Carlos Bazan

Spontaneous regression of optic glioma in a patient with neurofibromatosis

We describe a young girl with neurofibromatosis and enlargement of the optic chiasm and intracranial left optic nerve. Serial MRIs over 32 months demonstrated spontaneous, marked reduction in the size of these lesions. Spontaneous regression must be considered in evaluating therapies for optic glioma.

Prevalence of incidental intraspinal lipoma of the lumbosacral spine as determined by MRI

Study Design. The prevalence and appearance on MRI of lipomas of the filum terminale was studied in a random population referred to MRI for evaluation of the lumbosacral spine. The MRI scans of 100 patients selected at random were retrospectively reviewed. Objectives. The study sought to determine the frequency and MRI appearance of incidental filum lipomas in a random population. Summary of Background Data. Postmortem studies have reported a 4%-6% incidence of occult fibrolipmas of the filum terminale in what were thought to be otherwise normal spinal cords. The improved resolution of MRI imaging allows the detection of small amounts of fat associated with the filum terminale that heretofore had not been demonstrated on radiologic imaging examinations. Methods. The lumbosacral spine unenhanced MRI scans of 100 patients not previously operated upon were selected at random and were retrospectively reviewed by two of the authors (EB and JCM). Results. Of the 100 MRI examinations reviewed, four patients were found to have small lipomas of the filum terminale. No spinal dysraphism or cord tethering were present in these four patients. Their clinical symptoms were related to disc herniation in two patients, spinal stenosis in one, and discitis in one. The lipomatous tissue was hyperintense to cerebrospinal fluid (CSF) on T1-weighted images and hypointense to CSF on T2-weighted images. Conclusions. Incidental lipomas of the filum terminale were present in 4% of 100 lumbosacral spine MRI examinations in a random population.

Nerve root enhancement with MRI in inflammatory demyelinating polyradiculoneuropathy

thy. Myopathy has been noted in other collagen-vascular disord e r ~ ~ as well as in WG., In summary, we describe an instructive case of WG with two coexistent neuromuscular manifestations: (1) vasculitic neuropathy with focal median mononeuropathies superimposed on a symmetric distal axonal polyneuropathy, and (2) granulomatous myopathy causing symmetric proximal muscle weakness. Immunosuppressive therapy, guided by quantitative muscle strength testing, resulted in marked improvement.

Gadolinium‐enhanced MRI in a case of cytomegalovirus polyradiculopathy

Polyradiculopathy is an unusual neurologic complication in patients with AIDS. Cytomegalovirus (CMV) has been implicated as the etiology in several reportsl-3 of polyradiculopathy affecting primarily the lumbosacral roots. These AIDS patients presented with bilateral leg pain, progressive paraparesis, saddle anesthesia, and acute urinary retention. The upper extremities were relatively unaffected. In these 11 reported c a s e ~ l ~ five had neuroradiologic examinations of the spine. Two patients had myelograms,1,2 one had a CT myelogram,l and two had MRI examinations of the spine.3 Both myelograms and both MRI examinations were normal. Only the single CT myelogram was abnormal, with thickened and adherent roots in the cauda equina. This report details the first case of apositive MRI examination in CMV polyradiculopathy in a patient with AIDS. Case report. A 36-year-old, HIV-positive homosexual man with a history of Kaposi’s sarcoma complained of pmgmssive lower extremity weakness and inability to void. Twelve weeks prior to admission, the patient noted the insidious onset of right lower extremity weakness. Initially, the dista\ muscles were predominantly affected, followed by pmximal right leg weakness. He subsequently developed left lower ex. tremity weakness and bilateral distal leg numhness. Two weeks prior to admission, he noted anal and genital numbness. Three days before admission, he developed urinary retention and bowel incontinence. He complained of severe leg pain, worse on the right, but he denied low back pain or upper extremity weaknes or numbness. Physical examination revealed a cachectic man with oral thrush. Funduscopic examination revealed no evidence of retinitis. MultiplP Kaposi’s skin lesions were present as well as several perianal herpetic lesions. Rectal sphincter tone was decreased. Neurologic examination revealed intact cranial nerves. There was decreased pinprick sensation in the ano-genital region and patchy areas of numbness in the distal lower extremities. No discrete sensory level was present. Motor examination revealed grade 5 (MRC) strength in the upper extremities and grade 3-4 strength in the lower extremities with flaccid tone. Deep tendon reflexes were absent except for hypoactive biceps reflexes. Plantar responses were flexor bilaterally. Initially, the CSF examination revealed 210 RRCs and 1,720 WBCs of which 86% were polymorphonuclear leukocytes, 5% lymphocytes, and 8% monocytes. CSF VDRL, cryptococcal antigen, India ink stain, and bacterial cultures were negative. Repeat lumbar puncture 4 days later demonstrated 170 RBCs and 2,100 W C s (79% polymorphonuclear leukocytes, 10% lymphocytes, 11 76 monocytes), protein 384 mg/dl, and glucose 17 mg/dl. Racterial, mycobacterial, and fungal cultures were negative, as was cytologic analysis. MRI examination of the spine was performed on a GE Signa unit operating at 1.5 tesla. Sagittal images were obtained with TIand T,weighted acquisitions as well as T,-weighted images following intravenous administration of gadolinium-DTPA. The nonenhanced T, weighted images (figure, A) demonstrated a questionable focus of increased signal in the lumbar thecal sac. The T,-weighted images failed to demonstrate any abnormality. The gadoliniumenhanced TI weighted images (figure, B) were markedly abnormal. Multiple areas of pathologic enhancement were present in the lumbar t.hecal sac. Tho conus medullaris appeared normal. After admission to the hospital, the patient’s lower extremity weakness continued to progress (MRC grade 1-3), and he became nonambulatory with an L-1 sensory level. CMV polyradiculopathy was suspected clinically, and treatment with ganciclovir was begun empirically on the fourth day of hospitalization. By day 7, the pa tient’s lower extremity strength stabilized and perianal sensation had subjectively improved. Serum anti-CMV ELISA returned >6.12 and CSF cultures subsequently were reported as positive for CMV. The

