High-signal venous sinuses on MR angiography: discrimination between reversal of venous flow and arteriovenous shunting using arterial spin labeling.

PURPOSE: It is sometimes difficult to differentiate between high signals originating from a reverse flow on magnetic resonance angiography (MRA) and occult arteriovenous shunting. We attempted to determine whether arterial spin labeling (ASL) can be used to discriminate reversal of venous flow from arteriovenous shunting for high-signal venous sinuses on MR angiography. METHODS: Two radiologists evaluated the signals of the venous sinus on MRA and ASL obtained from 364 cases without arteriovenous shunting. In addition, the findings on MRA were compared with those on ASL in an additional 13 patients who had dural arteriovenous fistula (DAVF). RESULTS: In the 364 cases (728 sides) without arteriovenous shunting, a high signal due to reverse flow in the cavernous sinuses (CS) was observed on 99 sides (13.6%) on MRA and none on ASL. Of these cases, a high signal in the sigmoid sinus, transverse sinus, and internal jugular vein was seen on 3, 3, and 8 sides, respectively. All of these venous sinuses showed a high signal from the reverse flow on MRA images. CONCLUSION: ASL is a simple and useful MR imaging sequence for differentiating between reversal of venous flow and CS DAVF. In the sigmoid and transverse sinus, ASL showed false-positives due to the reverse flow from the jugular vein, which may be a limitation of which radiologists should be aware.

Subarachnoid Hemorrhage Caused by Ruptured Aneurysm of the Artery of Adamkiewicz: a Case Report.

A 66-year-old man presented with a 6-day history of progressive posterior cervical pain that included lower back pain and fever. Neurological examinations revealed neck stiffness. Computed tomography demonstrated convexity subarachnoid hemorrhage. A spinal T2-weighted image revealed a hypointense signal lesion with contrast enhancement of the intradural extramedullary space at Th12-L1. Digital subtraction angiography showed a fusiform aneurysm with a 10 mm diameter in the artery of Adamkiewicz. We diagnosed the patient's condition as a ruptured aneurysm of the artery of Adamkiewicz. By day 41 the aneurysm had disappeared following conservative treatment. Aneurysms arising from the artery of Adamkiewicz are extremely rare and can cause both convexity and spinal subarachnoid hemorrhages. Clinicians should therefore look for spinal lesions if patients with convexity subarachnoid hemorrhage of an unknown origin have lower back pain as their initial symptom.

Hypoglossal Nerve Palsy due to Compression by a Persistent Primitive Hypoglossal Artery: Case Report.

A 51-year-old Japanese woman was admitted to our hospital because of speech difficulty following severe headache. Neurological examination showed dysarthria and tongue weakness on the right side, indicating right hypoglossal nerve palsy. Needle electromyography of the right side of the tongue showed fibrillation potentials. Magnetic resonance angiography and computed tomography angiography revealed a right, persistent, primitive hypoglossal artery (PPHA) that met Lie's diagnostic criteria. Digital subtraction angiography showed an extended PPHA with irregular caliber in the portion running through the right hypoglossal canal. We diagnosed compression neuropathy of the hypoglossal nerve due to PPHA enlargement based on the findings of ipsilateral hypoglossal nerve palsy, fibrillation that indicated peripheral nerve palsy, and the enlarged diameter of the portion of the PPHA running through the right hypoglossal canal. We prescribed antihypertensive therapy. At 1 year after onset, her tongue weakness was alleviated. Clinicians should consider compression neuropathy due to a PPHA as one of the possibilities in the differential diagnosis of hypoglossal nerve palsy.

Effectiveness of intraarterial administration of fasudil hydrochloride for preventing symptomatic vasospasm after subarachnoid hemorrhage.

OBJECTIVE: We examined the effect of intraarterial administration of fasudil hydrochloride (IAFC), a Rho kinase inhibitor, for the prevention of symptomatic vasospasm after SAH by evaluating cerebral circulation. METHODS: We evaluated IAFC cases of 57 sides of 38 patients (12 men and 26 women, average age 60.2 years old) diagnosed with aneurysmal subarachnoid hemorrhage (SAH) from February 2012 to November 2012. All cases were treated by clipping or coil embolization within 48 h after onset. Indication for IAFC was the existence of a spastic change on follow-up digital subtraction angiography (DSA) compared with that of onset. RESULTS: Clipping was performed in 30 cases and coil embolization in 8 cases. IAFC was performed an average of 6.6 days after onset. Color gradient mapping demonstrated reduction of the circulation time after IAFC compared with before IAFC on 39 sides, no change on 15 sides, and extension on 3 sides. Average arterial circulation time before IAFC was 2.25 ± 0.57 s and after IAFC was 1.95 ± 0.55 s. IAFC significantly shortened average arterial circulation (P = 0.005). No case developed symptomatic vasospasm after IAFC. CONCLUSION: IAFC significantly reduced the cerebral circulation time after aneurysmal SAH and might be effective for the prevention of symptomatic vasospasm.

