Outcomes of distal sternocleidomastoid stump resection following selective denervation as revision surgery in refractory cervical dystonia

OBJECTIVE Cervical dystonia (or spasmodic torticollis) is a neurological condition that results in abnormal movements and head posture, for which initial surgical intervention typically involves selective denervation of the sternocleidomastoid (SCM) and paraspinal muscles. However, muscle reactivation of the distal SCM stump can result in recurrent symptoms. In this study, the authors present their preliminary experience with distal SCM stump resection following selective denervation, with the aim of evaluating the effectiveness of the procedure and identifying patients who may benefit from this technique. METHODS This is a retrospective single-center cohort study of patients who underwent SCM stump resection as revision surgery for cervical dystonia. RESULTS A total of 18 patients (10 males [56%]) were included with a median (range) age of 54 (40–70) years. All patients received selective denervation of the SCM at the authors’ institution prior to SCM stump resection at a median (range) time of 12 (3–198) months between surgical procedures. At preoperative baseline, 13 patients (72%) possessed a rotational torticollis component to their head deviation, 12 (67%) possessed a laterocollis component, and 2 (11%) possessed a retrocollis component. At the most recent follow-up (median [range] 16 [4–119] months), 6 patients had complete resolution of their cervical dystonia (33%), while 10 had residual deviation (56%) and 2 had recurrent deviation (11%). However, compared to their post–selective denervation head position, 12 patients experienced improvement in their head position (67%), 4 patients had no change in their head position (22%), and 2 had worsening of their cervical dystonia (11%) following SCM stump resection. Importantly, 12 patients experienced improvement in their pain following SCM stump resection (67%). Patients who had a history of other movement/spasmodic disorders were more likely to have improvement in head position and improvement in pain after SCM stump resection, though neither of these results achieved statistical significance (p = 0.054). Additionally, patients who experienced full resolution of their cervical dystonia had shorter time between initial selective denervation surgery and SCM stump resection, though this result also did not achieve statistical significance (p = 0.068). CONCLUSIONS Distal SCM stump resection following selective denervation is a simple, safe, and effective option for many patients in treating refractory cervical dystonia. Patients with more severe preoperative presentations may experience greater benefit from SCM stump resection, though additional investigations are needed.