Self-mutilation in young children following brachial plexus birth injury.

Brachial plexus injury in adults commonly produces persistent pain. Pediatric textbooks and case series suggest that perinatal brachial plexus injury is very rarely associated with pain, though this is difficult to determine in preverbal infants. Some of these young children self-mutilate the affected extremity, which may or may not reflect pain. This study was designed to characterize the clinical presentation and course of self-mutilation following perinatal brachial plexus injury. In this retrospective chart review, 280 patients were identified as having a perinatal brachial plexus injury from 1990-2002. Self-mutilation behavior was defined as excessive mouthing of or biting of any part of the affected limb, and/or loss of any parts of the affected limb secondary to biting and infection. Case reports were generated which described the severity of the primary injury, the types of surgical interventions, the duration and temporal relationship of behavior with surgical interventions and the nature of the self-mutilation behavior. Eleven patients demonstrated self-mutilating behavior, yielding a cumulative incidence of 3.9%. The median age of onset of this behavior was 17 (IQR=11-21) months, the median onset of the behavior was 8 (IQR) months after surgery and the median duration of this behavior was 6 (IQR=4-7) months. The incidence of self-mutilation among children who had undergone surgery was 6.8% (9 of 133 children) compared to the 1.4% (2 of 147 children) for non-surgical patients (P<0.05). Seven of 24 children (29.1%) who underwent brachial plexus dissection demonstrated self-mutilation, which was significantly different from the incidence of self-mutilation in children who did not have surgery (P < 0.001). Self-mutilation behavior in our population occurred more frequently in children following brachial plexus microsurgery. The reasons for this association are unclear, but may be related to either the surgery or the severity of the initial injury or both.