Multiple saccular aneurysms of the extracranial and intracranial internal carotid artery associated with convexobasia and arachnoid cyst in a 6-year-old boy: a case report

INTRODUCTION

We report an extremely rare case of multiple saccular aneurysms of the extracranial and intracranial internal carotid artery associated with convexobasia of the left temporal region and arachnoid cyst in a 6-year-old boy.

CASE REPORT

A 6-year-old male patient was admitted to the hospital with chief complaint of ptosis and engorgement of the left eyelid for 50 days. A 4 x 10-cm bony protuberance of the left temporal region with hemangiectasia was observed to beat with pulse without vascular murmur. computed tomographic angiography (CTA) showed two saccular aneurysms of the left internal carotid artery. The first one which was about 3 cm in length and 2 cm in maximum diameter was located in the middle of the petrous portion (including parts of C2 and C3). The second one which was about the same size was located from the middle of the cavernous portion to the upper end of the left internal carotid artery. Computed tomography showed an arachnoid cyst in the left temporal region and abnormality of the left temporal bone. According to the specific circumstances of this patient, we believe that surgical treatment is rather risky and the loss might outweigh the gain. Therefore, we suggested to the parents that the child should be followed up for the coming years for monitoring and possible treatment.

DISCUSSION

Multiple saccular aneurysms of extracranial and intracranial internal carotid artery in children are extremely rare. According to this case, the child had congenital bony protuberance of the left temporal region with hemangiectasia, which made this case particularly specific. Besides all those discovered abnormalities, this child was a healthy boy. Due to the difficulty and high risk of possible surgical treatment, we suggested that no further treatment be performed at the moment and the child should be followed up for a long period of time. Worthy examinations such as CT, CTA, and MRI are recommended for reviewing the development of aneurysms and CNS of this boy. Further treatment might be performed in the future. We welcome all forms of discussion about this case and similar cases around the globe.

[Curative effect of the fibrinogen gel for sacral canal arachnoid cyst]

OBJECTIVE

To evaluate curative effect of the fibrinogen gel for treating sacral canal arachnoid cyst.

METHODS

Nineteen patients with sacral canal arachnoid cysts included 7 males and 12 females; The average age was 48.4 years ranging from 19 to 68 years. The course was from 2 weeks to 7 months. Of all the patients, 9 were in level of S1, 4 were in level of S1 to S2, 5 were in level of S2, 1 was in level of S1 to S3. Cystis wall greater partial excision adopted in 11 cases, partial resection in 8, then all patients were treated by spray painting fibrinogen gel.

RESULTS

Nineteen patients were followed-up for 13 to 30 months (mean 21.3 months). The clinical symptom disappeared completely in 18 patients, and only one patient urinated incapably, but after 2 weeks returned to normal. No one found recurrence by MRI after 12 months.

CONCLUSION

This method of fibrinogen gel for treating sacral canal arachnoid cyst has advantages of easy performing, safety, achieve good results, less neck symptoms and early commencing of mobilization.

Management of intracranial arachnoid cysts: Institutional experience with initial 32 cases and review of the literature

Surgical indications and modalities in treatment of intracranial arachnoid cysts still remain controversial owing to limited understanding of the pathophysiologic mechanisms and natural history of this pathology. Current literature favours endoscopic interventions for arachnoid cysts. We retrospectively reviewed 32 intracranial arachnoid cysts managed over 11-year period in our institution. Post-therapeutic results were clinically and radiologically assessed. Supratentorial location of cysts was noted in 75% cases (n=24) while 25% cysts were located infratentorially (n=8). The mean cyst size was 54mm in largest dimension (range 10-100mm; median 50mm). Hemiparesis was noted in 37% cases, raised intracranial pressure and seizures in 34% cases each, while cranial nerve dysfunction was noted in 16% cases. Seventy five percent cases were surgically managed: excision and marsupialization was done in 53% cases (n=17), stereotactic aspiration in 12.5% cases (n=4), endoscopic fenestration in 6.25% cases (n=2) and cystoperitoneal shunting initially in 1 case (3%) and after recurrence of primarily excised cysts in 2 cases. Conservative treatment with regular clinical and imaging control was done in 25% cases (n=8). The mean follow-up was 72 months (range: 12-108 months). Good outcome was noted in 72% cases, 16% cases remained unchanged while only one case with giant suprasellar cyst worsened. With excision and marsupialization, 65% of cysts reduced in size (n=11/17), 17% cysts resolved completely (n=3/17). The overall recurrence rate was 29%. Surgery excision and marsupialization of symptomatic cases provided good results.

