A 58-year-old male vegetarian presented with progressive numbness and weakness in the lower extremities. Laboratory examinations showed reduced vitamin B12 level with megaloblastic anaemia. Spinal magnetic resonance imaging (MRI) revealed hyperintensity within the posterior and lateral columns on T2-weighted imaging. The diagnosis of subacute combined degeneration (SCD) of the spinal cord was established. Unexpectedly, the patient developed transitory syncope on the second day after hospitalization. The diagnostic computed tomography pulmonary angiography (CTPA) confirmed multiple small pulmonary emboli. An isolated significantly elevated level of homocysteine (117.1 µmol/l) was documented when screening for hypercoagulable markers. Except for a long-term vegetarian diet, no other risk factors for hyperhomocysteinaemia (such as a family history of homocysteinuria) was found. The severity of the hyperhomocysteinaemia found in this current patient was unusual for patients with an insufficient intake of vitamin B12. In SCD patients, elevated homocysteine may increase the risk of thrombosis, which may exacerbate existing problems. Knowing the risk factors should help physicians choose appropriate diagnostic and therapeutic strategies.
Keywords: Subacute combined degeneration of spinal cord; acute pulmonary embolism; hyperhomocysteinaemia; vitamin B12 deficiency.