[Intermittent high-dose vitamin C therapy in patients with HTLV-I-associated myelopathy].

: The aim of this study was to determine the efficacy and safety of intermittent high-dose vitamin C therapy in patients with HTLV-I associated myelopathy (HAM). Seven HAM patients (4 men and 3 women, aged 36 to 81 years), who were repeatedly given a daily oral dose of 1.5 to 3.0 g of vitamin C (40 mg/kg/day) for 3 to 5 successive days followed by a two-day withdrawal period, were followed for a mean period of 9.7 +/- 5.8 months after the therapy. The therapeutic efficacy was evaluated by a 10-grade disability scoring (DS) system, short somatosensory evoked potentials (SSEP) elicited by tibial nerve stimulation and several immunological parameters before and at 2.0 to 14 months after the therapy. All HAM patients responded well to intermittent high-dose vitamin C therapy, 6 being excellent responders (DS improvement > or = 2 grades) and one being a good responder (DS improvement of one grade). The grade of DS was decreased at 9.7 +/- 5.8 months after the therapy from 5.9 +/- 1.6 (baseline) to 3.0 +/- 1.5 (p < 0.01), indicating an excellent clinical outcome. SSEPs were obtained before and after the therapy in 4 of the patients. On SSEP before therapy, all the patients showed abnormally prolonged P37 peak latency. N20 was not recorded in 2 patients. After the therapy, N20 appeared and prolonged P37 peak latency improved in 2 patients. Immunoglobulin concentrations, T-B lymphocyte subsets and HTLV-I antibody titer in serum did not change.(ABSTRACT TRUNCATED AT 250 WORDS)