Benefits of Intraoperative Neurophysiological Monitoring (IONM) for the Localization, Mapping, and Resection of Tumors in the Fourth Ventricle: A Literature Review




Although uncommon, fourth ventricular tumors are considered a highly complicated and risky diagnosis. The fourth ventricle, which is part of the ventricular system of the brain, is one of the primary providers of cerebrospinal fluid (CSF), which, apart from supplying nutrients to the nervous system, also acts as a cushion-like substance, thus providing crucial neuroprotective properties to the nervous system. In addition to its saliency, the location of the fourth ventricle presents several challenges for medical professionals and surgeons when treating tumors in that region since crucial cortical areas and cranial nerve nuclei neighbor the limits of this ventricular cavity. Intraoperative Neurophysiological Monitoring (IONM) modalities such as Motor Evoked Potentials (MEPs), Somatosensory Evoked Potentials (SSEP), Brainstem Auditory Evoked Potentials (BAEP), and Electromyography (EMG), etc., play a fundamental role in providing the immediate tools and feedback in which the surgical team can rely on and use as a compass to prevent neural damage and significantly reduce the possibility of postoperative deficits.

The goal of this literature review is to investigate the different types of IONM modalities that have been recorded in the available literature to play a substantial role in surgical procedures involving fourth ventricular tumors and emphasize the importance and the protective critical role that using a multimodality IONM protocol could play in this type of surgeries. Furthermore, it discusses the possible causes, symptoms, statistics, and different types of fourth ventricular tumors, as well as the neuroanatomy delineating this crucial ventricular region.     


Sufianov, Rinat, David Pitskhelauri, and Andrey Bykanov. “Fourth Ventricle Tumors: A Review of Series Treated with Microsurgical Technique.” Frontiers in Surgery 9 (June 6, 2022).

Ferguson, Sherise D., Nicholas B. Levine, Dima Suki, Andrew J. Tsung, Fredrick F. Lang, Raymond Sawaya, Jeffrey S. Weinberg, and Ian E. McCutcheon. “The Surgical Treatment of Tumors of the Fourth Ventricle: A Single-Institution Experience.” Journal of Neurosurgery (JNS) 128, no. 2 (April 14, 2017): 339–51.

Ebrahim, Khaled Saeed, and Ahmed Faisal Toubar. “Telovelar Approach versus Transvermian Approach in Management of Fourth Ventricular Tumors.” Egyptian Journal of Neurosurgery 34, no. 1 (2019): 1–10.

Jahangiri, Faisal R., Mazhar Minhas, and John Jane. “Preventing Lower Cranial Nerve Injuries during Fourth Ventricle Tumor Resection by Utilizing Intraoperative Neurophysiological Monitoring.” The Neurodiagnostic Journal 52, no. 4 (2012): 320–32.

Miller, Jonathan, and Alan Cohen. “Management of Tumors of the Fourth Ventricle - Chapter 31 .” Essay. In IKnowledge - Clinical Gate , edited by Alia Hdeib. Accessed 2022.

Pautler, Katharine, Elizabeth Ekvall, Meredith Tucker, Angela Goodlin, Afia Islam, and Faisal R. Jahangiri. “Intraoperative Neurophysiological Monitoring for Brainstem Tumor Surgeries.” Web log. Axis Neuromonitoring(blog). Axis Neuromonitoring, August 27, 2020.

Singh, Vishram. “Fourth Ventricle.” Essay. In Textbook of Clinical Neuroanatomy, 2nd ed., 221–29, 2010. ISBN: 978-81-312-2307-9

Gupta, D. “Chapter 1 - Neuroanatomy.” Essay. In Essentials of Neuroanesthesia, 3–40. Amsterdam: Elsevier, 2017. Essentials of Neuroanesthesia.

Packer, Roger J., Larry E. Kun, and Gregory N. Fuller. “Tumors Of The Brain Stem, Cerebellum, and Fourth Ventricle.” Essay. edited by Henry S. Friedman, 171–92. Accessed 2022.