Peripetrosal arachnoid cysts

PURPOSE OF REVIEW

The present review summarizes the current theories on arachnoid cyst formation, the common presentations of cysts surrounding or eroding the temporal bone from the middle and posterior cranial fossae, the diagnostic strategies and the management considerations and options.

RECENT FINDINGS

Arachnoid cysts are most common in the middle cranial fossa and rarely present in association with the petrous apex. They are frequently found incidentally on imaging studies performed in the workup for unrelated symptoms. When they do cause symptoms, these are usually nonspecific. Thus it is important to establish the relationship between the two. Peripetrosal arachnoid cysts may cause cranial nerve deficits in addition to symptoms related to intracranial hypertension. Small asymptomatic cysts are managed conservatively with serial imaging. Large symptomatic cysts are often managed surgically with shunting, open excision or open or neuroendoscopic fenestration or marsupialization. The management of large asymptomatic cysts depends on the patient and cyst characteristics.

SUMMARY

Peripetrosal arachnoid cysts are often incidental findings. Careful selection of surgical candidates is of utmost importance. Multiple surgical options with similar success rates are available. The rates and profile of their complications may differ. Overall, approximately 70% of patients experience improvement in their symptoms with surgery.

Invasive Cerebrospinal Fluid Cysts and Cephaloceles of the Petrous Apex

OBJECTIVE

To describe the presentation, diagnostic evaluation, and surgical management of petrous apex cerebrospinal fluid (CSF) cysts and cephaloceles.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Six patients with symptomatic CSF cysts or cephaloceles.

INTERVENTION(S)

All patients underwent operative intervention.

MAIN OUTCOME MEASURE(S)

Presentation, imaging characteristics, operative findings, surgical approach, resolution of symptoms, and complications.

RESULTS

Six patients presented with various neurotologic symptoms including vertigo, otalgia, diplopia, meningitis, hearing loss, and retroorbital headaches. Four lesions were centered within the anterior petrous apex and were classified as a cephalocele originating from Meckel's cave. The remaining two lesions were arachnoid cysts that involved the posterior petrous apex. Cysts and cephaloceles both demonstrated bone erosion on computed tomography and were hyperintense on T2-weighted magnetic resonance imaging and isointense or hypointense on T1-weighted magnetic resonance imaging. A variety of surgical approaches was used to treat these lesions. Preoperative symptoms were improved in five of six cases. One patient developed a postoperative CSF leak that resolved with conservative measures.

CONCLUSION

Petrous apex CSF cysts and cephaloceles may present with a variety of neurotologic symptoms. Imaging often helps narrow the differential diagnosis, but these lesions can still be confused with other erosive skull base lesions such as cholesterol granulomas, epidermoids, or tumors. Optimal treatment of symptomatic posterior petrous apex CSF cysts is marsupialization via a posterior fossa approach (i.e., retrosigmoid or retrolabyrinthine). A middle fossa approach with obliteration of the anterior petrous apex may be used to treat symptomatic CSF cephaloceles arising from Meckel's cave.

Brucellar brain abscess and bilateral arachnoid cysts, unilaterally complicated by subdural haematoma

Arachnoid cysts are benign developmental cysts that occur along the cerebrospinal axis. Brucellar abscesses in the brain are relatively uncommon, with only a few cases reported in the literature. We report here a patient with a brucellar brain abscess and bilateral arachnoid cysts (one complicated with subdural haemorrhage), who was successfully managed with craniotomy and antibiotics.

