Imaging of the Postoperative Skull Base and Cerebellopontine Angle

AbstractLesions of the cerebellopontine angle (CPA) in young children are rare, with the most common being arachnoid cysts and epidermoid inclusion cysts. The authors report a case of an encephalocele containing heterotopic cerebellar tissue arising from the right middle cerebellar peduncle and filling the right internal acoustic canal in a 2-year-old female patient. Her initial presentation included a focal left 6th nerve palsy. Magnetic resonance imaging was suggestive of a high-grade tumor of the right CPA. The lesion was removed via a retrosigmoid approach, and histopathologic analysis revealed heterotopic atrophic cerebellar tissue. This report is the first description of a heterotopic cerebellar encephalocele within the CPA and temporal skull base of a pediatric patient.

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Surgical Approaches to Cerebellopontine Angle: A 17-Year Experience of Our Skull Base Team

Otolaryngology ◽

10.1177/0194599814541629a287 ◽

2014 ◽

Vol 151 (1_suppl) ◽

pp. P228-P228

Author(s):

Isabel A. Correia ◽

Vítor Sousa ◽

Luis Marques-Pinto ◽

Victor Gonçalves ◽

Ezequiel Barros

Keyword(s):

Skull Base ◽

Cerebellopontine Angle ◽

Surgical Approaches

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Surgical management of cerebellopontine angle and petrous lesions

Oxford Textbook of Neurological Surgery ◽

10.1093/med/9780198746706.003.0024 ◽

2019 ◽

pp. 281-296

Author(s):

Nicholas Hall ◽

Yuval Sufaro ◽

Andrew Kaye

Keyword(s):

Skull Base ◽

Cerebellopontine Angle ◽

Surgical Techniques ◽

Operating Microscope ◽

Critical Function ◽

Anatomical Structures ◽

Nerve Monitoring ◽

Mortality And Morbidity ◽

Harvey Cushing ◽

The Brain

At the turn of the twentieth century Harvey Cushing, the father of neurosurgery, described the cerebellopontine angle (CPA) region of the brain as ‘the gloomy corner of neurosurgery’, famously comparing this anatomical region with the bloody fence corner of the Gettysburg. With limited magnification and illumination, a modern skull base subspecialist neurosurgeon can understand the huge technical challenges that pioneers such as Cushing would have faced treating large tumours with major pre-existing morbidity in this location. At that stage Cushing advocated subtotal tumour debulking as the only rational strategy, however, shortly after that Dandy began to advocate safe total removal of cerebellopontine angle tumours. Since these early days introduction of more sophisticated anaesthesia, perioperative antibiotic prophylaxis, the operating microscope, and cranial nerve monitoring techniques have all resulted in significant advances in cerebellopontine angle surgery. The concentration of cases in subspecialty centres and the recognition of the importance of experience and meticulous technique has transformed skull base surgery into a subspecialty field with consequent reductions in mortality and morbidity. Although fragile and tenuous anatomical structures, supplying critical function, will always make treatment of pathology in this region a high-risk challenge, frequently, curative outcomes are now achieved with minimal morbidity for patients. This chapter aims to outline the anatomy and pathology of the cerebellopontine angle. The chapter describes the presentation of patients and investigations needed to make diagnoses for the different pathologies in this region, and the surgical techniques, approaches, and outcomes that we use to treat these lesions.

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Endoscopic endonasal surgical management of chondrosarcomas with cerebellopontine angle extension

Neurosurgical FOCUS ◽

10.3171/2014.7.focus14349 ◽

2014 ◽

Vol 37 (4) ◽

pp. E13 ◽

Cited By ~ 21

Author(s):

Paulo M. Mesquita Filho ◽

Leo F. S. Ditzel Filho ◽

Daniel M. Prevedello ◽

Cristian A. N. Martinez ◽

Mariano E. Fiore ◽

...

Keyword(s):

Skull Base ◽

Posterior Fossa ◽

Cerebellopontine Angle ◽

Tumor Resection ◽

Petrous Bone ◽

Petrous Apex ◽

Total Resection ◽

Endoscopic Endonasal ◽

Female Ratio ◽

Male Female Ratio

Object Skull base chondrosarcomas are slow-growing, locally invasive tumors that arise from the petroclival synchondrosis. These characteristics allow them to erode the clivus and petrous bone and slowly compress the contents of the posterior fossa progressively until the patient becomes symptomatic, typically from cranial neuropathies. Given the site of their genesis, surrounded by the petrous apex and the clival recess, these tumors can project to the middle fossa, cervical area, and posteriorly, toward the cerebellopontine angle (CPA). Expanded endoscopic endonasal approaches are versatile techniques that grant access to the petroclival synchondrosis, the core of these lesions. The ability to access multiple compartments, remove infiltrated bone, and achieve tumor resection without the need for neural retraction makes these techniques particularly appealing in the management of these complex lesions. Methods Analysis of the authors’ database yielded 19 cases of skull base chondrosarcomas; among these were 5 cases with predominant CPA involvement. The electronic medical records of the 5 patients were retrospectively reviewed for age, sex, presentation, pre- and postoperative imaging, surgical technique, pathology, and follow-up. These cases were used to illustrate the surgical nuances involved in the endonasal resection of CPA chondrosarcomas. Results The male/female ratio was 1:4, and the patients’ mean age was 55.2 ±11.2 years. All cases involved petrous bone and apex, with variable extensions to the posterior fossa and parapharyngeal space. The main clinical scenario was cranial nerve (CN) palsy, evidenced by diplopia (20%), ptosis (20%), CN VI palsy (20%), dysphagia (40%), impaired phonation (40%), hearing loss (20%), tinnitus (20%), and vertigo/dizziness (40%). Gross-total resection of the CPA component of the tumor was achieved in 4 cases (80%); near-total resection of the CPA component was performed in 1 case (20%). Two patients (40%) harbored high-grade chondrosarcomas. No patient experienced worsening neurological symptoms postoperatively. In 2 cases (40%), the symptoms were completely normalized after surgery. Conclusions Expanded endoscopic endonasal approaches appear to be safe and effective in the resection of select skull base chondrosarcomas; those with predominant CPA involvement seem particularly amenable to resection through this technique. Further studies with larger cohorts are necessary to test these preliminary impressions and to compare their effectiveness with the results obtained with open approaches.

