Computed tomographic and nuclear magnetic resonance correlation of canine ceroid-lipofuscinosis with aging.

Canine ceroid lipofuscinosis is a degenerative neuronal disorder which has as a distinct pathologic counterpart, neuronal ceroid lipofuscinosis or Batten's disease in humans. The disease occurs in English setters and is associated with abnormal accumulation of autofluorescent lipopigments. As such, a study of this animal model may allow insight into the aging process as well. This investigation explores the computed tomographic features of canine ceroid-lipofuscinosis and correlates these findings (progressive atrophy, inherent changes in CT/NMR tissue characteristics) with clinical and pathologic features.

Intracranial spread of squamous carcinoma along the trigeminal nerve.

Two patients with intracranial dissemination of squamous carcinoma along the trigeminal nerve had facial dysesthesias mistakenly diagnosed as tic douloureux. In one case, tumor originated in the skin of the lateral canthus and spread along an orbital nerve to involve the cavernous sinus and Gasserian ganglion. In the other, the primary site was the retromolar trigone, with preponderantly deep intraosseous growth. Perineural spread occurred along the inferior alveolar nerve to eventually involve the facial and the ocular motor nerves. Such neurotropic spread of tumors is unfamiliar to many clinicians, yet early diagnosis may be life-saving. If intracranial foramina have not been transgressed, surgery and radiotherapy have been curative; otherwise, treatment is largely palliative. Adequate initial treatment of the primary lesion would seem to be the best preventive measure. Treatment of recurrent lesions should include consideration of neural invasion.

Venous pressure measurements in vein of Galen aneurysms.

Venous pressures were measured within the vein of Galen aneurysm/straight sinus complex in 15 patients with Galenic arteriovenous fistulae and vein of Galen aneurysms. Pressures exceeded normal (less than 5 cm of H2O) in each instance, ranging between 9 and 55 cm of H2O. Measured values exceeding 20 cm of H2O were associated with an increased occurrence of brain calcification. Mean venous pressures were relatively higher in the patients with thalamic arteriovenous malformations, and relatively lower in patients with true vein of Galen fistulae and choroidal type malformations. A pressure gradient across the straight sinus was measured in one patient and suspected in three others when disproportionate dilatation of the vein of Galen occurred in the presence of a small or normal-sized straight sinus. No clear relationship existed between levels of venous pressure elevation and degree of ventriculomegaly. Refractory heart failure occurred only in neonates with choroidal type fistulae and no apparent venous outflow obstruction. It is likely that the degree of venous pressure elevation reflects the hemodynamic significance of arteriovenous shunt, provided it is interpreted in context with the current clinical status and the angioarchitecture of the Galenic fistula. Such data may assist in the timing of embolotherapy. Patients with lower venous pressure are not likely to develop brain calcification or seizures, and therefore can tolerate transtorcular embolotherapy staged at wider intervals.

Latex vascular occlusion balloons: histopathologic evaluation in a high-flow aortocaval fistula model.

The treatment of carotid-cavernous fistulae with intravascular, detachable latex balloons has become an accepted method. However, the histologic changes associated with such balloon embolization in a high-flow fistula state have not been described. This study evaluated the microscopic findings in a series of 12 rats studied over a 3-month period using an aortocaval fistula model. Small latex balloons were introduced into the venae cavae of rats in whom aortocaval fistulae had been surgically created 3 weeks earlier. The histopathologic changes associated with treatment of these fistulae were examined at 1, 2, 4, 6, 8, and 12 weeks. These changes can be characterized by an acute phase with thrombus formation and acute inflammation, followed by intermediate (or subacute) and chronic phases with diminishing inflammation and progressively increasing fibrosis of the fistula site. The latex balloon became encased by the fibrotic reaction but remained nonadherent and was easily removed at every study interval. No abscess formation or persistent vasculitis was apparent, and foreign-body giant cell reaction was minimal. Closure of the high-flow fistula site required the balloon to remain inflated for at least 7-9 days.

High-flow, aortocaval fistulae: radiologic and histopathologic evaluation in a rat model.

