The anatomical perspective of human occipital condyle in relation to the hypoglossal canal, condylar canal, and jugular foramen and its surgical significance

OBJECTIVEThe posterior petrosal approach is an established surgical method offering wide access to skull base lesions through mastoid air cells. The authors describe their experience with the endoscopic transmastoid “posterior petrosal” approach (EPPAP) for skull base tumors involving the internal auditory canal (IAC), jugular foramen, and hypoglossal canal.METHODSThe EPPAP was performed for 7 tumors (3 chordomas, 2 chondrosarcomas, 1 schwannoma, and 1 solitary fibrous tumor). All surgical procedures were performed under endoscopic visualization with mastoidectomy. The compact bone of the mastoid air cells and posterior surface of the petrous bone are carefully removed behind the semicircular canals. When removal of cancellous bone is extended superomedially through the infralabyrinthine space, the surgeon can expose the IAC and petrous portion of the internal carotid artery to reach the petrous apex (infralabyrinthine route). When removal of cancellous bone is extended inferomedially along the sigmoid sinus, the surgeon can safely reach the jugular foramen (transjugular route). Drilling of the inferior surface of petrous bone is extended further inferoposteriorly behind the jugular bulb to approach the hypoglossal canal and parapharyngeal space through the lateral aspect of the occipital condyle (infrajugular route).RESULTSOf the 7 tumors, gross-total resection was achieved in 4 (57.1%), subtotal resection (> 95% removal) in 2 (28.6%), and partial resection (90% removal) in 1 (14.2%). Postoperatively, 2 of 3 patients with exudative otitis media showed improvement of hearing deterioration, as did 2 patients with tinnitus. Hypoglossal nerve palsy and swallowing difficulty were improved after surgery in 2 patients and 1 patient, respectively. In 1 patient with severe cranial nerve deficits before surgery, symptoms did not show any improvement.CONCLUSIONSThe authors present their preliminary experience with EPPAP for skull base tumors in the petrous part of the temporal bone and the lateral part of the occipital condyle involving the cranial nerves and internal carotid arteries. The microscope showed a higher-quality image and illumination in the low-power field. However, the endoscope could offer wider visualization of the surgical field and contribute to minimizing the size of the surgical pathways, necessity of brain retraction, and eventually the invasiveness of surgery. Thus, the EPPAP may be safe and effective for skull base tumors in the petrous region, achieving balance between the radicality and invasiveness of the skull base surgery.

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Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach

Journal of Neurosurgery ◽

10.3171/jns.1997.87.4.0555 ◽

1997 ◽

Vol 87 (4) ◽

pp. 555-585 ◽

Cited By ~ 178

Author(s):

Hung T. Wen ◽

Albert L. Rhoton ◽

Toshiro Katsuta ◽

Evandro de Oliveira

Keyword(s):

Jugular Foramen ◽

Lateral Approach ◽

Occipital Bone ◽

Occipital Condyle ◽

Microsurgical Anatomy ◽

Posterior Portion ◽

Hypoglossal Canal ◽

Transcondylar Approach ◽

Far Lateral Approach ◽

Far Lateral

✓ Despite a large number of reports of the use of the far-lateral approach, some of the basic detail that is important in safely completing this exposure has not been defined or remains poorly understood. The basic far-lateral exposure provides access for the following approaches: 1) the transcondylar approach directed through the occipital condyle or the adjoining portions of the occipital and atlantal condyles; 2) the supracondylar approach directed through the area above the occipital condyle; and 3) the paracondylar exposure directed through the area lateral to the occipital condyle. The transcondylar approach provides access to the lower clivus and premedullary area. The supracondylar approach provides access to the region of, and medial to, the hypoglossal canal and jugular tubercle. The paracondylar approach, which includes drilling of the jugular process of the occipital bone in the area lateral to the occipital condyle, provides access to the posterior portion of the jugular foramen and to the mastoid on the lateral side of the jugular foramen. In this study, the anatomy important to completing the far-lateral approach and these modifications was examined in 12 cadaveric specimens. In the standard posterior and posterolateral approaches, an understanding of the individual suboccipital muscles is not essential. However, these muscles provide important landmarks for the far-lateral approach and its modifications. Other important considerations include the relationship of the occipital condyle to the foramen magnum, hypoglossal canal, jugular tubercle, the jugular process of the occipital bone, the mastoid, and the facial canal. These and other relationships important to completing these exposures were examined in this study.

