[Cerebral aneurysm and arachnoid cyst: about a case with intracystic hemorrhage]

Cerebral Aneurysm Associated with an Arachnoid Cyst: 3 Case Reports and a Systematic Review of the Literature

BACKGROUND

Arachnoid cysts and intracranial aneurysms are not rare, but it is unusual for an aneurysm to be associated with an arachnoid cyst. The objective of this study was to reveal the association between arachnoid cysts and intracranial aneurysms.

METHODS

Methods included to report 3 cases with these 2 pathologies and to perform a systematic review of the English and Japanese literature using PubMed, Scopus, and Ichushi Web.

RESULTS

The first case was of a 46-year-old man with a subarachnoid hemorrhage on the basal cistern and bilateral arachnoid cysts in the middle fossa, the second was that of a 29-year-old woman with a subarachnoid hemorrhage at the basal cistern and an arachnoid cyst in the left middle fossa, and the third was that of a 60-year-old man with a right putaminal hemorrhage and contralateral unruptured aneurysm and arachnoid cyst. A literature search for similar cases found 27 patients.

CONCLUSIONS

It was difficult to diagnose a ruptured aneurysm in some cases with an arachnoid cyst because computed tomography scan showed atypical findings, such as no hemorrhage, intracystic localized hemorrhage, or subdural hematoma. This review revealed that aneurysms and arachnoid cysts were significantly located ipsilaterally and that they occurred together in relatively young patients.

Communicating hydrocephalus accompanied by arachnoid cyst in aneurismal subarachnoid hemorrhage

The authors describe a case of communicating hydrocephalus accompanied by an arachnoid cyst in an aneurismal subarachnoid hemorrhage. A 69-year-old female was referred to our clinic due to the sudden onset of a headache. A head computed tomography scan demonstrated an arachnoid cyst in the right middle fossa with a mass effect and diffuse subarachnoid hemorrhage. Digital subtraction angiography then revealed a left internal carotid-posterior communicating artery aneurysm. The neck of the aneurysm was clipped successfully and the post-operative period was uneventful. However, two months after discharge, the patient reported that her mental status had declined over previous weeks. A cranial computed tomography scan revealed an interval increase in the size of the ventricle and arachnoid cyst causing a midline shift. Simultaneous navigation guided ventriculoperitoneal shunt and cystoperitoneal shunt placement resulted in remarkable radiological and clinical improvements.

Arachnoid cysts

Arachnoid cysts are fluid-filled duplications or splittings of the arachnoid layer with a content which is similar but not equal to the cerebrospinal fluid. Arachnoid cysts are not actual neurodegenerative disorders, rather the underlying defect of the texture of the arachnoid layer is probably congenital in nature. They can occur sporadically or can be associated with other malformations or diseases. Arachnoid cysts may be discovered in early childhood. However, they can develop de novo, grow or decrease in size. They may be diagnosed by ultrasound screening in the fetal period or be discovered during childhood or adulthood. Many arachnoid cysts are asymptomatic.Treatment strategies are discussed controversially. If they are diagnosed incidentally or are correlated with only very mild symptoms, a conservative management with follow-up imaging may be favored. If they grow, they can cause headaches, seizures or other neurological symptoms and require neurosurgical treatment. This chapter addresses aspects of pathogenesis, clinical symptoms, indication for neurosurgical treatment and treatment options.

Arachnoid cysts of the fourth ventricle - short illustrated review

Arachnoid cysts are frequent anomalies of the CNS. They are benign lesions within the arachnoid membrane and have been reported to occur in virtually all locations where arachnoid is present. An intraventricular location, however, is rare and occurrence within the fourth ventricle is particularly uncommon. The first report was published in 1979 on a paediatric patient. Since then, only a few further examples have been reported. Most of these patients presented with hydrocephalus. Shunting procedures were performed, but did not afford long-term improvement of symptoms. Definitive treatment consisted of open resection of the cyst-wall. We report a 34-year-old woman with a large arachnoid cyst within the fourth ventricle who suffered from progressive cerebellar dysfunction. MRI showed massive enlargement of the fourth ventricle by an intraventricular arachnoid cyst which contained multiple septations. Complete excision of the cyst was necessary to reinstitute free CSF-flow and was performed via a median suboccipital approach. This report gives an overview of examples published to date and discusses pathogenesis and clinical features of arachnoid cysts in this location as well as operative strategies including neuroendoscopic techniques.

