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Object: This study aims to show the relationship between clinical outcome in patients who underwent surgical decompression for Chiari malformation (CM) and postoperative imaging studies, with particular emphasis on the subarachnoid cisterns of the posterior fossa., Methods: One hundred seventy-seven patients with CM, including 97 with syringomyelia, underwent posterior fossa decompressive surgery. Both the dura and arachnoid were opened in 150 of these patients, and 135 underwent reduction of the cerebellar tonsils. The patients' clinical signs and symptoms were evaluated at 2 time points after surgery. Their imaging studies were analyzed specifically for the size of the retrotonsillar and subtonsillar cisterns and the syringomyelic cavities. The authors evaluated the relationship between these imaging findings and clinical parameters., Results: Clinical improvement correlated strongly with enlargement of the subarachnoid cisterns, and enlargement of the cisterns also correlated with reduction in size of the syrinx cavities. Symptoms related to syringomyelia responded to reduction in size of the syrinx cavities., Conclusions: Surgical decompression of the posterior fossa should aim to create relatively large subarachnoid cisterns and reduce the size of the syrinx cavity. Reduction of the cerebellar tonsils by surgical means, together with duraplasty, achieves this goal and thereby improves the clinical outcome for patients with CM. An incidental observation of the study is that obesity increases the likelihood of headache in patients with CM.

Fourteen MS patients took pentoxifylline at varying doses for up to 24 months. In vitro production of tumor necrosis factor alpha was reduced in patients taking 2,400 to 3,200 mg/day of pentoxifylline for 12 weeks or more. Twelve of the 14 patients experienced worsening of the disease during the study according to clinical, MRI, or visual evoked potential criteria. These results provide no hint of efficacy for pentoxifylline as a treatment for MS in progression phase.

Rationale and Objectives: The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation., Methods: Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet., Results: There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions., Conclusion: Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Schwannomas are tumors derived from nerve sheath cells, which are often located in the head and neck, including the CNS. Although a definitive vascular pattern has been previously characterized for these lesions, preoperative embolization of the more vascular schwannomas has not been described. In a review of eight patients with schwannomas who underwent angiography at our institution since 1987, a characteristic vascular pattern became apparent that helped distinguish these lesions from other lesions of the head and neck. The lesions were moderately vascular with tortuous tumor vessels. Scattered, small puddles of contrast medium seen in the mid-arterial, capillary, and venous phases were believed to be characteristic of these lesions. Multiple feeding vessels were noted in all but one case, but these were only minimally enlarged. No arteriovenous shunting or vascular encasement was identified. Six of eight lesions were embolized with significant devascularization and no morbidity or mortality. In patients with head and neck tumors whose angiographic findings include a pattern of moderate hypervascularity, tortuous tumor vessels, and, in particular, scattered contrast puddles without arteriovenous shunting or vascular encasement, schwannoma should be suspected. Embolization is a useful and safe presurgical adjunct in the treatment of vascular schwannomas.

The authors describe the novel combination of two traditional methods to facilitate diagnosis of Meckel cave lesions, which may otherwise require craniotomy to obtain adequate tissue samples. Fine-needle-aspiration biopsy cytology was performed on tissue obtained with a percutaneous approach via the foramen ovale with use of fluoroscopic guidance and intravenous analgesia during an outpatient procedure. This new application of fine-needle-aspiration biopsy cytology results in decreased patient morbidity and significant cost reduction.

A spectrum of embolic agents including PVA, avitene, gelfoam, ethanol, IBCA, silicone microspheres, metal and platinum coils, and balloons containing contrast of HEMA were imaged in vitro at 0.3 Tesla using spin echo, gradient echo, and inversion recovery sequences. Signal intensities associated with these agents and changes created by addition of blood are presented. The in vitro model is also correlated with clinical MR material. Recognition of embolic materials is important to avoid confusion with persistent flow void, hemorrhage, or thrombus.

Giant intracranial aneurysms (GIA) may simulate brain neoplasms on computed tomography (CT) scans. We present three cases in which a GIA was mistakenly diagnosed as a brain neoplasm on the basis of CT findings. The correct diagnosis was made in each case by cerebral angiography. The possibility of GIA must be considered when a nonenhanced CT study shows a well circumscribed mass without edema at the base of the brain and contrast infusion reveals homogeneous or inhomogeneous enhancement.

