Evaluation of Internal Laryngeal Muscles Related to Phonation and the Compensatory Mechanism in Patients with Unilateral Vocal Cord Paralysis Using (18)F-Fluorodeoxyglucose-Positron Emission Tomography / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES : Several studies have reported that (18)F-fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) imaging is physiologically increased at the intact vocal cord in patients with unilateral vocal cord paralysis, which is explained by a compensatory mechanism of the intact vocal cord. We aimed to evaluate internal laryngeal muscles related to phonation and the compensatory mechanism in patients with unilateral vocal cord paralysis. SUBJECTS AND METHOD : We performed (18)FDG-PET imaging and neck computed tomography (CT) scan in the normal control group composed of 13 subjects and the paralyzed group composed of 11 patients with unilateral vocal cord paralysis. The two groups were divided into two groups, phonating and silent, before performing (18)FDG-PET. (18)FDG-PET and neck CT images by Syntegra. A specialist in nuclear medicine performed all the test measurements, the standardized uptake value (SUV) in the interarytenoid muscle (IA), both thyroarytenoid muscles (TA), and both lateral cricoarytenoid muscles (LCA). The mean SUVs were statistically analyzed. RESULTS : In the Normal-Phonating group, the mean SUV of IA was the highest, with 3.68+/-0.96 (Mean+/-SD), followed by that of LCA, with 2.34+/-0.67. However, when compared with the same muscles in the Phonating-Silent group, only the SUV of IA was significantly increased by phonation. In the Paralyzed-Silent group, the SUV of TA in the intact side was the highest, with 2.30+/-0.39. In the Paralyzed-Phonating group, the SUV of TA in the intact side, IA, and LCA in the intact side were 5.88+/-2.65, 3.92+/-1.65, and 3.87+/-1.37, respectively. When compared with the same muscles in the Phonating-Silent group, the SUVs of TA and IA were significantly increased. CONCLUSION : The muscle related to the compensatory mechanism in patients with unilateral vocal cord paralysis is thyroarytenoid muscle in the intact side. The interarytenoid muscle plays a major role in the mechanism of phonation in humans.

Two Cases of Nasolacrimal Duct Cyst Developed in Neonate

Bilateral nasolacrimal duct cyst is an uncommon disease causing respiratory and feeding difficulty in neonates. It can either present pure intranasal cystic mass or be associated with dacryocystocele and/or dacryocystitis. Symptoms and signs of nasolacrimal duct cyst are different according to the patient's age and its bilaterality. Therefore, treatment should be individualized according to its presentation. The authors experienced one case of bilateral nasolacrimal duct cyst without dacryocystocele which caused respiratory difficulty and another case of nasolacrimal duct cyst associated with dacryocystocele. Both cases were treated by endoscopic marsupializaion of the cysts. We report these two cases with a brief review of the literature.