title: Myeloneuropathy and macrocytosis associated with nitrous oxide abuse.
abstract: After four months of excessive nitrous oxide (N2O) exposure, a dentist had myeloneuropathy with spastic paraparesis, Lhermitte's sign, sensory shading, loss of position and vibration sense, ataxia, and impotence. Macrocytosis, hypersegmented neutrophils, and a reduced vitamin B12 level were associated with normal findings on gastric analysis and Schilling test. Complete hematologic and neurologic recovery followed N2O avoidance and vitamin therapy for six months.
mesh_terms: D000328:Adult; D000748:Anemia, Macrocytic / Q000139:chemically induced*; D000749:Anemia, Megaloblastic / Q000139:chemically induced* / Q000175:diagnosis; D006801:Humans; D008297:Male; D009609:Nitrous Oxide; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced* / Q000175:diagnosis; D013118:Spinal Cord Diseases / Q000139:chemically induced* / Q000175:diagnosis; D019966:Substance-Related Disorders / Q000150:complications* / Q000175:diagnosis
chemical_list: D009609:Nitrous Oxide