Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery

Berra Bilgin; Mustafa Eren Yüncü; Erman Güler; Ali Karadag; Necmettin Tanrıöver

doi:10.19161/etd.1892578

EN TR

Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery

Abstract

Aim: The temporo–parieto–occipital junction (TPOJ) represents a critical convergence zone of the dorsal and ventral language pathways. Preservation of these tracts is essential during surgery for lesions involving this region. The aim of this study is to define the microsurgical anatomy of the dorsal and ventral language pathways at the TPOJ using the fiber dissection technique and to propose a surgical strategy based on the principles of fiber separation. Materials and Methods: Three formalin-fixed adult human cadaveric brains (six hemispheres) and two silicone-injected adult human cadaveric heads (four sides) were prepared using the Klingler fiber dissection technique. Stepwise microscopic dissections were performed from the cortical surface toward the deep white matter. The spatial relationships of the superior longitudinal fasciculus (SLF II–III), arcuate fasciculus (AF), inferior fronto-occipital fasciculus (IFOF), middle longitudinal fasciculus (MdLF), and extreme capsule (ExtC) were analyzed. Special attention was given to the depth, orientation, and natural separation planes between the dorsal and ventral language pathways. Results: The dorsal language system, mainly composed of SLF II–III and the arcuate fasciculus, was identified in all dissections as a superficial-to-intermediate layer beneath the U-fibers. The ventral language pathways, including the IFOF, MdLF, and extreme capsule system, were observed in deeper and more medial planes throughout the dissections. Between the dorsal and ventral systems, a distinct separation corridor was consistently identified, particularly along the interface between the arcuate fasciculus and the IFOF, across different cadaveric specimens. This corridor corresponded to a potential surgical plane for fiber separation techniques. Conclusions: At the TPOJ, the dorsal and ventral language pathways demonstrate a layered anatomical organization with distinct separation planes. Recognition of these natural separations may contribute to the development of fiber-preserving microsurgical strategies.

Keywords

Supporting Institution

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Ethical Statement

This study was conducted on donated human cadaveric specimens in the Microneurosurgery Laboratory of the Department of Neurosurgery, Istanbul University–Cerrahpaşa, Cerrahpaşa Faculty of Medicine, under institutional regulations. As the study involved only cadaveric anatomical dissections and no living human participants or patient data, formal ethics committee approval was not required. All procedures were performed in accordance with institutional guidelines and the ethical principles of the Declaration of Helsinki.

Thanks

We thank Medtronic, Inc. and this company’s representation in Turkey, for providing the Midas Rex legend system (Medtronic, Inc., Minneapolis, MN, USA) to the Microsurgical Neuroanatomy Laboratory in Istanbul University–Cerrahpasa, Turkey, Department of Neurosurgery.

Temporo-pariyeto-oksipital bileşkede dorsal ve ventral dil yollarının fiber diseksiyon anatomisi: Lif ayırma cerrahisi için çıkarımlar

Abstract

Amaç: Temporo-pariyeto-oksipital bileşke (TPOJ), dorsal ve ventral dil yollarının birleştiği kritik bir geçiş bölgesini temsil eder. Bu bölgeyi içeren lezyonlara yönelik cerrahi sırasında bu yolların korunması esastır. Bu çalışmanın amacı, fiber diseksiyon tekniğini kullanarak TPOJ düzeyinde dorsal ve ventral dil yollarının mikrocerrahi anatomisini tanımlamak ve lif ayırma prensiplerine dayanan bir cerrahi strateji önermektir. Gereç ve Yöntem: Üç adet formalinle fikse edilmiş erişkin insan kadavra beyni (altı hemisfer) ve iki adet silikon enjekte edilmiş erişkin insan kafa kadavrası (dört taraf) Klingler fiber diseksiyon tekniği kullanılarak hazırlandı. Kortikal yüzeyden derin beyaz cevhere doğru aşamalı mikroskopik diseksiyonlar gerçekleştirildi. Süperior longitudinal fasikül (SLF II–III), arkuat fasikül (AF), inferior fronto-oksipital fasikül (IFOF), middle longitudinal fasikül (MdLF) ve ekstreme kapsül (ExtC) arasındaki topografik ilişki analiz edildi. Dorsal ve ventral dil yolları arasındaki derinlik, yönelim ve doğal ayrım düzlemleri ayrıntılı değerlendirildi. Bulgular: Esas olarak SLF II–III ve AF’den oluşan dorsal dil sistemi, tüm diseksiyonlarda U-liflerinin altında yer alan yüzeyel–orta derinlikte bir katman olarak tanımlandı. IFOF, MdLF ve ExtC sistemini içeren ventral dil yolları ise diseksiyonlar boyunca daha derin ve daha medial düzlemlerde izlendi. Dorsal ve ventral sistemler arasında, özellikle AF ile IFOF arasındaki ara yüz boyunca, farklı kadavra örneklerinde benzer şekilde ortaya konabilen belirgin bir ayrılma koridoru gözlemlendi. Bu koridor, lif ayırma teknikleri açısından potansiyel bir cerrahi düzleme karşılık gelmekteydi. Sonuç: TPOJ’de dorsal ve ventral dil yolları, belirgin ayrılma düzlemleri ile düzenlenmiş katmanlı bir anatomik organizasyon gösterir. Bu doğal ayrımların tanınması, lif koruyucu mikrocerrahi stratejilerin geliştirilmesine katkı sağlayabilir.

