Hypointensity of draining veins on susceptibility-weighted magnetic resonance images might indicate normal venous flow and a lower risk of intracerebral hemorrhage in patients with intracranial arteriovenous shunt(s).

Patients with intracranial arteriovenous shunt(s) have a risk of intracerebral hemorrhage (ICH). We investigated the signal intensity of draining veins on susceptibility-weighted imaging (SWI) and the status of venous drainage shown by digital subtraction angiography (DSA). We then evaluated whether the signal intensity of draining veins on SWI is related to normal venous flow (NVF) and/or ICH. We analyzed SWI and DSA in 10 consecutive patients with intracranial arteriovenous shunt(s). Opacification of draining veins in the normal venous phase by DSA was judged as NVF. We evaluated the relationship between the intensity of draining veins on SWI and the presence of NVF before and after treatment. The relationship between the intensity of draining veins on SWI and the presence of ICH surrounding the draining veins was also evaluated. Of 10 patients with untreated arteriovenous shunt(s), two had arteriovenous malformation and eight had a dural arteriovenous fistula with cortical venous reflux. We analyzed 26 draining veins before treatment. In preoperative analysis, draining veins with hypointensity were significantly more likely to show NVF than were draining veins with isointensity or hyperintensity (45.5% vs. 0.0%, P = 0.007). While 69.2% of the areas surrounding draining veins with isointensity or hyperintensity showed ICH, no veins with hypointensity showed ICH (P = 0.011, odds ratio 0.036; 95% confidence interval 0.0017-0.80). In conclusion, draining veins with hypointensity on SWI may contain NVF, despite arteriovenous shunting. The areas surrounding these veins might have a lower risk of ICH because of less venous hypertension.

Concurrent Ossification of the Posterior Atlantoaxial Interlaminar Membrane and Atlas Hypoplasia: A Case Report.

An onset of cervical myelopathy due to ossification of the posterior atlantoaxial membrane (PAAM) is extremely rare in older patients, and its clinical characteristics are still unclear. We report an onset of ossification of PAAM with congenital atlas hypoplasia in an 81-year-old man who presented with a 2-year history of progressive cervical myelopathy. Cervical computed tomography (CT) revealed canal stenosis secondary to a hypoplastic posterior arch of the atlas with a diameter of 20.3 mm between the anterior and posterior process. Magnetic resonance imaging showed marked spinal cord compression at the level of C1-2 secondary to atlas hypoplasia as well as ossification of PAAM. The patient underwent laminectomy of C1 and partial C2, as well as removal of the ossification, without atlantoaxial fusion. His neurological status improved 1 year postoperatively. In older patients, cervical myelopathy secondary to PAAM ossification, in the absence of trauma and atlantoaxial instability, may be induced by age-related pathophysiology associated with congenital atlas hypoplasia.

[Anomalous Origin of the Ophthalmic Artery from the Anterior Cerebral Artery Associated with the Paraclinoid Internal Carotid Artery Aneurysm].

The ophthalmic artery usually arises from the supraclinoid portion of the internal carotid artery. Here, we present an extremely rare case of abnormal origin of the ophthalmic artery from the anterior cerebral artery associated with the paraclinoid internal carotid artery aneurysm. As the embryology of the ophthalmic artery is complex, this case provides additional insight into the variation of the ophthalmic artery.

Traumatic Middle Meningeal Arteriovenous Fistula of Non-fractured Site Detected by Four-dimensional Computed Tomography Angiography: A Case Report.

