Adult cerebellar medulloblastoma: imaging features with emphasis on MR findings.

PURPOSE: To describe the MR imaging features of cerebellar medulloblastoma in the adult. MATERIALS AND METHODS: The neuroimages and records of 15 adults with proved cerebellar medulloblastoma were retrospectively evaluated. In 12 patients, preoperative MR scans were reviewed; nine had Gd-DTPA-enhanced scans. RESULTS: Of the 12 tumors evaluated preoperatively, eight were hemispheric, two hemispheric-vermian, and two vermian. Tumor margins were well demarcated, except in three cases, two of which had large infiltrative tumors. In 10 cases, tumor extended to the brain surface, and in five of these, contiguity with the tentorium or cerebellopontine angle cistern was such than an extraaxial tumor was considered. The tumors were typically hypointense on T1 but a spectrum was seen on T2-weighted images. Enhancement ranged from minimal and patchy to marked. One tumor became isointense after Gd-DTPA. Other features included cystic changes, hemorrhage, exophytic invasion at the cerebellopontine angle, spinal cerebrospinal fluid seeding, intraventricular seeding, and bone metastasis. CONCLUSION: Although there is no pathognomonic MR appearance of adult cerebellar medulloblastoma, the finding of a well-demarcated, mild to moderately enhancing hemispheric mass involving the brain surface in a young adult is suggestive of medulloblastoma. Awareness that this tumor may resemble meningioma may avoid misdiagnosis and aid surgical planning.

The split notochord syndrome with dorsal enteric fistula.

Split notochord syndrome with dorsal enteric fistula is an extremely rare congenital anomaly that may be associated with meningomyelocele or meningocele, and genitourinary anomalies. This case presented with an additional finding of bladder exstrophy, raising the possibility of a relationship between this syndrome and the OEIS complex.

Intracerebral hemorrhage from a middle meningeal arteriovenous fistula with a giant venous varix.

A patient with a congenital arteriovenous fistula between the middle meningeal artery and a cortical vein with a giant venous varix is described. The patient presented with an intracerebral hemorrhage that had been evacuated. Permanent cure of the fistula was achieved without morbidity by embolization with Ivalon particles.

Spontaneous closure of a high-risk dural arteriovenous malformation of the transverse sinus.

The case of a 44-year-old woman with tinnitus of her left ear is presented. An arteriogram demonstrated a posterior dural arteriovenous malformation (AVM) on that side with drainage via dilated cortical veins into the superior sagittal sinus. No intervention was undertaken. When angiography was repeated 7 years later, no dural AVM was seen.

Traumatic pseudoaneurysm of the cervical carotid artery: the value of arteriography.

A patient who sustained a gunshot wound to the neck and subsequent blunt trauma is presented. No angiogram was performed after the initial injury. Subsequently, the patient developed a cerebral embolus from a thrombus dislodged from a pseudoaneurysm of the cervical carotid artery, resulting in complete occlusion of the distal internal carotid artery. After antiplatelet therapy, the distal internal carotid artery recanalized, and the pseudoaneurysm occluded spontaneously. We stress the need for the use of arteriography in the initial evaluation of penetrating injuries to the neck and the utility of repeated arteriograms for further treatment planning as these traumatic lesions can change with time.

Interventional neurovascular treatment of traumatic carotid and vertebral artery lesions: results in 234 cases.

