Sporadic Intradural Extramedullary Hemangioblastoma of Cauda Equina with Large Peritumoral Cyst—A Rare Presentation

Cauda equina intradural tumors commonly reported include ependymoma, schwannoma, neurofibroma, meningioma, and drop metastasis. Hemangioblastoma of the neural axis is a rare benign vascular tumor comprising only 1.6 to 6.4% of spinal tumors, and are usually associated with Von-Hippel Lindau disease. Sporadic intradural extramedullary hemangioblastoma involving cauda equina is very rare with only countable reports, and the presence of peritumoral cyst has been reported only once. We report one such case of hemangioblastoma with a large peritumoral cyst, which was diagnosed radiologically and confirmed by histopathology following surgical excision. Pertinent radiological characteristics, diagnostic clues, treatment, and surgical outcomes are discussed.

Development of a 3D-Printed High Temperature Resin Cecal Fistula Implant for Long-Term and Minimally Invasive Access to the Gut Microbiome

Microbiota dysbiosis has been associated with chronic diseases ranging from gastrointestinal inflammatory and metabolic conditions to neurological changes affecting the gut-brain neural axis, mental health, and general well-being. However, current animal studies using oral gavage and gnotobiotic animals do not allow for non-invasive long-term access to gut microbiome. The purpose of the present study was to evaluate the feasibility of 3D-printed fistula implants through the body wall and into the cecum of rats to obtain long-term access to gut microbiome. Cecal fistulas were designed and 3D-printed using a high temperature resin (Formlabs; acrylic and methacrylic mixture). Nine male Sprague-Dawley rats underwent the fistula implantation. Food intake, body weight, and body fat were measured to determine the impact of fistula manipulation. Gut microbiome, vagal afferents in the hindbrain, and microglia activation were analyzed to determine if fistula implantation disrupted the gut-brain neural axis. We found that the procedure induced a transient decrease in microbial diversity in the gut that resolved within a few weeks. Fistula implantation had no impact on food intake, body weight, fat mass, or microglia activation. Our study shows that 3D-printed cecal fistula implantation is an effective procedure that allows long-term and minimally invasive access to gut microbiome.

A Rare Case of Calcifying Pseudoneoplasms of the Neural Axis in Lumbar Spine

Calcified pseudoneoplasm of the neural axis (CAPNON) is a very rare, non-neoplastic, calcified pathological entity occurring anywhere in the central nervous system (CNS). Overall, less than 100 cases were reported, of which less than 50% were from the spine. We present a case of a 53-year-old lady with a history of L4–L5 radiculopathy, known case of rheumatoid arthritis, and with no previous history of trauma, tumor or infection. MRI showed calcified intradural mass, extending into the right lateral recess, which was isointense on T1- and T2-weighted sequences. Fenestration on right side along with complete resection of the lesion was done. Mass was found adherent around the dura, extending in to right L5 nerve root foramen, and histopathological examination confirmed the diagnosis of CAPNON. At 6 months follow-up, the patient is pain-free with no radicular symptoms. This entity should be taken in as differential in cases of calcified intraspinal and intracranial lesions. Surgical resection is the treatment of choice.

Microbial colonization induces histone acetylation critical for inherited gut-germline-neural signaling

The gut-neural axis plays a critical role in the control of several physiological processes, including the communication of signals from the microbiome to the nervous system, which affects learning, memory, and behavior. However, the pathways involved in gut-neural signaling of gut-governed behaviors remain unclear. We found that the intestinal distension caused by the bacterium Pseudomonas aeruginosa induces histone H4 Lys8 acetylation (H4K8ac) in the germline of Caenorhabditis elegans, which is required for both a bacterial aversion behavior and its transmission to the next generation. We show that induction of H4K8ac in the germline is essential for bacterial aversion and that a 14-3-3 chaperone protein family member, PAR-5, is required for H4K8ac. Our findings highlight a role for H4K8ac in the germline not only in the intergenerational transmission of pathogen avoidance but also in the transmission of pathogenic cues that travel through the gut-neural axis to control the aversive behavior.

Migration of liquid silicone, an emerging contraindication of neuraxial anesthesia

The illegal use of liquid silicone products or biopolymers in gluteal augmentation procedures is giving rise to multiple complications, with a significant negative health impact, both in the short and long-term. The migration of polymers to the sacral and lumbar region represents a major limitation to conducting neuraxial anesthesia procedures. This silicon migration is unpredictable through the superficial tissue as is widely described in the literature. Caudal, spinal and epidural anesthesia may cross the silicone in the fascia and contaminate the neural axis with substances that are highly capable of causing inflammation, edema and tissue necrosis. In order to improve the safety of neuraxial anesthetic procedures and avoid the potential risk of dissemination and contamination of the neural axis, this complication must be ruled out, or be considered an emerging contraindication for these anesthetic procedures.

