An Uncommon Case of Atraumatic Palsy of a Branch of the Anterior Interosseous Nerve with a Late Spontaneous Recovery

Atraumatic palsy of the anterior interosseous nerve (AIN) is rarely encountered, presenting an uncertain etiology which provokes a weakness of the flexor pollicis longus (FPL), flexor digitorum profundus (FDP), and pronator quadratus, while a lesion of one of the AIN branches is even rarer. In many cases, the diagnosis is based in motor deviations due to nerve's palsy. A palsy of the AIN can be “complete” or “incomplete.” In an incomplete palsy, only the FPL or the FDP of the index finger is paretic or paralyzed. There is a scientific debate concerning the effectiveness between surgical and conservative treatment approaches. Moreover, a patient may have the opportunity to decide whether to be submitted in an interventional procedure or not. The purpose of this paper is to report a case of an AIN's branch palsy and to suggest a possible delay of the surgical exploration, since a late self-recovery may occur.