Traumatic injuries to the head and neck that result in arteriovenous fistulae are often difficult to treat by direct surgical access. This is because of anatomic location, instability of the acutely injured patient, and difficulty in localizing the exact site of injury. Between 1974 and 1988, 234 consecutive cases of traumatic injuries to the carotid or vertebral artery were evaluated by our group for intravascular embolization therapy. This included 206 cases of direct and seven cases of indirect carotid-cavernous sinus fistulae and 21 cases of traumatic vertebral fistulae. A variety of devices including detachable balloons, liquid tissue adhesives, microcoils, and silk suture were used with the goal of fistula occlusion and preservation of the parent vessel. This was achieved in 193 cases (82%). In the remaining 41 cases (18%), the carotid or vertebral artery had to be occluded by endovascular occlusion techniques because of extensive vascular injury in 28 cases and subtotal occlusion of the fistula in 13 cases. Complications included transient cerebral ischemia in six cases, pseudoaneurysm formation in five cases, stroke in five cases, and peripheral nerve injury in one case. The development of interventional neurovascular techniques has altered the management of these acutely injured patients. The preferred method for treatment has shifted from direct surgical access under general anesthesia to endovascular therapy under local anesthesia.

Hematoma of optic nerve glioma--a cause for sudden proptosis. Magnetic resonance imaging findings.

Optic nerve glioma in patients with neurofibromatosis is a relatively benign neoplasm. It is slow growing and considered by some to be a hamartoma. Clinical presentation usually includes loss of vision and gradual, painless proptosis. We report a case in which abrupt proptosis of the right eye was shown on magnetic resonance imaging to be due to a hemorrhage into the tumor.

Septation in syringomyelia and its possible clinical significance.

A 3-year-old boy with a septated syrinx and several other dysraphic features is presented. The literature regarding the cause, diagnosis, and pathology of septation in syringomyelia is reviewed. This case raises two points. First, the septated pattern may be associated with an elevated pressure in the syrinx. Second, despite the septations, the syrinx may communicate freely.

Percutaneous transluminal angioplasty of the carotid artery.

Percutaneous transluminal angioplasty (PTA) is being extensively applied to treat arteriosclerotic lesions. However, this application has not been widely accepted for the treatment of carotid artery stenosis. Successful attempts to relieve cerebral ischemia from extracranial carotid arterial stenosis by PTA are reported. Twenty-seven patients with arteriosclerotic stenosis, fibromuscular disease, and Takayasu carotid arterial stenosis were treated by PTA. All anatomic carotid stenotic lesions were corrected without any neurologic complication. Follow-ups ranged from 3 months to 4 years without recurrent symptoms in any patient. These results may suggest that some patients with cerebral ischemia secondary to extracranial carotid artery stenosis may be treated safely and effectively by PTA.

Treatment of direct carotid cavernous sinus fistulae. Various therapeutic approaches and results in 148 cases.

From 1974 to 1986, 148 patients with carotid cavernous fistula (CCF) were evaluated for intravascular therapy. Four patients died from hemorrhage before treatment could be instituted and the CCF closed spontaneously in 5. Therapeutic approaches which resulted in complete occlusion in the remaining 139 cases were transarterial in 118, transvenous in 15 and external compression of the carotid artery and jugular vein in 6. The current treatment of choice of the direct CCF is intravascular embolization using detachable balloons, particulate emboli or liquid adhesive agents to occlude the CCF while attempting to preserve the carotid artery. In 15 patients it was technically too difficult to use the transarterial approach. The patients were therefore treated from a transvenous approach including access via the femoral vein, superior ophthalmic vein, intraoperatively from the inferior petrosal sinus or direct puncture of the cavernous sinus. Embolic agents used included detachable silicone balloons, steel minicoils, particulate emboli and isobutyl-2-cyanoacrylate. In 14 of these 15 patients total obliteration was achieved with marked improvement in symptoms. Complications occurred in 3 patients including perforation of the cavernous sinus resulting in subarachnoid hemorrhage, delayed pontine hemorrhage from subtotal occlusion of the fistula and transient increased proptosis.

Practical aspects of percutaneous transluminal angioplasty of the carotid artery.

