ORIGINAL ARTICLE Botulinum Toxin Type A for Poststroke Cricopharyngeal Muscle Dysfunction Deog Young Kim, MD, PhD, Chang-il Park, MD, PhD, Suk Hoon Ohn, MD, Ja Young Moon, MD, Won Hyuk Chang, MD, MS, Seung-woo Park, MD, PhD ABSTRACT. Kim DY, Park C, Ohn SH, Moon JY, Chang WH, Park S. Botulinum toxin type A for poststroke cricopha- ryngeal muscle dysfunction. Arch Phys Med Rehabil 2006;87: 1346-51. Objective: To evaluate the therapeutic effectiveness of bot- ulinum toxin type A (BTX-A) in poststroke patients with cricopharyngeal muscle dysfunction. Design: Before-after trial. Setting: University hospital. Participants: Eight poststroke patients. Intervention: BTX-A injection into the cricopharyngeal muscle under endoscope guidance for poststroke cricopharyn- geal muscle dysfunction. Main Outcome Measures: Clinical symptom score, disabil- ity rating scale for swallowing impairment, videofluoroscopic swallowing study, and upper esophageal sphincter (UES) ma- nometry. Results: Clinical symptom score, disability rating scale for swallowing impairment, residue in piriform sinus, and UES pressure were all significantly improved at 2 weeks after BTX-A injection compared with evaluations before injection (P.05). The effects on the clinical symptom score and dis- ability rating scale for swallowing impairment continued to be significantly improved to 12 weeks after injection (P.05). However, the residue in piriform sinus and the UES pressure at 12 weeks postinjection were reduced compared with before- injection evaluations; these results were not significant. The pharyngeal transit time was not changed after injection. There were no side effects observed in the patients studied. Conclusions: The results of the present study suggest that BTX-A injection may be an effective and safe treatment in patients with poststroke cricopharyngeal muscle dysfunction. Key Words: Botulinum toxin type A; Dysphagia; Pharyn- geal muscles; Rehabilitation; Stroke. © 2006 by the American Congress of Rehabilitation Medi- cine and the American Academy of Physical Medicine and Rehabilitation T HE PRESENCE OF DYSPHAGIA has been reported to be as high as 30% to 45% among poststroke patients. 1 Dys- phagia is associated with increased mortality, increased length of hospital stay, and a decreased level of functional outcome. 1 Common swallowing impairments associated with stroke are reduced lingual control, reduced pharyngeal peristalsis, de- layed swallowing reflex, and cricopharyngeal muscle dysfunc- tion. 2 The cricopharyngeal muscle acts as a muscular sling at the pharyngoesophageal junction, forming the upper esophageal sphincter (UES). The cricopharyngeal muscle normally re- mains in a contracted state and relaxes during swallowing. Incoordination or hypertonus of the cricopharyngeal muscle may lead to a range of symptoms including dysphagia and aspiration. Frequently, cricopharyngeal muscle dysfunction is caused by neuromuscular diseases or postoperative changes; however, the etiology remains unknown in a considerable num- ber of cases. 3 Cricopharyngeal muscle dysfunction has been identified in 5.7% of patients with neurologic disorder, 4.9% of patients with head and neck or esophageal tumors, and 8.9% of patients with other medical problems. 4 Bougienage and endo- scopic or transcervical cricopharyngeal myotomy have been suggested to lower the resting pressure of the cricopharyngeal muscle. However, the effect of these procedures has been debated, and they are associated with a variety of complica- tions. 5,6 Botulinum toxin type A (BTX-A), synthesized from the bacillus Clostridium botulinum, is a neurotoxin that blocks neuromuscular transmission by inhibition of acetylcholine re- lease at the presynaptic cholinergic nerve terminals. It has been found to have therapeutic value in patients with a variety of conditions characterized by muscle hyperactivity and spastic- ity. 7-10 For the treatment of cricopharyngeal muscle dysfunc- tion, BTX-A was used for the first time by Schneider et al 11 in 1994. Since Schneider’s report, there have been many studies reporting on BTX-A use to treat patients with cricopharyngeal muscle dysfunction. 12-17 Previous studies, however, included various etiologies of cricopharyngeal muscle dysfunction, in- cluding stroke. Haapaniemi et al 13 studied 2 stroke patients, 1 with lesions in the brainstem and the other with lesions in the middle cerebral artery. The stroke patient with brainstem le- sions was able to eat quite normally for 10 months after the injection. The stroke patient with middle cerebral artery lesions was able to tolerate oral feeding for 2 months. Ahsan et al 14 studied 2 stroke patients; 1 patient was not improved after injection, and the other patient was improved for 2 months and then relapsed. Alberty et al 15 studied 1 brainstem stroke patient, whose dysphagia symptom was not improved after injection. Shaw and Searl 16 studied 2 stroke patients. In 1 patient, sub- jective symptom relief continued for 14 months; however, there was no objective measure of the improvement. Murry et al 17 studied 13 patients including 6 stroke patients and reported the efficacy of BTX-A. These studies focused on patients with a variety of causes of cricopharyngeal muscle dysfunction, and the effect of BTX-A in a sample of only stroke patients has not yet been established. Therefore, the aim of this study was to evaluate the therapeutic effect of BTX-A injection on the cricopharyngeal muscle for poststroke patients with cricopharyngeal muscle dysfunction. From the Department and Research Institute of Rehabilitation Medicine (Kim, C Park, Ohn, Moon, Chang) and Department of Internal Medicine (S Park), Yonsei University College of Medicine, Seoul, South Korea. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Suk Hoon Ohn, MD, Rehabilitation Hospital, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-752, South Korea, e-mail: myeom@korea.com. 0003-9993/06/8710-10757$32.00/0 doi:10.1016/j.apmr.2006.06.018 1346 Arch Phys Med Rehabil Vol 87, October 2006