Reversible leukoencephalopathy associated with cerebral amyloid angiopathy.

The authors describe three patients with reversible leukoencephalopathy associated with cerebral amyloid angiopathy (CAA). Rapid progression of neurologic symptoms was followed by dramatic clinical and radiographic improvement. Pathologically, CAA was associated with varying degrees of inflammation ranging from none to transmural granulomatous infiltration. In the appropriate clinical context, the MRI finding of lobar white matter edema with evidence of prior hemosiderin deposition may indicate the presence of a reversible CAA leukoencephalopathy.

Urgent endovascular revascularization for symptomatic intracranial atherosclerotic stenosis.

BACKGROUND: Endovascular revascularization for intracranial atherosclerotic stenoses is being increasingly performed at major medical centers and has been reported to be technically feasible and safe. The authors report their experience with patients who underwent such a procedure for impending stroke and neurologic instability. METHOD: All 18 patients (21 intracranial lesions) treated between 1997 and 2002 at the authors' institution with endovascular revascularization were retrospectively reviewed. Each patient had failed maximal medical therapy and was thought to be at high risk for an imminent stroke. RESULTS: Endovascular revascularization was performed on eight distal internal carotid artery lesions, six middle cerebral artery lesions, four intracranial vertebral artery lesions, and three basilar artery lesions. Recanalization was complete in 5 arteries (Thrombolysis in Myocardial Infarction [TIMI] Grade III), partial in 14 arteries (TIMI Grade II), and complete occlusion (TIMI 0) developed in 1 artery. In a patient with a tight basilar stenosis, no angioplasty could be performed because of the inability to cross the stenosis with the guidewire. Major periprocedural complications occurred in 9 (50%) patients: intracranial hemorrhage in 3 (17%), disabling ischemic stroke in 2 (11%), and major extracranial hemorrhage in 4 (22%). Three patients died: one from intracerebral hemorrhage and two from cardiorespiratory failure. CONCLUSIONS: Endovascular revascularization of intracranial vessels is technically feasible and may be performed successfully. However, periprocedural complication and fatality rates in neurologically unstable patients are high. The results suggest that patient selection, procedure timing, and periprocedural medical management are critical factors to reduce periprocedural morbidity and mortality.

Pituitary lymphoma presenting as fever of unknown origin.

An 86-yr-old woman presented with fever of unknown origin. When laboratory evaluation revealed partial hypopituitarism, a magnetic resonance imaging scan of the head was performed and revealed a sellar mass consistent with a pituitary adenoma. Only after other possible etiologies for fever were excluded did she undergo transsphenoidal resection of the sellar mass, which proved to be a B-cell lymphoma. Primary central nervous system lymphoma of the pituitary region is a rare cause of a sellar mass, and this is the first reported case of pituitary lymphoma whose presenting manifestation was fever of unknown origin. Several disease processes can manifest themselves as fever and a sellar mass, including lymphomas. In our case, only surgical biopsy could make a diagnosis and distinguish this process from the more common pituitary adenoma.

Sarcoidosis within a pituitary adenoma.

