Preoperative embolization of cervical spine osteoblastomas: report of three cases

Our aim was to describe the technique and clinical results of preoperative embolization of cervical spine osteoblastomas. We treated 3 patients with these tumors with transarterial embolization and subsequent surgical excision. In all 3 patients, distal access to the tumor-supplying vessels was gained with a microcatheter and embolization was performed with polyvinyl alcohol particles. No complications occurred. Surgical resection was performed in all patients without relevant bleeding. The postoperative course was uneventful in all patients. Preoperative embolization is a valuable adjunct to the surgical treatment of osteoblastomas of the cervical spine.

Progressive multifocal leukoencephalopathy: value of diffusion-weighted and contrast-enhanced magnetic resonance imaging for diagnosis and treatment control

Progressive multifocal leukoencephalopathy (PML) is caused by the replication of JC virus in oligodendrocytes of immunocompromised patients. Diagnosis usually relies on the polymerase chain reaction (PCR)-based demonstration of JC virus DNA in the cerebrospinal fluid. As previous reports have suggested that some patients may benefit from antiviral therapy, non-invasive early diagnosis is highly desirable. Repetitive magnetic resonance imaging (MRI) examinations (two to nine) were obtained in seven patients (aged 40-67 years, six males, one female) with classical clinical and imaging findings of PML. Five patients had underlying hematological disorders and two acquired immune deficiency syndrome. PCR of the cerebrospinal fluid (CSF) specimen was positive for JC virus DNA in six patients. MRI sequences included T2-, T1- and diffusion-weighted (DW) images in all patients and diffusion-tensor imaging (DTI) in four cases. DTI was once performed at 3T, in the remaining patients at 1.5T. All patients received antiviral treatment with cidofovir in addition to the treatment of the underlying disorder. MRI showed areas of T2 hyperintensity with involvement of the subcortical U-fibers and restricted diffusion in all patients. Areas of diffusion abnormality correlated with disease progress. Contrast enhancement was encountered once after successful treatment and heralded clinical remission with virus elimination from the CSF. Hence, MRI including DW and contrast-enhanced images may be used to evaluate disease activity. Contrast enhancement may indicate an inflammatory response and thus herald immunologic virus elimination.

Kardiovaskuläre MR-Ganzkörperbildgebung bei Patienten mit symptomatischer Atherosklerose der peripheren Gefäße

PURPOSE

To examine patients with peripheral-arterial-occlusive-disease (PAOD) for systemic effects associated with atherosclerosis using a comprehensive state-of-the-art whole-body MR examination protocol. The protocol comprises the assessment of the complete arterial vasculature (except coronary arteries), the brain, and the heart.

MATERIALS AND METHODS

Multi-station whole-body 3D MR angiography was performed in sixty consecutive patients with clinical suspicion for PAOD at 1.5 T (Magnetom Avanto, Siemens, Erlangen, Germany). Functional and delayed enhancement cardiac images were acquired, as well as FLAIR images of the brain and TOF angiography of intracranial vessels. MR and DSA images were assessed by independent observers for atherosclerotic manifestations and other pathology. Sensitivity and specificity for the detection of vascular pathology was calculated for MR data using conventional DSA of the symptomatic region as standard-of-reference.

RESULTS

Sensitivity and specificity for the detection of significant vascular stenosis (> 70 % luminal narrowing) was 94 % and 96 % (PPV 87 %, NPV 98 %). Significant microangiopathic tissue alterations (n = 7) and/or cerebral infarction (n = 18) were diagnosed in 23/60 patients. Thirty-eight of 60 patients presented with systolic left ventricular wall motion abnormalities. In 24 patients subendocardial or transmural delayed enhancement was detected in corresponding regions, indicating prior myocardial infarction.

CONCLUSION

For patients with PAOD and suspected systemic atherosclerotic disease a comprehensive diagnosis of accompanying cardiovascular pathology and therefore staging of systemic atherosclerotic disease is feasible within one MR examination.

