Alteration of gap junction proteins (connexins) following lateral fluid percussion injury in rats.

Gap junctions are intercellular channels that mediate the cytoplasmic exchange of small hydrophilic molecules and are formed by a family of integral membrane proteins called connexins (Cxs). Cx43 is expressed predominantly in astrocytes, while Cx36 is expressed in neurons. In this study, we show alteration of Cx43 and Cx36 in the hippocampus after traumatic brain injury in rats. Adult male Sprague-Dawley rats were subjected to lateral fluid percussion injury of moderate severity. Brain coronal sections were used for immunohistochemistry with Cx43 and Cx36 antibodies. Cx43 immunoreactivity was increased in reactive astrocytes in the damaged hippocampus 24 hours after injury, and persisted for 72 hours. On the other hand, Cx36 immunoreactivity increased in CA3 neurons 1 hour after injury, and decreased later. These results indicate that gap junctions might participate in the pathophysiological process after traumatic brain injury.

Focal brain edema and natriuretic peptides in patients with subarachnoid hemorrhage.

Central salt wasting syndrome may be caused by pathological increases in serum natriuretic peptides after subarachnoid hemorrhage (SAH). However, it is unclear as to why the serum concentration of atrial natriuretic peptide (ANP) or brain natriuretic peptide (BNP) increases in the subacute phase of SAH. The present study was designed to assess the correlation between focal brain edema and serum concentration of ANP or BNP in patients with SAH. Focal brain edema was found in 8 SAH-patients and peaked between days 4 and 7 of SAH. The mean serum ANP and BNP levels in patients with focal brain edema were significantly higher than those in patients without focal brain edema between days 4 and 14 of SAH. These results suggest that focal brain edema might correlate with increased levels of ANP and BNP in the subacute phase of SAH.

Vascular endothelial growth factor expression in pituitary adenomas.

Vascular endothelial growth factor (VEGF) is known to be a mediator of angiogenesis and vascular permeability. A cystic component and hemorrhage are often found in pituitary adenomas. In the present study we assess the VEGF expression based on immunohistochemical examinations in 48 pituitary adenomas. All the adenomas showed some VEGF immunoreactivity mainly in the cytoplasm of tumor cells. Of the 48 adenoma-cases, 16 cases had a strong VEGF immunoreactivity, 26 cases had a moderate one, and 6 cases had a weak one. On the MR images, a cystic component was found in 16 cases (33.3%), and a hemorrhage was found in 18 cases (37.5%). The VEGF immunoreactivity had a significant relationship with the cystic component but neither the hemorrhage, size, recurrence, or HE classification. These findings suggest that VEGF might play a potential role in the pathogenesis of cystic formation in pituitary adenomas.

Extracellular superoxide dismutase following cerebral ischemia in mice.

We describe the changes in extracellular superoxide dismutase (EC-SOD) following cerebral ischemia in mice. Mice were subjected to transient forebrain ischemia and reperfusion. The measurements of EC-SOD using ELISA showed increased brain EC-SOD after 24 h of reperfusion. The immunohistochemical examination showed that EC-SOD immunoreactivity in cortical and striatal capillary wall was conspicuous after 3 h. EC-SOD immunoreactivity was also noted in cortical neurons after 24 h. Northern blot analysis showed an increased EC-SOD mRNA expression in the brain after 24 h. In situ hybridization study demonstrated no mRNA expression of EC-SOD following ischemia and reperfusion in the capillary wall. These findings suggest that serum EC-SOD might accumulate on brain endothelial cells, while cortical neurons produce EC-SOD themselves after cerebral ischemia with reperfusion.

Intracranial meningeal malignant fibrous histiocytoma mimicking parasagittal meningioma--case report.

A 69-year-old female presented with a rare intracranial meningeal malignant fibrous histiocytoma (MFH). The neuroimaging appearance of this tumor was very similar to parasagittal meningioma. The tumor was grossly totally removed, and local irradiation of 50 Gy was performed. The histological diagnosis was MFH. The patient recovered from the preoperative deficits, and no recurrence was observed by 27 months after surgery.

Anomalous internal carotid artery associated with ipsilateral cerebral arteriovenous malformation--case report.

A 15-year-old girl presented with an extremely rare anomalous origin of the internal carotid artery (ICA) from the common carotid artery, associated with an arteriovenous malformation in the brain and aberrant course of the ICA in the temporal bone. These anomalies, which were found on the same side, may be due to a maldevelopment of the vascular network including the aortic arches.

Transarterial embolization with HEMA-MMA of variant convexity-superior sagittal sinus dural arteriovenous fistula--case report.

A 62-year-old male presented with a variant dural arteriovenous fistula (DAVF) within the wall of the convexity-superior sagittal sinus, fed by branches of the bilateral external carotid arteries and only cortical venous drainage despite the presence of a patent sinus. Transarterial embolization with poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (HEMA-MMA) was performed, resulting in complete obliteration of the DAVF. Embolization with HEMA-MMA is an effective and safe procedure for the treatment of DAVF.

