Chiharu Kuromatsu

Hemifacial spasm due to tumor, aneurysm, or arteriovenous malformation

The authors report eight cases of so-called symptomatic hemifacial spasm. They had gross pathological lesions such as a tumor (one epidermoid, one neurinoma, and two meningiomas), vascular malformation (one medullary venous malformation and two arteriovenous malformations), and aneurysm. In all four cases with a tumor, no artery compressed the facial nerve at the root exit zone. In three of the four cases, the hemifacial spasm disappeared after removal of the tumor in contact with the facial nerve. Compression or encasement of the facial nerve by the tumor was the pathogenesis of the hemifacial spasm in these three cases. The remaining case with tumor (tentorial meningioma) did not have a mass or vessel that directly compressed the facial nerve at the root exit zone. However, the hemifacial spasm disappeared after the removal of the tumor. In a case with a medullary venous malformation with arterial component, an engorged draining vein compressed the root exit zone of the facial nerve. In the remaining three vascular cases--two cases of arteriovenous malformation and a case of saccular aneurysm--enlarged feeding arteries and an aneurysm directly compressed the root exit zone of the facial nerve. Not only arterial or venous but also mass compression can cause hemifacial spasm in some symptomatic cases. Surgical decompression of the facial nerve from the causative organic lesion is the primary choice of treatment.

Aneurysm of the posterior cerebral artery: report of eleven cases--surgical approaches and procedures.

Eleven cases of an aneurysm of the posterior cerebral artery are reported. All 11 aneurysms were saccular, and 3 were either giant or large. The aneurysms arose from the P1 segment in three patients, the P1-P2 junction in three patients, the P2 segment in three patients, and from the P3 segment in two patients. In all, 10 patients underwent surgery. All P1 and P1-P2 junction aneurysms were treated with the pterional approach. Three P2 and two P3 aneurysms were managed by the subtemporal approach. Two small aneurysms in the series were treated by coating the aneurysmal dome, two by clipping the afferent artery, and all other saccular type aneurysms were treated by clipping the aneurysmal neck. Seven patients had either an excellent or good outcome; two had poor results; and one patient died. The operative approaches and procedures are also discussed in relation to the anatomy of posterior cerebral artery aneurysms.

Aneurysm of the Posterior Cerebral Artery

Eleven cases of an aneurysm of the posterior cerebral artery are reported. All 11 aneurysms were saccular, and 3 were either giant or large. The aneurysms arose from the P1 segment in three patients, the P1-P2 junction in three patients, the P2 segment in three patients, and from the P3 segment in two patients. In all, 10 patients underwent surgery. All P1 and P1-P2 junction aneurysms were treated with the pterional approach. Three P2 and two P3 aneurysms were managed by the subtemporal approach. Two small aneurysms in the series were treated by coating the aneurysmal dome, two by clipping the afferent artery, and all other saccular type aneurysms were treated by clipping the aneurysmal neck. Seven patients had either an excellent or good outcome; two had poor results; and one patient died. The operative approaches and procedures are also discussed in relation to the anatomy of posterior cerebral artery aneurysms.

Diagnosis and surgical treatment of spasmodic torticollis of 11th nerve origin

Of 22 patients with spasmodic torticollis, 7 were treated by microsurgical decompression of the 11th nerve. In these patients, there was an intermittent horizontal torticollis characterized by aggravation of the symptoms when in a resting posture, presenting with a striking contrast to the torticollis of extrapyramidal origin that was alleviated while in the resting posture and aggravated by postural stress. A tight neurovascular contact was observed at the C1 level, occurring between the principal 11th nerve and the vertebral or posterior inferior cerebellar artery. Nerve decompression was achieved in 2 by transposing the compressing artery and in 5 by sectioning at C1 or C2 the branching root of the 11th nerve that had caused the tight cross contact by locking the nerve trunk to the dura mater. The symptoms had improved after an interval of 1 to 4 weeks. After an average follow-up of 3 years, full or satisfactory relief had been obtained in 5 and some improvement had occurred in 2 patients. Possible neural mechanisms related to torticollis of 11th nerve origin are discussed.

Symptomatic choroidal epithelial cyst in the fourth ventricle

A case of choroidal epithelial cyst in the fourth ventricle is described. The cyst occupied the fourth ventricle almost completely, and produced an intermittent hemiparesis and hemisensory disturbance. After removal of the cyst wall, the patient recovered completely. On light microscopy, a single epithelial layer with a basement membrane lining the cyst wall was observed. An electron microscopic study was also made.

Rathke's cleft cyst

Two cases of Rathkes cleft cyst which produced symptoms of compression of the optic chiasm are described. The first case has been followed for five years since the operation. No evidence of recurrence has been noticed. The prognosis after a partial removal of the cyst wall seems to be good with this lesion. In the second case, there was clinical and laboratory evidence of hypopituitarism and the CT scan revealed suggestive findings to differentiate the cyst from a pituitary adenoma.

Recurrent cystic meningioma

The authors report a case of recurrent meningothelial meningioma with a large cyst. At the first operation, the mural nodule was totally resected and the cyst wall was removed as much as possible. This cystic tumor recurred six years later at the site where the first operation was performed. Histologically, the cyst wall contained islands of the same neoplastic cells as were previously found in the mural nodule. The authors discuss the preoperative diagnosis and mechanism of cyst formation, and emphasize the importance of complete removal of the cyst wall for permanent cure.