Subacute combined degeneration of the spinal cord caused by nitrous oxide anaesthesia

Abstract

Vitamin B12 deficiency causes haematological, gastrointestinal and neurological diseases. Subacute combined degeneration (SCD) of the spinal cord is characterised by degeneration of the posterior and lateral columns. We report a case of SCD associated with nitrous oxide anaesthesia.

Toxic and Metabolic Myelopathies

“…Cobalamin or B 12 Vitamin Deficiencies Definition Vitamin B 12 deficiency causes myelopathy, neuropathy, and neuropsychiatric disturbances. In the spinal cord, it manifests as a subacute combined degeneration, characterized by degeneration of the lateral and posterior columns.…”

“…[1][2][3] intestinal infections and ileal abnormalities (Helicobacter pylori, Diphyllobothrium latum, human immunodeficiency virus, intestinal tuberculosis or lymphoma, celiac disease, Whipple's disease, inflammatory bowel disease, radiation enteritis, graft-versus-host disease, pancreatic disease, ZollingerEllison syndrome, and tropical sprue, bacterial overgrowth) lead to malabsorption 1,4 . Other conditions include elderly (related to atrophic gastritis-related hypochlorhydria induced food-Vitamin B 12 malabsorption), hereditary enzymatic defects and mutations in genes encoding endocytic receptors involved in ileal absorption and cellular Cbl uptake (Mutations in CUBN and AMN (selective Cbl malabsorption and proteinuria: Imerslund-Grasbeck syndrome), mutations in gastric intrinsic factor (GIF) or TCN2 (transcobalamin) leading to absence of the protein or presence of abnormal protein, disorders of intracellular processing and utilization of vitamin B 12 , disorders involving the synthesis of cobalamin cofactors (cblA to cblG), and medications (Antacids, H2 blockers, metformin, sunitinib). 1 Coenzyme vitamin B 12 (cobalamin), which together with folate, is essential for the formation of methionine from homocysteine tetrahydrofolate.…”

“…Other conditions include elderly (related to atrophic gastritis-related hypochlorhydria induced food-Vitamin B 12 malabsorption), hereditary enzymatic defects and mutations in genes encoding endocytic receptors involved in ileal absorption and cellular Cbl uptake (Mutations in CUBN and AMN (selective Cbl malabsorption and proteinuria: Imerslund-Grasbeck syndrome), mutations in gastric intrinsic factor (GIF) or TCN2 (transcobalamin) leading to absence of the protein or presence of abnormal protein, disorders of intracellular processing and utilization of vitamin B 12 , disorders involving the synthesis of cobalamin cofactors (cblA to cblG), and medications (Antacids, H2 blockers, metformin, sunitinib). 1 Coenzyme vitamin B 12 (cobalamin), which together with folate, is essential for the formation of methionine from homocysteine tetrahydrofolate. It is absorbed in the ileal microvilli after binding to the intrinsic factor.…”

“…Tetrahydrofolate is necessary for normal DNA synthesis and methionine is converted to S-adenosylmethionine that is necessary for methylation of myelin sheath phospholipids. B 12 deficiency results in decreased activity of cobalamin-dependent methylcobalamin esterase enzyme with resultant elevation of methylmalonic acid and reduced myelin basic protein methylation with fragile myelin that is susceptible to demyelination and vacuolization. 1,4 Clinical Presentations Vitamin B 12 deficiency may lead to serious neurologic complications including neuropathy, myelopathy, neuropsychiatric disturbances, and optic neuropathy.…”

“…Toxic and metabolic myelopathies may be further subdivided into (1) metabolic myelopathies associated with an identified nutrient deficiency including cobalamin or B 12 vitamin, folate, copper, or vitamin E deficiencies; (2) toxic myelopathies associated with drugs and chemical agents such as heroin abuse, organophosphate poisoning, chemotherapeutic agents, and radiation therapy; (3) metabolic myelopathies with geographical predilection such as lathyrism and Konzo seen in India, Bangladesh, and Ethiopia and, (4) other rare noninfectious and noninflammatory myelopathies including ketoacidosis myelopathy, spinal cord decompression illness, and surfer's myelopathy (Table 1). Toxic and metabolic myelopathies share clinical, electrophysiological, neuropathologic, and imaging features.…”