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Invasive Corridor of Clivus Extension in Pituitary Adenoma: Bony Anatomic Consideration, Surgical Outcome and Technical Nuances

Frontiers in Oncology ◽

10.3389/fonc.2021.689943 ◽

2021 ◽

Vol 11 ◽

Author(s):

Xiao Wu ◽

Han Ding ◽

Le Yang ◽

Xuan Chu ◽

Shenhao Xie ◽

...

Keyword(s):

Pituitary Adenoma ◽

Cortical Bone ◽

Cancellous Bone ◽

Early Stage ◽

Anatomical Study ◽

Jugular Foramen ◽

Petrous Apex ◽

Occipital Condyle ◽

Hypoglossal Canal ◽

Internal Acoustic Meatus

BackgroundIt is well known that the clivus is composed of abundant cancellous bone and is often invaded by pituitary adenoma (PA), but the range of these cancellous bone corridors is unknown. In addition, we found that PA with clivus invasion is sometimes accompanied by petrous apex invasion, so we speculated that the petrous apex tumor originated from the clivus cancellous bone corridor. The aim of this study was to test this hypothesis by investigating the bony anatomy associated with PA with clival invasion and its clinical significance.MethodsTwenty-two cadaveric heads were used in the anatomical study to research the bony architecture of the clivus and petrous apex, including six injected specimens for microsurgical dissection and sixteen cadavers for epoxy sheet plastination. The surgical videos and outcomes of PA with clival invasion in our single center were also retrospectively reviewed.ResultsThe hypoglossal canal and internal acoustic meatus are composed of bone canals surrounded by cortical bone. The cancellous corridor within clivus starts from the sellar or sphenoid sinus floor and extends downward, bypassing the hypoglossal canal and finally reaching the occipital condyle and the medial edge of the jugular foramen. Interestingly, we found that the cancellous bone of the clivus was connected with that of the petrous apex through petroclival fissure extending to the medial margin of the internal acoustic meatus instead of a separating cortical bone between them as it should be. It is satisfactory that the anatomical outcomes of the cancellous corridor and the path of PA with clival invasion observed intraoperatively are completely consistent. In the retrospective cohort of 49 PA patients, the clival component was completely resected in 44 (89.8%), and only five (10.2%) patients in the early-stage had partial residual cases in the inferior clivus.ConclusionThe petrous apex invasion of PA is caused by the tumor invading the clivus and crossing the petroclival fissure along the cancellous bone corridor. PA invade the clivus along the cancellous bone corridor and can also cross the hypoglossal canal to the occipital condyle. This clival invasion pattern presented here deepens our understanding of the invasive characteristics of PA.

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Posttraumatic Delayed Jugular Foramen Syndrome in a Toddler

Neuropediatrics ◽

10.1055/s-0040-1722684 ◽

2021 ◽

Author(s):

Cristina Toledo-Gotor ◽

Nerea Gorría ◽

Miren Oscoz ◽

Katia Llano ◽

Pablo la Fuente Rodríguez-de ◽

...

Keyword(s):

