[Astasia-abasia: psychogenic and non-psychogenic causes]

Astasia-abasia is defined as the inability to stand and to walk, despite sparing of motor function underlying the required balance and gestures. Initially, astasia-abasia was considered a psychogenic gait disorder, but later on, the description of "high-order" gait disorders mimicking this pure functional deficit led authors to refer to "astasia-abasia" as a pure descriptive term, without a presupposed etiological or anatomical substrate. In this paper, the main clinical characteristics of both psychogenic and non-psychogenic astasia-abasia are presented and discussed.