Giant intracranial aneurysm presenting as a posterior fossa mass

Development of a pontine cyst after endovascular coil occlusion of a basilar artery trunk aneurysm: case report

OBJECTIVE AND IMPORTANCE

Cyst formation within the brain parenchyma after endovascular coil occlusion of an intracranial aneurysm is a previously undescribed occurrence. We describe a 70-year-old woman who presented with a symptomatic pontine cyst 1 year after uncomplicated stenting and Guglielmi detachable coil occlusion of an unruptured basilar artery trunk aneurysm.

CLINICAL PRESENTATION

A 70-year-old woman presented with an episode of transient dysequilibrium and gait difficulty. Magnetic resonance imaging and cerebral angiography demonstrated a 15-mm distal basilar artery trunk aneurysm. Endovascular stenting and coil occlusion of the aneurysm were performed without technical complications. One year after the initial treatment, the patient developed progressive dysarthria, dysphagia, diplopia, and left hemiparesis. A large pontomesencephalic cyst adjacent to the coiled basilar aneurysm was identified on magnetic resonance imaging scans.

INTERVENTION

A subtemporal craniotomy and decompression of the pontomesencephalic cyst were performed. The patient's symptoms of brainstem dysfunction improved temporarily but recurred within 2 months, necessitating reoperation for cyst drainage and placement of a cyst-peritoneal shunt.

CONCLUSION

Intra-axial cyst formation after stenting and endovascular occlusion of an intracranial aneurysm is an unusual occurrence and should be considered in the differential diagnosis of new neurological deficits after endovascular treatment. The pathophysiological mechanism of cyst formation in this case is not known.

Growth of basilar artery aneurysm after ventriculo-peritoneal shunt

We report upon two cases of obstructive hydrocephalus produced by giant basilar artery aneurysms. They initially presented with symptoms of increased intracranial pressure, and were managed by a ventriculo-peritoneal (VP) shunt with good symptomatic improvement. With time, however, both showed a gradual deterioration of clinical symptoms due to increased aneurysm size. One, with a basilar tip aneurysm was treated by direct neck-clipping of the aneurysm, and was able to return to work. In the other patient, with a basilar trunk aneurysm, endovascular occlusion of one vertebral artery was attempted in an effort to decrease the aneurysm size, but the aneurysm enlarged precipitating brain stem failure. In conclusion, these cases reveal the risk of the VP shunt, which may induce aneurysmal growth, leading to clinical devastation, and emphasize the importance of definitive treatment for giant cerebral aneurysms whenever possible.

Giant basilar artery aneurysm with intramural hemorrhage and then disastrous hemorrhage: case report

OBJECTIVE AND IMPORTANCE

Intracranial giant aneurysms have been considered to grow by recurrence of intramural hemorrhage of the aneurysmal wall. However, it remains uncertain whether rupture of giant aneurysms is brought about by the same mechanism that causes the rupture of smaller saccular aneurysms. It is also unclear whether intramural hemorrhage is correlated with the rupture of giant aneurysms.

CLINICAL PRESENTATION

A 67-year-old woman was admitted with symptoms of gait disturbance and dementia. Computed tomographic scans revealed a large mass located in the prepontine region and extending into the third ventricle as well as moderate dilatation of the lateral ventricles. Angiography demonstrated a giant basilar tip aneurysm and multiple aneurysms located in the bilateral anterior and middle cerebral arteries.

INTERVENTION

Ventriculoperitoneal shunting was scheduled, but subarachnoid and intraventricular hemorrhage occurred and the patient died. Computed tomographic scans, performed immediately before the disastrous hemorrhage, displayed intramural hemorrhage in the wall of the giant basilar tip aneurysm. Ventricular drainage was performed, but the patient died.

CONCLUSION

It seems probable that intramural hemorrhage of the aneurysmal wall may cause both the growth and rupture of intracranial giant aneurysms.

Giant posterior communicating artery aneurysm presenting as third ventricle mass with obstructive hydrocephalus. Case report

The case of a giant posterior communicating artery (PCoA) aneurysm is reported in which the initial presentation was coma secondary to obstructive hydrocephalus. The primary radiological diagnosis was a probable craniopharyngioma. A cerebral angiogram revealed a partially thrombosed giant PCoA aneurysm on the right side. The patient underwent pterional craniotomy with aneurysm clipping and thrombectomy to relieve mass effect, and has made a good recovery. Review of the literature documents that giant PCoA aneurysms are rare. This is believed to be the first reported case of a PCoA aneurysm presenting as a third ventricle mass with obstructive hydrocephalus. The magnetic resonance imaging characteristics of those third ventricle masses that mandate vascular workup are discussed.

Management and prognosis of intracranial giant aneurysms. A report on 58 cases

Between 1975 and 1989, 58 patients, 32 females and 26 males, mean age 50 years, with intracranial giant aneurysms with a diameter more than 2.5 cm were treated at our clinic. 48% of the patients presented with subarachnoidal hemorrhage. The most of the other 30 patients presented with cranial nerve dysfunctions. The most common site of the aneurysm was the internal carotid artery (25 cases, 43%), followed by the anterior cerebral artery (14%), and the vertebro-basilar region (11 cases, 19%). In 14 patients direct surgery was not performed because of the poor general condition of the patient, the high risks, or non-consent. In seven patients (12%) the aneurysm had been misdiagnosed as meningeoma, pituitary-adenoma, craniopharyngeoma or glioblastoma. 47% of all patients were discharged as "independent" and 19% died. Patients without SAH had better chance of survival: 7% of patients without SAH died and 29% of patients with hemorrhage. 50% of patients without hemorrhage were discharged as "independent" but only 18% of patients with SAH. Because of the high incidence of hemorrhage and the better prognosis for patients without hemorrhage, we recommend routine surgical treatment of patients with giant aneurysms.