Hisatoshi Saitoh

Cerebral abscess as an unusual complication of coil embolization in a dural arteriovenous fistula: Case report

This 63-year-old man presented with a right temporoparietal cortical infarction. A dural arteriovenous fistula involving the right transverse sinus was diagnosed on cerebral angiography. Transvenous embolization using detachable coils was performed; however, postembolization angiograms demonstrated retrograde filling of a cortical draining vein that was not seen on initial angiography. The patient subsequently developed a cerebral abscess in the region of the previous cortical infarction 2 months after the embolization. The abscess was successfully treated with drainage and antibiotic therapy. The authors report this case to illustrate an unusual complication associated with this procedure and the possible contribution of the cortical draining vein in the pathogenesis of the cerebral abscess.

Intracerebral Hemorrhage Caused by a Neoplastic Aneurysm from Small-Cell Lung Carcinoma

A neoplastic cerebral aneurysm from lung cancer is an extremely rare occurrence despite its high metastatic potential to the brain. We report a neoplastic cerebral aneurysm from small-cell lung carcinoma that caused an intracerebral hematoma. A 63-year-old man underwent an urgent craniotomy for a massive intracerebral hematoma. After evacuation of the hematoma, an anomalous artery was found on the wall and a biopsy was done. The histological examination revealed that the artery was filled with neoplastic cells, and a part of the vessel wall was distended, forming an aneurysm. The histological feature of the tumor cells was consistent with small-cell lung carcinoma, which was disclosed in the left hilus.

Clear cell ependymoma of the fourth ventricle

Two cases of clear cell ependymoma (CCE) of the fourth ventricle are reported in a 49‐year‐old woman with dysphagia and a 59‐year‐old woman with dizziness and gait disturbance. CCE is a relatively new variant of ependymoma added to the WHO classification of tumors in 1993. Tumor cells display an oligodendroglioma‐like appearance with a clear perinuclear halo. Most infratentorial CCE tumors are located in the cerebellum. There are only three cases, including the present two cases, that have been reported to affect the fourth ventricle.

Ruptured aneurysms of the choroidal branches of the posterior inferior cerebellar artery: a review of the literature and a case report

Aneurysms of the choroidal branches of the posterior inferior cerebellar artery (PICA) are quite rare; only seven such cases have been reported thus far. In this study, we present a very rare case of a ruptured aneurysm of a choroidal branch of the PICA; the aneurysm was exposed by splitting the vermis and resected after proximal arterial ligation. We have also undertaken a thorough review of the literature on aneurysms in choroidal branches of the PICA, focusing on the clinical presentation, etiology, radiological findings, and surgical strategies. We found that the aneurysms in our patient and the aneurysms in seven published case reports were small, and frequently associated with vascular anomalies. Intraventricular hemorrhage (IVH) in the fourth ventricle was detected in all eight cases. The outcomes of surgical treatment were generally favorable, notwithstanding the high incidence of rebleeding after rupture of distal PICA aneurysms. The recognition of predominant fourth ventricular hemorrhage should raise the suspicion of the presence of an underlying aneurysm, and digital subtraction angiograms (DSAs) should be immediately obtained in order to detect small aneurysms of the choroidal branches of the PICA.

Magnetic resonance angiography for detection of occlusive neck and proximal vascular diseases

We reviewed magnetic resonance (MR) aortographies of the thoraco-cervical region of 422 patients. Two hundred sixty patients had ischemic cerebrovascular disease, 86 vertigo or dizziness, 22 syncope, 4 ischemic disease of the retina, 3 cervical bruit, and 47 had other intracranial diseases. MR aortography was performed on a 1.5 Tesla MRI using a special head-and-neck coil. Images were obtained using an overlapping multi-slab and three-dimensional time-of-flight technique. Of the 422 patients, 59 underwent conventional angiography, and the findings from their conventional arteriogram were compared with those of MR aortography. As a result, steno-occlusive lesions were found in the carotid system in 21.1% of the patients, in the vertebral system in 18.5%, and in the subclavian and innominate arteries in 2.1%. The diagnoses made based on the MR aortography were in accord with the diagnoses made with conventional arteriography in 49 patients (83.1%). In 8 patients (13.6%), however, the diagnosis based on the MR aortography was found to be overestimated compared with the definitive diagnosis with conventional angiography. In only 2 patients (3.3%), the MR aortography diagnosis was insufficient. Especially, subclavian steal was not diagnosed with the MR aortography, whereas the findings from the MR aortography helped to lead to the diagnosis of this abnormality. In conclusion, we found that MR aortography is a useful tool as a screening test for patients with occlusive extracranial cerebrovascular disease.