C-Fiber Loss as a Possible Cause of Neuropathic Pain in Schwannomatosis.

Schwannomatosis is the third form of neurofibromatosis and characterized by the occurrence of multiple schwannomas. The most prominent symptom is chronic pain. We aimed to test whether pain in schwannomatosis might be caused by small-fiber neuropathy. Twenty patients with schwannomatosis underwent neurological examination and nerve conduction studies. Levels of pain perception as well as anxiety and depression were assessed by established questionnaires. Quantitative sensory testing (QST) and laser-evoked potentials (LEP) were performed on patients and controls. Whole-body magnetic resonance imaging (wbMRI) and magnetic resonance neurography (MRN) were performed to quantify tumors and fascicular nerve lesions; skin biopsies were performed to determine intra-epidermal nerve fiber density (IENFD). All patients suffered from chronic pain without further neurological deficits. The questionnaires indicated neuropathic symptoms with significant impact on quality of life. Peripheral nerve tumors were detected in all patients by wbMRI. MRN showed additional multiple fascicular nerve lesions in 16/18 patients. LEP showed significant faster latencies compared to normal controls. Finally, IENFD was significantly reduced in 13/14 patients. Our study therefore indicates the presence of small-fiber neuropathy, predominantly of unmyelinated C-fibers. Fascicular nerve lesions are characteristic disease features that are associated with faster LEP latencies and decreased IENFD. Together these methods may facilitate differential diagnosis of schwannomatosis.

3 Tesla MRI brain scanning under general anaesthesia in a paediatric 3 Tesla-compatible cochlear implant recipient, first reported case: Clinical considerations and implications for future practice.

OBJECTIVES: To demonstrate the safety and feasibility of the first reported case of a 3 Tesla MRI scan in a paediatric 3 Tesla-compatible cochlear implant recipient under general anaesthesia. MATERIALS AND METHODS: A three-year-old child with bilateral optic pathway glioma treated with chemotherapy, who subsequently received a right sided 3 Tesla-compatible cochlear implant for sensorineural hearing loss was examined. The CI device chosen was implanted due to its purported MRI compatibility. Following informed consent and hospital executive approval, the child underwent a 3 Tesla MRI scan to assess for growth of the optic pathway glioma. RESULTS: A 3 Tesla MRI scan of the brain was performed under general anaesthesia. There was expected artefact due to the magnet of the receiver stimulator. There was no malfunction of the implant noted after the procedure, and no neurological or otological complications. The child had five more uneventful 3 Tesla MRI scans of the brain without complications. CONCLUSION: This is the first reported case of a child with a 3 Tesla-compatible cochlear implant undergoing a 3 Tesla MRI scan of the brain under general anaesthesia. Provided manufacturer guidelines are adhered to, 3 Tesla MRI scanning should not be contraindicated in paediatric cochlear implant recipients with a compatible device.

Current and Future Imaging Methods for Evaluating Response to Immunotherapy in Neuro-Oncology.

Imaging plays a central role in evaluating responses to therapy in neuro-oncology patients. The advancing clinical use of immunotherapies has demonstrated that treatment-related inflammatory responses mimic tumor growth via conventional imaging, thus spurring the development of new imaging approaches to adequately distinguish between pseudoprogression and progressive disease. To this end, an increasing number of advanced imaging techniques are being evaluated in preclinical and clinical studies. These novel molecular imaging approaches will serve to complement conventional response assessments during immunotherapy. The goal of these techniques is to provide definitive metrics of tumor response at earlier time points to inform treatment decisions, which has the potential to improve patient outcomes. This review summarizes the available immunotherapy regimens, clinical response criteria, current state-of-the-art imaging approaches, and groundbreaking strategies for future implementation to evaluate the anti-tumor and immune responses to immunotherapy in neuro-oncology applications.

How we read: the combined use of MRI and novel PET tracers for the characterisation and treatment planning of masses in neuro-oncology.

