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.

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.

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.

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.

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.

[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.

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.

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.

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.

Ruptured peripheral aneurysms in a collateral pathway associated with stenosis of a major cerebral artery: Report of two cases.

BACKGROUND: While hemodynamic stress can result in aneurysm formation, it rarely contributes to the development of peripheral aneurysms in collateral pathways. We report two patients with ruptured distal aneurysms in a collateral pathway associated with stenosis of a major cerebral artery. CASE DESCRIPTION: A 67-year-old man presented with intracerebral hemorrhage in the right frontal lobe. Digital subtraction angiography (DSA) revealed severe stenosis of the right middle cerebral artery and two aneurysms in the collateral pathway of the right anterior cerebral artery. The ruptured aneurysm was trapped and resected; histologically, it was a true saccular aneurysm. The unruptured aneurysm was clipped and the patient was discharged without additional neurological deficits. The second patient was a 73-year-old woman with subarachnoid hemorrhage. DSA revealed three arterial dilations. On the 7(th) day of hospitalization, one of the aneurysms in a posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomosis that functioned as a collateral pathway in the presence of severe basilar artery stenosis was found to be enlarged. It was treated by selective aneurysmal coil embolization with parent artery preservation. Her postoperative course was uneventful and she was discharged without any neurological deficits. CONCLUSION: We document the successful treatment of two patients with ruptured aneurysms in the peripheral portion of a collateral pathway. We discuss the histology of peripheral aneurysms and present a review of the literature.

[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.

Efficacy of middle meningeal artery embolization in the treatment of refractory chronic subdural hematoma.

BACKGROUND: There are no established treatment procedures for repeatedly recurring chronic subdural hematoma (CSH). In this study, we discussed the efficacy of middle meningeal artery (MMA) embolization in preventing recurrence of CSH. METHODS: We performed superselective angiography of MMA in four patients who suffered from repeated recurrence of CSH. After angiography, we performed embolization of MMA with endovascular procedure. RESULTS: In all cases, superselective angiography of MMA revealed diffuse abnormal vascular stains that seemed to represent the macrocapillaries in the outer membrane of CSH. In all the patients, there were no recurrences or enlargements of CSH after the embolization of the MMA. CONCLUSION: MMA embolization can be an effective adjuvant procedure in preventing the recurrence of CSH.

Serial angiography of dynamic changes of traumatic middle meningeal arteriovenous fistula: case report.

A 48-year-old woman suffered head trauma and presented with an acute epidural hematoma with a linear fracture of the right temporal bone across the middle meningeal groove. Initial angiography demonstrated no vascular abnormalities. Eight months later, she again suffered head trauma and computed tomography demonstrated traumatic subarachnoid hemorrhage. Right external carotid angiography revealed a middle meningeal arteriovenous fistula (AVF) which drained into the superficial sylvian veins via the sphenoparietal sinus. Serial angiography showed progressive dilation of the draining veins, but she refused surgical intervention and dropped out of our outpatient clinic. Fifteen years after the first head trauma, she presented with subarachnoid hemorrhage. Angiography demonstrated formation of venous aneurysms on the drainer of the AVF. The dilated superficial sylvian vein was removed together with the ruptured venous aneurysm. Histological examination of the drainer revealed an arterialized vein. The serial angiographic evaluations revealed dynamic changes of the traumatic middle meningeal AVF, including progressive dilation of the drainers, simplification of the drainage routes, and the formation of venous aneurysms, which presumably represents the entire natural course of traumatic middle meningeal AVF manifesting as hemorrhage. The present case of traumatic middle meningeal AVF with a deteriorating course suggests that surgical removal or embolization of the AVF is strongly indicated if follow-up angiography shows dilation of the drainers, which implies increased shunt flow.

[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.

Multiple isolated sinus dural arteriovenous fistulas associated with antithrombin III deficiency--case report--.

A 55-year-old man presented with a rare case of multiple isolated sinus dural arteriovenous fistulas (AVFs) associated with antithrombin (AT) III deficiency manifesting as sudden onset of headache and gait disturbance. Increased arterial shunting flow had caused intraventricular hemorrhage after incomplete repeated transarterial embolization procedures for dural AVFs. Multiple isolated sinus dural AVFs were located in the anterior superior sagittal sinus (SSS) and transverse sinus, which were completely embolized by direct packing of the isolated sinuses via the SSS. The development of dural AVF is complicated and associated with a number of factors, such as congenital abnormality, head trauma, craniotomy, radiation, hematological abnormality, and sinus thrombosis. Hematological abnormality is a risk factor of sinus thrombosis. In the present case, the multiple isolated sinus dural AVFs might have resulted from the aggravation of multiple dural AVFs and the coagulative tendency due to AT III deficiency. Direct sinus packing should be considered if transvenous catheterization is difficult or fails.

[A case of direct carotid cavernous fistula, whom three-dimensional computed tomographic angiography was helpful for decision making of selective coil embolization].

We reported the case of an 84-year-old female suffering from chemosis and exophthalmos. Carotid arteriograms revealed a direct carotid-cavernous fistula (CCF) but could not clearly show the fistula point because of its high-flow nature. We then performed three-dimensional computed tomographic angiography (3D-CTA) using a multi detector-row CT (MDCT) scanner. Multi-planar reformatted CT images distinctly revealed a right carotid aneurysm at the cavernous portion and a shunting point between the aneurysm and the cavernous sinus. Based on this information, we opted to performa transvenous coil embolization to treat this patient. Successful selective coil embolization was performed at the fistulous point was done with a smaller number of coils than ordinarily required in sinus packing. Performing 3D-CTA by using a MDCT was helpful in decision making for the selective coil embolization to treat direct CCF.

[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.