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Temporal bone and skull base

10.1093/med/9780199551002.003.0004 ◽

2018 ◽

Author(s):

Arangasamy Anbarasu ◽

Jack I. Lane

Keyword(s):

Skull Base ◽

Temporal Bone ◽

External Auditory Canal ◽

Cerebellopontine Angle

In this section the temporal base is covered in detail. The skull, Cerebellopontine angle, External Auditory Canal, and areas of the ear are all discussed. Various issues and problems are detailed with imagining techniques for each area.

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Clinical Studies and Pre-clinical Animal Models on Facial Nerve Preservation, Reconstruction, and Regeneration Following Cerebellopontine Angle Tumor Surgery–A Systematic Review and Future Perspectives

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.659413 ◽

2021 ◽

Vol 9 ◽

Author(s):

Isabel C. Hostettler ◽

Narayan Jayashankar ◽

Christos Bikis ◽

Stefan Wanderer ◽

Edin Nevzati ◽

...

Keyword(s):

New Zealand ◽

Facial Nerve ◽

Skull Base ◽

Clinical Studies ◽

Cerebellopontine Angle ◽

Experimental Studies ◽

Experimental Models ◽

Current Evidence ◽

Tumor Surgery ◽

New Zealand White Rabbits

Background and purpose: Tumorous lesions developing in the cerebellopontine angle (CPA) get into close contact with the 1st (cisternal) and 2nd (meatal) intra-arachnoidal portion of the facial nerve (FN). When surgical damage occurs, commonly known reconstruction strategies are often associated with poor functional recovery. This article aims to provide a systematic overview for translational research by establishing the current evidence on available clinical studies and experimental models reporting on intracranial FN injury.Methods: A systematic literature search of several databases (PubMed, EMBASE, Medline) was performed prior to July 2020. Suitable articles were selected based on predefined eligibility criteria following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Included clinical studies were reviewed and categorized according to the pathology and surgical resection strategy, and experimental studies according to the animal. For anatomical study purposes, perfusion-fixed adult New Zealand white rabbits were used for radiological high-resolution imaging and anatomical dissection of the CPA and periotic skull base.Results: One hundred forty four out of 166 included publications were clinical studies reporting on FN outcomes after CPA-tumor surgery in 19,136 patients. During CPA-tumor surgery, the specific vulnerability of the intracranial FN to stretching and compression more likely leads to neurapraxia or axonotmesis than neurotmesis. Severe FN palsy was reported in 7 to 15 % after vestibular schwannoma surgery, and 6% following the resection of CPA-meningioma. Twenty-two papers reported on experimental studies, out of which only 6 specifically used intracranial FN injury in a rodent (n = 4) or non-rodent model (n = 2). Rats and rabbits offer a feasible model for manipulation of the FN in the CPA, the latter was further confirmed in our study covering the radiological and anatomical analysis of perfusion fixed periotic bones.Conclusion: The particular anatomical and physiological features of the intracranial FN warrant a distinguishment of experimental models for intracranial FN injuries. New Zealand White rabbits might be a very cost-effective and valuable option to test new experimental approaches for intracranial FN regeneration. Flexible and bioactive biomaterials, commonly used in skull base surgery, endowed with trophic and topographical functions, should address the specific needs of intracranial FN injuries.

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Patterns for Differentiation of Posterior Fossa Neoplasms as Detected by Brain Scans

Nuklearmedizin ◽

10.1055/s-0038-1624720 ◽

1970 ◽

Vol 09 (04) ◽

pp. 303-316

Author(s):

Frank DeLand ◽

A. EveretteJames ◽

Henry Wagner

Keyword(s):

Skull Base ◽

Posterior Fossa ◽

Cerebellopontine Angle ◽

Lateral View ◽

Posterior Cranial Fossa ◽

Anatomical Location ◽

Posterior View ◽

Brain Scans ◽

Histological Characteristics ◽

Cranial Fossa

SummaryThe histological characteristics of neoplasms that occur in the posterior cranial fossa can often be predicted by a knowledge of the patient’s age and the specific anatomical location of the tumor. Dividing the posterior fossa into midline, cerebellar fossa and cerebellopontine angle provides a scheme to characterize abnormal accumulations of radioactivity according to their anatomical locations. Midline lesions arise from bases activity on the lateral view and are in the midline on the posterior view. Lesions of the cerebellar fossa may be adjacent to but do not appear to arise from the basal structures and are not in the midline. Cerebellopontine angle tumors are adjacent to and appear to arise from the normal radioactivity at the skull base but lie lateral to the midline. The expected distribution of histological types of neoplasms in each area according to age are discussed.

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