[Unusual forced head postures in congenital paralysis of the superior oblique muscle]

With congenital superior oblique palsy, an abnormal head posture which is different from the usual one (head tilt) has hardly been described. We performed this study to point out the spectrum of atypical head posture and its operative treatment procedures.

The charts of all 103 patients with congenital superior oblique palsy which were seen at our clinic between 1983 and 1993 were reviewed.

13 patients (13%) had an atypical head posture. Group 1: patients with a face turn to the non-involved side (n = 5). The vertical deviation increased abruptly starting from the primary position; is was comitant in adduction. Combined surgery of the obliques muscles was most often performed (n = 3). Group 2: patients with a vertical abnormal head posture. 3 Patients presented with a chin elevation. Their vertical deviation was incomitant, it was smallest in downgaze. An isolated recession of the inferior oblique muscle was performed in all cases. One patient had a chin depression; she also had an esotropia in downgaze. A recession of the inferior oblique muscle was performed. Group 3: patients with a face turn and a chin elevation (n = 4). Vertical deviation was maximal in adduction and was smallest in the lower and temporal field of gaze. We performed first a recession of the inferior oblique muscle and then-if necessary-a tuck of the superior oblique muscle or a recession of the contralateral inferior rectus muscle.

An atypical head posture can occur in about 10% of cases. Its cause can be explained after checking the incomitance of the vertical deviation and the motility disorder. These parameters also determine the operative procedures.