Neurological manifestations of B12 deficiency witi emphasis on its aetiology.

BACKGROUND It is believed that Pernicious anaemia (PA) is more common in the West. We postulate however that in India PA is probably an important aetiological factor as a cause of Vitamin B12 deficiency in patients having neurological disease. OBJECTIVE To investigate the aetiological factors resulting in Vitamin B12 (Vit B12) deficiency in patients with subacute combined degeneration (SACD) and other neurological manifestations. METHODS We undertook a prospective study of 50 patients, all clinically suspected to have Vit B12 deficiency; they were investigated clinically, haematologically, biochemically and radiologically. RESULTS There was a dominance of males (41 of 50) with the majority in the age group of more than 40 years of age. There was no correlation between the socio-economic and dietary status on the one hand and the clinical manifestation on the other. Anti intrinsic factor antibodies (AIFAB) were positive in 19 of 50 patients (38%) and anti parietal cell antibodies (APCAB) were positive in 28 of 50 (56%) patients. CONCLUSION We conclude that Pernicious anaemia is an important cause of various neurological manifestations including SACD in the Vitamin B12 deficient population in the age group of more than 40 years, irrespective of the socio-economic and dietary status in the Indian subcontinent. It is supported by the presence of AIFAB or APCAB in this group.