Middle meningeal arteriovenous fistula (MMAVF) of a non-fractured site is extremely rare, and the clinical characteristics are still unclear. We report a case of delayed onset of venous infarction due to an MMAVF following a fall accident. A 69-year-old man sustained multiple trauma due to a fall accident. Head computed tomography (CT) showed traumatic subarachnoid hemorrhage, a left subdural hematoma, and skull fracture in his right temporal bone, all of which were managed conservatively. Five days after his admission, he suddenly exhibited total aphasia and right hemiparesis. Emergent CT revealed sporadic low-density areas in his left cerebral hemisphere, and four-dimensional CT angiography (4D-CTA) showed dilatation of the left middle meningeal artery and early venous drainage in the cavernous sinus and anterior temporal diploic vein (ATDV). A series of hemodynamics of 4D-CTA revealed early venous filling of ATDV interrelated with retrograde upward flow to high convexity in the venous phase. The MMAVF was successfully obliterated by transarterial coil embolization. We herein describe this case of MMAVF in which 4D-CTA was useful for the diagnosis.

Surgical Venous Drainage Disconnection from Cavernous Sinus Dural Arteriovenous Fistula and Ruptured Varix.

BACKGROUND: Cavernous sinus dural arteriovenous fistulas (CS dAVFs) occasionally behave aggressively (e.g., intracranial hemorrhage, venous infarction, seizures) depending on the drainage flow and presence of a collateral route of cortical or basal cerebral venous drainage. When a CS dAVF with aggressive behavior is encountered, a radical cure is required to avoid catastrophic deficits. However, conventional transvenous cavernous sinus (CS) embolization via the inferior petrosal sinus does not always achieve shunt obliteration. We herein report a case of surgical venous drainage disconnection in an 83-year-old woman with a CS dAVF. CASE DESCRIPTION: The patient presented with coma and anisocoria due to intracranial hemorrhage. Because of the patient's critical condition, we had no choice but to perform emergency decompressive craniectomy and hematoma evacuation without detailed preoperative hemodynamic information obtained by digital subtraction angiography. Postoperative digital subtraction angiography showed a CS dAVF with retrograde venous drainage of the deep middle cerebral vein (DMCV) and varix formation in the affected DMCV, causing hemorrhagic episodes. Five days after admission, the patient's neurologic state worsened because of rebleeding from the varix, which had increased in size. The percutaneous transvenous approach failed because of compartmentalization within the CS. Open surgery was performed; the deep vasculature was exposed by the transsylvian approach, and the arterialized DMCV was permanently clipped at its proximal segment with disconnection from the venous varix and fistulous point. Shunt obliteration was successfully achieved. CONCLUSIONS: Surgical venous drainage disconnection from the fistulous point may be an alternative radical therapy for CS dAVFs with aggressive behaviors.

Impact of Mechanical Thrombectomy Device on Thrombus Histology in Acute Embolic Stroke.

BACKGROUND: Although many studies have evaluated the retrieved thrombus to assess the cause of stroke after mechanical thrombectomy for acute large vessel occlusion, the results remain controversial. We investigated the hypothesis that histology of the retrieved thrombus is enhanced by mechanical thrombectomy devices. METHODS: Thrombi were collected from consecutive patients who had undergone endovascular mechanical recanalization for large intracranial vessel occlusion. The mechanical thrombectomy device used was either an aspiration catheter or a stent retriever. The hematoxylin and eosin-stained specimens were quantitatively analyzed with respect to the relative fractions of the main constituents (erythrocytes and fibrin). Clinical and radiologic findings were also evaluated. RESULTS: Of 65 patients, an aspiration catheter was used in 27, and a stent retriever was used in 38. The presence of a preoperative susceptibility vessel sign on magnetic resonance imaging was not correlated with the percentage of erythrocytes. Thrombus cross-sectional area was larger in the aspiration group than in the stent group (P < 0.01). Conversely, the percentage of the fibrin component was higher in the stent group (P < 0.001). Preoperative intravenous administration of recombinant tissue plasminogen activator reduced thrombus cross-sectional area with a trend of increased percentage of fibrin and reduced percentage of erythrocyte in the stent group. CONCLUSIONS: Histologic differences in retrieved thrombi are enhanced by mechanical thrombectomy devices. Stent retrievers may crush the thrombus, which may have a synergistic effect with recombinant tissue plasminogen activator. Histology of the retrieved thrombi might be different from histology of the original thrombi.

