumor progression in this case suggests that a DNET in the cortex originates from the subependymal germinal layer near the ventricle.

Object Magnetic resonance imaging may show a fluid collection in the spinal epidural space of patients with spontaneous intracranial hypotension syndrome (SIHS), but the chronological changes remain unclear. Methods Brain and spine MR imaging findings were analyzed in 16 patients (9 women and 7 men, mean age 48.6 years) with SIHS before and after treatment. Results Diffuse dural enhancement was seen in 15 patients, and the epidural fluid collection in the spinal canal was clear in 15 and equivocal in 1. Symptoms disappeared after bed rest in 1 patient, and an epidural blood patch was performed in 15 patients, resulting in complete resolution of symptoms in 13. After the follow-up period (range 1–20 months, mean 5.0 months), 1 patient had persistent mild headache that gradually worsened in the afternoon, and another patient complained of heaviness of the eyes. Follow-up MR imaging demonstrated disappearance of the dural enhancement in all patients, but a fluid collection in the spinal canal remained in 4. Two of the 4 patients had persistent symptoms, but the other patients exhibited complete resolution of the symptoms. Conclusions An epidural blood patch is effective for sealing of CSF leaks, but the resolution of SIHS-related symptoms does not always imply complete eradication of the leakage.

This 11-year-old boy presented with a rare case of Castleman syndrome caused by a clear cell meningioma manifesting as persistent fever of unknown origin, 2 years after glomerulonephritis. Laboratory investigation of the patient showed an increased inflammatory reaction, as well as elevated polyclonal gamma globulin titer and serum level of C-reactive protein. Magnetic resonance imaging revealed a tumor at the cerebellopontine angle. Neurosurgical intervention was performed under the presumptive diagnosis of Castleman syndrome caused by intracranial tumor. Histological examination of the tumor verified that it was clear cell meningioma with infiltration of lymphoplasma cells, and surgical removal resulted in complete resolution of the patient's symptoms and biochemical abnormalities. The present case of clear cell meningioma manifesting as Castleman syndrome shows that the possibility of a brain tumor should be considered in patients presenting with fever of unknown origin, anemia, hypergammaglobulinemia, or other systemic illness.

A 75-year-old man was referred to our hospital with a thrombosed giant middle cerebral artery aneurysm manifesting as progressive memory disturbance and disorientation. Magnetic resonance imaging and conventional angiography revealed a partially thrombosed giant aneurysm of the left middle cerebral artery bifurcation and edema of the adjacent brain which had enlarged compared to 3 months before. Surgery was performed through a left frontotemporal craniotomy. After exposure of the aneurysm neck, we tried to apply a clip, which slipped due to the intraaneurysmal thrombus. Intraoperative motor evoked potential monitoring showed decreased amplitude. Therefore, the aneurysm dome was incised and the intraaneurysmal thrombus near the neck was shaved with the ultrasonic aspirator, followed by neck clipping of the aneurysm. The residual thrombus was safely removed. Transient right hemiparesis was observed after surgery, but his memory disturbance gradually improved. Giant thrombosed aneurysm can be treated by reduction of the thrombus from the far side to the lumen to reduce the duration of parent artery occlusion required for clipping.

OBJECTIVE: We prospectively investigated the predictive value of diffusion tensor tractography for motor functional outcome in a case series of patients with intracerebral hemorrhage. METHODS: Diffusion tensor tractography was performed in 17 patients with intracerebral hemorrhage (putamen, nine patients; thalamus, seven patients; combined, one patient) within 5 days after onset. Mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values along the corticospinal tracts at the level of the hematoma were measured bilaterally, and the ratios of values (hematoma side/contralateral side) were determined as FA and ADC ratios, respectively. Patients were evaluated for motor function on admission and at 3 months after onset using the manual muscle test score and then divided into good (manual muscle test, 4-5) and poor (manual muscle test, 0-3) motor function groups. RESULTS: FA ratio measured shortly after the onset of intracerebral hemorrhage correlated well with motor functional outcome at 3 months (P < 0.05) but not with motor function on adrntssion. FA ratios in the group with good motor functional outcome were significantly higher than those in the group with poor motor functional outcome (P < 0.01). The ADC ratio did not correlate with motor function either on admission or at 3 months. All patients with an FA ratio greater than 0.8 had a good motor functional outcome. In three patients, however, motor functional outcomes were favorable even though FA ratios were not high; in these patients, ADC ratios tended to be elevated. CONCLUSION: Motor functional outcome in patients with infracerebral hemorrhage can be predicted by measuring FA values using diffusion tensor tractography.

