Low W K
Department of Otolaryngology, Singapore General Hospital.
J Laryngol Otol. 1995 May;109(5):390-3. doi: 10.1017/s0022215100130269.
There is a paucity of studies investigating middle ear pressures (MEPs) in patients with nasopharyngeal carcinoma (NPC). This paper prospectively examines MEPs in patients with nasopharyngeal carcinoma before and after radiotherapy and discusses their clinical significance. Newly diagnosed patients with nasopharyngeal carcinoma were studied before and at three to 12 months (mean 7.5 months) after radiotherapy. MEPs were measured by tympanometry. Thirty-three patients completed the study. The mean MEP before and after radiotherapy was -55.2 mm water (range -250 to 45 mm water) and -73.1 mm water (range -215 to 35 mm water) respectively. About two-thirds of assessable ears had an increase in negative MEPs after irradiation and the rest had less negative MEPs after irradiation. Those ears which developed post-irradiation middle ear effusions were found to have pre-irradiation negative middle ear pressures of at least -45 mm water. These findings provide possible explanations for some unexplained audiometric observations previously made in patients with nasopharyngeal carcinoma after radiotherapy. Tympanometry before radiotherapy may prove to be useful in identifying ears with a high risk of developing post-irradiation middle ear effusion.
关于鼻咽癌（NPC）患者中耳压力（MEP）的研究较少。本文前瞻性地研究了鼻咽癌患者放疗前后的中耳压力，并探讨了其临床意义。对新诊断的鼻咽癌患者在放疗前以及放疗后3至12个月（平均7.5个月）进行了研究。通过鼓室图测量中耳压力。33例患者完成了研究。放疗前后的平均中耳压力分别为-55.2毫米水柱（范围为-250至45毫米水柱）和-73.1毫米水柱（范围为-215至35毫米水柱）。约三分之二可评估的耳朵在照射后负压性中耳压力增加，其余耳朵在照射后负压性中耳压力降低。发现那些放疗后出现中耳积液的耳朵在放疗前的中耳负压至少为-45毫米水柱。这些发现为先前在鼻咽癌放疗后患者中一些无法解释的听力测定观察结果提供了可能的解释。放疗前的鼓室图检查可能有助于识别放疗后发生中耳积液风险较高的耳朵。
