Autonomic dysreflexia triggered by hip joint position in patients with cervical cord injury : report of two cases

Two unusual cases of autonomic dysreflexia (AD) considered to have been triggered by hip joint position in males with complete tetraplegia due to C6 and C8 cervical cord injury are reported. In both cases, frequent repeated episodes of abnormal hypertension, bradycardia, and severe headache began to occur several months after injury, clearly constituting clinical AD. The cause was entirely unknown, since none of the common trigger factors, such as urinary distension or fecal impaction, was present. Subsequent clinical observations led to the assumption that hip joint position might be the cause, and blood pressure and heart rate in different positions were measured actually. In both cases, the trigger factor was the position of the hip joint. In the first case, the trigger was the neutral and extended positions; in the second, the trigger was the abducted position. As a result of this finding, it was possible to prevent AD by adjusting the hip joint position. The mechanism of this rare AD can be inferred to be stretching of the proximal leg muscles resulting from the hip position as a noxious stimulus via the peripheral nerves. Such hip positions are common during hospitalization and rehabilitation. When AD occurs frequently without any other conceivable reason, the possibility that it may be triggered by hip joint position should be considered