Association of a sylvian arachnoid cyst and trigonocephaly in a developing child: importance and management

INTRODUCTION

Trigonocephaly and arachnoid cysts are two different entities that may cause intracerebral pressure elevation: one by space occupying and the other by space restriction. The true incidence of association of trigonocephaly and sylvian arachnoid cyst is not known. We present a rare case of trigonocephaly associated with a sylvian arachnoid cyst in a patient that underwent forehead reconstruction and fenestration of the arachnoid cyst in the same operation.

CASE REPORT

Investigation of an 11-month-old girl suffering from triangular appearance of the forehead since birth revealed metopic suture synostosis and type II sylvian arachnoid cyst. Neurological examination was normal. There were no seizure history and no other systemic malformation that could be a part of any syndromes associated with cranial synostosis. Forehead reconstruction with forehead advancement for trigonocephaly and fenestration of the arachnoid cyst to the basal cisterns were performed in the same operation. Satisfactory outcome was achieved.

CONCLUSION

The coexistence of craniosynostosis and arachnoid cyst is rare. They can be treated surgically in a single session.

Cerebellopontine angle arachnoid cysts in adult patients: what is the appropriate management?

Arachnoid cysts can occur at different intracranial sites, including the cerebellopontine angle (CPA). The incidence of arachnoid cysts is 1 per cent of all intracranial lesions. Recent advances in MRI (magnetic resonance imaging) scan techniques have led to CPA arachnoid cysts being more frequently diagnosed and with a higher degree of certainty. The need for further understanding of their natural history as well as for the development of a management rationale has been highlighted with this increased rate of diagnosis.

We present a series of five adult patients with different clinical presentations attributed to CPA arachnoid cysts. These lesions have a characteristic location in the posterior-inferior aspect of the CPA below the facial and vestibulocochlear nerves. These cysts did not show change in size on repeated MRI scan and the patients’ symptoms did not progress over the period of follow up. Our findings would support a conservative management approach to the majority of these cysts.

Management of pilocytic astrocytoma with diffuse leptomeningeal spread: two cases and review of the literature

INTRODUCTION

Leptomeningeal dissemination of juvenile pilocytic astrocytoma (JPA) is a rare event. We report two children with disseminated JPAs treated with a chemotherapeutic agent, temozolomide, after progression of the disease despite surgery, traditional chemotherapy, and/or radiation therapy.

CASE REPORTS

Patient 1 presented with hydrocephalus and progressive lower extremity weakness, and was found to have a suprasellar mass as well as extensive spinal disease. Ventriculoperitoneal shunting, decompressive laminectomy with spinal tumor debulking, and chemotherapy with carboplatin and vincristine were initially employed. However, disease progressed and craniospinal irradiation and temozolomide were used. Patient 1 remains in a fair condition today, 2 years later. Patient 2 presented at 8 months of age with failure to thrive. Imaging revealed a cystic lesion in the hypothalamic region with extensive subarachnoid metastatic disease to the spine. Biopsy was performed followed by chemotherapy with vincristine, cyclohexylchloroethylnitrosourea (CCNU), 6-TG, and procarbazine. Due to the continued progression of the disease, cytoreductive surgery was performed and her chemotherapeutic regimen was switched to temozolomide. Two years after initial presentation patient 2 is clinically much improved with stable residual disease.

DISCUSSION

We review the literature and discuss treatment strategies for this challenging disease.

[Intracranial arachnoid cysts]

INTRODUCTION

Arachnoid cysts are intra-arachnoid collections of cerebrospinal fluid; congenital in origin, they account for about 1% of all atraumatic intracranial mass lesions. They cause neurological deficit through expansion that can compress normal neural tissue and obstruct cerebrospinal fluid flow.

DEVELOPMENT

We review the pertinent literature of the formation and evolution of congenital arachnoid cyst and the epidemiological, clinical, neuroradiological aspects and treatment of intracranial arachnoid cyst.

