ダウン症患者における中耳の鼓膜区画の構造解析。側頭骨の研究

A Structural Analysis of Tympanic Compartments of the Middle Ear in Patients With Down's Syndrome: A Temporal Bone Study.

• Taketoshi Nogaki
• Michael M Paparella
• Sebahattin Cureoglu

抄録

:仮説。ダウン症（DS）児の側頭骨には特有の所見があるかもしれない。本研究の目的は、ダウン症児の側頭骨の病理組織を調べることである。

: Hypothesis: There may be findings peculiar to the temporal bones of children with Down's syndrome (DS). The purpose of this study is to investigate the temporal bone histopathology of the children with DS.

背景:

胸水を伴う中耳炎はDS患者に多くみられる疾患である。鼓膜の容積や鼓膜吻合部の面積を知ることは、これらの患者さんに多くみられる滲出性中耳炎の病態を解明する上で重要であると考えられます。

BACKGROUND: Otitis media with effusion is a highly prevalent condition with DS. Knowledge of the volume of the tympanic compartments and the area of the tympanic isthmus might be important to find out the pathogenesis of highly prevalent otitis media with effusion in those patients.

方法:

DS患者の側頭骨における上胸骨、中胸骨の体積、耳管の鼓膜吻合部と鼓膜開口部の面積を比較した。また、耳管の病理組織学的調査も行った。

METHODS: We compared the volume of the epitympanum, mesotympanum, and the areas of the tympanic isthmus and tympanic orifice of eustachian tube in temporal bones from patients with DS. We also investigated the eustachian tube histopathologically.

結果:

上胸骨と中胸骨の平均容積は、DS群では対照群に比べて有意に小さかった。前胸骨開口部と鼓膜開口部の平均径には両群間で有意差は認められなかった。また，鼓膜開口部と鼓膜開口部の平均最小面積についても，両群間で有意差は認められなかった．耳管や軟骨の未熟な発達が見られた。また，DS群ではすべての標本で上胸骨および中胸骨にメenchymeが残存しており，対照群では5標本でメenchymeが残存していた．

RESULTS: The mean volume of the epitympanum and the mesotympanum was significantly smaller in the DS group than the control group. We found no significant difference in the mean diameter of the protympanic opening and tympanic orifice between the two groups. The mean narrowest area of the aerated and bony tympanic isthmus also was not significantly different between the two groups. An immature development of eustachian tube and cartilage was seen. We found mesenchyme remaining at the epitympanum and/or mesotympanum in all specimens in the DS group, and in five specimens in the control group.

結論:

小中耳、未発達な耳管、テンソル筋の存在下では、悪循環が生じ、胸水を伴う中耳炎の解消は困難である。

CONCLUSION: In the presence of the small middle ear, poorly developed eustachian tube, and tensor muscle, a vicious circle occurs, making otitis media with effusion difficult to resolve.