Dissecting aneurysm of the vertebral artery causing subarachnoid hemorrhage after non-hemorrhagic infarction--case report.

A 45-year-old male presented with lateral medullary infarction. Cerebral angiography showed dissecting aneurysm as pearl and string sign in the right vertebral artery (VA). Conservative treatment was administered with antiplatelet agent. However, subarachnoid hemorrhage occurred 2 days after admission, inducing coma. Intraaneurysmal embolization and proximal occlusion of the right VA by intravascular surgery resulted in only mild neurological deficits. Conservative treatment including strict control of blood pressure is the first choice of treatment. Antiplatelet therapy and anticoagulant therapy should not be administered. Patients must be followed up by serial angiography and surgery considered if signs of aneurysmal progression are seen.

Pseudoaneurysm of the superficial temporal artery following craniotomy--case report.

A 48-year-old male without marked blood coagulation disorder developed a pseudoaneurysm of the superficial temporal artery (STA) following craniotomy. Cerebral angiography revealed a pseudoaneurysm on the parietal branch of the STA. Total extirpation was performed, and the postoperative course was uneventful. Most pseudoaneurysms of the STA develop after trauma. Lesions rarely develop after craniotomy. However, pseudoaneurysm of the STA should be considered as a possible surgical complication.

[Dural arteriovenous fistula of the transverse-sigmoid sinus with intraventricular hemorrhage: a case report].

We report a case of dural arteriovenous fistula of the transverse-sigmoid sinus (TS-DAVF) with intraventricular hemorrhage. An 83-year-old woman presented with headache and vomiting. Neurological examination showed no defects. CT scans demonstrated intraventricular hemorrhage. Left external carotid angiograms showed a dural arteriovenous fistula of the isolated transverse-sigmoid sinus fed by the occipital and middle meningeal arteries. The draining vein was the leptomeningeal vein. Left internal carotid angiograms demonstrated venous congestion in the left temporal and occipital lobes. This case was grade 4 according to Lalwani's classification. 123I-IMP SPECT revealed a low perfusion are in the left temporal and occipital regions. Dynamic CT scans revealed venous congestion in the left temporal and occipital regions. We considered that the venous congestion was the cause of intraventricular hemorrhage. Initially, we embolized the DAVF using a transarterial approach with liquid material. However, the embolization of the DAVF was not complete. Therefore, we treated the DAVF by sinus packing with coils using a small craniotomy. Angiographic cure was obtained and the postoperative course was uneventful. We discuss the clinical features, the hemodynamic findings and the management of this case.

[Dural arteriovenous fistula of the transverse sigmoid sinus after transvenous embolization of the carotid cavernous fistula].

We report a case of dural arteriovenous fistula of the transverse-sigmoid sinus after transvenous embolization of the carotid cavernous fistula. A 72-year-old woman presented with left exophthalmos, chemosis, bruit and left abducens nerve palsy in June 1996. Bilateral external and internal carotid angiograms revealed the dural arteriovenous fistula of the cavernous sinus. We embolized the dural arteriovenous fistula using a transvenous approach via the left inferior petrosal sinus. Angiograms demonstrated the complete disappearance of the dural arteriovenous fistula. Two years and six months later, she complained of tinnitus at the retroauricular region. Left external carotid angiograms showed a dural arteriovenous fistula of the transverse-sigmoid sinus fed by occipital, posterior auricular, middle meningeal and superficial temporal arteries. We embolized the dural arteriovenous fistula using a transarterial approach. Her symptoms disappeared but the dural arteriovenous fistula did not disappear completely. We discussed the clinical features and etiology of this case.

Embolization of posterior circulation aneurysms with detachable coils.

SUMMARY: We evaluated the usefulness of endovascular treatment of posterior circulation aneurysms with GDCs and IDCs. Five cases were treated with IDCs, and 15 cases were treated with GDCs. In this study, 8 aneurysms were identified at the basilar bifurcation, 3 at the PI segment of the posterior cerebral artery, 1 at the origin of the superior cerebellar artery, 2 at the vertebrobasilar junction, 1 at the origin of the posterior inferior cerebellar artery, 1 at the distal anterior inferior cerebellar artery, and 4 dissecting aneurysms at the vertebral artery. Thirteen of the aneurysms were small (< 12 mm), 5 were large (13-24 mm), and 2 were giant (> 25 mm). Of the 20 patients, 14 patients returned to their previous occupation. Patients with permanent deficits included 2 patients with infarction caused by thromboembolic complications during the embolization procedure, and 2 with infarction caused by vasospasm. There were 2 deaths. The outcomes of the patients seemed favorable. However, long-term followup is necessary to determine the usefulness of detachable coils.