Q and A: about health and research

Overview and Pathophysiology Pernicious anemia is a chronic autoimmune disorder that results in vitamin B12 (cobalamin) deficiency due to impaired absorption in the gastrointestinal tract. The condition develops when the immune system mistakenly produces antibodies against intrinsic factor or against the gastric parietal cells responsible for intrinsic factor production. Without sufficient intrinsic factor, vitamin B12 cannot be properly absorbed in the terminal ileum of the small intestine. Vitamin B12 plays a crucial role in red blood cell formation, DNA synthesis, and maintenance of the nervous system. When absorption is impaired, progressive hematologic and neurological complications may occur. What Causes Pernicious Anemia? Under normal physiological conditions, dietary vitamin B12 is released from food in the stomach and binds to intrinsic factor, a glycoprotein secreted by parietal cells in the gastric mucosa. The intrinsic factor–B12 complex then travels to the terminal il...

Case Presentation A young adult presented to the emergency department with progressive sensory disturbances and weakness in both arms and legs. There were no signs of bladder dysfunction, infection, prior significant medical conditions, or a vegetarian diet. The patient reported recreational nitrous oxide (N₂O) use over the past six months, with approximately 150 applications, several times per week. Clinical and Diagnostic Findings Neurological examination revealed a transverse spinal cord syndrome, with symptoms more pronounced in the lower extremities and a defined sensory level at thoracic segment T8. Magnetic resonance imaging (MRI) of the cervical spine (T2-weighted) demonstrated a long segment of intramedullary hyperintensity from vertebral body C2 to C5. Axial images showed a characteristic inverted “V” pattern in the posterior columns—typical for subacute combined degeneration (SCD) or funicular myelopathy. There was no radiological or clinical evidence of peripheral nerve ...