Physical Examination ◽

Cranial Nerves ◽

Jugular Foramen ◽

Exceptional Case ◽

Cerebellar Tonsil ◽

Occipital Condyle ◽

Lower Cranial Nerve ◽

Cranial Nerve Palsies ◽

Blunt Head Trauma ◽

Condyle Fracture

Abstract Background Multiple lower cranial nerve palsies have been attributed to occipital condyle fractures in older children and adults, but no clinical details of other possible mechanisms have been described in infants. Case Report A 33-month-old boy suffered blunt head trauma. A bilateral skull base fracture was diagnosed, with favorable outcome during the first days after trauma. On the sixth day, the patient began to refuse drinking and developed hoarseness. Physical examination and additional investigations revealed paralysis of left VII, IX, X, and XI cranial nerves. A follow-up computed tomography (CT) scan disclosed a left petrous bone fracture involving the lateral margin of the jugular foramen, and a cranial magnetic resonance imaging (MRI) study showed a left cerebellar tonsil contusion. He improved after methylprednisolone was started. Three months later, he was asymptomatic, although mild weakness and atrophy of the left sternocleidomastoid and trapezius muscles remained 1 year later. Discussion A posttraumatic “jugular foramen syndrome” is rare in children, but it has been reported shortly after occipital condyle fracture, affecting mainly IX, X, and XI cranial nerves. In this toddler, delayed symptoms appeared with unilateral involvement. While an occipital fracture was ruled out, neuroimaging findings suggest the hypothesis of a focal contusion as a consequence of a coup-contrecoup injury. Conclusion This exceptional case highlights the importance of gathering physical examination, anatomical correlation, and neuroimaging to yield a diagnosis.

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Solitary Paraganglioma of the Hypoglossal Nerve: Case Report

Neurosurgery ◽

10.1227/neu.0b013e31820a16b5 ◽

2011 ◽

Vol 68 (4) ◽

pp. E1170-E1174 ◽

Cited By ~ 5

Author(s):

Kazim Raza ◽

Chandrasekaran Kaliaperumal ◽

Michael Farrell ◽

John A. O'Dwyer ◽

Christopher Pidgeon

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Hypoglossal Nerve ◽

Jugular Foramen ◽

Low Grade ◽

Resonance Imaging ◽

Stereotactic Radiation ◽

Hypoglossal Canal ◽

Suboccipital Craniotomy ◽

History Of

Abstract BACKGROUND AND IMPORTANCE: We report the case history of solitary hypoglossal paraganglioma in a 64-year-old woman. The surgical difficulties encountered in the removal of this challenging tumor are discussed and as a literature review provided. CLINICAL PRESENTATION: A 64-year-old woman presented with a short history of dysphonia, occasional dysphagia, tinnitus, altered taste, and unilateral left-sided tongue wasting. On examination, there was left lower motor hypoglossal paralysis. Imaging showed a discrete enhancing lobulated mass, measuring 2 × 2 cm, in the region of the hypoglossal nerve extending into the hypoglossal canal suggestive of hypoglossal paraganglioma. A left dorsolateral suboccipital craniotomy was performed with the patient in the sitting position. The hypoglossal nerve appeared to be enlarged, and the jugular foramen was normal. Complete surgical debulking of the tumor was not attempted because of its vascular nature. The nerve was decompressed, and neuropathology confirmed a low-grade paraganglioma arising from the hypoglossal nerve. The patient was scheduled to receive stereotactic radiation for further management. CONCLUSION: When a case of solitary hypoglossal paraganglioma is encountered in clinical practice, the aim of management should be mainly focused on achieving a diagnosis and preserving the hypoglossal nerve function. If there is evidence of vascularity in the lesion noted on magnetic resonance imaging, a preoperative angiogram should be obtained with a view for embolization. We decompressed the hypoglossal canal and achieved good improvement in the patient's symptoms. We recommend stereotactic radiosurgery for remnant and small hypoglossal tumors and regular follow-up with magnetic resonance imaging scans.

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Modified classification of infralabyrinthie cholesteatoma and scale of cholesteatoma extention

Medical Council ◽

10.21518/2079-701x-2020-16-86-94 ◽

2020 ◽

pp. 86-94

Author(s):

K. M. Diab ◽

O. S. Panina ◽

O. A. Pashchinina

Keyword(s):