CONCLUSIONS

Arachnoid cysts are benign congenital collections of cerebrospinal fluid. They usually arise in areas that are rich in arachnoid, and 50% are located in the sylvian fissure. Symptoms depend on size and location. Seizures and headache are said to be the most common symptoms of middle cranial fossa cysts. The definitive treatment for arachnoid cysts is surgery and the indications for surgery most likely are the presence of progressive hydrocephalus or intracranial hypertension.

Cystoventricular shunting of intracranial arachnoid cysts

Ten patients with intracranial arachnoid cysts were treated with direct shunting of the cyst to a lateral ventricle. The strategic goal of cystoventricular shunting is to establish physiologically normal intracranial pressure relationships, rather than cyst obliteration. Cystoventricular shunts were successful in treating single and multiple intracranial cysts in supratentorial and infratentorial locations and in patients with normal and enlarged lateral ventricles. Cystoventricular shunting is conceptually simple as well as effective and reliable.

Posterior fossa arachnoid cysts can mimic Meniere’s disease

Arachnoid cysts constitute 1% of all intracranial space-occupying lesions. In the posterior fossa, they typically produce vague, nonspecific symptoms. However, a subset of these lesions can produce signs and symptoms indistinguishable from those of Meniere's disease. We discuss the clinical and laboratory features of 2 cases of posterior fossa arachnoid cysts mimicking Meniere's disease as well as the substantial resolution of symptoms in 1 patient after cysto-peritoneal shunt. Posterior fossa arachnoid cyst must be considered in the differential diagnosis of patients presenting with signs and symptoms of Meniere's disease.

[Arachnoid cyst and pregnancy. Report of a case]

The arachnoid cysts are intracranial liquid collections with a congenital etiology. It is necessary to establish the absence of bibliographical information about this disease and its relation with pregnancy. A case is presented related to the treatment of a nineteen year old pregnant patient with a 31 week pregnancy and a history of arachnoid cysts with convulsions as the main symptom.

[De novo arachnoid cyst treated with a cystoperitoneal shunt]

INTRODUCTION

Arachnoid cysts (AC) are benign pathological structures that are typically found during childhood, and represent approximately 1% of all intracranial lesions. Unlike cases of secondary cysts with a known causation, which can be attributed to inflammatory processes or traumatic brain injuries, the causation of the primary cysts is unknown. In the cases reported to date, the cysts present from the first imaging study conducted, which is why they are considered to be of a prenatal origin.

CASE REPORT

A boy who, at the age of 5 months, is found to have an AC of considerable dimensions that did not appear in a transfontanellar echographic study carried out for other reasons at the age of 2 months.

CONCLUSION

The importance of this case lies in the fact that it has been possible to show the appearance of a cyst after birth in a sequence of images in the case of a pathology which, according to all the theories and tests, is considered to have a congenital causation.

Huge arachnoid cyst of the posterior fossa with cerebellar tentorium dysplasia associated with juvenile polyposis

We report an infant with a huge arachnoid cyst of the posterior fossa with dysplasia of the cerebellar tentorium and meningeal sinus and associated juvenile polyposis. Neuroimaging studies disclosed a huge median cystic lesion extending posterosuperiorly over the cerebellum. The cerebellar tentorium was raised to the parietal area; the vermis was normoplastic. Cystography showed no direct communication with the 4th ventricle or subarachnoid space. We discuss the differential diagnosis of median cysts of the posterior fossa and the association of juvenile polyposis.

Cranial MRI scans are indicated in all girls with central precocious puberty

AIMS

(1) To assess the value of cranial magnetic resonance imaging (MRI) scans in the investigation of girls with central precocious puberty (CPP); and (2) to determine the clinical predictors of abnormal cranial MRI scans in these patients.

METHODS

A retrospective study of 67 girls diagnosed with CPP who underwent cranial MRI scans at diagnosis. Patients with neurological signs or symptoms at presentation were excluded.

