Psychogenic movement disorders (PMD) after war or mass vaccination was reported and well known disease entity already. However, we have seldom been met those patients because we don’t have any chance to experience of those events. Recently, influenza A (H1N1) spreads around world, and many countries have a program of mass vaccination of H1N1. Although PMD in adult is well characterized, childhood-onset PMD has not been extensively studied.

We present four children of psychogenic gait disorders (PGDs) after mass school vaccination of H1N1. They had fluctuating weakness and their prognosis was good. We confirmed all patients as PGD by placebo.

Our four cases have two common characteristics. One is that all were young and their prognosis was good. And the other is that all were induced their abnormal gait symptoms after mass school vaccination. We observed that mass PMD has a different characteristics comparing to personal PMD, and PMD in children is differ from adult onset PMD.