Guillain Barre Syndrome-like Presentation of Subacute Combined Degeneration of Spinal Cord and Association with Neuroendocrine Tumour of GIT

Subacute combined degeneration (SCD) refers to the gradually progressive myelopathic or myeloneuropathic presentation of vitamin B12 deficiency. While polyneuropathy has been well recognised with vitamin B12 deficiency, it has been debated whether neuropathy can manifest in isolation without myelopathy. SCD would seldom pose as a clinical or electrophysiological mimicker of Guillain-Barre syndrome (GBS). We describe the case of a middle age gentleman who presented with two weeks of rapidly progressive sensory predominant neuropathic syndrome with conduction findings consistent with a demyelinating process. In view of certain clinical-electrical discrepancies patient was further imaged with MRI revealing features classical of SCD with nearly undetectable Vitamin B12 levels. Upper gastrointestinal endoscopy as part of evaluation revealed a polyp in body of stomach with histopathological diagnosis of WHO II neurogastroendocrine tumour (carcinoid tumour) along with chronic atrophic gastritis. As far as to our knowledge, the association between gastric carcinoid and SCD have not been reported. We also discuss the relevant clinical points of this GBS-like presentation of SCD and possible pathomechanisms of the association with carcinoid. With parenteral Vitamin B12 supplementation patient had near complete resolution of symptoms and improvement in conduction parameters on follow-up.