Sub-acute combined degeneration of the spinal cord - Inverted ‘ V’ sign a clue to avoid morbidity.

Abstract

SCD(Subacute combined degeneration) also known as Lichtheim's disease, refers to degeneration of the posterior and lateral columns of the spinal cord due to various causes - vitamin B12 deficiency (most common), copper deficiency or vitamin E deficiency. The clinical manifestation of this entity lagging behind spinal Magnetic resonance (MR) imaging, demands MRI to be used as a screening tool. However it is not possible to use a costly screening tool in a large scale and for a entity which is not a frequent clinical encounter. Hence early imaging diagnosis has a useful role, when incidentally detected thus allowing the clinician to intervene early using this clinic-radiological lag time to benefit the patient and reduce morbidity and by any luck completely prevent it. Inverted V sign / Rabbit ear sign is classical MR imaging feature for SCD and the appearance is due to selective involvement of the dorsal columns and progressive involvement of lateral and anterior column of the cord. However always complete Inverted V sign may not be seen in all cases with few variants as seen in our 3 cases, of which 2 patients were asymptomatic. Various Biochemical investigations were performed which confirmed the MR imaging findings of SCD in all three cases. Two asymptomatic patients were followed up post treatment(Vitamin B12 injections) after 2 months with Axial T2 screening of the cervical cord which showed complete resolution in the form of absent inverted v sign seen earlier.