Temporal Bone ◽

Surgical Approach ◽

Internal Auditory Canal ◽

Petrous Bone ◽

Jugular Foramen ◽

Petrous Apex ◽

Occipital Condyle ◽

Epidermal Cyst ◽

Scientific Center

Introduction. Petrous temporal bone (PTB) cholesteatoma is an epidermal cyst, which is the result of uncontrolled growth of keratinizing squamous epithelium in the petrous part of the temporal bone. Cholesteatoma is classified into congenital, acquired, and iatrogenic.Objective. To discuss the classification of infralabyrinthine petrous bone cholesteatoma (PBC), add modified classificationand to propose adequate differential surgical management.Methods. The setting was a National Medical Scientific Center of Otorhinolaryngology FMBA (Russia). The data of 14 patients who underwent surgery for different variations of infralabyrinthine PBC from 2017 till 2020 were analyzed and included into the study (with respect to localization type of the approach used, complications, recurrences and outcome). The follow-up period ranged from 6 to 34 months with a median of 18 months.Results. Based on preoperative CT scans and intraoperative findings a Scale of Cholesteatoma extension CLIF(APO) and Modified classification of infralabyrinthine cholesteatoma (in relation to mastoid segment of the facial nerve) are proposed. The scale includes the main anatomical structures of the temporal bone and the adjacent parts of the occipital and sphenoid bones, which may be involved in the cholesteatoma process: cochlea, vestibule and semicircular canals, internal auditory canal, jugular foramen, bony chanal of the internal carotid artery, petrous apex, occipital condyle. Based on the modified classification and scale we present an algorithm for decision making and surgical approach choosing.Conclusion. The implementation of the Scale of Cholesteatoma Extension in Otology and Radiology practice will allow to preoperatively diagnose the extension of PBC, unify the data of the localization of cholesteatoma; allows standardization in reporting and continuity at all stages of treatment. The modified classification proposed by us in this article facilitate the algorithm for selecting the type of surgical approach and determine whether to perform less aggressive combined microscopic approaches with endoscopic control.

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Endoscopic endonasal extreme far-medial approach for a lower clivus osteochondroma in a patient with hereditary multiple exostoses: illustrative case

Journal of Neurosurgery: Case Lessons ◽

10.3171/case2153 ◽

2021 ◽

Vol 1 (20) ◽

Author(s):

Yusuke Morinaga ◽

Hiroyoshi Akutsu ◽

Hiroyoshi Kino ◽

Shuho Tanaka ◽

Hidetaka Miyamoto ◽

...

Keyword(s):

Jugular Foramen ◽

Neurological Deficits ◽

Occipital Condyle ◽

Illustrative Case ◽

Endoscopic Endonasal ◽

Hereditary Multiple Exostoses ◽

Lateral Tilt ◽

Multiple Exostoses ◽

The Right ◽

Lower Clivus

BACKGROUND The authors reported on the use of endoscopic endonasal surgery (EES) for clivus osteochondroma in a patient with hereditary multiple exostoses (HME), a rare pediatric disorder characterized by the formation of osteochondromas adjacent to the growth plates of the axial and appendicular skeletal elements. OBSERVATIONS A 26-year-old man with a family history of HME reported progressive hoarseness and dysphagia over the previous 6 months. He was referred to us after magnetic resonance imaging (MRI) showed a bone tumor in the lower clivus. MRI revealed tumor proliferation in the lower clivus and its extension to the bilateral occipital condyle and jugular tubercle. The hypoglossal canal and jugular foramen were encased on the right side, whereas the medulla oblongata was compressed. The tumor was subtotally resected with EES, and the brainstem was successfully decompressed. The pathological diagnosis was exostoses. Transient postoperative worsening of dysphagia improved within 1 month without other neurological deficits. The patient underwent posterior occipitoaxial fixation 3 months after EES to correct instability and local lateral tilt of the right atlanto-occipital joint. LESSONS The authors’ experience showed that EES is effective for resection of lower clivus osteochondromas, including the cartilaginous cap, and may improve clinical outcomes in patients with HME.

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The Supracondylar Triangle: An Anatomic Guide in Drilling the Occipital Condyle and Accessing the Hypoglossal Canal—Description of Microsurgical Anatomy

10.1055/s-0039-1679466 ◽

2019 ◽

Author(s):

Srikant Chakravarthi ◽

Alejandro Monroy-Sosa ◽

Lior Gonen ◽

Laila Mena ◽

Sammy Khalili ◽

...