Background:Misdiagnosis of spontaneous intracranial hypotension remains a problem, despite increasing recognition.Methods:Three patients with spontaneous intracranial hypotension presented with typical findings on lumbar puncture, magnetic resonance (MR) imaging, and radioisotope cisternography. All patients showed subdural effusions in the posterior fossa on axial T2-weighted MR imaging. Axial MR images of 112 patients with other conditions were also screened for this finding.Results:One of three patients had typical orthostatic headache, and the other two had continuous headache. The finding of subdural effusions in the posterior fossa on axial T2-weighted MR imaging disappeared after treatment. Similar findings were found in 14 of 112 patients with other conditions. Most of the patients were over 60 years old or had dementia or previous radiation therapy.Conclusion:Subdural effusions in the posterior fossa can be identified by T2-weighted axial MR imaging, and are useful for the diagnosis of spontaneous intracranial hypotension and for verifying the effectiveness of treatment.

Objective.—We investigated the value of the jugular compression test (JCT) in screening patients with chronic headache attributable to persistent cerebrospinal fluid (CSF) leakage. Methods.—Clinical records of 35 consecutive patients who underwent both 111In-diethylenetriamine pentaacetic acid radioisotope (RI) cisternography and JCT were retrospectively analyzed. Results.—A strong correlation was seen between JCT and RI cisternographic findings. Most patients who reported a feeling of fullness in the ear, hearing loss or headache during JCT had positive findings on RI cisternograms indicative of CSF leakage. In contrast, no RI study abnormalities were seen in patients reporting no symptoms in JCT. Conclusions.—Among patients complaining of refractory headache and other miscellaneous symptoms, JCT may represent a simple, economic, and reliable technique in the screening of candidates for RI cisternography to evaluate CSF leakage. A subgroup of patients with chronic headache may have persistent CSF leakage.

We describe a rare case where a patient developed intracranial pial arteriovenous (AV) fistula due to dural tenting. The patient was a 63-year-old woman who had undergone neck clipping for an unruptured middle cerebral artery (MCA) aneurysm. The surgery was performed without any problems and her postoperative course was uneventful. Two weeks after cerebral angiography operation revealed a pial AV fistula fed by the right MCA and drained into the vein of Trolard through the Sylvian vein which had not existed before surgery. Being diagnosed as de novo pial AV fistula, surgical repair was performed. The AV fistula was located just beneath the dural tenting. The fistulous point was confirmed with fluorescein video angiography and obliterated using a clip. Although rare, we should pay attention to the AV fistula due to dural tenting as the complications of cranial surgery.

As the indication for surgical treatment of incidentally discovered small aneurysms remains controversial.We retrospectively investigated the characteristics of small ruptured aneurysms and examined the relationship between the size and location of ruptured intracranial aneurysms and the sex, age, lifestyle, and medical history of 280 patients with ruptured aneurysm treated at our institute.The mean diameter of ruptured aneurysms in this series was 7.6 mm. In diameter, 135 (48.2%) ranged between 5 and 10 mm; 73 (26.1%) were smaller than 5 mm. The size of the ruptured aneurysms was significantly smaller (mean 6.5 mm) in patients with non- or poorly controlled hypertension than in normotensive patients (mean 8.3 mm) (p0.05). Ruptured aneurysms in the anterior communicating artery (AcomA) and anterior cerebral artery (ACA) were significantly smaller (p0.01) than those in the internal carotid artery or middle cerebral artery. Among 58 patients with multiple aneurysms, only 7 (12%) suffered rupture of aneurysms smaller than 5 mm (p0.01). Patients younger than 40 years and patients with a family history of subarachnoid hemorrhage appeared to predispose to the rupture of small-sized aneurysms, although those did not affect the statistical significance.This study shows that even aneurysms smaller than 10 mm may rupture. However, treatment decisions for unruptured aneurysm should not be based solely on the size of the unruptured aneurysms. Our data implies that even small aneurysms in the AcomA and ACA had an increased tendency for rupture, and that hypertensive patients were at higher risk for the rupture of small aneurysms.