Keywords

Supporting Institution

Bu araştırma, kamu, ticari veya kar amacı gütmeyen sektörlerdeki fon kuruluşlarından herhangi bir özel hibe almamıştır.

Ethical Statement

Bu çalışma, İstanbul Üniversitesi Cerrahpaşa Tıp Fakültesi Nöroşirürji Anabilim Dalı Mikrocerrahi Laboratuvarı'nda, kurumsal düzenlemeler çerçevesinde bağışlanmış insan kadavra örnekleri üzerinde gerçekleştirilmiştir. Çalışma sadece kadavra anatomik diseksiyonlarını içermekte olup, canlı insan katılımcıları veya hasta verileri içermediğinden, resmi etik kurul onayı gerekmemiştir. Tüm prosedürler, kurumsal kılavuzlar ve Helsinki Bildirgesi'nin etik ilkeleri doğrultusunda gerçekleştirilmiştir.

Thanks

Medtronic, Inc. ve bu şirketin Türkiye temsilciliğine, İstanbul Üniversitesi Cerrahpaşa Tıp Fakültesi Nöroşirürji Anabilim Dalı Mikrocerrahi Nöroanatomi Laboratuvarı'na Midas Rex legend sistemi (Medtronic, Inc., Minneapolis, MN, ABD) sağladıkları için teşekkür ederiz.

References

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Details

Primary Language

English

Subjects

Clinical Sciences (Other)

Journal Section

Research Article

Authors

Berra Bilgin
0000-0003-2477-3991
Türkiye

Mustafa Eren Yüncü
0000-0002-4371-7015
Türkiye

Erman Güler
0000-0001-9474-5430
Türkiye

Ali Karadag ^*
0000-0002-6280-8131
Türkiye

Necmettin Tanrıöver
0000-0001-7628-9443
Türkiye

Publication Date

September 3, 2026

Submission Date

February 18, 2026

Acceptance Date

May 15, 2026

Published in Issue

Year 2026 Volume: 65 Number: 3

DOI

https://doi.org/10.19161/etd.1892578

IZ

https://izlik.org/JA43WF48LW

Cite

RIS / Bibtex

APA

Bilgin, B., Yüncü, M. E., Güler, E., Karadag, A., & Tanrıöver, N. (2026). Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery. Ege Tıp Dergisi, 65(3), 477-486. https://doi.org/10.19161/etd.1892578

AMA

1.Bilgin B, Yüncü ME, Güler E, Karadag A, Tanrıöver N. Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery. EJM. 2026;65(3):477-486. doi:10.19161/etd.1892578

Chicago

Bilgin, Berra, Mustafa Eren Yüncü, Erman Güler, Ali Karadag, and Necmettin Tanrıöver. 2026. “Fiber Dissection Anatomy of the Dorsal and Ventral Language Pathways at the Temporo–parieto–occipital Junction: Implications for Fiber Separation Surgery”. Ege Tıp Dergisi 65 (3): 477-86. https://doi.org/10.19161/etd.1892578.

EndNote

Bilgin B, Yüncü ME, Güler E, Karadag A, Tanrıöver N (September 1, 2026) Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery. Ege Tıp Dergisi 65 3 477–486.

IEEE

[1]B. Bilgin, M. E. Yüncü, E. Güler, A. Karadag, and N. Tanrıöver, “Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery”, EJM, vol. 65, no. 3, pp. 477–486, Sept. 2026, doi: 10.19161/etd.1892578.

ISNAD

Bilgin, Berra - Yüncü, Mustafa Eren - Güler, Erman - Karadag, Ali - Tanrıöver, Necmettin. “Fiber Dissection Anatomy of the Dorsal and Ventral Language Pathways at the Temporo–parieto–occipital Junction: Implications for Fiber Separation Surgery”. Ege Tıp Dergisi 65/3 (September 1, 2026): 477-486. https://doi.org/10.19161/etd.1892578.

JAMA

1.Bilgin B, Yüncü ME, Güler E, Karadag A, Tanrıöver N. Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery. EJM. 2026;65:477–486.

MLA

Bilgin, Berra, et al. “Fiber Dissection Anatomy of the Dorsal and Ventral Language Pathways at the Temporo–parieto–occipital Junction: Implications for Fiber Separation Surgery”. Ege Tıp Dergisi, vol. 65, no. 3, Sept. 2026, pp. 477-86, doi:10.19161/etd.1892578.

Vancouver

1.Berra Bilgin, Mustafa Eren Yüncü, Erman Güler, Ali Karadag, Necmettin Tanrıöver. Fiber dissection anatomy of the dorsal and ventral language pathways at the temporo–parieto–occipital junction: Implications for fiber separation surgery. EJM. 2026 Sep. 1;65(3):477-86. doi:10.19161/etd.1892578