Kim, Seung Ja, Kee Hyun Chang, Keon Ha Kim, Ja Young Choi, Bae Joo Kwon, and Moon Hee Han. “Various Tumors in the 4th Ventricle in Adults: MRI Findings.” Journal of the Korean Radiological Society 49, no. 3 (2003): 155.

Qutub, Luma, Bandar Y Sulaimani, Khalid T Alghamdi, Ahmed A Mulla, and Hussam Kutub. “Choroid Plexus Papilloma of the Fourth Ventricle in a Pediatric Patient: A Case Report.” Cureus, May 10, 2022, 1–3.

Farhan R, Chen Wang and Faisal R. Jahangiri. “Chapter 14: Cranial Nerve Surgeries”. In Introduction to Neurophysiology by Faisal R. Jahangiri, Dubuque, IA.: Kendall Hunt, 2023.

Umair, Muhammad, Muhammad Roshan Asghar, and Faisal R. Jahangiri. “The Incidence Rate of Motor Evoked Potential Alerts in 1,159 Lumbar Spinal Surgeries.” Journal of Neurology & Neurophysiology 13, no. 10 (2022): 001–003.

Sala, Francesco, Matevž J. Kržan, and Vedran Deletis. “Intraoperative Neurophysiological Monitoring in Pediatric Neurosurgery: Why, When, How?” Child’s Nervous System 18, no. 6–7 (2002): 264–87.

Lee, Cheng-Chia, Chun-Fu Lin, Tsui-Fen Yang, Sanford P.C. Hsu, Hsin-Hung Chen, Shao-Ching Chen, and Yang-Hsin Shih. “Telovelar Approach for Choroid Plexus Papilloma in the Foramen of Luschka: A Safe Way Using a Neuromonitor.” Clinical Neurology and Neurosurgery 114, no. 3 (2012): 249–53.

Gläsker, Sven, Ulrich Pechstein, Vassilios I. Vougioukas, and Vera Van Velthoven. “Monitoring Motor Function during Resection of Tumours in the Lower Brain Stem and Fourth Ventricle.” Child’s Nervous System 22, no. 10 (2006): 1288–95.

Lee, Cheng-Chia, Chun-Fu Lin, Tsui-Fen Yang, Yang-Hsin Shih, and Sanford P.C. Hsu. “Adult Brainstem Ganglioglioma Bulging into the Fourth Ventricle.” Formosan Journal of Surgery 47, no. 3 (2014): 116–21.

Deletis, Vedran, and Isabel Fernández-Conejero. “Intraoperative Monitoring and Mapping of the Functional Integrity of the Brainstem.” Journal of Clinical Neurology 12, no. 3 (2016): 262.

Kodama, Kunihiko, Mani Javadi, Volker Seifert, and Andrea Szelényi. “Conjunct SEP and MEP Monitoring in Resection of Infratentorial Lesions: Lessons Learned in a Cohort of 210 Patients.” Journal of Neurosurgery 121, no. 6 (2014): 1453–61.

Lim, Yong Chuan, Dennis D. Doblar, and Winfield Fisher. “Intraoperative Monitoring of Brainstem Auditory Evoked Potentials during Resection of a Cavernous Hemangioma in the Fourth Ventricle: An Indirect Monitor of the Fifth and Seventh Nerves.” Journal of Neurosurgical Anesthesiology 6, no. 2 (1994): 128–31.

Leppanen, Ronald E. “Intraoperative Monitoring of Segmental Spinal Nerve Root Function with Free-Run and Electrically-Triggered Electromyography and Spinal Cord Function with Reflexes and F-Responses.”

Morota, Nobuhito, Satoshi Ihara, and Vedran Deletis. “Intraoperative Neurophysiology for Surgery in and around the Brainstem: Role of Brainstem Mapping and Corticobulbar Tract Motor-Evoked Potential Monitoring.” Child’s Nervous System 26, no. 4 (2010): 513–21.

