[A case of unruptured fusiform aneurysm in a middle cerebral artery branch].

We report a case of a 55-year-old female presenting with headache. Neuroradiological investigations revealed a fusiform aneurysm at the M3 part of the right middle cerebral artery. The aneurysm rapidly developed in the course of one year. She underwent a craniotomy for superficial temporal artery middle cerebral artery bypass (STA-MCA bypass) and resection of the aneurysm. Pathological examination suggested that atherosclerosis was a predisposing factor for aneurysm formation. Although she had developed transient dysarthria and left-hand clumsiness after the operation, she was able to be discharged after 26 days with no neurological deficits. On reviewing the literature, fusiform aneurysms seem to be an important cause of subarachnoid hemorrhage and cerebral infarction of unverified origin. Etiology and treatment of spontaneous fusiform aneurysms in a branch of the middle cerebral artery are also discussed.

[Spontaneous umbilical fistula as a complication of ventriculo-peritoneal shunt: case report].

We report a rare case of a spontaneous umbilical fistula as a complication of ventriculo-peritoneal shunt. A 36 year-old male was admitted our hospital complaining serous discharge from the umbilicus. Two years before admission, he underwent ventriculo-peritoneal shunt for the hydrocephalus due to right hypertensive intracranial hematoma and intraventricular hemorrhage. A shuntgraphy was done and it revealed the cerebrospinal fluid leakage from the umbilicus through an urachal remnant. The abdominal shunt tube was removed at the surgery, and the patient was discharged uneventfully without shunt revision. The possible etiology of this rare complication in this case was supposed to be due to the persistence of the urachus.

Surgically treated aneurysm of the trunk of the persistent primitive trigeminal artery--case report.

A 62-year-old man presented with a very rare cerebral aneurysm arising from the trunk of the persistent primitive trigeminal artery (PPTA) manifesting as subarachnoid hemorrhage. Angiography showed a saccular aneurysm at the curved mid-section of the trunk of the left PPTA of the adult type. The patient underwent surgery via the left subtemporal approach, and the aneurysm was successfully eliminated by clipping without sequelae. Aneurysm formation at this point was probably due to hemodynamic stress. The perforating arteries from the PPTA may be important in supply of the hindbrain, so PPTA patency should be preserved if possible.

A recurrent intradural cervical neurenteric cyst operated on using an anterior approach: a case report.

The neurenteric cyst is an uncommon congenital lesion. In most reported cases, it has been operated on via a posterior approach using a laminectomy, despite the fact that the cyst is usually located ventral to the spinal cord. Reports have shown that early postoperative results have been good with the posterior approach, but very few studies of the long-term postoperative recurrence of neurenteric cysts have been conducted. Here, we report on a case of recurrent neurenteric cyst that was operated on using an anterior approach.A 42-year-old woman presented with a cervical neurenteric cyst that had recurred eight years after its partial removal via a posterior approach. The patient complained of pain on the lateral side of her upper arms, and an magnetic resonance imaging showed that the recurrent cyst was located ventral to the spinal cord and compressed the cord dorsally at the C4-6 level. The patient was operated on via an anterior approach using a vertebrotomy at the lower half of C5 and the upper half of C6. The cyst was attached to the spinal cord firmly and was subtotally removed, with the thickest portion adhering to the cord not being removed. The caudal end of the cyst was observed with the assistance of a rigid endoscope.A neurenteric cyst may recur after partial removal, and the patient's condition may deteriorate during postoperative follow-up. The anterior surgical approach provides good visualization and facilitates safe removal of the lesion.

Operative findings in cases of trigeminal neuralgia without vascular compression: proposal of a different mechanism.

Trigeminal neuralgia is known to be caused by vascular compression at the trigeminal root entry zone (REZ) and microvascular decompression provides good outcome in most of cases. However, in some cases, no vascular compression was observed at the REZ. Over the last 2(1/2) years, the first author operated on 53 cases of trigeminal neuralgia with microvascular decompression and encountered nine cases where no offending vessels were noted at or near the REZ. They were divided into two groups: five cases involving an initial operation and four cases involving a second operation. In the former, arachnoid thickening, angulation or torsion of the root axis were common findings. Dissection of thick arachnoid around the root along the whole length reversed the root to be straight and flaccid. Complete pain relief was noted in four of five cases. In one case of atypical pain, constant facial pain remained. In the latter four cases, where the first operations were done more than 4 years before, thick granulation was noted around REZ without new offending vessels in two cases. In the remaining two cases, where no offending vessels were noted in the first operation, thick adhesion of a distal portion of the root with dura on the pyramidal bone was noted. Meticulous dissection of t he whole length of the root was done and complete pain relief was obtained. Delayed but complete pain relief in these nine cases was noted. Based on operative findings, arachnoid thickening or granulomatous adhesion between the root and surrounding structures can cause an abnormal course of the trigeminal nerve root, which causes root angulation and/or torsion. They can also cause pulsatile movement of the trigeminal nerve root. This tethering effect can promote abnormal root stretching force, especially at REZ, which might promote hyperexitability of the nerve. This speculative mechanism suggests that it is important to make the root free along the entire length, especially at its distal portion in cases with no offending vessels.