RESULTS

The mean age of onset of puberty was 6.2 years (range 2.0-7.9). Intracranial abnormalities were present in 10 (15%) patients (MR+), while 57 (85%) had no abnormalities (MR-). There was no statistical difference between MR+ patients and MR- patients at presentation with respect to age of onset of puberty, pubertal stage, bone age advance, pelvic ultrasound findings, or height or body mass index standard deviation scores (SDS).

CONCLUSION

Girls with CPP should have a cranial MRI scan as part of their assessment since clinical features, including age, are not helpful in predicting those with underlying pathology. Implementation of such an approach may have a substantial effect on clinical practice and healthcare cost.

Intra-CSF administered recombinant adenovirus causes an immune response-mediated toxicity

High doses of adenotk were injected into the cerebrospinal fluid of rats and nonhuman primates (Macaca mulatta). Vector administration was followed by ganciclovir administration for 14 days. Despite the absence of clinical symptoms, analysis of the cerebrospinal fluid (CSF) and histopathological examination of the central nervous system (CNS) of the monkeys (3 weeks after vector injection) were consistent with a viral meningitis. Immunohistochemical analysis of the inflammatory infiltrates in the monkeys revealed the presence of T and B lymphocytes, indicating a combined cellular and humoral immune response to the vector. This latter was supported by the finding of intrathecal anti-adenovirus antibody synthesis. Rats receiving high intrathecal adenotk doses showed a transient and dose-dependent clinical toxicity consisting of lethargy, hyperemic eyes and weight loss. Histopathological examination of the meninges showed a shift from polymorphonuclear infiltrates during the first post-injection days to clusters of mononuclear cells after 7 days. Acute toxicity is probably related to the early, innate immune response to the vector. In a separate experiment, high levels of IL-8 and IL-6, were measured during the first 2-3 post-injection days in the CSF of two monkeys which received intrathecal adenoLacZ. Therefore, these cytokines seem to play an important role in initiating the nonspecific immune response. In one monkey which received adenotk, recombinant adenovirus was cultured from serum samples obtained at the 7th post-injection day. At this time-point, no vector could be isolated from CSF samples. Based on these preclinical data, we recommend careful dose finding for clinical studies that aim to treat patients with leptomeningeal metastases.

[Intracranial arachnoid cysts. A review]

The diagnosis of arachnoid cyst has become easier and more frequent with the general use of CTscanner and MRI. Their congenital origin is usually accepted. They correspond to liquid formations surrounded by an arachnoid sheet but their pathophysiologie remains unclear. When they are asymptomatic and incidentally discovered, they do not require any peculiar treatment. Variable neurological signs depending on location may be inaugural, although intracranial hypertension is the most frequent. The treatment of these symptomatic cysts remains surgical. Several options are possible: direct approach of the cyst, derivation of the cyst with different modalities, or endoscopic fenestration. This last technique, the most recent, seems to give interesting results especially for deep located cysts or those close to the ventricles.

[The radiological findings in surgically and conservatively treated intracranial arachnoid cysts]

PURPOSE

To determine which appearances on CT or MRI are indications for surgical treatment of intracranial arachnoid cysts.

METHOD

The images obtained from 26 patients treated either by surgery or conservatively were compared retrospectively. The features evaluated were the size of the cyst, evidence of a space-occupying lesion, cerebral abnormalities near the cyst and skull deformities.

RESULTS

In 6 patients (23%), surgical treatment was indicated because of the presence of obstructive hydrocephalus. The presence of all other radiological findings did not differ significantly between the two analysed groups. 92% of the patients treated surgically benefited from the treatment. Fenestration and shunting produced similar results in respect to reduction in size of the cyst and the clinical and neurological symptoms.

CONCLUSION

The only indication for surgery is the presence of obstructive hydrocephalus. The other features were seen equally amongst the patients treated conservatively and the surgical patients and had no influence on the decision to operate.