Primary central nervous system lymphomas (PCNSL): MRI response criteria revised

The authors investigated the applicability of Macdonald response criteria to patients with primary CNS lymphoma (PCNSL). Four of 68 patients with persisting contrast-enhancing lesions after primary therapy did not receive further therapy, and none showed tumor progression after up to 54 months. Because contrast enhancement may not necessarily indicate residual, biologically active lymphoma, the authors propose a modification of the Macdonald response criteria.

Surviving glioblastoma for more than 5 years: The patient's perspective

The authors performed a comprehensive analysis of the functional outcome of 10 patients who had survived 5 years from a diagnosis of glioblastoma. Neurologic deficits were mild in most patients, but neuropsychological testing demonstrated cognitive deficits in all patients. Depression and anxiety were common. Although most patients thought that their social functioning and work ability were impaired, little reduction in overall quality of life was perceived.

[Detection of subclinical and overt hepatic encephalopathy and treatment control after L-ornithine-L-aspartate medication by magnetic resonance spectroscopy ((1)H-MRS)]

Hepatic encephalopathy (HE) is a common problem in liver cirrhosis and is associated with typical changes of cerebral metabolite pattern observed by proton magnetic resonance spectroscopy (MRS). In HE, a reduction of the cerebral myo-inositol (mI) and choline (Cho) and an increase of glutamine/glutamate (Glx) can typically be detected with this method. In the present study MRS was used to assess prospectively specific parameters of cerebral metabolism before and after 6 days of treatment with a low-protein diet and with L-ornithine-L-aspartate (LOLA). 6 patients with liver cirrhosis were included in this pilot study. According to standardized neuropsychological tests overt HE or subclinical HE was detected in all patients. All patients received a low-protein diet (< 60 g/d) and were treated additionally with LOLA (20 g QD i. v.). MRS examinations were done before and after 6 days of treatment and the results were compared with those of healthy volunteers. Before treatment mI/Cr ratios in the grey matter were reduced significantly in cirrhotic patients as compared to healthy volunteers (0.30 +/- 0.22 vs. 0.68 +/- 0.11; P = 0.028). In addition, patients showed a (non-significant) reduction of the Cho/Cr-ratio (0.19 +/- 0.03 vs. 0.25 +/- 0.02; P = 0.17) and an elevated Glx/Cr-ratio (1.84 +/- 0.63 vs. 1.29 +/- 0.31; P = 0.05). After 6 days of treatment a significant increase of the Cho/Cr ratio (0.23 +/- 0.03 vs. 0.19 +/- 0.03; P = 0.028) was detectable and 5 of the 6 patients showed a (not significant) decrease of the elevated Glx/Cr ratios. After cessation of treatment an improvement in neuropsychological tests as shown by number-connection testing (P = 0.046) as well as a decrease of elevated pre-treatment ammonia blood levels were noted. These findings, however, did not correlate with the Child-Pugh classification or evidence of clinical/subclinical HE. Using (1)H-MRS it is possible to observe a specific pattern of cerebral metabolites in patients with overt and subclinical HE. In this pilot study a fast change of cerebral metabolite pattern after specific therapy of HE with LOLA was detected. Therefore, future studies with larger patient groups are needed to establish (1)H-MRS as an objective method for detection and treatment control in overt and subclinical HE, especially when compared to commonly used parameters such as ammonia levels or standardized neuropsychological tests.

Eosinophilic meningomyelitis in toxocariasis: case report and review of the literature

Toxocariasis is a worldwide-occurring parasitic infection leading to tissue damage in various organs due to wandering Toxocara larvae (visceral larva migrans). More than 40 cases of CNS involvement in children and immunocompetent adults have been documented in detail to date. Here, we present evidence of eosinophilic meningomyelitis in an adult without known risk factors and with positive Toxocara antibody response in CSF, but not in blood. Toxocariasis has to remain among the differential diagnosis in patients with eosinophilic CNS infection even if serological tests in blood are negative. Adult cases seem to be more frequent than previously thought (about 60%).