The optimum management for elderly patients with aneurysmal subarachnoid hemorrhage (SAH) remains controversial. The surgical indications for aneurysmal SAH in elderly patients were investigated. Materials and methods: This study retrospectively reviewed 148 elderly patients over 70 years old among 1019 patients surgically treated for SAH. The patients were divided into three groups: group A, 93 patients aged 70–74 years; group B, 33 patients aged 75–79 years; and group C, 22 patients aged over 80 years. The outcomes were evaluated using the Glasgow Outcome Scale, with good recovery and moderate disability considered as favorable. The surgical outcome was analyzed compared with the preoperative Hunt and Kosnik grade, location of the aneurysm and causes of complication. Results: A favorable outcome for patients in preoperative Hunt and Kosnik grades I and II was achieved in 84.8% of group A, 63.8% of group B and 57.1% of group C, and for patients in grades III–V, 40.4% of group A, 15.4% of group B and 12.5% of group C. The rate of favorable outcome decreased with age and worse preoperative clinical grade. In patients remaining conscious before operation, the differences in recovery rates were not statistically significant by advancing age. For those patients with disturbance of consciousness, however, the recovery rate was significantly worse in groups B and C as compared with group A. The causes of poor outcome were primary brain damage, vasospasm and muscle weakness due to extended bed rest. In addition, more than half of the patients in a severely disabled or vegetative state at the time of discharge resulted in death within 5 years. Conclusion: Surgery should be considered for elderly patients with aneurysmal SAH leading a normal life before onset and without severe systemic disease, even in those over 80 years, but not in patients with disturbance of consciousness due to primary brain damage.

The dimensions of the 10 triangles around the cavernous sinus were measured to define the anatomical characteristics of the triangles and to compare their consistency in shape and area. Twelve tissue blocks containing the bilateral cavernous sinuses and medial two-thirds of the middle cranial fossae were obtained from Japanese adults at autopsy, fixed to a stereotactic frame, and examined with an operative microscope. The dimensions of each triangle were measured with calipers and compared, based on the same point and border. The anteromedial triangle and the superolateral (Parkinson's) triangle were more consistent in shape than the paramedial and oculomotor triangles, but the oculomotor triangle was larger in area than these other triangles. The posteromedial (Kawase's) triangle was more consistent in shape and larger than the anterolateral, lateral, and the posterolateral (Glasscock's) triangles. The anteromedial and superolateral (Parkinson's) triangles are important for the combined epi- and subdural approach to cavernous sinus lesions. The posteromedial (Kawase's) triangle is important for gaining access to the posterior cranial fossa from the middle cranial fossa.

Object. In this study the authors investigated the relationship between variations in the circle of Willis observed on magnetic resonance (MR) angiograms and locations of cerebral aneurysms, and evaluated the risk of aneurysm formation. Methods. One hundred thirty-one patients with cerebral aneurysms were retrospectively selected from a series of 4518 patients who underwent MR angiography at one neurosurgical institute. Variations in the anatomy of the circle of Willis were simply classified into Type A, in which there was no visualization of a unilateral A1 segment, and Type P, in which there was a fetal type of posterior cerebral artery that was continuously delineated from the internal carotid artery (ICA) through the posterior communicating artery. All other variations in the circle of Willis were defined as Type O (ordinary type of variations). An additional 440 patients who did not harbor cerebral aneurysms were randomly selected for a comparison. Anterior communicating artery aneurysms were significantly related to the Type A anatomy and ICA aneurysms to Type P anatomy. Male patients who did not harbor aneurysms tended to have Type A anatomy, whereas women had a significantly greater incidence of Type P. Conclusions. This sex-linked difference in anatomical variations may be correlated to the well-known sex-linked difference in aneurysm distribution.

The natural history of cerebral aneurysms was investigated by measuring the prevalence of incidentally found unruptured aneurysms in the general population and evaluating the characteristics including risk factors. 'De novo' formation of aneurysm was also demographically estimated. The prevalence of incidental aneurysm was evaluated among 4518 patients who underwent magnetic resonance (MR) angiography for various reasons in a neurosurgical institute. Double the number of patients were randomly selected from the remaining patients without aneurysm as the Control group so that sex and age group were matched to the Aneurysm group. 127 patients (2.8%) had diagnoses of aneurysm. The prevalence of asymptomatic aneurysm among middle-aged and elderly patients was predominant in women and increased with age in both sexes. Patients with aneurysms had significantly more hypertension and family history of subarachnoid hemorrhage compared to the controls. The prevalence was markedly increased in the 8th decade in men and the 7th decade in women, and new aneurysms seemed to develop predominantly around these decades. Cerebral aneurysms become detectable on MR angiography in the middle or later decades, and women tend to develop aneurysm earlier than men. Hypertension and family history of subarachnoid hemorrhage are probably risk factors for the development of aneurysm.

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.

