Clinical Reasoning: A Young Man With Subacute Onset of Spastic Paraparesis.

Leukodystrophies are a group of rare neurodegenerative disorders, usually presenting in infancy with a variable combination of cognitive, motor, and coordination impairment. Adult-onset cases are even more rare, often representing a diagnostic challenge even for experienced neurologists. Here, we present a case of a 44-year-old man with subacute and rapidly progressive spastic paraplegia, whose brain MRI revealed white matter abnormalities compatible with a diagnosis of leukodystrophy. We discuss how to apply a simplified diagnostic algorithm to distinguish acquired leukoencephalopathies from leukodystrophies and how to delve into the maze of genetic testing for white matter diseases. In our patient, we reached the diagnosis of a treatable disorder, whose early recognition is essential to prevent severe neurologic deterioration.

Neuro-Oncology Multidisciplinary Tumor Board: The Point of View of the Neuroradiologist.

BACKGROUND: The multi-disciplinary tumor board (MTB) is essential to quality cancer care and currently recommended to offer the best personalized clinical approach, but little has been published regarding MTBs in neuro-oncology (nMTBs). The aim of the present paper is to describe our nMTB, to evaluate its impact on clinical management decisions, and to assess the role of neuroradiologists. METHODS: The retrospective evaluation of the cases discussed at our nMTB from March 2017 to March 2020. From the electronic records, we extracted epidemiological, clinical and other specific data of nMTB. From the radiological records, we calculated data relating to the number, time for revision, and other specifications of MRI re-evaluation. Statistical analysis was performed. RESULTS: a total of 447 discussions were analyzed, representing 342 patients. The requests for case evaluations came from radiation oncologists (58.8%) and neurosurgeons (40.5%), and were mainly addressed to the neuroradiologist (73.8%). The most frequent questions were about the treatment's changes (64.4%). The change in patient treatment was reported in 40.5% of cases, 76.8% of these were based on the neuroradiologic assessment. A total of 1514 MRI examinations were re-evaluated, employing approximately 67 h overall. The median of the MRI exams reviewed per patient was 3 (min-max 1-12). CONCLUSIONS: Our study supported that the multidisciplinary approach to patient care can be particularly effective in managing brain tumors. A review by an expert neuroradiologist impacts patient management in the context of nMTBs, but has costs in terms of the time and effort spent preparing for it.

MRI findings of olivary degeneration after surgery for posterior fossa tumours in children: incidence, time course and correlation with tumour grading.

PURPOSE: Olivary degeneration is due to many posterior cranial fossa (PCF) lesions affecting the dentato-rubro-olivary pathway, also known as Guillain-Mollaret triangle. Triangle damage results in hyperexcitation and consequently in hypertrophy of the inferior olivary nucleus (ION). The aim of our study was to evaluate the incidence of magnetic resonance (MR) imaging changes in the ION after surgery in a large cohort of paediatric patients and to determine their correlation with tumour grade. MATERIALS AND METHODS: We retrospectively evaluated 58 patients treated surgically for PCF tumours who underwent MR imaging between 2007 and 2014, 1 week to 5 years after surgery. Histopathology revealed 29 medulloblastomas (WHO IV), 6 ependymomas (WHO II), 2 anaplastic ependymomas (WHO III) and 21 pilocytic astrocytomas (WHO I). ION MR imaging changes were correlated with surgery-to-MR interval and with tumour grading. RESULTS: ION MR imaging changes were observed in 19/64 (33 %), and all consisted of T2 signal alterations, 15 bilateral and four unilateral, with dentate nucleus damage in all cases. Olivary enlargement was observed in few cases only (7/19). ION T2 hyperintensity was always present between 1 and 6 months after surgery with a trend to decrease, becoming faint after 1 year. The Fisher test demonstrated a significant (p = 0.005) correlation between ION MR imaging changes and high tumour grade. CONCLUSIONS: Our results demonstrate that olivary degeneration, with or without hypertrophy, is a relatively frequent consequence of posterior fossa surgery, particularly in children treated for high-grade tumours. Knowledge of this condition can prevent misdiagnoses and unnecessary investigations.

Magnetic resonance image findings of primary intradural Ewing sarcoma of the cauda equina: case report and review of the literature.