An animal model for a high-flow, aorta-to-vena cava fistula has been developed using microsurgical techniques in the rat. This model provides a means for histopathologic and angiographic evaluation of the natural evolution of major vessel, artery to vein fistulae. Data obtained from such a model may have relevance to the successful treatment of high-flow, head and neck fistulae using detachable intraarterial occlusive balloons. This microsurgical technique is unique, since it requires no intervening sutures or graft material that would alter the histopathologic process. After a series of such aortocaval fistulae were created, serial histologic and angiographic features were elucidated for intervals between 1 day and 6 months. Three stages of evolution are noted including: an initial hemorrhagic dissection phase; a subacute phase where organization of the thrombus and actual formation of a fistulous tract occurs; and a chronic phase characterized by pseudoaneurysm formation, arterialization of the vena cava, and proximal vasodilatation of the aorta.

Vein of Galen aneurysms: a review and current perspective.

Our approach to treating a patient with a vein of Galen aneurysm is, of course, influenced greatly by the age of the patient, the clinical symptoms, and the angiographic architecture of the malformation. Therapeutic options are primarily based on whether a true AVM is present or if the malformation represents an arteriovenous fistula involving the vein of Galen. Arterial endovascular approaches, microneurosurgery, and/or radiosurgery are preferred for management of the former; the transvenous endovascular approach has become the cornerstone of treatment in the latter. The most critical group, however, is the neonates in extreme cardiovascular distress. In this case our therapeutic intervention is initially endovascular from the venous side, either transfemoral or transtorcular. The immediate goal is to increase resistance to right ventricular output. Advantages of this approach over a transarterial approach include a shorter anesthesia time, minimal fluid and/or contrast administration, and creation of a wire "basket" or "bird's nest" on the venous side that helps prevent emboli that may be deposited on the arterial side in subsequent embolizations from passing through the malformation. The transvenous approach can be easily repeated multiple times and may be supplemented by transarterial embolizations. Endovascular coils have been the mainstay for such venous embolizations. The end point of treatment is not complete occlusion of the fistula but improvement in cardiac function. Often, more than one stage is required to reach our goal. The results in recent years have been encouraging and are to a large degree attributable to the advances in endovascular approaches. With future improved tools for diagnosis and treatment, perhaps the prognosis for this difficult malady also will continue to improve.

Intraarterial use of sodium methohexital for provocative testing during brain embolotherapy.

PURPOSE AND METHODS: To assess its vascular effects and safety, we used sodium methohexital (Brevital)--an ultrashort-acting barbiturate--as the provocative intraarterial agent in a series of 30 patients with arteriovenous malformations at a 1% concentration and at doses of less than 5 mg per injection. Digital vascular imaging was performed just prior to and just after the injections. RESULTS: No angiographic or clinical evidence of apparent vasospasm occurred in the trial population (66 vascular pedicle injections in 30 patients). When functional tissue was perfused with 1-6 mg of the 1% Brevital solution, evidence of altered neurologic status became immediately apparent, but cleared within 2 minutes in all cases. None of the patients experienced either prolongation of the induced clinical symptoms or seizures to suggest any adverse effects related to either crystallization of the Brevital or the effects of injecting an alkaline solution in the cerebral circulation. CONCLUSION: Though the full effects of methohexital in the cerebral circulation remain to be elucidated, existing reports suggest it is a safe provocative agent for use prior to embolotherapy for brain arteriovenous malformations.

Retrorectal cyst-hamartomas and sacral dysplasia: MR appearance.

Retrorectal cyst-hamartoma, an uncommon lesion, arises from hindgut embryonic remnants and may be associated with sacral anomalies. Such a lesion is presacral, multicystic, and lined with glandular or transitional epithelium. Malignant transformation of these lesions has been reported. We describe the clinical, pathologic, and imaging findings in an infant.

Histopathologic analysis of intraarterial polyvinyl alcohol microemboli in rat cerebral cortex.

Polyvinyl alcohol (PVA) foam particles have been used with success in both experimental and clinical embolization of vascular lesions. Cellular response to PVA has been well documented outside, but not within, the central nervous system. This study was directed specifically at the cellular response to PVA in rat brain vasculature. By using small numbers of microparticles, an effort was made to define the response to PVA alone, rather than associated occlusions or infarctions. It was determined that PVA elicited no significant inflammatory response in the embolized vessels nor in the surrounding tissue. The isolated fragments did not appear to alter the blood-brain barrier. The PVA microemboli were extremely adherent to vascular endothelium, lodging in vessels of larger diameter and in relatively high-flow locations without actually wedging within the vessel lumen. On the basis of this analysis, it was determined that PVA foam has properties suitable for an intracerebral vascular embolic agent.

Fracture and complete dislocation of the thoracic or lumbosacral spine: report of three cases.