MRI and proton MR spectroscopy in acute disseminated encephalomyelitis

INTRODUCTION

Acute disseminated encephalomyelitis (ADEM) is one of a group of demyelinating disorders of the central nervous system (CNS). It is said to be attributed to an overshooting immunologic response following an infection or vaccination. The clinical course and type of manifestation is heterogeneous. The early application of corticosteroids has been shown to be beneficial to outcome; thus, an early diagnosis is highly desirable.

METHODS

The potential diagnostic value of advanced MR techniques such as proton MR spectroscopy and diffusion-weighted imaging (DWI) was investigated in two paediatric patients with ADEM, one of whom had a remitting and relapsing clinical course and presented with additional cranial nerve involvement. Proton MR spectroscopy revealed typical signs of acute demyelination, such as increased macromolecules, not found in other forms of non-necrotising pathology.

CONCLUSION

The addition of proton MR spectroscopy and DWI adds to the diagnostic power of MRI in the setting of post-infectious demyelinating disorders of the CNS or ADEM and may obviate the need for biopsy.

Transient encephalopathy after intrathekal methotrexate chemotherapy: diffusion-weighted MRI

Methotrexate (MTX) is an indispensable antimetabolite for the treatment of oncological and immunological disorders in all age groups. Chronic leukoencephalopathy is a well know side effect of MTX, especially in conjunction with intrathecal administration and whole brain radio therapy. However, acute neurotoxicity with confusion, disorientation, seizures and focal deficits has also been reported. Because acute neurological symptoms in patients under chemotherapy for neoplastic disorders may have many reasons, MR-imaging is usually necessary to identify the underlying pathology. Apart from conventional sequences, diffusion-weighted imaging (DW-MRI) is frequently performed. We report on clinical and imaging findings of reversibly restricted diffusion in a patient with transient encephalopathy after intrathecal administration of MTX for recurrent acute lymphatic leukaemia.

Experimental Autoimmune Encephalomyelitis (EAE): Lesion Visualization on a 3 Tesla Clinical Whole-body System after Intraperitoneal Contrast Injection

PURPOSE

To investigate the intravital visibility of CNS lesions in rats with experimental autoimmune encephalomyelitis (EAE), the animal correlate of multiple sclerosis, using a 3-Tesla (T) whole-body MR system.

MATERIALS AND METHODS

Three healthy Dark Agouti (DA) rats and 16 DA rats with clinical signs of EAE were examined on a 3T whole body-system using a normal wrist coil. In total, 25 examinations were preformed using T2- and T1-weigthed images in transverse and sagittal orientation with a slice thickness of 2 mm or 1 mm (voxel size up to 0.2 x 0.2 x 1 mm). Sedation was achieved by intraperitoneal injection of ketamine and xylazine. In addition, T1-weighted images were obtained after the instillation of 1.0 ml of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.5 mmol/ml) into the peritoneal cavity.

RESULTS

T2- and T1-weighted images of the brain and spinal cord with high spatial and contrast resolution could be obtained in all animals. The anatomical details of the olfactory bulb glomeruli, cerebellum foliae, ventricles and corpus callosum were clearly visible. The EAE lesions presented as hyperintense areas in T2-weighted images and could be demonstrated in all clinically affected animals by MRI and histologically verified. In total, the 16 affected rats had 28 cerebral and 2 spinal cord lesions (range 1 to 4, median 2). Contrast enhancement was noted in 12 animals and ranked as severe in ten and moderate in two cases. No adverse effects were noted due to sedation or intraperitoneal contrast injection.

CONCLUSIONS

The intravital demonstration of cerebral and spinal cord EAE lesions in rats is possible on a 3T whole-body MR scanner using a normal wrist coil. Intraperitoneal injection of ketamine/xylazine and contrast agent is an easy, safe and effective procedure in rats.

Bilateral Wallerian degeneration of the middle cerebellar peduncles due to paramedian pontine infarction: MRI findings

Wallerian degeneration is a frequent finding in lesions of the pyramidal tract, but has been observed after damage of the other fibre systems as well. Few reports exist about Wallerian degeneration of cerebellar fibres after distant lesions to the axons. Here, we report on a patient who developed degeneration of both middle cerebellar peduncles after a paramedian pontine infarction.