Technical advances in imaging are well demonstrated by MRI (Magnetic Resonance Imaging) and PET (Positron Emission Tomography). Excellent anatomical detail and a lack of ionising radiation make MRI the standard of care for most neuroimaging indications, and advanced sequences are providing an ever-growing ability for lesion characterisation. PET utilising the tracer fluorine-18 fluorodeoxyglucose is widely used in oncology, while newer PET tracers are able to target a growing number of metabolic pathways and cell membrane receptors. The sequential use of these modalities harnesses the strengths of both, providing complementary diagnostic and therapeutic information.Here we outline the ways in which we use MRI and PET in a complementary manner to improve lesion characterisation in neuro-oncology. Most commonly, an abnormality is detected on either PET or MRI, and the addition of the other modality allows a more confident diagnosis and/or demonstrates additional lesions, guiding treatment decisions and, in some cases, obviating the need for biopsy. These modalities may also be combined to guide the treatment of intracranial masses for which the diagnosis is known, such as neuro-endocrine tumour metastases or meningiomas refractory to conventional therapies.

Brain white matter fibre tracts: a review of functional neuro-oncological relevance.

State-of-the-art glioma treatment aims to maximise neuro-oncological benefit while minimising losses in quality of life. Optimising this balance remains hindered by our still limited understanding of information processing in the human brain. To help understand individual differences in functional outcomes following neuro-oncological treatment, we review mounting evidence demonstrating the fundamental role that white matter connections play in complex human behaviour. We focus on selected fibre tracts whose destruction is recognised to elicit predictable behavioural deficits and consider specific indications for non-invasive diffusion MRI tractography, the only existing method to map these fibre tracts in vivo, in the selection and planning of neuro-oncological treatments. Despite remaining challenges, longitudinal tract imaging, in combination with intraoperative testing and neuropsychological evaluation, offers unique opportunities to refine our understanding of human brain organisation in the quest to predict and ultimately reduce the quality of life burden of both surgical and non-surgical first-line neuro-oncological therapies.

Congenital hemangioma in spondylocostal dysostosis: a novel association

Abstract Congenital hemangioma is a benign tumor caused by dysfunction in embryogenesis and vasculogenesis, which progresses during fetal life to manifest as fully developed at birth. Although hemangiomas are the most common tumor of infancy, rapidly involuting congenital hemangioma has not been described in spondylocostal dysostosis. I report the novel association of congenital hemangioma and spondylocostal dysostosis in a Mexican newborn female patient with neural tube defects. Given the embryological relationship between skin and nervous system, I surmise that this association is not coincidental. I also propose that these morphologic alterations be incorporated to the spondylocostal dysostosis phenotype and specifically looked for in other affected children, in order to provide appropriate medical management and genetic counseling.

The impact of routine surveillance screening with magnetic resonance imaging (MRI) to detect tumour recurrence in children with central nervous system (CNS) tumours: protocol for a systematic review and meta-analysis.

BACKGROUND: The aim of this study is to assess the impact of routine MRI surveillance to detect tumour recurrence in children with no new neurological signs or symptoms compared with alternative follow-up practices, including periodic clinical and physical examinations and the use of non-routine imaging upon presentation with disease signs or symptoms. METHODS: Standard systematic review methods aimed at minimising bias will be employed for study identification, selection and data extraction. Ten electronic databases have been searched, and further citation searching and reference checking will be employed. Randomised and non-randomised controlled trials assessing the impact of routine surveillance MRI to detect tumour recurrence in children with no new neurological signs or symptoms compared to alternative follow-up schedules including imaging upon presentation with disease signs or symptoms will be included. The primary outcome is time to change in therapeutic intervention. Secondary outcomes include overall survival, surrogate survival outcomes, response rates, diagnostic yield per set of images, adverse events, quality of survival and validated measures of family psychological functioning and anxiety. Two reviewers will independently screen and select studies for inclusion. Quality assessment will be undertaken using the Cochrane Collaboration's tools for assessing risk of bias. Where possible, data will be summarised using combined estimates of effect for time to treatment change, survival outcomes and response rates using assumption-free methods. Further sub-group analyses and meta-regression models will be specified and undertaken to explore potential sources of heterogeneity between studies within each tumour type if necessary. DISCUSSION: Assessment of the impact of surveillance imaging in children with CNS tumours is methodologically complex. The evidence base is likely to be heterogeneous in terms of imaging protocols, definitions of radiological response and diagnostic accuracy of tumour recurrence due to changes in imaging technology over time. Furthermore, the delineation of tumour recurrence from either pseudo-progression or radiation necrosis after radiotherapy is potentially problematic and linked to the timing of follow-up assessments. However, given the current routine practice of MRI surveillance in the follow-up of children with CNS tumours in the UK and the resource implications, it is important to evaluate the cost-benefit profile of this practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016036802.