Symptomatic vasospasm in elderly patients with aneurysmal subarachnoid hemorrhage: comparison with nonelderly patients.

OBJECTIVE: To clarify the influence of age on the occurrence of symptomatic vasospasm (SVS), we retrospectively compared 34 elderly (over 70 years) and 71 nonelderly patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: Between 2008 and 2010, at our hospital 105 patients (Hunt and Kosnik grades I-IV) underwent aneurysm surgery within 72 h of the insult. They were divided into four groups based on their age (younger/older than 70 years) and treatment (aneurysmal clipping or coiling). In all patients, we used the same protocol, which included the delivery of intrathecal urokinase and intravenous fasudil chloride; in patients with angiographic evidence of vasospasm, we also injected fasudil chloride intra-arterially. RESULTS: Among the elderly patients, 4.3% of those treated by clipping and 9.1% of those treated by coiling experienced SVS; the comparative incidence in younger patients was 6.5% and 4.0%, respectively. The differences were not statistically significant (p = 0.40). The ratio of ventriculo peritoneal (VP) shunts was higher in the elderly patients (p = 0.00007). The incidence of favorable treatment outcomes was significantly lower in elderly patients (p = 0.00004). CONCLUSION: Under our treatment protocol, patient age did not affect the incidence of SVS. Our protocol may be effective for the prevention of SVS after aneurysmal SAH regardless of patient age.

[An operated case of a meningioma causing acute subdural hematoma].

We report a rare case of a meningioma causing acute hematoma. A 67-year-old woman presented with sudden headache. No evidence of trauma was seen. CT demonstrated a subdural hematoma in the convexity of the fronto-temporal lobe. Magnetic resonance imaging showed marked signal heterogeneity in the convexity of the frontal lobe. One week later, the patient underwent hematoma evacuation and tumor resection including the attached dura mater. The histological diagnosis was meningothelial meningioma. The clot was connected directly to the tumor and the origin of the subdural hematoma was identified as the meningioma. Postoperative course was uneventful, and the headache improved. Meningiomas have a relatively benign course but rarely present with hemorrhage. Surgical exploration is the effective and recommended treatment.

Fatal subarachnoid hemorrhage caused by Aspergillus arteritis without angiographic abnormalities.

No source of bleeding is detected by angiogram in 15-20% of patients with nonaneurysmal subarachnoid hemorrhage (SAH). This negative angiographic finding might suggest a benign prognosis. We describe a case of fatal SAH caused by Aspergillus arteritis without formation of fusiform dilatation or aneurysms. A 76-year-old man with a 2-month history of progressive visual loss due to pachymeningitis around the optic nerves suffered from SAH in the bilateral sylvian fissures. Repetitive serum galactomannan assay and angiography showed no abnormality. Post mortem examination revealed marked proliferation of Aspergillus in the granulomas of the frontal base dura mater. In addition, major trunks and several branches of the bilateral middle cerebral arteries were invaded by Aspergillus hyphae, which destroyed the walls in the absence of dilatation and aneurysms. Invasive aspergillosis of the CNS often forms a mycotic aneurysm. However, four autopsy cases of nonaneurysmal SAH due to invasive aspergillosis have been reported. The present case is the second autopsy case of Aspergillus arteritis without angiographic abnormality, resulting in fatal SAH. Aggressive and continuous antifungal therapy is absolutely necessary in suspected cases of invasive aspergillosis of the CNS, even if angiography is negative and therapeutic markers of aspergillosis are normal.

[Flow dynamics analysis in patients with a ruptured middle cerebral artery aneurysm. A case report].