Impact of basal ganglia damage after successful endovascular recanalization for acute ischemic stroke involving lenticulostriate arteries.

OBJECTIVE: Regional ischemic vulnerability of the brain reportedly differs between the cortex and basal ganglia and has been poorly assessed in the setting of endovascular mechanical thrombectomy. This study was conducted to determine the fate of an ischemic basal ganglia and its contribution to the clinical outcome after successful endovascular recanalization for acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries. METHODS: Clinical and radiological findings were retrospectively analyzed in consecutive patients with acute ischemic stroke characterized by large vessel occlusion involving the lenticulostriate arteries. Mechanical thrombectomy was performed in all patients using a stent retriever. The fate of ischemic basal ganglia based on location (lentiform nucleus, caudate nucleus, and internal capsule) and insular cortex was assessed according to the Alberta Stroke Programme Early CT Score (ASPECTS). RESULTS: Of 170 patients with large intracranial vessel occlusion who achieved successful endovascular recanalization, defined as a thrombolysis in cerebral infarction grade of ≥ 2B, involvement of the lenticulostriate arteries was seen in 55 patients (internal carotid artery, n = 35; proximal middle cerebral artery, n = 20). Preoperative infarction was detected in the lentiform nucleus (66.7%), internal capsule (11.1%), and caudate nucleus (33.3%), all of which showed secondary advancement despite successful recanalization (85.4%, 27.3%, and 54.5%, respectively; p < 0.05). Lenticulostriate arteries with a lateral proximal and/or medial proximal origin significantly affected the development of mature infarction in the lentiform nucleus. Postoperative hemorrhagic transformation was detected in 25 of 55 patients, mostly in the lentiform nucleus. Involvement of insular ribbon infarction was significantly high in patients with hemorrhagic transformation in the basal ganglia. Age, initial National Institutes of Health Stroke Scale (NIHSS) score, initial ASPECTS, postoperative ASPECTS, postoperative infarction in the insular ribbon, and lesions in the middle cerebral artery area (M1-M6) were significantly different between patients with good and poor modified Rankin Scale scores. Interestingly, no differences were detected in postoperative infarction or hemorrhagic transformation in the basal ganglia. Multivariate analysis showed that only age (p = 0.02, OR 0.88) and the initial NIHSS score (p = 0.01, OR 0.86) independently affected favorable clinical outcomes. CONCLUSIONS: The basal ganglia are vulnerable and readily develop secondary infarction and hemorrhagic transformation despite successful recanalization. However, this does not have a significant impact on the clinical outcome of acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries.

Adaptability of Napiergrass (Pennisetum purpureum Schumach.) for Weed Control in Site of Animals Buried after Foot-and-Mouth Disease Infection.

After the infection of foot-and-mouth disease outbreaks in Miyazaki, Japan, in 2010, cattle and swine were slaughtered and buried in a site of 100 ha, where weed control is difficult and costly since lands are unlevelled and prohibited to be plowed for 3 years. To consider the adaptability of napiergrass (Pennisetum purpureum Schumach.) to the animal burial site for weed control, two napiergrass varieties, normal Wruk wona (WK) and dwarf late-heading variety (DL), were transplanted, compared with sowing of maize (MZ) and sorghum (SR) in both burial (BU) and neighboring bordered area (BO) in mid-June 2011. Even though several weed control methods were subjected to lands, MZ and SR failed to be established stably at only 1/3-1/2 due to the suppression of growth by indigenous weeds, while WK and DL successfully established as high as 82-91% and 73-85%, respectively, in 2011. The poor establishment of MZ and SR after sowing tended to be increased with the year from establishment. Plant dry matter yield and cellulose concentration were the highest in WK in 2011, while overwintering ability was constantly higher in DL in the 3 years. It is necessary to consider the utilization of forage plants on the animal burial site.