Incidence of vincristine induced neurotoxicity in children with acute lymphoblastic leukemia and its correlation with nutritional deficiencies.

Injection vincristine is an important component of therapy for acute lymphoblastic leukemia (ALL). An important adverse effect of vincristine is neurotoxicity. The incidence of this adverse effect is well studied. The present was undertaken to determine the incidence of vincristine-induced neurotoxicity in children with ALL after the induction of remission phase of chemotherapy and to ascertain its correlation with undernutrition, vitamin B12, folate and iron deficiency. Thirty children (1-18 years) with ALL were enrolled at the commencement of chemotherapy. The electrophysiological evaluation was done at baseline and repeated after four doses of vincristine (1.5 mg/m2/dose). Clinical evaluation was done regularly. Anthropometry and serum B12, folate and ferritin levels were assessed at baseline. Twelve children over a 4-week period of observation had peripheral neuropathy clinically. The autonomic system was most commonly involved followed by motor and sensory system respectively. On electrophysiological testing, half of the patients had evidence of neuropathy. Micronutrient deficiencies were present in a significant number of patients-63.3% had a B12 deficiency, 20% were deficient in folate and 43.3% in iron. The incidence of vincristine-induced neuropathy in patients with/without these micro-nutrient deficiencies was not statistically significantly different. Vincristine-induced neuropathy is common in Indian children with ALL. The present study did not find any correlation between the occurrences of vincristine-induced neuropathy and nutritional deficiencies. Larger studies are warranted to evaluate the contribution of micronutrient deficiencies to the development of peripheral neuropathy in childhood ALL.