What MRI can tell us about neurogenic tumors and rhabdomyosarcoma.

This review focuses on the MRI features of neurogenic tumors and rhabdomyosarcoma in children. Neurogenic tumors include those arising from a nerve sheath and neuroblastic tumors that arise from the sympathetic nervous system. Nerve sheath tumors can be benign or malignant and occur sporadically or in association with neurofibromatosis type 1. Neuroblastic tumors comprise a spectrum of tumors ranging from highly malignant neuroblastoma to the benign ganglioneuroma. These neurogenic tumors arise in typical locations within the chest, abdomen and pelvis and have distinctive and characteristic imaging features that should suggest their diagnosis. Rhabdomyosarcoma encompasses a variety of histological subtypes that exhibit varying degrees of aggressiveness and biological behavior. While some abdominal and pelvic locations are well known to give rise to rhabdomyosarcoma, this tumor can arise in any tissue in the body except bone. The paper reviews the MRI and clinical features of neurogenic tumors and rhabdomyosarcoma and the imaging findings that can aid in clinical management.

Congenital hemangioma in spondylocostal dysostosis: a novel association.

Congenital hemangioma is a benign tumor caused by dysfunction in embryogenesis and vasculogenesis, which progresses during fetal life to manifest as fully developed at birth. Although hemangiomas are the most common tumor of infancy, rapidly involuting congenital hemangioma has not been described in spondylocostal dysostosis. I report the novel association of congenital hemangioma and spondylocostal dysostosis in a Mexican newborn female patient with neural tube defects. Given the embryological relationship between skin and nervous system, I surmise that this association is not coincidental. I also propose that these morphologic alterations be incorporated to the spondylocostal dysostosis phenotype and specifically looked for in other affected children, in order to provide appropriate medical management and genetic counseling.

A modified method for locating parapharyngeal space neoplasms on magnetic resonance images: implications for differential diagnosis.

The parapharyngeal space (PPS) is an inverted pyramid-shaped deep space in the head and neck region, and a variety of tumors, such as salivary gland tumors, neurogenic tumors, nasopharyngeal carcinomas with parapharyngeal invasion, and lymphomas, can be found in this space. The differential diagnosis of PPS tumors remains challenging for radiologists. This study aimed to develop and test a modified method for locating PPS tumors on magnetic resonance (MR) images to improve preoperative differential diagnosis. The new protocol divided the PPS into three compartments: a prestyloid compartment, the carotid sheath, and the areas outside the carotid sheath. PPS tumors were located in these compartments according to the displacements of the tensor veli palatini muscle and the styloid process, with or without blood vessel separations and medial pterygoid invasion. This protocol, as well as a more conventional protocol that is based on displacements of the internal carotid artery (ICA), was used to assess MR images captured from a series of 58 PPS tumors. The consequent distributions of PPS tumor locations determined by both methods were compared. Of all 58 tumors, our new method determined that 57 could be assigned to precise PPS compartments. Nearly all (13/14; 93%) tumors that were located in the pre-styloid compartment were salivary gland tumors. All 15 tumors within the carotid sheath were neurogenic tumors. The vast majority (18/20; 90%) of trans-spatial lesions were malignancies. However, according to the ICA-based method, 28 tumors were located in the pre-styloid compartment, and 24 were located in the post-styloid compartment, leaving 6 tumors that were difficult to locate. Lesions located in both the pre-styloid and the post-styloid compartments comprised various types of tumors. Compared with the conventional ICA-based method, our new method can help radiologists to narrow the differential diagnosis of PPS tumors to specific compartments.

Neurolymphomatosis in a patient with extranodal NK/T-cell lymphoma, nasal-type: a case report and literature review.

A 47-year-old man presented with a fever and lower extremity paresthesia. A physical examination revealed sensory deficits in the left hand, distal arm and right sole. A bone marrow aspiration demonstrated infiltration of extranodal NK/T-cell lymphoma, nasal type, and (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) disclosed extensive involvement of the peripheral nerves. These findings were consistent with a diagnosis of neurolymphomatosis (NL). The lymphoma progressed soon after the patient underwent cord blood transplantation, and he died on day 33 after transplantation. NL is a rare manifestation of lymphoma characterized by infiltration of the peripheral nerves, leading to neuropathy. It is an increasingly recognized entity and can be the first indication of lymphoma.