Keyword(s):

Occipital Condyle ◽

Microsurgical Anatomy ◽

Hypoglossal Canal

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Morphometry of the Hypoglossal Canal, Occipital Condyle, and Foramen Magnum

Neurosurgery Quarterly ◽

10.1097/01.wnq.0000214018.49915.49 ◽

2006 ◽

Vol 16 (3) ◽

pp. 121-125 ◽

Cited By ~ 9

Author(s):

Emine Dondu Kizilkanat ◽

Neslihan Boyan ◽

Roger Soames ◽

Ozkan Oguz

Keyword(s):

Foramen Magnum ◽

Occipital Condyle ◽

Hypoglossal Canal

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FORAMINA OF THE POSTERIOR CRANIAL BASE: A STUDY OF ADULT INDIAN SKULLS. 89 Las foraminas de la base posterior del cráneo: Un estudio en cráneos de indios adultos

Revista Argentina de Anatomía Clínica ◽

10.31051/1852.8023.v3.n2.13925 ◽

2016 ◽

Vol 3 (2) ◽

pp. 89-98

Author(s):

Namita A Sharma ◽

Rajendra S Garud

Keyword(s):

Indian Subcontinent ◽

Jugular Foramen ◽

Cranial Base ◽

Foramen Magnum ◽

Hypoglossal Canal ◽

Stylomastoid Foramen ◽

Posterior Condylar ◽

Human Skulls ◽

Mastoid Foramen ◽

Bilateral Difference

Introducción: Las foraminas craneales son los únicos puntos de entrada a un cráneo que, de otra manera, permanecería cerrado. La evaluación de estas foraminas es una parte muy importante para el diagnóstico médico y debería ayudar al clínico en su enfoque quirúrgico a esta delicada región. El presente estudio se centra en las foraminas de la base posterior del cráneo incluyendo los pares de fosas yugulares, el agujero estilomastoideo, el canal hipogloso; el impar agujero magno y otras foraminas auxiliares tales como el agujero mastoideo y el canal condíleo posterior. Material y Método: El estudio se llevo a cabo en 50 cráneos adultos, secos y macerados, pertenecientes todos ellos al subcontinente indio. Para ello se utilizó un calibre vernier con una precisión de 0.01 mm. Resultados: Se obtuvo una amplia variación en las dimensiones de la fosa yugular. La diferencia máxima bilateral en el mismo cráneo fue de 6.72 mm. La bóveda y la septación incompleta existían en un 20% de los cráneos. El tamaño del agujero estilomastoideo osciló entre 0.9-5.3 mm. Una de las 100 foraminas estudiadas se mostró estenosada. La duplicación se vio en el 4% de los cráneos. Las septaciones en el canal hipogloso se produjeron exclusivamente en el aspecto endocraneal y se observó bilateralmente en un 4% y unilateralmente en un 20% de los cráneos. En uno de los cráneos se encontró occipitalización del atlas. La salida del agujero magno estaba deformada y estenosada. Este fue el único cráneo con un índice en el agujero magno menor de 1. El agujero mastoideo estuvo presente bilateralmente en un 74% y unilateralmente en un 16% de los cráneos, mientras que las cifras correspondientes para el canal condíleo posterior fueron de 62% y 26% respectivamente. Introduction: Cranial foramina are the only portals to an otherwise closed cranium. Evaluation of these foramina is an important part of diagnostic medicine and would aid the clinician in his surgical approach to this complicated region. The present study is of foramina in the posterior cranial base including the paired jugular foramen, stylomastoid foramen, the hypoglossal canal; the unpaired foramen magnum and accessory foramina such as the mastoid foramen and the posterior condylar canal. Materials and Method: The study was done on 50 dried, macerated, adult human skulls, all belonging to the Indian subcontinent, using a vernier caliper with a precision of 0.01 mm. Results: There was wide variation in the dimensions of the jugular foramen. The maximum bilateral difference within the same skull was 6.72mm.Dome and incomplete septation coexisted in 20% skulls. The size of stylomastoid foramen ranged from 0.9-5.3 mm. One out of the 100 foramina studied showed a stenosed foramen. Duplication was seen in 4% skulls. Septations in the hypoglossal canal were exclusively on the endocranial aspect and were seen bilaterally in 4% and unilaterally in 20% skulls. In one skull there was occipitalisation of the atlas. The magnum outlet was distorted and stenosed. This was the only skull with a ‘foramen magnum index’ less than 1. The mastoid foramen was present bilaterally in 74% and unilaterally in 16% skulls while the corresponding figures for the posterior condylar canal were 62% and 26% respectively.

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