Correlation between serum lipoamide dehydrogenase activity and phosphatidylcholine therapy in Friedreich's ataxia.

Serum lipoamide dehydrogenase activity and kinetics were studied in nine patients with Friedreich's ataxia before and three months after therapy with oral lecithin. Results disclosed a significant reduction in LAD inhibition by NADH in all patients after therapy. Three patients normalized their increased Km for lipoamide and one patient showed the opposite results after therapy. Two patients ceased lecithin after one month. All seven patients who remained in the trial group and one additional patient, showed subjective and objective signs of improvement in physical resistance. This study has offered some biochemical basis for the apparent clinical improvement in patients with Friedreich's ataxia who undergo lecithin therapy.