Clinical and laboratory features and response to treatment in patients presenting with vitamin B12 deficiency-related neurological syndromes

AIMS AND OBJECTIVES: To study the clinical and laboratory features of patients admitted with vitamin B₁₂ deficiency-related (B12def) neurological syndromes.
SETTINGS AND DESIGN: A hospital-based retrospective and prospective study conducted at a referral teaching hospital.
MATERIALS AND METHODS: Consecutive patients admitted with vitamin B₁₂deficiency-related neurological disorders during a three-year period from June 2000 to May 2003 were included. Data regarding clinical and laboratory features were obtained. Follow-up was done at least six months following treatment with parenteral vitamin B₁₂. Chi-square test was used for statistical analysis.
RESULTS: A total of 63 patients (52 males) with a mean age of 46.2 years were studied. The mean duration of symptoms at presentation was 10.3 months. Myeloneuropathy (54%) was the commonest neurological manifestation, followed by myeloneuropathy with cognitive dysfunction (34%), and peripheral neuropathy (9%). Neuropsychiatric manifestations and dementia were observed in 38% and 19% of patients respectively. All the patients had megaloblastic changes in the bone marrow smear. Eleven (17.5%) patients had both hemoglobin and the mean corpuscular volume (MCV) within the normal range. Follow-up after at least six months of therapy with parenteral B₁₂ showed improvement in 54% patients.
CONCLUSIONS: A high index of suspicion of B12def is required in patients presenting with myelopathy, cognitive decline, or neuropathy. A normal hemoglobin or MCV does not exclude B12def; therefore, other tests such as bone marrow smear and serum vitamin B₁₂ assay are essential, as the condition is often reversible with treatment.