We investigated the prevalence and clinical significance of cerebral aneurysm cases that were associated with occlusion of the internal carotid artery (IC). We found 10 such patients (0.9%) among serial patients who were operated on by a senior neurosurgeon. All 3 cases with bilateral occlusion had aneurysms in the P1P2 junction. Cases with unilateral occlusion had a total of 10 aneurysms; 4 in the contralateral A1A2 junction, 3 in the basilar artery or P1P2 junction, 2 in the contralateral IC and 1 in the ipsilateral IC. Four of 11 patients (36%) with P1P2 junction aneurysm were combined with carotid artery occlusion. These findings strongly suggest that hemodynamic stress plays an important role in formation of those aneurysms. Though surgical outcome of those patients did not statistically differ from other patients without IC occlusion, hemodynamic compromise should be considered in treatment of such patients. Furthermore, in patients with occlusion of the major cerebral artery, incidental aneurysm should be taken into account.

The clinical factors affecting the outcome of patients with ruptured distal anterior cerebral artery (ACA) aneurysms were analyzed using multiple logistic regression analysis. The medical records were reviewed of 52 patients (57 aneurysms) with ruptured distal ACA aneurysms operated on by the same neurosurgeon over 25 years. The standard policy was early surgery for patients in Hunt and Kosnik grades I to IV. Age, sex, Hunt and Kosnik grade, timing of operation, size of aneurysms, number of aneurysms, association of intracerebral haemorrhage (ICH), intraventricular haemorrhage, and azygos ACA, use of temporary clipping, occurrence of premature rupture, and presence of psychiatric change were investigated. Univariant analysis disclosed that clinical grade (P = 0.0006), size of aneurysm (P = 0.005), and size of ICH (P = 0.012) affected the outcome of patients. Multiple logistic regression analysis found that Hunt and Kosnik grade (P = 0.010) and timing of operation (P = 0.033) affected the outcome. There was no significant relationship between long-term outcome and clinical factors, although a close relationship was found with Hunt and Kosnik grade (P = 0.071). Clinical grade and timing of the operation affected the outcome of patients with ruptured distal ACA aneurysms. Patients harboring ICH of over 3 cm diameter in poor grades should also be carefully treated.

The aim of this study is to investigate the usefulness and problems with spinal motor evoked potential (MEP) recording, especially the reasons for failed recording. We report our personal experience over the last 8 years in patients with lesions adjacent to the primary motor cortex.MEP records of 50 consecutive patients were retrospectively reviewed. MEP was recorded by a catheter electrode inserted in the cervical epidural space. Stimulation electrodes were placed on the cortical surface during surgery. SEP recording was also performed in 29 of 50 patients.MEP was obtained in 40 cases, and SEP was recorded in all 29 cases. The central sulcus was identified in 93% of patients in whom both MEP and SEP were performed, whereas in only 86% of patients who underwent only MEP. The main reason for MEP failure were inadequate exposure of the motor cortex, pre-existing hemiparesis and technical errors. Postoperative deterioration of motor function was closely related to intra-operative MEP changes.MEP is a useful tool to determine the motor cortex and to predict postoperative motor function. However, precise pre-operative craniotomy planning and combination with intra-operative SEP is essential to reduce the MEP failure.

OBJECTIVE: The goals of this study were to evaluate the relationship between postoperative oculomotor nerve palsy and other clinical factors and to improve preoperative estimations of the risk. Such an evaluation has not been previously described in the literature. METHODS: Patient records for 77 basilar tip aneurysm cases and 28 basilar superior cerebellar artery aneurysm cases treated between 1981 and 1997 were reviewed. Clinical and radiological parameters were separately analyzed using the X 2 test, and then multiple-regression analysis was used. RESULTS: Postoperative oculomotor palsy occurred in 25 (32%) patients with basilar tip aneurysms and 11 (39%) patients with basilar superior cerebellar artery aneurysms, in addition to 2 patients with basilar tip aneurysms and 3 patients with basilar superior cerebellar artery aneurysms who exhibited oculomotor palsy before surgery. For both type of aneurysms, the size and direction of the aneurysms were closely related to oculomotor nerve palsy. The complication also tended to occur in early surgery cases, in younger patients, and in patients of poor-clinical grade status. CONCLUSION: In this study, some clinical and radiological factors were found to be associated with postoperative oculomotor nerve palsy.