A 54 year old man presented with frontal headaches for one year. A CT scan of the head revealed a pituitary mass. He denied a change in vision or galactorrhea, but did have decreased frequency of erections and a recent episode of renal stones. On physical exam, the cranial nerves were normal. Visual field exam revealed mild bilateral temporal defects. The genitalia were normal and the testes were soft. Laboratory evaluation revealed: Na, 134 mM/l; K, 6.7 mM/l; Cl, 104 mM/l; HCO3, 22 mM/l; BUN, 47 mg/dl; Cr, 8.3 mg/dl; Ca, 12.5 mg/dl; Phos, 5.5 mg/dl; prolactin, 32.0 ng/ml; T4, 4.46 microg/dl; TSH, 2.07 microU/ml; LH, 18.1 mIU/ml; FSH 3.2 mIU/ml; alpha subunit 1.6 ng/ml; testosterone 255 ng/dl; cortisol, 20.3 microg/dl; cortisol after 250 microg cortrosyn, 38.5 microg/dl (time 60 minutes); growth hormone, 1.4 ng/ml; IGF-1, 47 ng/ml; PTH, <1 pg/ml; 25-hydroxyvitamin D, 14 ng/ml; 1,25-dihydroxyvitamin D, 69 pg/ml. These results were felt to be consistent with a non-PTH-mediated hypercalcemia, such as humoral hypercalcemia of malignancy, or a vitamin D-mediated hypercalcemia, such as lymphoma, sarcoidosis or tuberculosis. Head MRI demonstrated a 3.5 x 3.5 x 2.5 cm heterogeneous mass enlarging the sella, deforming the clivus and compressing the cavernous sinus, basilar artery and left side of the optic chiasm. There was a small focus of high signal in the superior part of the mass on the T1-weighted image from either a proteinaceous cyst with early calcium deposition or sub-acute blood. These radiographic findings were felt to be consistent with a pituitary adenoma. The patient was treated with intravenous hydration and thyroxine 50 microg daily and underwent a transsphenoidal resection of the pituitary lesion. Pathologic examination revealed a pituitary adenoma with multiple granulomas and crystalline material; this was consistent with sarcoid within the adenoma. Post-operatively, the serum LH fell to 5.5 mIU/ml. A subsequent transbronchial biopsy revealed multiple non-caseating granulomas. A serum ACE level was elevated at 132.6 U/l. He received oral prednisone 60 mg daily with resolution of the hypercalcemia. Neurosarcoidosis occurs in 5 to 15% of patients with sarcoidosis and can involve the hypothalamus and pituitary gland. This is the first reported case of sarcoidosis occurring within a pituitary adenoma.

A modified transorbital baboon model of reperfused stroke.

BACKGROUND AND PURPOSE: Although pathophysiological studies of focal cerebral ischemia in nonhuman primates can provide important information not obtainable in rodent models, primate experimentation is limited by considerations of cost, availability, effort, and ethics. A reproducible and quantitative model that minimizes the number of animals necessary to detect differences between treatment groups is therefore crucial. METHODS: Eight male baboons (weight, 22+/-2 kg) underwent left transorbital craniectomy followed by 1 hour of temporary ipsilateral internal carotid artery occlusion at the level of the anterior choroidal artery together with bilateral temporary occlusion of both anterior cerebral arteries (A1) proximal to the anterior communicating artery. A tightly controlled nitrous oxide-narcotic anesthetic allowed for intraoperative motor evoked potential confirmation of middle cerebral artery (MCA) territory ischemia. Animals survived to 72 hours or 10 days if successfully self-caring. Outcomes were assessed with a 100-point neurological grading system, and infarct volume was quantified by planimetric analysis of both MRI and triphenyltetrazolium chloride-stained sections. RESULTS: Infarction volumes (on T2-weighted images) were 32+/-7% (mean+/-SEM) of the ipsilateral hemisphere, and neurological scores averaged 29+/-9. All animals demonstrated evidence of hemispheric infarction, with damage evident in both cortical and subcortical regions in the MCA vascular territory. Histologically determined infarction volumes differed by <3% and correlated with absolute neurological scores (r=0.9, P:=0.003). CONCLUSIONS: Transorbital temporary occlusion of the entire anterior cerebral circulation with strict control of physiological parameters can reliably produce reperfused MCA territory infarction. The magnitude of the resultant infarct with little interanimal variability diminishes the potential number of animals required to distinguish between 2 treatment regimens. The anatomic distribution of the infarct and associated functional deficits offer comparability to human hemispheric strokes.

Management of residual dysplastic vessels after cerebral arteriovenous malformation resection: implications for postoperative angiography.

