Subacute Combined Degeneration Presenting With Prominent Autonomic Symptoms 12 Years After Total Gastrectomy: A Case Report.

Subacute combined degeneration (SCD) is a neurological disorder caused by vitamin B12 deficiency, predominantly affecting the posterior and lateral columns of the spinal cord. While it is frequently associated with pernicious anemia or nutritional deficiency, SCD can also emerge long after gastrectomy due to impaired cobalamin absorption. Although sensory and motor deficits are hallmark features, cases occurring more than a decade post-gastrectomy with prominent, yet reversible, autonomic dysfunction are relatively rare. We report the case of a 48-year-old man who developed SCD approximately 12 years after undergoing total gastrectomy for stage II gastric cancer. Upon admission, he presented with spastic paraparesis, loss of proprioception, and striking autonomic symptoms, including postprandial disturbances resembling late dumping syndrome, bilateral leg edema, and orthostatic hypotension. Laboratory investigations revealed macrocytic anemia, vitamin B12 deficiency, and hyperhomocysteinemia. Spinal MRI demonstrated symmetric T2-weighted hyperintensities localized to the posterior columns of the thoracic cord. Although conventional nerve conduction studies were normal, somatosensory evoked potentials showed significant delays. Treatment with intramuscular vitamin B12 combined with rehabilitative therapy led to substantial recovery of both neurological and autonomic functions, enabling the patient to resume occupational activities within four months. This case highlights the potential reversibility of autonomic dysfunction associated with SCD and emphasizes the importance of early recognition through detailed clinical assessment, particularly when conventional neurophysiological studies fail to detect abnormalities.