Evaluation of endoscopy in the treatment of rare meningoceles: preliminary results

BACKGROUND

Endoscopy is used on different occasions-for instance, to open the floor of the third ventricule in triventricular hydrocephalus, to open a cyst into the cerebrospinal fluid circulation, for biopsy or for partial resection of some tumors, or to insert a shunt in hydrocephalus or syringohydromyelia. However, the use of endoscopes for evaluating and treating meningoceles remains to be assessed.

METHODS

Five different kinds of rare meningoceles are presented. In each, neuroendoscopy was used as the main tool for exploration and treatment.

RESULTS

Two sacral meningoceles and one oral cephalocele were cured through a keyhole opening under endoscopic control. One posterior sacral meningocele was explored and no communication with normal subarachnoid spaces was observed, allowing a simple suture of the posterior to the anterior walls. And, last, a complex case with three intrasacral meningocles was explored and partially treated.

CONCLUSIONS

Meningocles with very small communication within the normal subarachnoid spaces appeared the most suitable to be cured by an endoscopic procedure. In case of a larger communication, the meningocele could be treated, or at least the morphology can be better understood, by using a keyhole procedure under endoscopic control. In all cases the surgery was of short duration (less than 1 hour) and very well tolerated.

[Arachnoid cyst as the differential diagnosis of ischemic optic neuropathy in type-II diabetes]

HISTORY AND CLINICAL FINDINGS

A 71-year-old woman, a diabetic (type IIb) for 27 years, developed bilateral hemianopsia over a period of about 2 years. A few weeks before hospital admission the defect in her visual fields increased more rapidly and double vision occurred intermittently. The hemianopsia was demonstrated by finger perimetry. There was no evidence of heart failure or peripheral vascular disease. Muscle reflexes were normal, but there was a decrease in vibratory sensation in both feet. The cause of the visual disturbance was at first thought to be an ischaemic optic neuropathy.

INVESTIGATIONS

Biochemical tests showed an HbA1 of 12.8%, blood sugar levels were between 230 and 359 mg/dl, and there was increased intravascular platelet activation. Ophthalmological examination confirmed bitemporal hemianopsia and early retinopathy. Magnetic resonance imaging of the skull revealed an intra- and suprasellar cystic space-occupying lesion extending to the right optic chiasma. These findings, taken together, indicated an arachnoidal cyst.

TREATMENT AND COURSE

After the diabetic metabolic state had been normalized with insulin treatment (average of 30 IU of an intermediary insulin) and dietary measures, the cyst was evacuated stereotactically. The hemianopsia quickly improved markedly and the patient was discharged 4 days after the operation with her vision nearly fully restored.

Percutaneous catheter placement for cyst drainage in the subarachnoid space

A technique for percutaneous catheter drainage of cystic masses in the subarachnoid space was developed and shown to be safe and effective in an 18-year-old boy with life-threatening, recurrent neuroenteric cysts that compressed the brain stem, cerebellum, and spinal cord. Percutaneous drainage through a C1-C2 approach was performed on 11 separate occasions. Decompression was always accomplished and no infection or other complication occurred, even with continuous catheter drainage for 9 months. This technique provides opportunities for interventional neuroradiologic therapy in the subarachnoid space. It appears to be suited for percutaneous drainage of intraspinal and intracranial cysts when surgery is not indicated due to intractability or inaccessibility.

Neurologic complications of systemic cancer

Neurologic complications of systemic cancer are common. Metastatic complications include intracranial metastasis, spinal metastasis, leptomeningeal metastasis, and metastasis to peripheral nerves. Treatment is often effective in preventing further neurologic disability and pain. Early diagnosis is important. Nonmetastatic complications of systemic cancer include a wide variety of neurologic illnesses that can also occur in the noncancer population. The most common is toxic metabolic encephalopathy. Other nonmetastatic complications include cerebrovascular complications, complications of treatment, immunocompromised infections, and paraneoplastic syndromes.