MRI of cervical facet dislocation

Abstract The MRI examinations of eight patients with cervical vertebral dislocation demonstrated by conventional radiography were reviewed. All patients had axial and sagittal T 1- and T 2-weighted imaging on a 1.5-T unit. This revealed unilateral partial facet dislocation (in two patients), bilateral partial facet dislocation (in two), unilateral complete dislocation (in two) and bilateral complete facet dislocation (in two). In six patients there was cord contusion, three had focal disc protrusions and four unilateral absence of normal flow void in one of the cervical vertebral arteries. In all cases, the dislocated facets were shown well on the far-lateral sagittal images.

MR of disc protrusion engendered by infectious spondylitis

PURPOSE The purpose of this study was to determine if infection-related disc protrusion formed a component of the perispinous/epidural mass in patients with intervertebral disc infection. METHOD A retrospective review was undertaken of 16 consecutive patients with intervertebral disc space infection who were referred for gadolinium-enhanced MRI. Possible correlation was sought between disc infection and the presence of associated posterior disc protrusion as determined by MRI. RESULTS Of the 16 infected discs, 10 cases were in the lumbosacral spine, 3 in the thoracic spine, and 3 in the cervical spine. Four cases had isolated posteriorly directed disc protrusion, and 12 showed both posterior and anterior disc protrusions. The infection in patients with disc protrusion was related to Staphylococcus aureus in 14 patients, Salmonella enteritidis in 1, and Streptococcus pneumoniae in 1. CONCLUSION This study showed that disc protrusion occurred in combination with disc space infections. Local factors such as the secretion by hyaluronidase from Staphylococcus aureus may play an important role in causing focal disc protrusion. The clinical importance of this finding is in the recognition that a significant part of the compromise of the spinal canal in cases of disc infection can be related to disc fragments engendered by the infectious process.

MRI of radiation induced spinal cord glioma

SummaryRadiation induced neoplasms of the spinal cord are rare lesions. This report details the MR evaluation of a patient with radiation induced astrocytoma of the cervical cord. The diagnosis of second primary neoplasm should be considered in patients with prior radiation therapy when MRI demonstrates an intramedullary lesion.

Ruptured spinal dermoid cyst with chemical arachnoiditis and disseminated intracranial lipid droplets

A 33-year-old man presented with a 3-month history of gradually progressive leg weakness. Spinal MRI and myelography with CT demonstrated an extensive intradural abnormality suggesting a diffuse inflammatory or neoplastic process. Only after cranial CT and MRI demonstrated lipid droplets was the diagnosis of a ruptured spinal dermoid cyst suggested. Subsequent laminectomy revealed a ruptured intradural dermoid cyst in the lumbar spine, with chemical arachnoiditis.

Intrinsic Resting-State Functional Connectivity in the Human Spinal Cord at 3.0 T

PURPOSE To apply resting-state functional magnetic resonance (MR) imaging to map functional connectivity of the human spinal cord. MATERIALS AND METHODS Studies were performed in nine self-declared healthy volunteers with informed consent and institutional review board approval. Resting-state functional MR imaging was performed to map functional connectivity of the human cervical spinal cord from C1 to C4 at 1 × 1 × 3-mm resolution with a 3.0-T clinical MR imaging unit. Independent component analysis (ICA) was performed to derive resting-state functional MR imaging z-score maps rendered on two-dimensional and three-dimensional images. Seed-based analysis was performed for cross validation with ICA networks by using Pearson correlation. RESULTS Reproducibility analysis of resting-state functional MR imaging maps from four repeated trials in a single participant yielded a mean z score of 6 ± 1 (P < .0001). The centroid coordinates across the four trials deviated by 2 in-plane voxels ± 2 mm (standard deviation) and up to one adjacent image section ± 3 mm. ICA of group resting-state functional MR imaging data revealed prominent functional connectivity patterns within the spinal cord gray matter. There were statistically significant (z score > 3, P < .001) bilateral, unilateral, and intersegmental correlations in the ventral horns, dorsal horns, and central spinal cord gray matter. Three-dimensional surface rendering provided visualization of these components along the length of the spinal cord. Seed-based analysis showed that many ICA components exhibited strong and significant (P < .05) correlations, corroborating the ICA results. Resting-state functional MR imaging connectivity networks are qualitatively consistent with known neuroanatomic and functional structures in the spinal cord. CONCLUSION Resting-state functional MR imaging of the human cervical spinal cord with a 3.0-T clinical MR imaging unit and standard MR imaging protocols and hardware reveals prominent functional connectivity patterns within the spinal cord gray matter, consistent with known functional and anatomic layouts of the spinal cord.

Subependymoma of filum terminale: MR appearance.

This report describes a subependymoma of the filum terminale evaluated by MRI. The mass demonstrated hyperintense signal on conventional spin echo T1-weighted, proton density, and T2-weighted imaging and nonenhancement after intravenous gadolinium administration. These characteristics distinguish this lesion from other more common neoplastic and inflammatory lesions arising in the lumbar spinal canal that are typically isointense on T1-weighted spin echo acquisitions, hyperintense on T2-weighted imaging, and enhance variably after intravenous gadolinium administration.