Despite advancement of diagnostic and treatment modalities, subarachnoid hemorrhage (SAH) is still an entity of neurosurgical emergency with poor outcome. Recent reports indicated that hemodynamic stress might play an important role in rupture or the growth of cerebral aneurysms, but there is no consensus about how or which hemodynamic factor contribute to this phenomenon. In this report, magnetic resonance (MR)-based flow dynamics analysis was performed for a patient with SAH and the data obtained were directly compared with intraoperative findings. This 74-year-old woman was admitted for sudden onset headache. Head computed tomography scan showed SAH on the right sylvian fissure and intracerebral hematoma on the right temporal tip. Digital subtraction angiography showed a right middle cerebral artery aneurysm, which was considered to be the ruptured one. The aneurysm had two blebs, and the bleb around the aneurysm tip was exposed to low magnitude and high oscillation of wall shear stress (WSS). On the other hand, another bleb was exposed to high magnitude and low oscillation of WSS. Next day, the patient underwent open surgery and intraoperative findings showed the aneurysm tip was the ruptured point. MR-based flow dynamics analysis might be a useful diagnostic modality for patients with SAH. Although low magnitude and high oscillation of WSS might contribute to the aneurysm rupture, further case accumulation is necessary to reach a conclusion whether or not this is so.

Arterial Spin Labeling Was Useful for Evaluating the Treatment Response of a Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: A Case Report.

Objective: We report the case of a patient in whom arterial spin labeling (ASL) was useful for assessing the effects of treatment for a transverse-sigmoid sinus dural arteriovenous fistula (TSS-dAVF). Case Presentation: The patient was a 65-year-old man. Cerebral angiography demonstrated an aggressive dAVF involving the TSS, superior sagittal sinus (SSS), and the sinus confluence, with severe cortical and deep venous reflux. We performed multiple transarterial and transvenous embolizations for the TSS and sinus confluence lesion. The shunt disappeared almost completely after embolization. A high signal intensity that had been apparent in the SSS and straight sinus (StS) on ASL imaging before embolization disappeared after embolization. ASL imaging 3 months after embolization revealed slightly a high signal intensity in the StS, which was considered to be due to recurrence of the lesion. Moreover, recurrence of the confluence and TSS-dAVF was observed on cerebral angiography 6 months after embolization. As additional embolization was considered difficult, radiation therapy was recommended, but the patient refused; therefore, follow-up was performed. As ASL imaging findings were consistent with cerebral angiography findings, careful examination and monitoring of changes on ASL imaging were subsequently performed. Conclusion: Follow-up using ASL imaging is useful to assess the effects of treatment performed for a dAVF.

[Choice of intentional partial coiling for a ruptured intracranial aneurysm in the acute stage followed by clipping in the chronic stage].

The inpact of the International Subarachnoid Aneurysm Trial (ISAT) trial publication in 2002 and major technical advances in neuroimaging, endovascular devices and techniques have resulted in increasing numbers of patients with ruptured aneurysms undergoing endovascular coiling, as first-line treatment for aneurysm occlusion. We treated six cases of ruptured aneurysms with this strategy, with choice of clipping as as additional treatment following intentional partial coiling. In this series, patients ranged in age from 36 to 74 years and included one man and five women. Three aneurysms were located in AcomA, 1 in ACA, and 2 in MCA. The reasons for the choice of this strategy were clinical and angiographical spasm in 2, high general surgical risk in 2, and other reasons in 2 cases, respectively. The mean interval between the first partial coiling and final clipping was 33 days. All cases were successfully clipped without difficulties and coil removal were performed in 3 cases for follow up examination. It is proposed that the choice of this strategy contributes to progresses in overall outcomes in cases of aneurysmal subarachnoid hemorrhage.

Arterial Spin Labeling Imaging of a Giant Aneurysm Leading to Subarachnoid Hemorrhage following Cerebral Infarction.

An 83-year-old Japanese man was admitted with dysarthria and right hemiparesis. He had had a large intracranial aneurysm on the left internal carotid artery 5 years before admission and had been followed up under conservative treatment. On admission, diffusion-weighted imaging revealed a hyperintense signal on the left anterior choroidal artery territory. Time-of-flight magnetic resonance angiography demonstrated poor visibility of the middle and anterior cerebral arteries and the inferior giant aneurysm, suggesting distal emboli from aneurysm thrombosis or a reduction of blood outflow due to aneurysm thrombosis. Arterial spin labeling (ASL) signal increased in the giant aneurysm, suggesting blood stagnation within the aneurysmal sac, and decreased in the left hemisphere. We diagnosed cerebral infarction due to aneurysm thrombosis, and started antithrombotic therapy. On day 2, he suddenly died of subarachnoid hemorrhage due to rupturing of the giant aneurysm. When thrombosis occurs in a giant aneurysm, increasing ASL signal within the aneurysm and decreasing ASL signal with poor visibility on magnetic resonance angiography in the same arterial territory may indicate the danger of impending rupture of the giant aneurysm.

