
==== Front
Malays J Med Sci
Malays J Med Sci
Malaysian Journal of Medical Sciences
The Malaysian Journal of Medical Sciences : MJMS
1394-195X
2180-4303
Penerbit Universiti Sains Malaysia

10.21315/mjms2024.31.4.20
20mjms3104_le
Letter to the Editor
Minimally Invasive Intervention for Trigeminal Neuralgia
ismail Muhammad Ihfaz Conceptualization Methodology Writing – original draft Writing – review & editing 12
Ang Song Yee Writing – original draft Writing – review & editing 12
Fitzrol Diana Noma Writing – original draft Writing – review & editing 12
Zakaria Zaitun Writing – original draft Writing – review & editing 12
1 Department of Neurosciences and Brain and Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
2 Hospital Universiti Sains Malaysia (HUSM), Universiti Sains Malaysia, Kelantan, Malaysia
Correspondence: Dr. Muhammad Ihfaz Ismail, MBBS (International Islamic University Malaysia), MSc Surgery (Neurosurgery) (Universiti Sains Malaysia), Department of Neurosciences and Brain Behaviour Cluster (BBC), School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia. Tel: +6019 9845919, Fax: +609 76773833, E-mails: ihfazrose5919@gmail.com, ihfazrose5919@usm.my
8 2024
27 8 2024
31 4 228229
22 3 2024
28 3 2024
© Penerbit Universiti Sains Malaysia, 2024
2024
https://creativecommons.org/licenses/by/4.0/ This work is licensed under the terms of the Creative Commons Attribution (CC BY) (http://creativecommons.org/licenses/by/4.0/).
==== Body
pmcDear Editor,

We read with interest an article entitled ‘Pain as a guide in Glasgow Coma Scale status for neurological assessment’ by Nallaluthan et al. (1).

We would like to mention a case of the endoscopic treatment of trigeminal neuralgia a cause of facial pain in a concious patient. An endoscopic technique, either retrolabyrinthine or retrosigmoid allows visualisation of the root entry zone (REZ) of the trigeminal nerve (TN). The TN, known as the largest of the cranial nerves originates in the midlateral surface of the pons, near the middle cerebellar peduncle (2, 3). Operating close to the brainstem with a narrow endoscopic window requires a surgeon to have intimate anatomical knowledge of the surrounding neurovascular bundles (3). Thus, we raised a point that variation in the patient’s skull shape and foramen (3) in particular the posterior fossa is one of the determiners of safe approach to REZ. The height of the posterior fossa is higher in males than in females. The distance from the internal auditory meatus to the transition of the transverse into the sigmoid sinus is longest in African Americans followed by Asian and Americans (4) with significant differences between these ethnicities. Moreover, the small posterior fossa is significantly associated with trigeminal neuralgia due to superior cerebellar artery (SCA) neurovascular conflict (5).

Furthermore, the sphenoid bone underwent remodelling during the prenatal and postnatal period; consequently, the foramen ovale and rotundum have different shapes and sizes, while the distance between these two foramina varies with age. In patient with idiopathic trigeminal neuralgia, the width of the foramen ovale is smaller than on the asymptomatic side, which is a potential risk factor of recurrence for whichever technique is selected (6). Hence, we highlighted this anatomical variation for the surgeon to be aware that excessive drilling (or even the heat from the drilling) of the bone may inadvertently traumatise the adjacent structure.

Endoscopic retrolabyrinthine approach is a feasible approach to the trigeminal dorsal root entry zone. However, this article significantly revealed the absence of suprameatal tubercle will complicate this approach in addition to high-riding jugular bulb (7). Hence, pre-operative assessment of these two factors is important when using the retrolabyrinthine presigmoid approach. This endoscopic approach is a notable adjunct procedure to address the limits imposed by labyrinthine complex preservation. It ensures complete visualisation of the intracanalicular portion of the schwannoma, thus improving the rate of a radical tumour resection (8). Therefore, the findings reported in the article provide concrete evidences of the feasibility of the approach and an important skill to familiarise with and to master in lateral skull base surgery.

Acknowledgements

None.

Conflict of Interest: None.

Funds: None.

Authors’ Contributions: Conception and design: MII

Drafting of the article: MII, ZZ, ASY, DNF

Critical revision of the article for important intellectual content: MII, ZZ, ASY, DNF
==== Refs
References

1 Nallaluthan V Guan Yan T Mohamed Fuad M Pain as a guide in Glasgow Coma Scale status for neurological assessment Malays J Med Sci 2023 30 5 221 235 10.21315/mjms2023.30.5.18 37928790
2 Rodella LF Buffoli B Labanca M Rezzani R A review of the mandibular and maxillary nerve supplies and their clinical relevance Arch Oral Biol 2012 57 4 323 334 10.1016/j.archoralbio.2011.09.007 21996489
3 Aksoy S Sayın Şakul A Görür Dİ Şakul BU Orhan K Evaluation of anatomoradiological findings on trigeminal neuralgia patients using computed tomography and cone-beam computed tomography Diagnostics 2021 12 1 73 10.3390/diagnostics12010073 35054240
4 Dao Trong P Beynon C Unterberg A Schneider T Jesser J Racial differences in the anatomy of the posterior fossa: neurosurgical considerations World Neurosurg 2018 117 e571 e574 10.1016/j.wneu.2018.06.089 29935317
5 Almqvist Téran N Loayza R Wikström J Ericson H Abu Hamdeh S Svedung Wettervik T Posterior fossa volume and dimensions: relation to pathophysiology and surgical outcomes in classic trigeminal neuralgia World Neurosurg 2023 179 e397 e403 10.1016/j.wneu.2023.08.102 37652132
6 Li S Liao C Qian M Yang X Zhang W Narrow ovale foramina may be involved in the development of primary trigeminal neuralgia Front Neurol 2022 13 1 9 10.3389/fneur.2022.1013216
7 Roser F Maiti T Elhammady MS Endoscopic-assisted resection of vestibular schwannomas in high-riding jugular bulb Neurosurg Focus: Video 2021 5 2 V4 10.3171/2021.7.FOCVID2198
8 Muelleman TJ Maxwell AK Peng KA Brackmann DE Lekovic GP Mehta GU Anatomic assessment of the limits of an endoscopically assisted retrolabyrinthine approach to the internal auditory canal J Neurol Surg B Skull Base 2021 82 S 03 e184 e189 10.1055/s-0040-1712180 34306935