Modulation of serotonin in the gut-liver neural axis ameliorates the fatty and fibrotic changes in non-alcoholic fatty liver

ABSTRACTThe etiology of non-alcoholic fatty liver disease (NAFLD) consists of various factors, including neural signal pathways. However, the molecular mechanisms of the autonomic neural signals influencing NAFLD progression have not been elucidated. Therefore, we examined the involvement of the gut-liver neural axis in NAFLD development and tested the therapeutic effect of modulation of this axis in this study. To test the contribution of the gut-liver neural axis, we examined NAFLD progression with respect to body weight, hepatic steatosis, fibrosis, intestinal tight junction, microbiota and short-chain fatty acids in NAFLD models of choline-deficient defined L-amino-acid and high-fat diet-fed mice with or without blockades of autonomic nerves from the liver. Blockade of the neural signal from the liver to the gut in these NAFLD mice models ameliorated the progression of liver weight, hepatic steatosis and fibrosis by modulating serotonin expression in the small intestine. It was related to the severity of the liver pathology, the tight junction protein expression, microbiota diversity and short-chain fatty acids. These effects were reproduced by administrating serotonin antagonist, which ameliorated the NAFLD progression in the NAFLD mice models. Our study demonstrated that the gut-liver neural axis is involved in the etiologies of NAFLD progression and that serotonin expression through this signaling network is the key factor of this axis. Therefore, modulation of the gut-liver neural axis and serotonin antagonist ameliorates fatty and fibrotic changes in non-alcoholic fatty liver, and can be a potential therapeutic target of NAFLD.This article has an associated First Person interview with the first author of the paper.

First person – Masayoshi Ko

ABSTRACTFirst Person is a series of interviews with the first authors of a selection of papers published in Disease Models & Mechanisms, helping early-career researchers promote themselves alongside their papers. Masayoshi Ko is first author on ‘ Modulation of serotonin in the gut-liver neural axis ameliorates the fatty and fibrotic changes in non-alcoholic fatty liver’, published in DMM. Masayoshi is an MD and PhD student in the lab of Kenya Kamimura and Shuji Terai at Niigata University, Japan, investigating the involvement of multi-organ linkage via autonomic nerves in non-alcoholic fatty liver (NAFLD).

Brainstem tumors in children: a review

The brainstem is defined as the portion of the neural axis between the diencephalon and the cervical spinal cord. Brainstem gliomas (BSGs) can occur anywhere within this region and account for 10% to 15% of primary pediatric intracranial tumors. The development of neuroimaging allied to the refinement of surgical tools, such as improved magnification and visualization of the surgical field with more powerful surgical microscopes and sources of light, followed by the introduction of ultrasonic aspirator, anesthetic and intraoperative neurophysiological monitoring provided the neurosurgeon with conditions for a much safer surgical management of these tumors. This article reviews the current state of knowledge with regard to tumors arising in the brain stem in children, the therapeutic options available and provides recommendations with regard to management.

Foot Drop: A Rare Post COVID-19 Complication

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus which has caused Coronavirus Disease 2019 (COVID-19) pandemic, may also affect neural axis at different levels including Central Nervous System (CNS) and Peripheral Nervous System (PNS). There is increasing evidence of neurological complications caused by SARS-CoV-2. Though isolated facial nerve involvement has been reported in literature, isolated peroneal nerve palsy secondary to SARS-CoV-2 infection is a rare occurrence. This article reported two such rare cases (53-year-old male/45-year-old male) of foot drop where isolated peroneal nerve involvement was present on nerve conduction study. It was possibly caused by an immune mediated mechanism in patients who had recovered from COVID-19 infection.

A rare case of extremely delayed osseous metastasis of pineoblastoma

Pineoblastoma is a rare, primitive, and malignant tumor arising from the parenchyma of the pineal gland. It typically metastasizes along the cerebral neural axis, with rare extraneural metastasis and even more rare intraosseous extraneural metastasis. A patient with pineoblastoma, initially treated with chemotherapy, presented 10 years after initial diagnosis with multiple osseous metastases including his pelvis, femur, and vertebrae, and is currently undergoing chemotherapy.