The authors are reporting a total of 41 patients undergoing percutaneous transluminal angioplasty (PTA) at different levels of the carotid artery. The procedure for proximal carotid artery was performed on 17 patients, for mid or distal common carotid artery on 4 patients, for carotid bifurcations on 5 patients, for internal carotid artery on 6 patients, for external carotid artery on 4 patients, and for fibromuscular dysplasia of the internal carotid artery on 5 patients. We also collected research on an additional 53 patients from the literature for a total of 94 patients. To date, we have not encountered any mortalities nor neurologic complications in performing this procedure. Thus, we believe that PTA may be performed with reasonable safety and as an alternate procedure in the treatment of carotid artery stenosis.

Solitary osteochondroma with spinal cord compression.

Osteochondromas are unusual in the spine, and they are very rarely present with compression of the spinal cord. Two cases are reported with delineation of the tumor by metrizamide myelography and computed tomography.

Arterial digital subtraction angiography with particulate intravascular embolization and angioplasty.

The authors are reporting their experience with arterial digital subtraction angiography to monitor particular intravascular embolization in hypervascular tumors and malformations and angioplasty. Arterial digital subtraction angiography may reduce the time of waiting for regular film developing and subtraction. The smaller amount of contrast material being used in arterial digital subtraction angiography minimizes the discomfort to the patients. It also prevents further renal damage in those patients with poor renal function. The arterial digital subtraction angiography may detect the early warning signs of embolotherapy. From the past experience, the authors have found that arterial digital subtraction angiography should be considered as a better alternative way to performing the particulate embolization and angioplasty than being monitored by conventional angiography.

Therapeutic embolization for vascular trauma of the head and neck.

Therapeutic embolization is an effective and relatively safe method for managing many cases of head and neck trauma. In the last 5 years, 78 traumatic vascular lesions--10 arterial transections and 68 arteriovenous fistula--were treated by intravascular embolization at four medical centers. Selection of embolic materials is discussed and different types of lesions are illustrated. Treatment was successful in every instance. Complications were limited to one case of cerebral infarction and two cases of temporary oculomotor weakness. The indications for embolization have widened beyond life-threatening hemorrhage alone, and continued improvement in techniques and embolic agents should see an increased use of this form of treatment.

A new method for treating carcinomatous biliary obstruction with intracatheter radium.

We describe a new method for relieving biliary obstruction due to malignant solid tumors. The method consists of placement of radium needles in a Ring biliary drainage catheter for three days. After removing the radium needles, the catheter is left in place to allow for repair of irradiated tissues, then it is removed. The object is to leave the patient with a patent biliary tree without a biliary drainage prosthesis. The clinical course of six patients treated by this method is described, and the autopsy findings in three cases are outlined. Three patients died with a serum total bilirubin ranging from 1--4.5 mg/100 ml, two to three months after removing the drainage catheter. Two patients died before the bile drainage catheter could be removed. One patient is alive with a bile drainage catheter in place. Possible modifications in technique and catheters are being considered.

Subdural metastases from prostatic adenocarcinoma.

Adenocarcinoma of the prostate commonly metastasizes to lymph nodes and bones, with occasional visceral deposits; lesions in the brain are rare. Although leptomeningeal carcinomatosis secondary to prostatic tumor has been reported, discrete cranial dural metastases from prostatic adenocarcinoma have not been described previously. The case of a patient having a unique adenocarcinoma of the prostate with bone, lymph node, and subdural metastatic lesions is presented.

Diagnosis of cerebellopontine angle tumors with small quantities of air.

Difficulty in detecting small acoustic neuromas has encouraged us to study patients suspected of having a tumor by air cisternography augmented with computed tomography. Ninety patients were examined without complication. Five cubic centimeter of air was introduced via lumbar puncture and manipulated into the cerebellopontine angle cisterns. Scanning is commenced immediately. Filling of both internal auditory canals and identification of the neurovascular bundle in the cerebellopontine angle cistern was possible in all patients except those with tumors. The diagnostic accuracy, speed, and lack of morbidity have made this procedure the initial radiologic examination at our institution for patients suspected of having acoustic neuroma.