Progressive neurolymphomatosis with cutaneous disease: response in a patient with mycosis fungoides.

Peripheral neurolymphomatosis is a rare manifestation of advanced lymphoproliferative disorders. It is often associated with B cell lymphomas and rarely with cutaneous T cell lymphomas, such as mycosis fungoides and Sézary syndrome. In this case report, we present a 78-year-old male with a long-standing history of mycosis fungoides. The patient initially presented with chronic peripheral neuropathy in an ulnar nerve distribution. After an unsuccessful ulnar nerve transposition, the ulnar nerve was re-explored and a mass consistent with diffuse lymphomatous infiltration was diagnosed. Magnetic resonance (MR) imaging of the left brachial plexus and later of the sacral plexus demonstrated diffuse thickening and peripheral nodularity in keeping with neurolymphomatosis. The patient's clinical course rapidly deteriorated thereafter and the patient succumbed to his disease. Although uncommon, neurolymphomatosis may be considered in patients with chronic peripheral neuropathy and an underlying history of a lymphoproliferative disorder. US and MR may serve as helpful non-invasive adjuncts in making the diagnosis and identifying sites for biopsy.

EANM 2012 guidelines for radionuclide imaging of phaeochromocytoma and paraganglioma.

PURPOSE: Radionuclide imaging of phaeochromocytomas (PCCs) and paragangliomas (PGLs) involves various functional imaging techniques and approaches for accurate diagnosis, staging and tumour characterization. The purpose of the present guidelines is to assist nuclear medicine practitioners in performing, interpreting and reporting the results of the currently available SPECT and PET imaging approaches. These guidelines are intended to present information specifically adapted to European practice. METHODS: Guidelines from related fields, issued by the European Association of Nuclear Medicine and the Society of Nuclear Medicine, were taken into consideration and are partially integrated within this text. The same was applied to the relevant literature, and the final result was discussed with leading experts involved in the management of patients with PCC/PGL. The information provided should be viewed in the context of local conditions, laws and regulations. CONCLUSION: Although several radionuclide imaging modalities are considered herein, considerable focus is given to PET imaging which offers high sensitivity targeted molecular imaging approaches.

Bilateral vagus nerve neurolymphomatosis diagnosed using PET/CT and diffusion-weighted MRI.

In neurolymphomatosis, malignant lymphocytes infiltrate the peripheral nervous system in the presence of a known or unknown hematological malignancy. This report describes the findings of diffusion-weighted MRI and F-FDG PET/CT in a 65-year-old man with hoarseness. Results revealed a mass with restricted diffusion on diffusion-weighted imaging in the right visceral vascular space, increased uptake of F-FDG, and other masses at distant peripheral nerves. Restaging PET/CT showed involvement of the right brachial plexus and right sciatic nerve. Biopsy and immunohistochemistry of the right vagus nerve and cervical lymphadenopathy revealed a diffuse large B-cell non-Hodgkin lymphoma.

Increasing importance of 18F-FDG PET in the diagnosis of neurolymphomatosis.

Neurolymphomatosis (NL) is a rare clinical entity that is defined as infiltration of the nervous system by a known or unknown haematological malignancy and is difficult to diagnose. Fluorine-18 fluorodeoxyglucose (18F-FDG) PET imaging is increasingly being used in haematological malignancies. This article focus on the role of 18F-FDG PET in the diagnosis and management of NL by presenting a review of cases described in the literature. Reports on NL that used PET with or without computed tomography (CT) as a diagnostic modality were extracted from Medline and evaluated. A total of 58 patients described in 49 case reports on NL were found. In 36 distinctive patients 18F-FDG PET with or without CT was used as a diagnostic modality. In 91% of patients PET showed uptake in various structures in the central or peripheral nervous system, suggesting involvement of lymphoma. Predilection localizations were the brachial and lumbar plexuses, along the course of peripheral nerves of the extremities, and the trigeminal nerve root. MRI, cerebrospinal fluid or bone marrow analysis were frequently negative. In the cases described in the literature 18F-FDG PET assisted in diagnosing NL by providing a whole-body evaluation, showing frequent uptake in affected nervous structures and supported disease management by defining a target for biopsy, monitoring progression and evaluating response to treatment. As other diagnostic methods may be negative, the importance of PET-CT is increasing in the diagnosis and management of this rare clinical entity.

