Background: Because of heterogeneous manifestations of MS, an incorrect diagnosis is not uncommon. Tests
supporting the diagnosis of MS, including magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) examination and evoked potentials help to make diagnosis as early as possible. One of the diseases that is usually considered in differential diagnosis of MS is vitamin B12 deficiency. Differential diagnosis however may be difficult because neurological and hematological disorder may develop independently and with various intensity, pernicious anemia may respond to steroid therapy, MRI findings in vitamin B12 deficiency may be similar to that in MS and MS may coexist with low vitamin B12 level. Here, we present two cases of Vitamin B12 deficiency
in young women that was misdiagnosed as MS.
Case Report: In both cases besides the neurological symptoms of gait disturbances and paresthesia, MR
scan showed high signal of T2-weighted imaging lesions periventricular and affecting corpus callosum. In one case, oligoclonal bands were positive in CSF examination. Both patients were
diagnosed as MS and treated with high dose of methylprednisolone with no improvement. Since
the level of vitamin B12 was found lower in both cases, they were treated with intramuscular
injection of vitamin B12 and improved gradually. In both, macrocytic anemia was present but
independently of neurological symptoms.
Conclusions: However clinical features and MRI findings closely resembled signs of MS, low vitamin B12 level and good response to vitamin B12 supplementation allowed to establish diagnosis of vitamin B12 deficiency.

Keywords: cyanocobalamin, Multiple Sclerosis, subacute spinal cord degeneration