舌骨・喉頭の変位と嚥下障害

舌骨・喉頭の変位と嚥下障害の関連を見た論文を紹介します。

Steele CM, Bailey GL, Chau T, Molfenter SM, Oshalla M, Waito AA, Zoratto DC. The relationship between hyoid and laryngeal displacement and swallowing impairment. Clin Otolaryngol. 2011 Feb;36(1):30-6. doi: 10.1111/j.1749-4486.2010.02219.x.

第2頸椎から第4頸椎の距離と比較して、舌骨と披裂が嚥下時にどの程度、上方と前方に移動したかを%で評価しています。結果ですが、舌骨は34-63%、披裂は18-66%移動しました。披裂の前方移動は男性のほうが有意に少なかったです。

舌骨と披裂の前方移動が少ない場合、侵入・誤嚥を多く認めました。また披裂の前方移動が少ない場合、嚥下後の咽頭残留を多く認めました。以上より、舌骨と喉頭の前方移動（上方移動ではなく）が少ないと、嚥下障害のリスクがあるという結論です。

個人的には今まで、舌骨と喉頭の前方移動より上方移動を気にしてみていました。この研究だけで断定的なことは言えませんが、舌骨と喉頭の前方移動も診察時に気気をつけてみます。仮説ですが、サルコペニアの嚥下障害も関与している可能性があると感じます。

Abstract

OBJECTIVES:

Reduced range of hyoid and laryngeal movement is thought to contribute to aspiration risk and pharyngeal residues in dysphagia. Our aim was to determine the extent to which movements of the hyoid and larynx are correlated in the superior and anterior directions in swallowing, and whether movement range is predictive of penetration-aspiration or pharyngeal residue.

DESIGN:

Prospective, single-blind study of penetration-aspiration and pharyngeal residue with objective frame-by-frame measures of hyoid and laryngeal excursion from videofluoroscopy.

SETTING:

Tertiary hospital and rehabilitation teaching hospital.

PARTICIPANTS:

Twenty-eight participants referred for videofluoroscopy: 13 women, aged 57-77; 15 men, aged 54-70. Individuals with known neurodegenerative diseases or prior surgery to the neck were excluded. Each swallowed three boluses of 40% w/v thin liquid barium suspension.

OUTCOMES:

Two speech-language pathologists independently rated penetration-aspiration, vallecular and pyriform sinus residue. Cervical spine length, hyoid and laryngeal displacement were traced frame-by-frame. Predictive power was calculated.

RESULTS:

Cervical spine length was significantly greater in men. Hyoid displacement ranged from 34-63% of the C2-4 distance. Arytenoid displacement ranged from 18-66%, with significantly smaller anterior displacement in men. Positive hyoid-laryngeal movement correlations in both axes were the most common pattern observed. Participants with reduced displacement ranges (≤ first quartile) and with abnormal correlation patterns were more likely to display penetration-aspiration. Those with reduced anterior hyoid displacement and abnormal correlation patterns had a greater risk of post-swallow pharyngeal residues.

CONCLUSIONS:

It is difficult for clinicians to make on-line appraisals of the extent to which hyoid and laryngeal movement may be contributing to functional swallowing consequences during videofluoroscopy. This study suggests that it is most important for clinicians to discern whether reduced anterior displacement of these structures is contributing to a patient's swallowing impairment. Measures of structural displacement in thin liquid swallowing should be corrected for variations in participant height. Reductions in anterior hyoid and laryngeal movement below the first-quartile boundaries are statistically associated with increased risk for penetration-aspiration and post-swallow residues.