A series of myelographies performed with a smaller than customary dose (3.75 g) of metrizamide was compared with a series using the larger customary dose. While little decrease in the incidence of headache and vomiting resulted from the decreased dose, there was a heartening drop in the incidence of psychoneurologic side effects. Little difference in diagnostic quality between the two series resulted when the contrast agent was injected close to the site of main interest, but total spinal canal myelography performed with the low dose is often inadequate.

Dural arteriovenous fistulae of the transverse and sigmoid sinuses are highly variable in symptomatology and prognosis. However, we have identified a subgroup of patients who have a high risk of hemorrhage and dementia due to severe venous overload caused by high arterial flow into the fistulae and by occlusive changes of the transverse and sigmoid sinuses. Three representative cases selected from 31 patients with dural arteriovenous fistulae of the transverse and sigmoid sinuses are presented, and 45 reported similar cases are reviewed to discuss pathophysiology and problems encountered during treatment.

The normal anatomy of the nasopharynx and floor of the middle cranial fossa was analyzed with magnetic resonance (MR) imaging. MR images from five healthy volunteers were correlated with whole-organ cryomicrotome sections from three cadavers. Anatomic connections exist between the paranasopharyngeal spaces and the surface structures of the skull base. These anatomic connections include the intimate relationship between the eustachian tube and the pharyngobasilar fascia, the attachment of the muscles of mastication and deglutition to the skull base, and vascular and nervous structures in the foramina. The inherent contrast between the soft tissues of the nasopharynx and related structures and the bone of the floor of the middle cranial fossa allowed excellent visualization of these anatomic connections.

Numerous causes of peripheral facial nerve paralyses have been described; however, none has satisfactorily explained the genesis of the most common type of paralysis, Bell's palsy. Two patients undergoing an experimental embolization of vascular intracranial tumors suffered a total peripheral facial nerve paralysis when occlusion of the middle meningeal artery had been accomplished. It is speculated that this paralysis resulted from ischemia of the horizontal portion of the facial nerve, an observation that has not previously been described and that might be applicable as well to the etiology of Bell's palsy.

Four cases of spontaneous arteriovenous fistula seen in association with fibromuscular dysplasia of the parent artery are presented. In two patients, the fistula was between the carotid artery and cavernous sinus; in two others, the fistula involved the vertebral artery and paravertebral veins. It is postulated that the angiopathy was responsible for the fistula. Treatment by detachable balloon embolization was successful in each case; however, the presence of the fibromuscular dysplasia made treatment more difficult.

A headholder system is described for use in the correlation of images obtained with positron computed tomography (PCT) and other neuroradiological imaging modalities. Methods are described for defining brain anatomy from PCT images by the use of projection schemes from tomographic data. Cross-correlation of images between positron CT and standard lateral skull films, X-ray computed tomography (XCT), and two-dimensional rectilinear positron images are discussed. Such methods allow for improved reproducibility of head positioning and more precise cortical localization necessary in studies of normal brain function as well as in neuropathological conditions.

Normal structure and basic functional anatomy of the brainstem were studied using anatomic sections obtained with a cryomicrotome whole-organ sectioning technique. Major tracts and nuclei were identified and their function summarized. Magnetic resonance imaging of the brainstem was performed on 10 normal volunteers. By comparing these images with the corresponding anatomic sections, normal structures, including major tracts and nuclei, were identified. Knowledge of location and function of clinically important brainstem nuclei and tracts is necessary for optimal magnetic resonance image interpretation.

Four cases of pneumosinus dilatans of the sphenoid sinus are reported, supplementing the eight cases previously reported in the literature. This rare entity is characterized by expansion of a paranasal sinus that contains only air. In one patient, severe visual loss due to compression of the optic canal by the adjacent enlarged sinus was seen. Galactorrhea occurred in one patient, and three of the four patients reported headaches. There was dehiscence of the sinus roof in two cases, which apparently resulted in a cerebrospinal fluid fistula in one. Previous reports of this entity are reviewed, and the radiographic findings and clinical presentations are discussed. It is proposed that the term "pneumosinus dilatans" be used to describe all dilated, air-filled sinuses with outwardly bulging walls when the primary cause is uncertain.

Percutaneous transluminal angioplasty (PTA) for atherosclerotic lesions of the subclavian, vertebral, and brachiocephalic vessels is being performed in selected cases. Clinically patients presented with symptoms of vertebral basilar insufficiency, multiple transient ischemic attacks, subclavian steal syndrome, and motor weakness of the upper extremity. Thus far, 22 procedures have been performed with good results. This included 16 subclavian, 4 vertebral, and 2 innominate arteries. Follow-up has ranged from 8 to 26 months (mean 17 months). No permanent neurologic complications have occurred with this technique, and all patients had significant clinical and radiographic improvement following this procedure.