[Intracranial osteolytic hemangiopericytoma manifesting as a rapidly enlarging extracranial soft tissue mass lesion].

Hemangiopericytoma is a highly vascular and rapidly growing tumor, which tends to recur at distant locations. Complete surgical resection is often difficult because of intraoperative excessive hemorrhage or brain swelling. A 31-year-old male presented with intracranial osteolytic hemangiopericytoma manifesting as a rapidly enlarging extracranial soft tissue mass lesion causing a subcutaneous mass in the forehead. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated a lesion in the frontal lobe. Careful follow up was performed because the patient suffered no neurological deficits. The subcutaneous mass rapidly enlarged for 6 months. CT and MR imaging showed an osteolytic intracalvarial lesion with an extradural soft tissue component. Angiography demonstrated obstruction of the superior sagittal sinus and dense tumor staining with slow circulation and venous drainage. Gross total surgical resection was performed following endovascular embolization of the feeding arteries. Histological examination demonstrated an hemangiopericytoma. Although rare, hemangiopericytoma should be included in the differential diagnosis of rapidly enlarging subcutaneous mass. Preoperative endovascular treatment may allow less invasive surgery.

Fatal rupture following intra-aneurysmal embolization for the distal posterior inferior cerebellar artery aneurysm with parent artery preservation.

This 70-year-old female was admitted to our hospital 1 day after a sudden consciousness disturbance. Computed tomography (CT) showed subarachnoid hemorrhage (SAH), and angiogram revealed an irregular-shaped aneurysm at the lateral medullary segment of the left posterior inferior cerebellar artery (PICA). The patient was treated by intra-aneurysmal embolization with Guglielmi detachable coil (GDC) with parent artery preservation. Post-operative angiogram showed obliteration of the aneurysm except for the neck remnant, but she presented with rerupture 19 days after the onset and died 3 days later. Postmortem examination revealed massive hematoma around the aneurysm, which compressed medulla oblongata from behind. Histological assessment showed the 'entry' where the aneurysmal wall lacked internal elastic lamina, providing evidence of dissecting aneurysm. The present case suggests that embolization of distal PICA aneurysm with parent artery preservation should be avoided because radiological evaluation may fail to rule out the possibility of dissection, where the aneurysmal wall is affected not only at the 'entry' but also in the adjacent region.

Vertebrobasilar artery dissection presenting with simultaneous subarachnoid hemorrhage and brain stem infarction: case report.

BACKGROUND: Intracranial dissecting aneurysms have been associated with subarachnoid hemorrhage (SAH) or cerebral ischemia. We encountered a patient presenting with simultaneous subarachnoid hemorrhage and brainstem infarction caused by a dissecting aneurysm of the vertebrobasilar artery, which was diagnosed by magnetic resonance imaging (MRI) but did not show abnormal findings on cerebral angiography. CASE DESCRIPTION: A 55-year-old man had sudden onset of headache and left abducens palsy. Computed tomography revealed a subarachnoid hemorrhage localized in the left prepontine cistern and the left cerebellomedullary fissure. Cerebral angiography showed neither a saccular aneurysm nor fusiform dilatation causing the subarachnoid hemorrhage. MRI demonstrated a small infarction in the left dorsal pons, and an intramural hematoma of the left vertebral artery and lower basilar artery. CONCLUSION: This is a rare case of a vertebrobasilar dissecting aneurysm that simultaneously caused both SAH and brain stem infarction. MRI should be performed in the acute phase of SAH of unknown origin to determine the possible coexistence of a dissecting aneurysm, as occurred in this case.

Posterior encephalopathy subsequent to cyclosporin A presenting as irreversible abulia.