A 26-year-old female pianist suffered from an intracerebral hematoma caused by an arteriovenous malformation of the left occipital parasplenial region, which was operated on seven months after the onset. Incomplete right hemianopsia, mild pure alexia, partially disturbed naming of visual objects persisted several months after the removal of the malformation. Evaluation of musical ability one and three months after surgery showed that her auditory recognition of music was intact. She could sing and play melodies already learned and could dictate well the notes after hearing tones. However, she had difficulty in reading music, especially the pitch of notes, even for simple sequences of 4 notes. In contrast, her rhythm reading was fairly good. Her visual recognition of other symbolic figures like road signs was also markedly impaired. These results suggest that her visual recognition of written music as well as of other symbolic figures underwent a preliminary verbal decoding in the left hemisphere and that pitch reading was more dependent on verbal processing than rhythm reading.

We describe a case of arteriovenous fistula (AVF) successfully treated by coil embolization with an anchor coil inserted in the varix to facilitate dense packing at the shunting site. AVF of the left anterior choroidal artery (AChoA) draining into the ipsilateral basal vein of Rosenthal was incidentally found in a newborn female. A single detachable coil was inserted as an anchor into the varix adjacent to the shunt, and the microcatheter was pulled back to the shunting point. Three more detachable coils were delivered at the shunting point without migration under the support of the anchor coil, and the AVF was successfully obliterated with preservation of AChoA blood flow. The anchor coil technique can reduce the risk of coil migration and the number of coils required.

Background To visualize blood flow in the arteries and aneurysm during surgery, intravenous fluorescence videoangiography has been used. However, the image contrast with this procedure is diminished by repeated study because the dye remains for about 10 minutes after injection. Objective To determine the optimal dye concentration and to clarify the usefulness of fluorescein videoangiography by intra-arterial dye injection. Methods In the pilot study, fluorescein sodium dissolved at various concentrations was illuminated with excitation light, and fluorescence was detected by cameras. The fluorescence of 0.001% fluorescein sodium solution mixed with plasma at various concentrations was then examined. In 13 aneurysm patients, dye solution was administered through the catheter for intraoperative digital subtraction angiography. The intravenous injection method was also performed, and the findings were compared. Results Dye was clinically used at a concentration of 0.005% to 0.1% on the basis of the results of the pilot study. Fluorescence emission from the vessels and aneurysms was clearly observed by both methods; however, arterial injection provided brighter emission, resulting in clearer demonstration of the bloodstream than venous injection. Dye clearance was also quicker, which allowed repeat injections without delay. Dye filling in the aneurysm indicating incomplete occlusion was detected in 2 cases, and occlusion of the perforating artery was observed in 2 cases. Conclusion Intra-arterial fluorescein videoangiography provides brighter and clearer imaging of blood flow with a smaller dose of dye than intravenous videoangiography. It can be repeated within a short time and is useful for detecting incomplete clipping or unexpected obstruction of arteries.

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.

Multiple arterial dissections in the anterior circulation with simultaneous onset are extremely rare. We report a patient with infarctions caused by simultaneous arterial dissections in the right anterior cerebral artery and the left middle cerebral artery and discuss the characteristic feature of this vascular disorder. A 53-year-old woman presented with a severe headache and a mild aphasia. Magnetic resonance imaging revealed multiple acute cerebral infarctions in the left temporal and right frontal lobes. The initial angiographic findings revealed arterial dissections of the anterior cerebral, left middle cerebral, and right vertebral arteries. The follow-up angiographic examination found improvement of the stenosis in both the anterior cerebral and middle cerebral arteries. We have concluded that the lesion of the vertebral artery was not in an acute stage, because no interval change was seen during the radiologic evaluation. She underwent conservative therapy, and her symptoms disappeared. Multiple arterial dissections are rare, especially those developing simultaneously in different arteries. This is the first case of multiple arterial dissections of the different arteries in the anterior circulation manifesting cerebral infarction simultaneously.

In this report, a rare case of dysembryoplastic neuroepithelial tumor (DNET) initially presented as a small white matter lesion with calcification adjacent to the lateral ventricle and extending to the frontal cortex after 7 years. This 1-year-old boy initially suffered from partial seizures. Initial CT revealed a small, low-density area surrounding a tiny calcified mass in the deep white matter of the left frontal lobe. Seven years later, his seizures had become intractable to antiepileptic agents, and MR imaging demonstrated a relatively large mass extending from the calcified lesion up to the adjacent cortical surface. He underwent surgery and the tumor was subtotally removed. Histological examination of the tumor verified it as a DNET consisting of clusters of small oligodendrocytes with floating neurons in the mucoid background. The pattern of the tumor progression in this case suggests that a DNET in the cortex originates from the subependymal germinal layer near the ventricle.