Severe fracture/dislocation of the thoracic (T) or lumbar (L) spine is usually associated with complete neurological dysfunction below the level of injury. Three cases of severe spinal fracture/dislocation are presented in this report. Two of these patients suffered only partial neurological deficit, which improved after open reduction, internal fixation, and bone fusion. Severe fracture/dislocation of the T or L spine may be quite obvious on lateral roentgenograms. Occasionally, however, the fracture site may be obscured by the overlying shoulders, hips, or soft tissues. If no lateral displacement is evident on anteroposterior (AP) films, a false impression of normal alignment may be given, as was the case in two of our patients. A careful interpretation of the AP view will provide the diagnosis in such cases. The subtle AP radiographic changes suggesting fracture/dislocation of the T or L spine are detailed. The mode of injury, physical findings, prognosis, and surgical treatment of such severe injuries are also briefly reviewed.

Angiographically cryptic cerebrovascular malformations.

Three cases of angiographically cryptic cerebrovascular malformations are presented and a review of the cases in the English literature is tabulated. The typical patient is a 30- to 40-year-old woman with a history of seizures and headache. There is no antecedent history suggesting hemorrhage. On nonenhanced computerized tomographic scans, these lesions are denser than normal brain. They enhance with contrast administration. The angiogram demonstrates an avascular mass. The history, physical findings, and radiographic studies suggest brain tumor. An accurate diagnosis requires operation and pathological examination of the lesion.

Cervical carotid dissecting aneurysms.

Thirteen cases of cervical carotid dissecting aneurysm have been seen at the University of Florida during the past 3 years. In our experience, two groups of patients with this disease can be distinguished clearly by either clinical or angiographic criteria. One group of cervical carotid dissecting aneurysms is characterized by spontaneous onset, unilaterality, and the absence of pseudoaneurysm formation. These lesions have a strong tendency to resolve with appropriate medical therapy. The other group is characterized by an association with obvious predisposing factors, such as fibromuscular dysplasia, angiography, or trauma. These lesions are often associated with pseudoaneurysms and rarely resolve spontaneously. These two groups of lesions probably represent a spectrum of the same basic disease process. The natural history of patients who survive a cervical carotid dissection is usually one of stability or improvement. A trial of medical therapy (to prevent embolic symptoms) and repeat arteriography are indicated before the consideration of surgical therapy.

Cavernous angioma: a review of 126 collected and 12 new clinical cases.

The histopathological, clinical, and radiological features of the intracranial cavernous angioma are reviewed, based on an analysis of 138 symptomatic, histologically verified cases. Twelve of the cases are from our own series and 126 were collected from appropriately documented reports in the modern literature. The analysis indicated that, at the time of diagnosis, one-third of the patients (49 cases) were being evaluated for seizures, one-third (40 cases) for clinical evidence of hemorrhage, and one-third (49 cases) for mass lesions. Unlike the other two groups, the group presenting with clinical evidence of hemorrhage was distinguished by a dominant age at the time of diagnosis (41% were diagnosed during the 4th decade of life), by a high incidence of prior neurological evaluation (43%), by a higher rate of diagnosis at autopsy (28%) than at operation, and by the absence of microscopic calcification within the lesion.

The transtorcular embolization of vein of Galen aneurysms.

Vein of Galen malformations are a diverse group of deeply located high-flow vascular lesions that are difficult to eradicate with standard surgical techniques. New nonsurgical interventional techniques offer encouraging results as alternative therapeutic choices in these complicated vascular shunts. Use of a new procedure of transtorcular embolization with Gianturco embolic coils is described in three patients harboring vein of Galen aneurysms. Two of the three patients had a satisfactory outcome. This technique is simple and quick, and can produce progressive thrombosis in these high-flow vascular fistulas.

Radiation-induced optic neuropathy: a magnetic resonance imaging study.

Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

Aneurysms of the posterior inferior cerebellar artery. A clinical and anatomical analysis.

