Faculty Bibliography

PURPOSE: To evaluate the role of T2*-weighted echo-planar perfusion imaging by using a first-pass gadopentetate dimeglumine technique to determine the association of magnetic resonance (MR) imaging-derived cerebral blood volume (CBV) maps with histopathologic grading of astrocytomas and to improve the accuracy of targeting of stereotactic biopsy. MATERIALS AND METHODS: MR imaging was performed in 29 patients by using a first-pass gadopentetate dimeglumine T2*-weighted echo-planar perfusion sequence followed by conventional imaging. The perfusion data were processed to obtain a color map of relative regional CBV. This information formed the basis for targeting the stereotactic biopsy. Relative CBV values were computed with a nondiffusible tracer model. The relative CBV of lesions was expressed as a percentage of the relative CBV of normal white matter. The maximum relative CBV of each lesion was correlated with the histopathologic grading of astrocytomas obtained from samples from stereotactic biopsy or volumetric resection. RESULTS: The maximum relative CBV in high-grade astrocytomas (n = 26) varied from 1.73 to 13.7, with a mean of 5.07 +/- 2.79 (+/- SD), and in the low-grade cohort (n = 3) varied from 0.92 to 2.19, with a mean of 1.44 +/- 0.68. This difference in relative CBV was statistically significant (P < .001; Student t test). CONCLUSION: Echo-planar perfusion imaging is useful in the preoperative assessment of tumor grade and in providing diagnostic information not available with conventional MR imaging. The areas of perfusion abnormality are invaluable in the precise targeting of the stereotactic biopsy

Angiogenesis is a crucial process in inflammatory reactions as well as in tumor implantation and growth. Tumors with high rates of invasion and recurrence such as gliomas, are specially dependent on neovascularization. This suggests that inhibition of angiogenesis might reduce the growth of these tumors. Thalidomide has been previously shown to inhibit angiogenesis induced by basic fibroblast growth factor in vivo, using the rabbit corneal micropocket assay. Therefore, the effect of thalidomide and a thalidomide analogue (cc-1069) on the proliferation in vitro of endothelial and glioma cells was tested. We observed a decrease in endothelial cell proliferation in cultures treated with thalidomide or the thalidomide analogue cc-1069. The analogue inhibited endothelial cell proliferation more efficiently than thalidomide. The inhibition occurred in association with a marked decrease in the activity of the nuclear factor SP1 and a moderate inhibition of NF-kappaB activation in nuclear extracts of endothelial cells. The drugs did not impair cell viability. There was no effect of thalidomide or the thalidomide analogue on the proliferation of the glioma cell line (U251) in vitro

BACKGROUND AND PURPOSE: Progressive multifocal leukoencephalopathy (PML) is typically occult at angiography and fails to enhance on MR images. After observing angiographic abnormalities characterized by arteriovenous shunting and pathologic parenchymal blush in patients with AIDS-related PML, often in the absence of contrast enhancement on MR images, we hypothesized that there might be distinct changes in the cerebral microvasculature that account for the reduction in vascular transit time (arteriovenous shunting) in the absence of blood-brain barrier dysfunction. METHODS: The imaging studies and neuropathologic specimens of six patients with biopsy-proved PML were reviewed retrospectively. In all patients contrast-enhanced MR imaging and CT, followed by cerebral angiography, were performed before stereotactically directed biopsy. The angiograms were evaluated for the presence of vascular displacement, pathologic parenchymal blush, arteriovenous shunting, and neovascularity. The CT and MR studies were reviewed for the presence of enhancement of the PML lesions. Biopsy specimens were examined for the presence of necrosis, perivascular inflammation, and neovascularity. RESULTS: All patients had oligodendrocytic intranuclear inclusions diagnostic of PML, together with perivascular inflammation and neovascularity to a varying extent; no other neuropathologic processes were identified. Angiographic abnormalities, characterized by a pathologic parenchymal blush and arteriovenous shunting, were identified in four of the six patients. In only one of these cases, however, was abnormal enhancement identified on cross-sectional imaging studies (MR and CT), and this patient had florid perivascular inflammatory infiltrates histologically. CONCLUSION: The pathologic parenchymal blush and arteriovenous shunting seen angiographically in some patients with PML reflect small-vessel proliferation and perivascular inflammatory changes incited by the presence of the JC virus in infected oligodendrocytes