This 11-year-old boy presented with a rare case of Castleman syndrome caused by a clear cell meningioma manifesting as persistent fever of unknown origin, 2 years after glomerulonephritis. Laboratory investigation of the patient showed an increased inflammatory reaction, as well as elevated polyclonal gamma globulin titer and serum level of C-reactive protein. Magnetic resonance imaging revealed a tumor at the cerebellopontine angle. Neurosurgical intervention was performed under the presumptive diagnosis of Castleman syndrome caused by intracranial tumor. Histological examination of the tumor verified that it was clear cell meningioma with infiltration of lymphoplasma cells, and surgical removal resulted in complete resolution of the patient's symptoms and biochemical abnormalities. The present case of clear cell meningioma manifesting as Castleman syndrome shows that the possibility of a brain tumor should be considered in patients presenting with fever of unknown origin, anemia, hypergammaglobulinemia, or other systemic illness.

We aimed to study tracer kinetics in radioisotope (RI) cisternography. For this purpose, we analyzed the RI images of 36 individuals in whom absence of cerebrospinal fluid (CSF) leakage was confirmed. For the semiquantitative assessment of tracer clearance, the geometric mean of the RI count in the anterior and posterior images was obtained for the entire head as well as for the whole spinal axis. After correcting for the radioactive decay of the tracer, tracer clearance was expressed as a ratio of the count in the range of the whole CSF space at different time points to that at the time of tracer delivery. Tracer clearance from the CSF space was not related to the degree of cranial transport of the tracer in 1 hour, but was significantly related with the age of the patients. At 24 hours after the injection, tracer clearance was significantly faster in the younger patients (Group I: age40 years) than in the older patients (Group II: ageor = 40 years). The cranial transport of the tracer appeared to be rapid in group I; however, the difference between these 2 groups was not significant. These results indicate that age should be taken in account while establishing the reference values for tracer kinetics in normal individuals.

A fifty-year-old man who had a history of minor head injury a month previously presented with headache, visual disturbance and papilloedema. Brain MR imaging showed bilateral subdural effusion and fat saturated orbital MR imaging demonstrated dilated subarachnoid space around the optic nerve. The diameter of the subarachnoid space behind the globe was 7.0 mm and that of the optic nerve was 3.5 mm. Bilateral simple drainage was performed to prevent deterioration of the visual disturbance. Light bloody fluid with a subdural pressure of 10.5 cmH2O was drained from the burr hole at the left side, and colorless fluid was drained from the right. Orbital MR imaging during continuous drainage revealed shrinkage of the subarachnoid space around the optic nerve. However, follow-up MR imaging 5 months after drainage showed disappearance of the subdural effusion and the reappearance of the subarachnoid space around the optic nerve, even though the size was smaller than before surgery. These findings suggest that the diameter of the optic subarachnoid space co-relates with the intracranial pressure, and may be an indication for increased intracranial pressure.

Object The subarachnoid space around the optic nerve in the orbit can be visualized using T2-weighted MR imaging with the fat-saturation pulse sequence. The optic nerve sheath (ONS) diameter can be estimated by measuring the outer diameter of the subarachnoid space. Dilated ONS is associated with idiopathic intracranial hypertension and hydrocephalus, and is believed to reflect increased intracranial pressure (ICP). The relationship between dilated ONS and ICP is unclear because of the difficulty in obtaining noninvasive measurements of ICP. The authors investigated the relationship between subdural pressure measured at the time of surgery and ONS diameter measured on MR images in patients with chronic subdural fluid collection. Methods Twelve patients underwent bur-hole craniostomy with continuous drainage for chronic subdural hematoma or hygroma in 2006. Orbital thin-slice fat-saturated MR images were obtained before and after surgery, and the ONS diameters were measured just behind the optic globe. Subdural pressure was measured using a manometer before opening of the dura mater. Results A significant correlation was found between the ONS diameter and the subdural pressure (correlation coefficient 0.879, p = 0.0036). The ONS diameter before surgery (6.1 ± 0.7 mm) was significantly reduced after surgery (4.8 ± 0.9 mm, p = 0.003; measurements are expressed as the mean ± standard deviation). Conclusions Increased ONS diameter measured on coronal orbital thin-slice fat-saturated T2-weighted MR images is a strong indicator of increased ICP, and helps to differentiate between passive subdural fluid collection due to brain atrophy and subdural hygroma with increased ICP.