Two cases of atypical meningioma with pulmonary metastases: a comparative cytogenetic analysis of chromosomes 1p and 22 and a review of the literature.

We present two cases of atypical meningioma WHO grade II with a history of multiple local recurrences and late pulmonary metastases. Comparative cytogenetic analyses on 1p and 22q confirmed clonal origin of the primary intracranial meningiomas and the pulmonary metastases in both cases. These cases illustrate the importance of close neuroradiological follow-up to detect tumor recurrence in patients with atypical meningiomas WHO grade II even with clinically stable disease and should sensitize clinicians to late extracranial metastases of these tumors, especially to the lung. In an effort to elucidate common clinical features of metastatic meningiomas, especially to the lung, the literature was reviewed from 1995 to 2014, identifying a total of 45 published cases.

Postoperative MRI examinations in patients treated by deep brain stimulation using a non-standard protocol.

BACKGROUND: MRI in patients bearing deep brain stimulation (DBS) electrodes may induce cerebral lesions due to electrode heating. To avoid neurological deficits related to MRI, post-operative MRI protocol was installed in our institution. However, our protocol comprised a higher specific absorption rate (SAR) and different positioning of lead excess than the later released electrode manufacturer's guidelines. The objective was to evaluate the safety using this protocol. METHODS: Between January 2000 and May 2008, post-operative MRI was performed in all patients. In selected patients, additional MRI scans were performed with the implanted generator. MRI was acquired at 1.5 T with a RF transmit/receive head coil comprising a T2-weighted fast spin echo (FSE) and a T1-weighted inversion recovery FSE sequence. Local cranial SAR values measured up to 0.9 W/kg compared to the manufacturer's recommendation of 0.1 W/kg. Initial scans (1-7 days after surgery) were performed with externalized leads, long-term scans (>30 days after surgery) with a connected generator. New neurological deficits were assessed before and after MRI. Additional MRIs were compared to the initial postoperative MRI with emphasis on new lesions. RESULTS: In 211 patients, 243 MRIs were performed, including 212 initial post-operative MRI. In 12% (n = 24), 31 additional MRI examinations for various clinical reasons were achieved. No patients demonstrated new neurological deficits during or after MRI acquisitions. CONCLUSIONS: No complications were observed using this MRI protocol in DBS patients. Our results suggest that, within this setting, higher SAR values may be feasible for DBS patients than in the manufacturer's guidelines.

Spastin related hereditary spastic paraplegia with dysplastic corpus callosum.

Thin corpus callosum has been recently observed in two patients with an autosomal dominant trait of hereditary spastic paraplegia (HSP) linked to a novel mutation in the spastin gene (SPG4). In the same two patients cerebellar atrophy has been found. Reportedly, in other members of the same family, there has been a variable presence of mental retardation. We report on the clinical and genetic investigation of an Austrian family with a novel mutation in the spastin gene. Genetic analysis of the SPG4 locus revealed a mutation (C1120A) and a known intronic polymorphism (996-47G>A) of the spastin gene. In one affected family member, previously undescribed dysplasia of the corpus callosum (CC) was found in conjunction with otherwise uncomplicated HSP. Dysplastic CC was not paralleled with cortical atrophy, cognitive impairment or other phenotypic variations. Two further affected family members showed the same mutation and polymorphism, but no evidence of CC abnormalities. We conclude that apparently pure HSP may present with MRI features of dysplastic CC. This finding extended the spastin-related phenotype which is distinct from previous reports of thin CC in HSP.

MRI assessment of the effects of acetazolamide and external lumbar drainage in idiopathic normal pressure hydrocephalus.

BACKGROUND: The objective was to identify changes in quantitative MRI measures in patients with idiopathic normal pressure hydrocephalus (iNPH) occurring in common after oral acetazolamide (ACZ) and external lumbar drainage (ELD) interventions. METHODS: A total of 25 iNPH patients from two clinical sites underwent serial MRIs and clinical assessments. Eight received ACZ (125-375 mg/day) over 3 months and 12 underwent ELD for up to 72 hours. Five clinically-stable iNPH patients who were scanned serially without interventions served as controls for the MRI component of the study. Subjects were divided into responders and non-responders to the intervention based on gait and cognition assessments made by clinicians blinded to MRI results. The MRI modalities analyzed included T1-weighted images, diffusion tensor Imaging (DTI) and arterial spin labelling (ASL) perfusion studies. Automated threshold techniques were used to define regions of T1 hypo-intensities. RESULTS: Decreased volume of T1-hypointensities and decreased mean diffusivity (MD) within remaining hypointensities was observed after ACZ and ELD but not in controls. Patients responding positively to these interventions had more extensive decreases in T1-hypointensites than non-responders: ACZ-responders (4,651 ± 2,909 mm(3)), ELD responders (2,338 ± 1,140 mm(3)), ELD non-responders (44 ± 1,188 mm(3)). Changes in DTI MD within T1-hypointensities were greater in ACZ-responders (7.9% ± 2%) and ELD-responders (8.2% ± 3.1%) compared to ELD non-responders (2.1% ± 3%). All the acetazolamide-responders showed increases in whole-brain-average cerebral blood flow (wbCBF) estimated by ASL (18.8% ± 8.7%). The only observed decrease in wbCBF (9.6%) occurred in an acetazolamide-non-responder. A possible association between cerebral atrophy and response was observed, with subjects having the least cortical atrophy (as indicated by a positive z-score on cortical thickness measurements) showing greater clinical improvement after ACZ and ELD. CONCLUSIONS: T1-hypointensity volume and DTI MD measures decreased in the brains of iNPH patients following oral ACZ and ELD. The magnitude of the decrease was greater in treatment responders than non-responders. Despite having different mechanisms of action, both ELD and ACZ may decrease interstitial brain water and increase cerebral blood flow in patients with iNPH. Quantitative MRI measurements appear useful for objectively monitoring response to acetazolamide, ELD and potentially other therapeutic interventions in patients with iNPH.

