Inverted V sign: subacute combined degeneration of the spinal cord

A Case of Subacute Combined Degeneration Secondary to Recreational Whippet Use

'Whippets' or nitrous oxide (N2O) abuse is a rare etiology of B12 deficiency and subacute combined degeneration (SCD). Often used in the medical field as an anesthetic, recreational use has rapidly increased given its euphoric effects. Easy accessibility over the counter at local stores due to the fact that it has bacteriostatic effects useful for canisters of creams and perishable goods. This makes N2O, or "laughing gas," easy to obtain. Long-standing abuse of N2O can lead to deleterious effects on the central nervous system, including SCD, polyneuropathy, and death. Presentation includes frequent falls, ataxic gait, weakness in the lower extremities, and neuropathy. Herein, we present a case of a 25-year-old male with no past medical history presenting with SCD in the setting of longstanding recreational whippet use. Our case highlights an important consideration for all specialties, including emergency medicine, psychiatry, family medicine, and internal medicine physicians.

Distinguishing Intramedullary Spinal Cord Neoplasms from Non-Neoplastic Conditions by Analyzing the Classic Signs on MRI in the Era of AI

Intramedullary lesions can be challenging to diagnose given the wide range of possible pathologies. Each lesion has unique clinical and imaging features, which are best evaluated on magnetic resonance imaging. Radiological imaging is unique with rich, descriptive patterns and classic signs-which are often metaphorical. In this review, we present a collection of classic MRI signs, ranging from neoplastic to non-neoplastic lesions, within the spinal cord. The differential diagnosis (DD) of intramedullary lesions can be narrowed down by careful analysis of the classic signs and pattern of involvement in the spinal cord. Furthermore, the signs are illustrated memorably with emphasis on the pathophysiology, mimics and pitfalls. Artificial intelligence (AI) algorithms, particularly deep learning, have made remarkable progress in image recognition tasks. The classic signs and related illustrations can enhance a pattern recognition approach in diagnostic radiology. Deep learning can potentially be designed to distinguish neoplastic from non-neoplastic processes by pattern recognition of the classic MRI signs.

Acute Transverse Myelitis Following COVID-19 Vaccination

An increasing number of people are undergoing vaccination for COVID-19 because of the ongoing pandemic. The newly developed, genetically engineered mRNA vaccines are critical for controlling the epidemic disease. However, major adverse effects, including neuroimmunological disorders, are being attributed to this vaccine. For instance, several cases of acute transverse myelitis (ATM) after COVID-19 vaccination have been reported in clinical trials. Here, we report an exceedingly rare case of longitudinally extensive transverse myelitis (LETM), a rare subtype of ATM involving three or more vertebral segments, that occurred shortly after vaccination with the Moderna COVID-19 (mRNA-1273) vaccine, with a comorbidity of vitamin B12 deficiency. The findings of subsequent investigations suggest the possibility that autoimmune responses are triggered by the reactions between anti-SARS-CoV-2 spike protein antibodies and tissue proteins, as well as the interaction between spike proteins and angiotensin-converting enzyme 2 receptors.

Metabolic and Toxic Myelopathies

PURPOSE OF REVIEW

This article describes the clinical presentation, relevant diagnostic investigations, and treatment of metabolic and toxic myelopathies.

RECENT FINDINGS

Metabolic myelopathies, including those due to deficiency of vitamin B12, folate, copper, or vitamin E, are preventable and typically respond to supplementation. In metabolic myelopathy, early recognition and treatment are important to reduce morbidity, particularly due to subacute combined degeneration of the spinal cord. Toxic myelopathies, including those due to medical interventions (eg, methotrexate, radiation), dietary toxins (eg, lathyrism, konzo), and drugs of abuse (eg, heroin), typically result in permanent neurologic deficits. Toxic myelopathy due to hepatic dysfunction may be reversible if patients receive early intervention, whereas nitrous oxide myelopathy responds to vitamin B12 replacement and cessation of exposure. In toxic myelopathy, it is best to avoid the provoking factor when possible or attempt to mitigate risk by identifying risk factors for developing myelopathy.

SUMMARY

Metabolic and toxic myelopathies are important causes of morbidity that require a high index of suspicion for diagnosis.

Rare anterior funiculus lesions in subacute combined degeneration of the spinal cord: a case report and literature review

Objective: Anterior funiculus lesion is uncommon in subacute combined degeneration of the spinal cord with few data available. Aim of the study was to describe a case with the rare manifestation and summarize existing literatures.Methods: We report a case of a 42-year-old woman with anterior and lateral funiculus lesions on cervicothoracic spine magnetic resonance imaging, who presented with unsteady gait, sensory level and weakness of lower limbs. Besides, we reviewed and analyzed literatures about subacute combined degeneration of the spinal cord with anterior funiculus lesions published during the past two decades.Results: The diagnosis of subacute combined degeneration of the spinal cord was considered due to her presence of low serum vitamin B12 levels, pernicious anemia and gastric carcinoid.Conclusion: Physicians should consider subacute combined degeneration of the spinal cord as a possible differential diagnosis when faced with atypical lesions distributed in the anterior funiculus.