OBJECTIVE: The verification of surgical resection of cerebral arteriovenous malformations (AVMs) relies on angiography. Abnormal vasculature often is identified after removal of the AVM. Differentiation of dysplastic feeding vessels that resemble the neovascularity of moyamoya disease, as distinct from residual AVM, is crucial for preserving critical brain areas. We review a large experience with immediate postoperative angiography after AVM resection and discuss the implications for management of abnormal dysplastic vessels discovered after AVM resection. METHODS: Beginning in 1992, 86 consecutive patients with AVMs underwent operations by standard protocol for immediate postoperative angiography under the same general anesthetic. Angiographic interpretation dictated admission to the intensive care unit or return to the operating room for further resection. RESULTS: In 78 patients, the angiogram revealed complete resection. Two patients were returned to the operating room, one for residual malformation with an early draining vein, and one for resection of residual dysplastic vessels. There was one postoperative hemorrhage in a patient whose postoperative angiogram was falsely negative for AVM. Six patients with residual dysplastic vessels mimicking residual AVM, but without an early draining vein, were managed conservatively. Delayed follow-up angiography demonstrated spontaneous involution of these abnormal vessels in all of these patients. CONCLUSION: Residual dysplastic feeding vessels resembling the neovascularity of moyamoya disease but not associated with an early draining vein do not necessarily represent residual malformation after AVM resection. The abnormal vessels will proceed to complete spontaneous resolution. Given the difficulty of interpreting intraoperative angiography, immediate postoperative angiography may be a viable alternative after AVM resection.

Massive intracranial arachnoid cyst in a developmentally normal infant: case report and literature review.

Intracranial arachnoid cysts are developmental anomalies that are generally asymptomatic. We describe a 6-month-old boy with macrocephaly but normal neurological development who was found to have a rare, massive basal arachnoid cyst occupying most of the cranium and extending superiorly, causing significant shift due to mass effect. A cystoperitoneal shunt was placed, producing both a decrease in the arachnoid cyst dimensions and a concomitant reexpansion of parenchyma. After consideration of various management options, such a shunt system appears to offer a low risk of complications and a high likelihood of success.

Atlantoaxial degenerative articular cysts.

Cysts associated with spinal joints are not a common cause of neurological symptoms. The authors report a series of five patients with cysts of the atlantodental articulation and review five additional cases from the literature. The patients ranged from 60 to 85 years of age and included three men and seven women. No patient had evidence of rheumatoid arthritis or previous trauma. The cysts caused ventral cervicomedullary compression, did not enhance on magnetic resonance imaging, and were not associated with widening of the anterior atlantodental interval or osseous degeneration of the dens. All patients improved postsurgery. Fusion was required if a transoral procedure was performed. Patients undergoing posterior decompressions were clinically and radiographically stable after operation.

Effects of coregistration of MR to CT images on MR stereotactic accuracy.

Coregistration of different modality imaging serves to increase the ease and accuracy of stereotactic procedures. In many cases, magnetic resonance (MR) stereotaxis is supplanting computerized tomography (CT). The advantages of increased anatomical detail and multiplanar imaging afforded by MR, however, are offset by its potential inaccuracy as well as the more cumbersome and less available nature of its hardware. A system has been developed by one of the authors by which MR imaging can be performed separately without a stereotactic fiducial headring. Then, immediately prior to surgery, a stereotactic CT scan is obtained and software is used to coregister CT and MR images anatomically by matching cranial landmarks in the two scans. The authors examined this system in six patients as well as with the use of a lucite phantom. After initially coregistering CT and MR images, six separate anatomical (for the patients) and eight artificial (for the phantom) targets were compared. With coregistration, in comparison to CT fiducial scans, errors in each axis are less than or equal to 1 mm using the Cosman-Roberts-Wells system. In fact, the coregistered images are more accurate than MR fiducial images, in the anteroposterior (p = 0.001), lateral (p < 0.05), and vertical (p < 0.03) planes. Three-dimensional error was significantly less in the coregistered scans than the MR fiducial images (p < 0.005). The coregistration procedure therefore not only increases the case of MR stereotaxis but also increases its accuracy.

Fetomaternal hemorrhage as an etiology of neonatal stroke.

We report a term infant who presented with focal seizures and was diagnosed with a large left hemispheral infarct. Evaluation revealed extensive fetomaternal hemorrhage and subsequent neuroimaging disclosed a classic border zone infarct consistent with a hypoperfusion injury. We postulate that fetomaternal hemorrhage should be considered in the differential causation of neonatal stroke. The unilaterality of the lesion in this patient is difficult to explain.

Gadolinium-MRI in acute transverse myelopathy.

A patient with acute transverse myelopathy (ATM) had serial magnetic resonance imaging (MRI) studies before and after administration of gadolinium (Gd-DTPA). Gd-DTPA-MRI was useful in estimating the pathologic extent and residual deficit expected in ATM.