Intracranial aneurysm and arachnoid cyst: a rare association between two cerebral malformations

Intracranial aneurysms and arachnoid cysts are cerebral disorders of a high prevalence. However, association between both malformations is a rare finding. The aim was to analyse this association with regard to the different clinical presentations according to the haemorrhage types, as well as the pathogenesis of this association. We searched the English language literature in MEDLINE database in order to include all manuscripts in which this association was found. A new case of a 55-year-old man with a large posterior communicating artery aneurysm and a middle cranial fossa arachnoid cyst presenting with headache and seizure was added to review of the literature and presented as an illustrative case. Nine cases were found. Six were male and three were female. The mean age was 42 years (range 29-66 years). All but one arachnoid cysts were located at middle cranial fossa, aneurysms arose from middle cerebral artery in three cases, internal carotid artery bifurcation in two cases, posterior communicating segment of carotid artery in two cases, anterior communicating artery in one case and azygos pericallosal artery in one case. Clinical presentation was related to aneurysmal rupture in six cases (subarachnoid haemorrhage in four, subdural haematoma in one and intracystic haematoma in two) and related to arachnoid cysts in three cases, where the most common symptoms were seizures and headache. Association between intracranial aneurysms and arachnoid cysts is a rare finding that can present with signs and symptoms related to aneurysm rupture, or with mass effect and seizures related to the cyst. The aneurysmal haemorrhage may be atypical, since it can be into the subarachnoid space, into the arachnoid cyst, or into the subdural space.

A FORM OF DYSPLASIA OR A FORTUITOUS ASSOCIATION? A CEREBRAL ANEURYSM INSIDE AN ARACHNOID CYST

OBJECTIVE

Although arachnoid cysts and intracranial aneurysms are very common lesions, their association in the same patient is rare. We present a case of a middle cerebral artery aneurysm ruptured into an arachnoid cyst. We found only six cases with intracystic hemorrhage reported in the literature. The presence of an arachnoid cyst can mislead clinical presentation. The patient presented a paradoxically small temporal fossa and thickening of the temporal and sphenoid bone. The authors suggest that this uncommon association (arachnoid cyst, atypical cranial vault, and “mirror-like” cerebral aneurysm) could represent a form of dysplasia.

CLINICAL PRESENTATION

A 46-year-old patient presented with a 3-week history of slight headaches, which had worsened in the last 3 days before presentation. Computed tomographic scans showed a cystic lesion located in the middle cranial fossa and sylvian fissure with suspected aneurysm dilation inside. Magnetic resonance imaging scans showed an intracystic hemorrhage but not subarachnoid hemorrhage. Paradoxically, changes in the cranial vault around the cyst were noted. Digital subtraction angiography showed bilateral “mirror” middle cerebral artery aneurysms.

INTERVENTION

A large right pterional craniotomy was performed with full microsurgical removal of the arachnoid cyst walls and aneurysm clipping. The aneurysm was in the medial wall of the arachnoid cyst with its dome inside the cyst. The contralateral aneurysm was clipped 2 weeks later. The follow-up period was uneventful, and the patient returned to normal life.

CONCLUSION

Rupture of a cerebral aneurysm into an arachnoid cyst is rare. Clinical presentation may be unusual because the cyst can prevent subarachnoid hemorrhage. A middle fossa cranial arachnoid cyst in the presence of temporal bone depression, small middle fossa, and thickness of squamous temporal bone and the lesser wing of sphenoid is rare and suggests that congenital factors may play an important role in their development. The exceptional association between “mirror” aneurysms and arachnoid cyst with bone changes suggests a possible congenital form of dysplasia.