Download PDF
CC BY-NC-ND 4.0 · Indian J Radiol Imaging 2022; 32(03): 308-313
DOI: 10.1055/s-0042-1753468
Original Article

Correlation of Trigeminopontine Angle with Severity of Trigeminal Neuralgia due to Neurovascular Conflict over Medial Aspect of Nerve: Can We Prognosticate the Reduction in Pain in Patients on Medical Management?

Pundalik Umalappa Lamani
1   Department of Radiology and Imageology, Nizam's Institute Of Medical Sciences, Hyderabad, Telangana, India
,
Abhishek J. Arora
2   Department of Radio-Diagnosis, All India Institute of Medical Sciences, Bibinagar, Hyderabad, Telangana, India
,
Kiran Kumar Reddy Kona
1   Department of Radiology and Imageology, Nizam's Institute Of Medical Sciences, Hyderabad, Telangana, India
,
Jyotsna Yarlagadda
1   Department of Radiology and Imageology, Nizam's Institute Of Medical Sciences, Hyderabad, Telangana, India
› Author Affiliations
› Further Information
   Permissions and Reprints

Abstract

Background Neurovascular conflicts (NVCs) are one of the major causative factors in patients presenting with trigeminal neuralgia (TN). We found a wide range of variation in degrees of acute angle formed between medial border of trigeminal nerve and anterior border of pons in patients with TN, i.e., medial trigeminopontine angle (mTPA), and tried to find its correlation with pain severity due to NVC over the medial aspect of nerve (mNVC).

Aims and Objectives To correlate mTPA measurement with severity of TN due to mNVC. To calculate the reduction in pain in patients kept on medical management and its correlation with mTPA.

Materials and Methods This was a retrospective observational study conducted between May 2018 and October 2020. A total of 41 patients presenting with TN and showing corresponding NVC were included in the study. Out of the total cases with NVC, 30 cases showed NVC over the medial surface of the nerve. All the patients were evaluated on MAGNETOM Skyra 3T magnetic resonance imaging (MRI; Siemens). Using the two-line Cobb angle method, the trigeminopontine angle was calculated. Pretreatment pain intensity and posttreatment pain relief of each patients were assessed by using the numeric rating scale (NRS) with numbers from 0 to 10 (“no pain” to “worst pain imaginable”). Relevant clinical details regarding pre- and posttreatment pain score, after a standard treatment plan of 600 mg of oxcarbazepine for 2 weeks, were collected.

Results Patients showing response of more than or equal to 50% (≥50%) are considered as “good response” and those with response of less than 50% (<50%) are considered as “poor response.” In our study with trigeminopontine angle threshold of 45 degrees, 7 out of 8 (87.5%) patients with >45° mTPA showed poor response and 15/22 (68.2%) patients with ≤45° showed good response to medical management for TN with statistical significance difference with a p-valve of 0.007.

Conclusion We found a negative correlation between the mTPA and percentage pain relief in patients kept on medical management and realized that mTPA measurement could become an important tool for prognosticating pain relief for patients of TN on medical therapy; however, more evidence and multicentric studies are required for the same.

Keywords

trigeminal neuralgia - trigeminopontine angle - neurovascular conflict


Publication History

Article published online:
31 July 2022

© 2022. Indian Radiological Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

 

  • References

  • 1 Majoie CB, Verbeeten Jr B, Dol JA, Peeters FL. Trigeminal neuropathy: evaluation with MR imaging. Radiographics 1995; 15 (04) 795-811
    CrossrefPubMedGoogle Scholar
  • 2 Ko AL, Lee A, Raslan AM, Ozpinar A, McCartney S, Burchiel KJ. Trigeminal neuralgia without neurovascular compression presents earlier than trigeminal neuralgia with neurovascular compression. J Neurosurg 2015; 123 (06) 1519-1527
    CrossrefPubMedGoogle Scholar
  • 3 Hughes MA, Frederickson AM, Branstetter BF, Zhu X, Sekula Jr RF. MRI of the trigeminal nerve in patients with trigeminal neuralgia secondary to vascular compression. AJR Am J Roentgenol 2016; 206 (03) 595-600
    CrossrefPubMedGoogle Scholar
  • 4 Tanrikulu L, Scholz T, Nikoubashman O, Wiesmann M, Clusmann H. Preoperative MRI in neurovascular compression syndromes and its role for microsurgical considerations. Clin Neurol Neurosurg 2015; 129: 17-20
    CrossrefPubMedGoogle Scholar
  • 5 Blitz AM, Northcutt B, Shin J. et al. Contrast-enhanced CISS imaging for evaluation of neurovascular compression in trigeminal neuralgia: improved correlation with symptoms and prediction of surgical outcomes. AJNR Am J Neuroradiol 2018; 39 (09) 1724-1732
    CrossrefPubMedGoogle Scholar
  • 6 Jamjoom AB, Jamjoom ZA, al-Fehaily M, el-Watidy S, al-Moallem M. , Nain-Ur-Rahman, Trigeminal neuralgia related to cerebellopontine angle tumors. Neurosurg Rev 1996; 19 (04) 237-241
    CrossrefPubMedGoogle Scholar
  • 7 Tanrikulu L, Hastreiter P, Bassemir T. et al. New clinical and morphologic aspects in trigeminal neuralgia. World Neurosurg 2016; 92: 189-196
    CrossrefPubMedGoogle Scholar
  • 8 Leal PR, Froment JC, Sindou M. MRI sequences for detection of neurovascular conflicts in patients with trigeminal neuralgia and predictive value for characterization of the conflict (particularly degree of vascular compression) [in French]. Neurochirurgie 2010; 56 (01) 43-49
    PubMedGoogle Scholar
  • 9 Hardaway FA, Holste K, Ozturk G. et al. Sex-dependent posterior fossa anatomical differences in trigeminal neuralgia patients with and without neurovascular compression: a volumetric MRI age- and sex-matched case-control study. J Neurosurg 2019; 132 (02) 631-638
    CrossrefPubMedGoogle Scholar
  • 10 Breivik H, Borchgrevink PC, Allen SM. et al. Assessment of pain. Br J Anaesth 2008; 101 (01) 17-24
    CrossrefPubMedGoogle Scholar