Neuroepithelial cyst of the lateral ventricle. Clinical features and treatment

This report concerns eight patients with noncolloid neuroepithelial cyst of the lateral ventricle, including four surgical and four conservative cases. Of the surgical patients, two had headache, one had orbital pain, and one had seizures. In the conservative group there were no symptoms due to the cysts and no changes in computed tomography scan during follow-up for an average of 1.4 years. Magnetic resonance imaging was performed in five cases and showed a cyst with an intensity similar to cerebrospinal fluid, while a cyst membrane was also detected in three cases. Our findings suggest that (1) the majority of symptomatic neuroepithelial cysts in the lateral ventricle are located in the trigone; (2) the cause of symptoms suggestive of obstruction, such as headache, is an isolated ventricle that demonstrates dilatation of the inferior horn on computed tomography and magnetic resonance imaging; (3) the operative indication is obstructive symptoms; and (4) cyst-peritoneal shunt is an effective procedure.

[Psychiatric and neuropsychological symptoms in children with arachnoid cysts--a case report]

Arachnoid cysts (AC) are intracranial, extracerebral cysts. They can produce a wide variety of neurological symptoms, but they can also be asymptomatic or produce psychological or psychiatric symptoms. First, a short overview of the clinical manifestations of AC is given. There is an astonishing lack of literature dealing with psychological problems in children with AC. The case of a 12-year-old boy with a large left temporofrontal AC without increased intracranial pressure is presented. The psychiatric symptoms, which had begun only a few months earlier, included lack of interest, attention deficit, difficulties in contact and communication, severe outbursts of aggression and obsessive-compulsive, inhibited behavior. The main neuropsychological finding was slow and hesitant expression of thoughts despite an intelligence level in the upper normal range. The findings and course are described in detail. They are discussed as signs of an organic psychosyndrome due to the AC.

Diagnosis and treatment of arachnoid cysts of the posterior fossa

Arachnoid cysts of the posterior fossa are rare. When arachnoid cysts are encountered, the presenting symptoms are frequently otologic, with hearing loss and imbalance occurring commonly. Three cases are presented with a previously unreported otologic symptom, that of bilateral hearing loss, which in one case was fluctuant. None of the patients had the common symptoms of unilateral hearing loss and headache. With the advent of computed tomography and magnetic resonance imaging, these cysts may be readily identified, usually with diagnostic imaging alone. Unfortunately there is often a delay in diagnosis because of the vague and fleeting nature of the symptoms. Because no single diagnostic symptom pattern is able to characterize all cases, it is believed computed tomography or magnetic resonance imaging or both are indicated in patients with long-standing otologic complaints--even in the absence of unilateral symptoms. Treatment of posterior fossa arachnoid cysts primarily consists of surgical procedures designed to decompress the cyst. In this series, treatment with diuretics alone resulted in improvement of symptoms during several years of followup, with no evidence of enlargement of the cysts.

Computerized tomographic stereotaxy in the management of 200 consecutive intracranial mass lesions. Analysis of indications, benefits and outcome

Two hundred consecutive stereotactic procedures were performed. These were 153 biopsies and 43 therapeutic procedures. The latter included aspiration of craniopharyngiomata, arachnoid cysts, deep-seated abscesses, and the destruction of colloid cysts. Cryogenesis was used to treat an arteriovenious malformation (AVM) in one case. In four cases, the system was used to locate lesions during open surgery. Leksell stereotactic systems were used throughout. The ages of the patients ranged between 12 months and 83 years. Overall, in 35% of biopsies the preoperative diagnosis was not confirmed. When the provisional diagnosis was glioma 70% were confirmed; 21% of them were benign, with 9% some other form of malignancy. Biopsy provided tissue on which a histological diagnosis could be made in 140 procedures. In eight cases the biopsy was repeated and in seven cases a positive diagnosis was subsequently made. Mortality was 1%; there was transient deterioration postoperatively in 5% and prolonged deterioration in 1%. These observations suggest that stereotactic surgery is far superior to freehand burr hole biopsy in the management of these lesions. No radiation treatment should be considered without histological confirmation.