A case of cyclosporin A (Cys A)-induced posterior encephalopathy developed into persistent abulia despite rapid and marked improvement of abnormal T2- and FLAIR MRI hyperintense regions. Diffusion-weighted MRI signal intensity was also high at the onset. This change is atypical in Cys A-induced encephalopathy and was thought to predict poor recovery from the encephalopathy. Persistent abulia was probably due to marked hypoperfusion in the whole cortex including bilateral frontal lobes and basal ganglia as detected by SPECT. Apart from the breakdown of the blood-brain barrier, direct toxicity of Cys A to the brain may play a role in the pathogenesis of chronic, irreversible encephalopathy.

Optochiasmal arachnoiditis following cotton wrapping of anterior communicating artery aneurysm treated by surgical removal of granuloma.

We report the case of a 50 year old female who presented with visual disturbance due to optochiasmal arachnoiditis and foreign body granuloma 9 months after cotton wrapping for ruptured anterior communicating artery (AcomA) aneurysm. Magnetic resonance imaging (MRI) revealed enhanced mass lesion around AcomA complex and hyperintense signal on optic chiasm and right optic tract by fluid-attenuated inversion recovery image. Despite the repeated steroid pulse therapy, she deteriorated and MRI showed expansion of the granulomatous lesion over 5 months. Surgical removal of foreign body granuloma resulted in marked improvement of visual disturbance as well as of the MRI findings. We conclude that the use of cotton sheet close to the optic nerve should be avoided, and that surgical removal of the granuloma would be the optimal choice especially for the patient in whom steroid therapy fails to improve clinical symptoms.

[Endovascular treatment of a ruptured aneurysm associated with unilateral moyamoya disease].

We report a case presenting with subarachnoid hemorrhage due to a ruptured aneurysm associated with unilateral moyamoya disease. The patient was a 29-year-old woman exhibiting sudden onset headache. Computed tomography revealed subarachnoid hemorrhage around the brain stem. Cerebral angiography showed a saccular aneurysm at the junction of the left P1 portion of the posterior cerebral artery and its perforator. The right internal carotid artery was occluded at the terminal portion, and the right middle cerebral artery territory was perfused anterogradely via abnormal moyamoya vessels in the basal ganglia. The aneurysm was completely embolized with preservation of the perforator. We suggest that as compared to surgical clipping by craniotomy, endovascular therapy is safe and effective for treatment of intracranial aneurysms associated with moyamoya disease.

[A case presenting brain abscess with multiple infectious aneurysms].

We report a case presenting a brain abscess with multiple infectious aneurysms. A 59-year-old man was transferred to our hospital suffering from left hemiparesis. MRI demonstrated a huge mass in the right frontal lobe with marked brain edema in the surrounding area. Diffusion-weighted image revealed heterogenous intensity, which is not typical in cases of brain abscess. Surgical removal was planned, and preoperative angiography was performed. Angiography demonstrated aneurysms at the distal branch of both the right middle cerebral artery and the anterior cerebral artery. These aneurysms were surgically resected, and the abscess was totally removed. Postoperative course was uneventful. Left hemiparasis was resolved, and there was no ischemic lesion seen on postoperative MRI. In the treatment of brain abscess, stereotactic aspiration has recently been preferred to removal by craniotomy. We conclude that cerebral angiography might be necessary to evaluate cerebrovascular complications including infectious aneurysms, in cases presenting atypical findings in neuroimaging study.

Distinctive flow pattern of wall shear stress and oscillatory shear index: similarity and dissimilarity in ruptured and unruptured cerebral aneurysm blebs.

OBJECT: The difference in the hemodynamics of wall shear stress (WSS) and oscillatory shear index (OSI) between ruptured and unruptured aneurysms is not well understood. The authors investigated the hemodynamic similarities and dissimilarities in ruptured and thin-walled unruptured aneurysm blebs. METHODS: Magnetic resonance imaging-based fluid dynamics analysis was used to calculate WSS and OSI, and hemodynamic and intraoperative findings were compared. The authors also compared ruptured and unruptured thin-walled blebs for the magnitude of WSS and OSI. RESULTS: Intraoperatively, 13 ruptured and 139 thin-walled unruptured aneurysm blebs were identified. Twelve of the ruptured (92.3%) and 124 of the unruptured blebs (89.2%) manifested low WSS and high OSI. The degree of WSS was significantly lower in ruptured (0.49 ± 0.12 Pa) than in unruptured (0.64 ± 0.15 Pa; p < 0.01) blebs. CONCLUSIONS: Ruptured and unruptured blebs shared a distinctive pattern of low WSS and high OSI. The degree of WSS at the rupture site was significantly lower than in the unruptured thin-walled blebs.