Demonstration of the anterior surface of the spinal cord is an important step in performing a percutaneous cordotomy. Metrizamide has been found to be a superior agent for this purpose, permitting visualization of the cord shadow in the anteroposterior as well as the lateral projection, and thereby also enabling the surgeon to visualize displacement of the spinal cord during the procedure. Tissue impedance and spinal cord stimulation techniques are used in conjunction with metrizamide. No adverse effects have resulted from the use of this technique.

Evidence on magnetic resonance (MR) images of disk degeneration and herniation, as well as of cord and root impingement, may be regarded either as normal, age-related changes or as causative of symptoms. Individuals referred for MR examinations of the larynx without symptoms referable to the cervical spine were studied retrospectively (35 patients) or prospectively (65 patients) over a 2-year period. With a solenoid surface coil, 5-mm-thick sections were acquired in sagittal, axial, and coronal planes with T1-weighted spin-echo pulsing sequences. Disk protrusion (herniation/bulge) was seen in five of 25 (20%) patients aged 45-54 and 24 of 42 (57%) patients older than 64 years of age. Posterolateral protrusions were seen in only nine of 100 patients and occurred with greatest frequency in patients over 64 years of age. In no patient was obliteration of the intraforaminal fat seen. Spinal cord impingement was observed in nine of 58 (16%) patients under 64 years of age, and in 11 of 42 (26%) patients over 64 years of age. Cord compression was observed in seven of 100 patients and occurred solely secondary to disk protrusion in all cases. The percentage of cord area reduction never exceeded 16% and averaged approximately 7%.

A retrospective clinical and radiographic analysis of 20 patients with orbital venous malformations was performed. The malformations were fed by other veins rather than arteries. They may nearly always be demonstrated by orbital or jugular phlebography, though occasionally they will fill only following direct puncture. There appeared to be varied etiologies. A few were related to trauma or to other causes of increased intraorbital pressure. There is an association with periorbital hemangiomas suggesting developmental or congenital origin.

A case of ependymoma of the conus medullaris and cauda equina is described in which spinal angiography demonstrated rapid arteriovenous shunting, an angiographic sign which is typical of arteriovenous malformations and which has not been previously reported to occur with ependymomas.

Ten normal human volunteers and 44 patients with pathology of the brainstem or cranial nerves were scanned using a. 3 Tesla permanent MR imaging system. MR images were obtained of the cranial nerves and brainstem using various spin-echo pulse sequences and scanning planes. 4 mm thick sections with .75 mm pixels on a 256 display matrix were used whenever possible. The normal MR images were correlated with thin section cryodissection specimens of fresh human cadavers. Brainstem structures including major nuclei and tracts were then identified. The cranial nerves were followed through the subarachnoid cisterns and the base of the skull. Pathological involvement of the brainstem by tumors, infarcts, and demyelinating disease was well shown and correlated with clinical findings. Examples of optic glioma, fifth, eighth, and twelfth nerve schwannomas as well as other cranial nerve pathology were also demonstrated. Magnetic resonance produces excellent images of cranial nerves and brainstem with high contrast resolution. Unlike CT, there is no beam hardening artifact from bone. T1 weighted images maximize brainstem-CSF contrast and are useful for demonstrating the external anatomy of the brainstem and cranial nerves. The T2 weighted images show internal brainstem anatomy, CSF within neural foramina, and highlight many pathological conditions.

Forty children with enlarged heads were studied by pneumoencephalography and/or computer assisted tomography (CAT). Ventricular dimensions from CAT scans of 70 normal children formed a control group. In the group of 40 children with neither hydrocephalus nor brain tumor, CAT more reliably showed ventricular enlargement in patients with neurologic impairment.

We report our experience with intraoperative digital subtraction neuroangiography to demonstrate its application as a diagnostic and therapeutic technique. Intraoperative neuroangiography was performed on 53 occasions in 43 patients using a portable imaging system. Thirty-two procedures were performed for diagnostic purposes after resection of arteriovenous malformations, clipping of aneurysms, or carotid endarterectomy. Unexpected problems were disclosed in seven cases and were surgically remedied immediately in four. In addition, angiography was used as a therapeutic tool in 21 cases to facilitate intraoperative embolization of a vascular lesion or to enable the angioplasty of a vessel inaccessible without direct surgical exposure. We found that by allowing a combined interventional neuroangiographic and neurosurgical approach, intraoperative angiography opened new avenues for treatment of intracranial vascular abnormalities.