PET radiotracers for molecular imaging in the brain: past, present and future.

Neuroimaging of brain receptors began in the early 1980s. Now, some thirty-five years later, PET imaging is still an expanding field of preclinical and clinical investigations. In addition to improvements in PET cameras and image analysis, the availability of suitable radiotracers is a crucial factor leading this expansion. Radiotracers have been developed to visualize and quantify a growing numbers of brain receptors, transporters, enzymes and other molecular targets. The development of adequate PET radiotracers represents an exciting challenge, given the large number of targets and neurochemical functions that have yet to be explored. In this article, we review the main evolutions led by preclinical radiotracers and clinical radiopharmaceuticals. The current main contributions of PET radiotracers are described in terms of imaging of neuronal metabolism, receptor and transporter quantification and neurodegenerative, neuroinflammatory and neurooncologic process imaging. In the last part, we highlight some applications presenting a potential for novel functional explorations of the brain.

[Clinical manifestation and radiological features of small cell lung cancer (SCLC)]. / Obraz kliniczny i radiologiczny drobnokomórkowego raka pluca.

INTRODUCTION: Small cell lung cancer (SCLC) includes 10-15% of primary lung tumors and it is very aggressive neoplasm. The aim of this study was to evaluate radiological and clinical features of SCLC and its spread. MATERIAL AND METHODS: The retrospective analysis included 31 patients (18 women, 13 men, mean age: 68.2 +/- 8.34 years).The extensive disease (ED) in most patients was present. 25 patients (80,6%) reported habitual cigarette smoking. Localization of primary tumor, metastases, clinical symptoms and main blood abnormalities were assessed. RESULTS: The most common locations of the primary tumor were: the lung hilus--15 (48.4%), the upper lobe of lung--6 (19.3%) and mediastinum--3 (9.7%). In most cases, mediastinal, subcarinal--both (41.9%) and hilus--(32.2%) lymph nodes were involved. Distant metastases were present in 20 patients (64.5%) at the moment of diagnosis. The most common locations of metastases were: liver--12 (60%), lungs--7 (35%), suprarenal glands--6 (30%), bones--3 (15%) and CNS--3 (15%). The most common symptoms were: cough (77.4%), weakness (51.6%), dyspnea (45.2%), chest pain (41.9%) and the weight loss (30%). Superior vena cava syndrome occurred in 4 patients (13%). The symptoms lasted an average 115 days, but the most persistent were: cough (216 days) and dyspnea (150 days). The main blood tests abnormalities were increased activities of: CRP (mean 63.4 mg/L), AspAT (65U), LDH (1852.7 U/l) and D-dimer (1892.5 microg/l). CONCLUSIONS: SCLC was mainly manifested in CT as central mass lung involving hilus or mediastinum. In most cases, distant metastases were present at the moment of diagnosis.

Congenital agenesis of right parotid gland confounds MIBG scan interpretation in craniocervical neuroblastoma.

A 10-month-old boy with left infraorbital temporal neuroblastoma presented for I-123 metaiodobenzylguanidine scan with SPECT/CT for staging. Symmetrical metaiodobenzylguanidine uptake in salivary glands is usually considered normal. In this case of right parotid agenesis, symmetrical uptake was misleading. Tumor in the right mandibular ramus masqueraded as normal parotid gland. Repeat imaging 3 months after chemotherapy revealed absence of physiologic right parotid gland activity. Correlation with CT from SPECT/CT demonstrated right parotid agenesis, confirmed on MRI. Few cases of unilateral parotid agenesis are reported in published literature. We also discuss the potential added value of higher-quality CT images in SPECT/CT tumor imaging.

Clinical sonopathology for the regional anesthesiologist: part 1: vascular and neural.

The use of ultrasound to facilitate regional anesthesia is an evolving area of clinical, education, and research interests. As our community's experience grows, it has become evident that anesthesiologists performing "routine" ultrasound-guided blocks may very well be confronted with atypical or even pathologic anatomy. As an educational resource for anesthesiologists, the following articles present examples of common sonopathology that may be encountered during ultrasound-guided regional anesthesia. This present article describes sonopathology related to blood vessels and nerves.