Long-term efficacy of docosahexaenoic acid (DHA) for Spinocerebellar Ataxia 38 (SCA38) treatment : an open label extension study

Introduction: Spinocerebellar Ataxia 38 (SCA38) is caused by ELOVL5 gene mutation, with significant reduction of serum docosahexaenoic acid (DHA) levels. DHA supplementation has been proven effective at short-term follow-up. In the present paper, we evaluated long-term safety and efficacy of 600 mg/day oral DHA in SCA38 by a 2-year open label extension study. Methods: Nine SCA38 patients underwent standardised clinical assessment at 62 (T1), 82 (T2) and 104 (T3) weeks, and compared to pre-treatment scores (T0). Brain 18-Fluorodeoxyglucose Positron Emission Tomography and electroneurography were performed at T0 and T3. Results: We found a significant maintenance of clinical symptom improvement at each follow-up time-point (p < 0.001) as compared to T0, a sustained increase of cerebellar metabolism at T3 as compared to T0 (p = 0.013), and no worsening of neurophysiological parameters. No side effect was recorded. Conclusions: Long-term DHA supplementation is an eligible treatment for SCA38.