A method for accurate localization of intracranial lesions on CT scans is described, using a marker wire and a radiograph exposed by the CT scanner.

A patient who presented with multiple episodes of subarachnoid hemorrhage was diagnosed as having a large mid-basilar artery aneurysm that had no definable surgical neck. Balloon embolization was performed utilizing two detachable silicone balloons to occlude the mid-basilar artery and the aneurysm. The procedure was carried out with the patient fully awake and alert. One day after the procedure, the patient developed pontine and cerebellar ischemia which completely resolved after 5 days on heparin therapy. A follow-up angiogram performed immediately after the procedure and at 3 months demonstrated complete occlusion of the mid-basilar artery and the aneurysm. The patient was intact neurologically upon discharge 5 days after the embolization procedure and has since resumed his normal activities. Balloon embolization therapy may offer some advantages over surgical methods for the treatment of such therapeutically challenging aneurysms.

A material of 120 cases with posterior fossa tumors examined with scanning, vertebral angiography and encephalography was reviewed to determine the value of the information and accuracy these methods provide. Encephalography was the most accurate procedure (98% positive) compared to angiography (81%) and scanning (44%).

Metrizamide is an attractive myelographic agent with several advantages over other available myelographic agents. Radiographic detail is generally superior to Pantopaque and gas myelography, the material need not be aspiradted and does not appear to result in long-term complicaitons. Because of its low neuro-toxicity, it may be allowed to come into contact with the spinal cord and brain, unlike other water-soluble agents. Its main disadvantages are its tendency to diffuse into the CSF when run from one portion of the spinal canal to another and the occurrence of acute toxic effects such as vomiting and, rarely, seizures.

Patients with rhinocerebral mucormycosis and rhinocerebral aspergillosis had computed tomography (CT) as well as other studies. Characteristic sinus involvement was demonstrated by CT and conventional tomography, but the latter produced a better image of bone destruction. CT was clearly superior in demonstrating orbital involvement, the most common of which included lateral displacement of a thickened medial rectus muscle, increased density of the orbital apex, and often enlargement of the optic nerve. Orbital venography and carotid arteriography were diagnostically helpful. Recognition of the characteristic pattern of sinus and orbital involvement should be helpful in leading to early biopsy and treatment.

The treatment of intracranial aneurysms from a transvascular approach, with preservation of the parent vessel is now being performed in selected cases. From a transfemoral approach, a silicone detachable balloon is flow-directed up the carotid or vertebral-basilar artery, guided directly into the aneurysm and detached. The aneurysm is thus excluded from the circulation and the parent artery is preserved. Thus far, this technique has been successful in treating aneurysms in the cavernous carotid, carotid ophthalmic, posterior communicating, distal basilar, and posterior cerebral artery distributions. The indications and techniques of detachable balloon embolization therapy are presented.

Closed injuries to the neck, occasionally associated with mandibular fractures, can result in trauma to the internal carotid artery at the high cervical level opposite the uppermost cervical vertebrae. Such arterial injuries range from spasm to intimal tear with thrombus formation, medial tear, and aneurysm formation. These types of lesions may overlap. Ten patients are presented, five with traumatic carotid occlusions and five with traumatic aneurysms. The clinical diagnosis of traumatic cervical carotid occlusion may be difficult because of the absence of physical trauma to the neck. The diagnosis of aneurysm poses fewer problems. Oculopneumoplethysmography, computerized tomographic head scanning, and carotid arteriography with cross compression are the most useful diagnostic techniques. Thrombectomy should be carried out early, particularly in the presence of fluctuating neurological signs. Aneurysms that cannot be approached directly may necessitate carotid ligation.

Magnetic resonance imaging has become the study of choice for the majority of abnormalities of the craniocervical junction as well as for demonstration of primary pathology of the spinal cord, and brain stem. Although the applications of MR are currently limited by its high cost, relatively long scan time, and low sensitivity to calcification, new pulse sequences, faster scan strategies, and lower cost MR scanner are changing this situation. MR contrast agents and the use of 3-D imaging techniques combined with gradient echoes promise to play a role in MR of the craniocervical junction in the near future.