Bertalanffy, Helmut, Nadir Tissira, Niklaus Krayenbühl, Oliver Bozinov, and Johannes Sarnthein. “Inter- and Intrapatient Variability of Facial Nerve Response Areas in the Floor of the Fourth Ventricle.” Operative Neurosurgery 68 (2011).

Kodama, Kunihiko, Karl F. Kothbauer, and Vedran Deletis. “Mapping and Monitoring of Brainstem Surgery.” Intraoperative Neuromonitoring, 2022, 151–61.

Rauschenbach, Laurèl, Alejandro N. Santos, Thiemo F. Dinger, Annika Herten, Marvi Darkwah Oppong, Börge Schmidt, Mehdi Chihi, et al. “Predictive Value of Intraoperative Neuromonitoring in Brainstem Cavernous Malformation Surgery.” World Neurosurgery 156 (2021).

Kullmann, Marcel, Marcos Tatagiba, Marina Liebsch, and Guenther C. Feigl. “Evaluation of the Predictive Value of Intraoperative Changes in Motor-Evoked Potentials of Caudal Cranial Nerves for the Postoperative Functional Outcome.” World Neurosurgery 95 (2016): 329–34.

Winkler, Ethan A., Harjus Birk, Michael Safaee, John K. Yue, John F. Burke, Jennifer A. Viner, Melike Pekmezci, et al. “Surgical Resection of Fourth Ventricular Ependymomas: Case Series and Technical Nuances.” Journal of Neuro-Oncology 130, no. 2 (2016): 341–49.

Lim, Yong Chuan, Dennis D. Doblar, and Winfield Fisher. “Intraoperative Monitoring of Brainstem Auditory Evoked Potentials during Resection of a Cavernous Hemangioma in the Fourth Ventricle: An Indirect Monitor of the Fifth and Seventh Nerves.” Journal of Neurosurgical Anesthesiology 6, no. 2 (1994): 128–31.

Yagyu, Kazuyori, Keitaro Sueda, Hideaki Shiraishi, Naoko Asahina, Kotaro Sakurai, Shinobu Kohsaka, Yutaka Sawamura, and Shinji Saitoh. “Direct Correlation between the Facial Nerve Nucleus and Hemifacial Seizures Associated with a Gangliocytoma of the Floor of the Fourth Ventricle: A Case Report.” Epilepsia 52, no. 12 (2011).

Grabb PA, Albright AL, Sclabassi RJ, Pollack IF. Continuous intraoperative electromyographic monitoring of cranial nerves during resection of fourth ventricular tumors in children. J Neurosurg. 1997 Jan;86(1):1-4.

Eisner, Wilhelm, Urs D. Schmid, Hanns-Jürgen Reulen, Reinhard Oeckler, Vladimir Olteanu-Nerbe, Claudius Gall, and Karl Kothbauer. “The Mapping and Continuous Monitoring of the Intrinsic Motor Nuclei during Brain Stem Surgery.” Neurosurgery 37, no. 2 (1995).

Navarro-Olvera, José Luis, Juan Camilo Covaleda-Rodriguez, Jose Armando Diaz-Martinez, Gustavo Aguado-Carrillo, José Damian Carrillo-Ruiz, and Francisco Velasco-Campos. “Hemifacial Spasm Associated with Compression of the Facial Colliculus by a Choroid Plexus Papilloma of the Fourth Ventricle.” Stereotactic and Functional Neurosurgery 98, no. 3 (2020): 145–49.

Strauss, Christian, Johann Romstöck, and Rudolf Fahlbusch. “Pericollicular Approaches to the Rhomboid Fossa. Part II. Neurophysiological Basis.” Journal of Neurosurgery 91, no. 5 (1999): 768–75.




How to Cite

Alvarez , C. M., Farhan, R., & Jahangiri, F. R. (2023). Benefits of Intraoperative Neurophysiological Monitoring (IONM) for the Localization, Mapping, and Resection of Tumors in the Fourth Ventricle: A Literature Review. J of Neurophysiological Monitoring, 1(1), 22–36.

Most read articles by the same author(s)

1 2 > >>