Investigation of the relationship between idiopathic intracranial hypertension and superior semicircular canal dehiscence.

Abstract

Purpose: The etiology of superior semicircular canal dehiscence (SSCD) is not yet clear; however, several theories implicate cumulative erosive changes. Here, using thin-section temporal bone CT images, we aimed to investigate the relationship between the bone roof thickness overlying the SSC and idiopathic intracranial hypertension (IIH) which may cause repetitive microtrauma.
Materıals and methods: Between January 2017-December 2019, temporal bone CT scans from 18 patients with a diagnosis of IIH, and 21 age- and sex-matched controls were analyzed retrospectively. Multiplanar reformatted images (Pöschl and Stenver) were reconstructed from the scans and the roof thickness of the SSC bone was measured and SSCD was classified in 4 grades.
Results: A total of 78 thin-section temporal bone CT scans were evaluated. Although grade-II dehiscence was most frequent in both groups, grade-IV was only observed in both temporal bones of one patient in the IIH group. Grade-III and grade-IV dehiscence rates were significantly higher in the IIH group (p=0.006). There was a significant difference between IIH and control groups in terms of SSC bone roof thickness (p=0.03).
Conclusıon: Increased CSF pressure in patients with IIH may cause chronic, progressive, and irreversible damage to the bone that covers the superior semicircular canal, and may play a role as a predisposing factor for SSCD.

Keywords

• Superior semicircular canal dehiscence
• temporal bone CT
• idiopathic intracranial hypertension

İdiopatik intrakranial hipertansiyon ile superior semisirküler kanal dehissansı arasındaki ilişkinin araştırılması

Abstract

Amaç: Superior semisirküler kanal dehissansının (SSKD) etyolojisi henüz net olarak bilinmemekle birlikte etyolojide kümülatif erozif değişikliklerin olabileceğine dair teoriler bulunmaktadır. Bu çalışmada ince kesit temporal kemik BT ile elde edilen görüntülerde SSK üzerindeki kemik çatı kalınlığının tekrarlayıcı mikrotravmalara sebebiyet verebilecek idiopatik intrakranial hipertansiyon ile ilişkisinin araştırılması amaçlanmıştır.
Gereç ve yöntem: Ocak 2017-Aralık 2019 tarihleri arasında idiopatik intrakranial hipertansiyon (İİH) tanısı ile takip edilen, ince kesit temporal kemik BT‘si bulunan 18 hasta ve yaş-cinsiyet açısından eşleştirilmiş 21 sağlıklı gönüllü retrospektif çalışmamıza dahil edildi. Görüntüler üzerinden multiplanar reformat rekonstrüksiyon imajlar (Pöschl ve Stenver) elde edildi ve SSK üzerindeki kemik çatı kalınlığı ölçülerek SSKD 4 ayrı gruba sınıflandırıldı.
Bulgular: Toplam 78 ince kesit temporal kemik BT değerlendirildi. Her iki grupta en sık grade 2 dehissans gözlenirken; grade 4 sadece İİH hasta grubunda bir hastanın her iki temporal kemiğinde izlendi. Grade 3 ve 4 dehissans oranı kontrol grubuyla karşılaştırıldığında İİH hasta grubunda anlamlı olarak yüksek saptandı (p=0,006). İİH ve kontrol grubu arasında SSK kemik çatı kalınlığı açısından anlamlı fark görüldü (p=0,03).
Sonuç: İİH hastalarında artmış beyin omurilik sıvı basıncı superior semisirküler kanal kemik çatısında kronik, ilerleyici ve geri dönüşümsüz hasara neden olabilir ve SSKD için predispozan bir faktör olarak rol oynayabilir.

Keywords

• Superior semisirküler kanal dehissansı
• temporal kemik BT
• idiopatik intrakranial hipertansiyon

References

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