A 10-year-old girl, with congenital heart disease, harboring a brain stem abscess, was recently treated at the UCLA Hospital. Needle aspirations of the abscess was performed through a posterior occipital craniectomy, and thorium dioxide (Thorotrast) was placed within the abscess cavity as a marker. Postoperatively, the patient improved temporarily but died 18 days later. Autopsy examination included radioactive analysis of brain and liver tissue. Radioautographs were superimposed on H&E preparations of the abscess wall to localize the extent of activity of the thorium dioxide. The unusual occurrence of this abscess in a young patient, clinically diagnosed and treated by operation, provided a rare opportunity to assess the problem of the surgical accessibility of brain stem abscess as well as to reevaluate a role for thorium dioxide as a marker for intracranial purulent collections.

A middle-aged man with a cervical lymph node metastasis underwent nasopharyngeal biopsy in search of the primary tumor. Following biopsy his eye became swollen and painful with unilateral loss of vision. A carotid-cavernous fistula was demonstrated, as was deficient ossification at the base of the skull. The fistula was successfully treated with balloon embolization.

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.

The computed tomography (CT) scans and other radiographic studies of 23 patients with cerebral cysticercosis were reviewed. Parenchymal calcifications, the most common finding, are somewhat better seen on CT scans than on skull films. Ventricular cysts may be suspected by disproportionate enlargement of the involved ventricle. Cysts in subarachnoid cisterns are best detected by performing both CT and pneumoencephalography. Contrast enhancement was not seen with cisternal or ventricular cysts but may be with parenchymal cysticercus lesions.

From 1974-1986, 152 patients with carotid cavernous sinus fistulae (CCF) have been evaluated. Progressive closure of both dural and direct types of CCF have been noted utilizing intermittent external manual compression of the cervical carotid artery and jugular vein. In a group of 71 patients in whom this treatment was attempted, we have observed that 7 of 23 patients (30%) with dural CCF, and 8 of 48 patients (17%) with direct CCF had complete closure of their fistulae with no recurrence either clinically or at angiography done one year later. Closure occurred at varying times, from several minutes to 6 months (mean 41 days) following compression therapy. In those patients with CCF without rapidly progressive visual deterioration, cerebral ischemia, or other complicating factors, we recommend this technique with serial clinical follow-up and angiography before more definitive therapy is employed.

This case report concerns a woman who presented an atypical clinical pattern with some features of encephalitis and other features of brain tumor. Cerebral angiography showed a unilateral cerebral mass with prominence of deep medullary veins, usually interpreted as evidence of a neoplasm. Brain biopsy was interpreted as astrocytoma. Subsequent spontaneous clinical remission and regression of angiographic findings led to a reappraisal of the microscopic interpretation with a final diagnosis of encephalitis. The pathogenesis of cerebral angiographic abnormalities observed with encephalitis is reviewed. The transient prominence of deep medullary veins is probably due to hyperemia. Followup angiography is recommended when encaphalitis is suspected.

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.

The present report describes a 19-yr-old female with progressive hypopituitarism and diabetes insipidus. Pneumoencephalography demonstrated gross atrophy of the hypothalamus and a small pituitary gland. In the face of documented hypothyroidism and hypogonadism, basal pituitary trophic hormones were consistently detectable and responded briskly to releasing factor administration. This combination of an atrophic lesion of the hypothalamus with gradually evolving hypopituitarism but detectable and stimulable anterior pituitary hormones appears to represent a unique form of hypothalamic failure.

The intracranial extension of tumors of the nasopharynx and related spaces presents a difficult imaging problem. Unlike computed tomography (CT) scans, magnetic resonance (MR) images are not limited by beam-hardening artifacts from bone or dental amalgam. Forty-six patients with malignant tumors of the nasopharynx and related spaces affecting the skull base underwent MR imaging. MR images were obtained with a 0.3-T permanent-magnet imaging system in axial, sagittal, and coronal planes. MR findings were compared with clinical records, plain radiographs, CT scans, and pathologic correlates when available. MR imaging could demonstrate neoplastic invasion of the bone of the floor of the middle cranial fossa and the vital soft-tissue structures related to it as well as or better than CT. Tumor extension was viewed directly as a continuous mass or indirectly by marrow replacement or displacement of normal structures. Specific anatomic routes through which tumors extend from the nasopharynx to the middle cranial fossa were inferred from MR findings.