We present the case of a young man with a diagnosis of a childhood-onset pervasive developmental disorder who developed a progressive neurologic deterioration with persistent catatonia and right hemiparesis. On his initial evaluation approximately three years after the onset of mutism, he manifested right hemiparesis and catalepsy. Two years later, although catalepsy had subsided, motor function had deteriorated so that he could not use his hands to feed or dress himself. Oral-facialbuccal dyskinesia manifested by blepharospasm and grimacing were present constantly during waking hours. Quantitative electroencephalography demonstrated markedly decreased amplitude, a finding associated with catatonia. Left sural nerve biopsy indicated large axon cylinder degeneration. Left deltoid biopsy demonstrated perimysial fibrosis and type II fiber predominance. Although magnetic resonance imaging of the head without contrast was normal, positron emission tomography indicated hypometabolism of the right cerebral and the right cerebellar hemispheres. The patient continues to deteriorate despite a course of 25 electroconvulsive treatments. He continues to manifest criteria for catatonia including motoric immobility, mutism, and peculiarities of voluntary movement such as prominent grimacing. We suspect an inherited neurodegenerative disorder. Since catatonia is a treatable condition frequently associated with medical and neurological diseases, examination for the features of catatonia must be included in the assessment of patients with progressive brain degeneration. This report is an attempt to clarify the traits of a serious variant of progressive brain degeneration

OBJECTIVE: We report a group of nine patients with atypical, nonneoplastic intramedullary spinal cord lesions. By retrospectively reviewing these patients, we hoped to elucidate characteristics that would identify these patients as harboring nonneoplastic lesions before surgical intervention. METHODS: We reviewed the histological findings of 212 patients undergoing surgery for intramedullary spinal cord tumors between 1989 and 1994. We identified nine patients with nonneoplastic lesions (4%); case histories and radiographs were reviewed. RESULTS: All patients were evaluated preoperatively using magnetic resonance imaging. The extent of enhancement with gadolinium varied from homogeneous enhancement to no enhancement. All lesions showed marked T2 changes. There was a lack of significant spinal cord expansion associated with the lesions in all cases. All patients underwent surgery. The histology of the surgical specimens showed demyelinating lesions in four patients, sarcoidosis in two patients, amyloid angiopathy in two patients, and a mass of nonneoplastic inflammatory cells of unknown origin in one patient. CONCLUSION: Although it was difficult to antecedently distinguish these lesions from neoplastic spinal cord tumors by case history and physical examination, the most consistent clue was absent or minimal spinal cord expansion on the preoperative magnetic resonance images

OBJECTIVE: Cerebral Nocardia abscesses are rare, accounting for approximately 1 to 2% of all cerebral abscesses. Prompt aggressive surgical treatment involving craniotomy and excision of these lesions has been advocated by many authors, because these lesions have significantly higher morbidity and mortality rates than do most other cerebral abscesses. We report an atypical presentation of cerebral nocardiosis localized to the choroid plexus of the lateral ventricle. CLINICAL PRESENTATION: A 56-year-old man presented with a 3-week history of fever, cough, and progressive headache and an ensuing 3-day history of progressive lethargy, confusion, and gait ataxia. Radiographic studies demonstrated a loculated contrast-enhancing left lateral ventricular lesion with significant perilesional parenchymal edema that was thought preoperatively to be a neoplasm. INTERVENTION: The patient underwent a craniotomy for resection of the lesion. Intraoperatively, a reddish gray lesion with purulent exudate was encountered within the left lateral ventricle intimately adherent to the choroid plexus as well as to the ependyma and subependymal veins. A frozen section demonstrated an organizing abscess wall. The lesion was resected in its entirety, and multiple cultures were sent for analysis. CONCLUSION: Microbiology cultures grew Nocardia asteroides. A course of intravenous antibiotics was started, which included trimethoprim-sulfamethoxazole, amikacin, and ceftriaxone. Two weeks after surgery, at the time of discharge, the patient's neurological status had improved considerably. Although Nocardia abscesses have been documented to occur throughout the central nervous system, the presentation of a lesion confined to the choroid plexus of the lateral ventricle with significant parenchymal edema is unusual and demonstrates that Nocardia abscesses must be considered in the differential diagnosis of a contrast-enhancing intraventricular mass lesion involving the choroid plexus