BACKGROUND CONTEXT: Involvement of the cauda equina in Ewing sarcoma (ES) is extremely rare, and only few cases are reported in literature. However, ES of cauda equina shares some neuroradiological features with other neoplasms that can involve the intradural space. Therefore, differential diagnosis with other tumors of cauda equina should be considered by neuroradiologists and neurosurgeons to provide appropriate treatment. PURPOSE: To present a rare case of intradural extramedullary primary ES. STUDY DESIGN: Case report. METHODS: We report a case of a 44-year-old woman presenting with the rapid onset of cauda equina syndrome. Radiological analysis showed multiple intradural masses, extending from L1 to S3 level. After radical surgery, lesions were histologically defined as ES. We present a literature review, analyzing magnetic resonance image (MRI) features of primary intradural ES of the cauda equina. RESULTS: Four cases of primitive ES arising from the cauda equina have been reported in the literature. CONCLUSIONS: Because of the low number of reported cases, it is not possible to describe pathognomonic MRI findings for intradural ES of the cauda equina. However, few tumors show similar MRI features. Therefore, despite its rarity, intradural ES should be taken into account in the differential diagnosis of spinal tumors involving cauda equina.

Spontaneous modifications of contrast enhancement in childhood non-cerebellar pilocytic astrocytomas.

INTRODUCTION: Pilocytic astrocytoma (PA) is classified by the World Health Organization as a grade I tumor. Magnetic resonance imaging (MRI) is the gold standard in the diagnosis and follow-up of this neoplasm, and assessment of contrast enhancement (CE) pattern is essential. The purpose of this study was to investigate CE changes of non-cerebellar PA (n-C PA) stable in size with serial MRI. METHODS: Nine hundred and twelve MRI exams of 140 children with histologically proven PA were retrospectively reviewed. Patients were chosen for study inclusion if they were off therapy, without neurofibromatosis type 1, and without dimensional changes of tumor/residual tumor. In patients with CE changes, tumor size and CE size were calculated with a cross product. Descriptive statistics were calculated for continuous variables; effects of possible factors influencing changes of contrast-enhanced areas were tested. RESULTS: Of 39 n-C PA satisfying the inclusion criteria, 12 showed CE changes in terms of appearance/increase or disappearance/decrease of CE areas. Three of these 12 PA were infratentorial and nine supratentorial. There were no significant correlations between age, gender, tumor localization, tumor size, and modification of CE areas. CONCLUSION: In our experience, n-C PA may show variable CE over time in the absence of tumor/residual tumor dimension change. We recommend that CE fluctuations alone cannot be considered an indicator of tumor progression/regression.

Contrast-enhanced MR imaging of the spine: when, why and how? How to optimize contrast protocols in MR imaging of the spine.

The optimal protocols and the role of contrast agents in spinal MR imaging are controversial. Although the diagnosis of many common spinal diseases can be reliably achieved by means of unenhanced images, contrast use is often necessary to improve lesion detection and differential diagnosis. The heterogeneity of the different spinal compartments and the wide variety of spinal pathology require tailored imaging strategies. Thus, the rules to achieve optimization of contrast protocols for MR imaging of the spine are frequently very different to those for brain imaging, and depend on the location and site of origin of the lesions in a specific spinal compartment, on the findings of unenhanced imaging, and on the concomitant use of fat-suppression techniques. Furthermore, in most cases, the small size of the examined structures requires a meticulous technique, and the administration of a contrast agent with high relaxivity, such as MultiHance, is advisable to enable the detection of tiny areas of contrast enhancement. The applications and clinical utility of post-contrast MR imaging are discussed with regard to different spinal diseases.

Neuroimaging of thalamic tumors in children.

INTRODUCTION: Thalamic tumors are typical deep brain tumors; their incidence is not precisely known because of the different definition criteria. However, taking only lesions arising in the thalami into consideration (and excluding those secondarily involving the thalami from adjacent structures) approximately 40% of thalamic tumors affect patients under 18 years of age and thalamic neoplasms account for 2-5% of all intracranial tumors in children. MATERIALS AND METHODS: In the present paper we have focused attention on the neuroimaging features of thalamic tumors in a pediatric population; based upon personal experience, we suggest a rational neuroradiological approach to the diagnostic evaluation, describe CT and MRI findings of the most common tumors, and attempt to define basic patterns in order to provide the most reliable "pathological" diagnosis.