After MRI studies suggested the efficacy of ethyl-EPA in reducing the progressive brain atrophy in Huntington disease, trials were conducted to test its efficacy as a treatment for Huntington disease. Trials continued for six months did not find any significant improvement urging discontinuation of the drug. However, trials continued for 12 months indicated improvement of motor functions in these patients.
We searched 12 electronic databases to find randomized clinical trials relevant to our inclusion criteria. After screening, only five papers were included. Continuous and binary variables were analyzed to compute the pooled mean difference (MD) and risk ratio (RR), respectively. Quality effect model meta-analysis was used as a post hoc analysis for studies at 12 months.
Meta-analysis indicated that ethyl-eicosapentaenoic acid has no significant effect on any scale of HD at six months. At 12 months, two studies suggested significant improvements of the total motor score and total motor score −4 in both fixed and quality effect model [MD = −2.720, 95% CI (−4.76; −.68), P = 0.009], [MD = −2.225, 95% CI (−3.842; −0.607), P = 0.007] respectively. maximal chorea score showed significant results [MD = −1.013, 95% CI (−1.793; −0.233), P = 0.011] in only fixed effect model, while no improvement was detected for Stroop color naming test or symbol digit modality.
Meta-analysis indicated a significant improvement of motor scores only after 12 months. These results should be interpreted cautiously because only two studies had assessed the efficacy of ethyl-EPA after 12 months with one of them having six months open-label phase.