The clinical and anatomical features of 21 surgically treated saccular aneurysms of the posterior inferior cerebellar artery (PICA) are analyzed. Seventeen of these lesions originated from the PICA-vertebral junction, and four arose from distal PICA branching sites. Twelve lesions arose from the left PICA, nine were right-sided, and all were small (less than 12.5 mm). Most of these aneurysms occurred in females (16 of 21) and presented as classic subarachnoid hemorrhage. The lack of specific focal deficits prevented an accurate pre-angiographic determination of aneurysm location in most instances. Clinically significant vasospasm and aneurysm multiplicity occurred with approximately equal frequency as at other locations. The angiographic and surgical features of these lesions are determined by the course of the vertebral artery and PICA; that is, they occur at branching sites and at curves in the parent vessel, and point in the direction in which flow would have continued if the curve at the aneurysm's origin had not been present. Aneurysms at the PICA-vertebral junction usualthese lesions are determined by the course of the vertebral artery and PICA; that is, they occur at branching sites and at curves in the parent vessel, and point in the direction in which flow would have continued if the curve at the aneurysm's origin had not been present. Aneurysms at the PICA-vertebral junction usualthese lesions are determined by the course of the vertebral artery and PICA; that is, they occur at branching sites and at curves in the parent vessel, and point in the direction in which flow would have continued if the curve at the aneurysm's origin had not been present. Aneurysms at the PICA-vertebral junction usually occur at least 1 cm above the foramen magnum level, arise distal to the PICA origin in the angle between the two vessels, and are best approached by a paramedian incision with the patient in the lateral recumbent position. Isolated clipping of the aneurysm neck is essential in this instance, as trapping may compromise vital perforating arteries of the brain stem. More distal (retromedullary) PICA aneurysms are sometimes associated with another vascular anomaly (two cases in this series), and are best handled through a bilateral suboccipital craniectomy. Clipping of the neck is the preferred treatment, but trapping is usually safe, if necessary.

Calcified cystic lesions in a patient with epilepsy and progressive dementia.

A 67-year-old woman had intractable epilepsy and developed a progressive dementia with upper motor neuron signs over the last 6 years. Magnetic resonance imaging (MRI) revealed multiple areas of large calcified cysts, which increased in number and size over the last 3 years. Discussion includes the appearance of these lesions radiologically and pathologically, as well as their differential diagnosis and clinical significance, focusing on the increasing detection of these lesions with current imaging techniques.

In vivo MR evaluation of Gd-DTPA conjugated to dextran in normal rabbits.

A dextran-Gd-DTPA compound has been recently synthesized utilizing 70,800 Da molecular weight dextran. This polymeric contrast agent for magnetic resonance imaging has been found chemically to be very stable and to demonstrate in vitro improved relaxivities of 1.5 to 2.3 times that of monomeric Gd-DTPA at 100 MHz. This MR experiment examines the in vivo distribution and relaxivity of the 70,800 Da molecular weight dextran-Gd-DTPA compound in a rabbit model by measuring the change in signal-to-noise ratio of a variety of organs (renal cortex, renal medulla, liver, brain, and torcula herophile) compared to the preinjection state. Results demonstrate prolonged (beyond 60 min) enhancement of the renal cortex, renal medulla, liver and torcula, and no enhancement of brain parenchyma.

Brainstem and other malignant gliomas: II. Possible mechanisms of brain infiltration by tumor cells.

Gliomas that arise in the brain stem and other malignant gliomas constitute approximately 60% of all brain tumors and have eluded effective therapy, in part because they are able to infiltrate the normal brain. Histopathologic studies have confirmed the presence of infiltrating tumor cells very distant from the glioma mass. We review the neuroimaging and pathologic features of glioma-cell infiltration and some of the complex cellular and biochemical determinants of tumor-cell motility and invasiveness. Understanding how glioma cells become motile and invasive is pivotal to therapeutically targeting the machinery that enables gliomas to infiltrate the brain.

Magnetic resonance imaging features and classification of central nervous system malformations in Joubert syndrome.

This article examines the magnetic resonance imaging features that typify the Joubert malformation. Specific morphologic features include: (1) dysgenesis of the isthmic portion of the brain stem at the pontomesencephalic junction, (2) abnormally thick superior cerebellar peduncles perpendicular to the brain stem, (3) hypoplasia of the cerebellar vermis with consequent enlargement of the 4th ventricle and rostral shift of the fastigium, and (4) sagittal vermic clefting. At least two of these features were present in every patient and all were present in some. The only cerebral anomaly identified was mild prominence of the ventricles and subarachnoid spaces. The "Joubert-plus anomaly" has been defined as the Joubert malformation plus additional anomalies of either the mesencephalon or the caudal 4th ventricle; this likely represents a similar but more extensive embryologic defect. By placing a relative numeric value on each morphologic feature, a classification scheme has been created that can quantitate the extent of the Joubert malformation in any individual case.