Prospective study of swallowing function in patients with cervical dystonia undergoing selective peripheral denervation

Objective-To characterise swallowing function in patients with cervical dys tonia with botulinum toxin treatment failure, before and after selective pe ripheral denervation surgery. Methods-Twelve patients with cervical dystonia had a thorough examination i ncluding standardised assessment for cervical dystonia, scoring of subjecti ve dysphagia, and videofluoroscopic swallow. Videofluoroscopy was scored by consensus opinion between a speech and language therapist and an independe nt blinded radiologist using a validated scoring system. Results-Seven patients with cervical dystonia experienced no subjective dys phagia either before or after surgery, although in all these patients there was objective videofluoroscopic evidence of underlying mild to moderate or opharyngeal dysphagia preoperatively and postoperatively. The most common f inding was delayed initiation of swallow. Three other patients, also withou t subjective dysphagia before surgery, developed postoperative dysphagia. I n these patients, videofluoroscopy showed a delayed swallow reflex before s urgery, which was worse postoperatively in two. The remaining two patients had mild subjective dysphagia before surgery that improved postoperatively in one and deteriorated in the other. In the first, videofluoroscopy was no rmal preoperatively and postoperatively, and in the second, oral bolus prep aration was moderately abnormal preoperatively and swallow initiation was d elayed postoperatively. Mean subjective dysphagia scores did not change sig nificantly. Apart from a significant improvement of tongue base retraction, videofluoroscopic scores were not significantly different after surgery. P ostoperatively there was significant improvement of overall cervical dyston ia severity and abnormal head rotation in the group as a whole. There was n o correlation between age, duration of symptoms of cervical dystonia, preop erative or postoperative cervical dystonia severity, subjective dysphagia s cores, or videofluoroscopic scores. However, in the five patients with pers isting anterior sagittal head shift as part of the torticollis, tongue base retraction was less likely to improve after surgery compared with those wi thout head shift. Conclusion-Surgical denervation of dystonic neck muscles, leading to improv ed neck posture, can also improve tongue base retraction, which is a key co mponent of normal bolus propagation. However, delayed swallow initiation, a common feature in patients with cervical dystonia, can be further compromi sed by surgery, leading to subjective dysphagia. In general, selective peri pheral denervation seems to be a safe procedure with no major compromise of swallowing function.