Granulomatous tissue response in germinoma, a diagnostic pitfall in endoscopic biopsy.

We report a case of a 24-year-old man with a right thalamic germinoma that initially mimicked a granulomatous inflammation, compatible with neurosarcoidosis based on clinical symptoms, imaging results and histology of an endoscopically navigated biopsy. A second biopsy, prompted by clinical course, and performed openly from parieto-lateral revealed the underlying germinoma, obscured in the first biopsy by a granulomatous tissue response, particularly at the tumor edge. The present case highlights granulomatous inflammatory tissue response on the tumor edge of germinoma as a tumor-immanent diagnostic challenge. This diagnostic problem is aggravated by stereotactic and endoscopic approaches. We conclude that granulomatous inflammation in a specimen obtained by biopsy of a midline lesion should always be considered for the differential diagnosis of germinoma. Stereotactic and endoscopic surgery should sample several different target points within the lesion. Because of tumor heterogeneity of germinoma, the open biopsy approach is advantageous compared to endoscopic or stereotactic techniques for germinoma and should be considered if a germinoma is in the differential diagnosis and if allowed by the clinical situation.

CSF flow imaging in the management of third ventriculostomy with a reversed fast imaging with steady-state precession sequence.

The aim of this study was evaluation of a fast and slow-flow sensitive 2D steady-state free-precession sequence for its capability to prove the patency of endoscopic third ventriculostomy (TVS) in obstructive hydrocephalus, and to exclude communicating third ventricle prior to TVS. We compared gated and ungated variants of this sequence for this purpose. Twenty-three patients with obstructive hydrocephalus underwent 36 MR examinations with a 2D reversed fast imaging with steady-state precession (PSIF) sequence in a retrospectively cardiac gated (cine) and a faster but ungated version beside T1- and T2-weighted sequences in three planes. Thirteen patients were examined both before and after TVS, 4 patients solely before, and 6 patients solely after TVS. Imaging diagnoses were compared with intraoperative findings and clinical findings after TVS. Preoperative diagnosis of non-communicating third ventricle and cisterns was intraoperatively confirmed in 16 of 17 cases. Preoperative MRI was inconclusive in 1 case. Postoperative MRI revealed sufficient TVS in 16 of 19 cases and obstructed TVS in 3 of 19 cases due to several reasons. Findings at MRI were consistent in 19 of 19 cases with the clinical course and intraoperative results. The faster but ungated PSIF sequence was found to be diagnostically equivalent to the cardiac gated cine sequence. The CSF flow imaging with a 2D reversed fast imaging with steady-state precession sequence in conjunction with conventional T1- and T2-weighted images is a fast and reliable tool for pre- and postoperative functional evaluation in third ventriculostomy.

Differentially expressed genes in neurofibromatosis 1-associated neurofibromas and malignant peripheral nerve sheath tumors.

Neurofibromas represent one of the hallmarks of neurofibromatosis 1 (NF1) patients. Tumor progression of neurofibromas to malignant peripheral nerve sheath tumors (MPNST) is a frequent and life threatening complication. To learn more about processes involved in malignant transformation, we evaluated differential gene expression in plexiform neurofibroma and MPNST from the same NF1 patient. Suppression subtractive hybridization (SSH) yielded 133 differentially expressed genes confirmed by reverse Northern blotting. Virtual Northern blots were employed to validate 23 genes. To independently verify differential expression, immunohistochemical analyses with antibodies to matrix metalloproteinase 13 (MMP13), platelet-derived growth factor receptor alpha (PDGFRA) and fibronectin (FN1) were performed on 9 dermal and 9 plexiform neurofibromas and 16 MPNST from 19 NF1 patients. All three proteins proved to be up-regulated in MPNST. MMP13 expression was observed in 44% of MPNST but was absent in neurofibromas. PDGFRA was expressed in all tumors, but the number of cells expressing it was below 30% in neurofibromas and over 50% in MPNST. Likewise, FN1 was expressed in all tumors, but less than 30% of the cells in neurofibromas and more than 70% of the cells in MPNST exhibited antibody binding. Our data point to several genes not previously recognized to be differentially expressed, and provide a framework for future studies on progression-associated gene expression in low- and high-grade nerve sheath tumors.