Analysis of extraocular muscle volumes in idiopathic hypertrophic pachymeningitis patients
Suppakul Kitkamolwat, Supichaya Soonthornpusit, Akarawit Eiamsamarng, Natthapon Rattanathamsakul, Niphon Chirapapaisan, Chanon Ngamsombat
Abstract
Idiopathic hypertrophic pachymeningitis (HP) is a rare chronic inflammatory condition without an identifiable cause characterized by fibrous thickening of the dura mater, which can involve the extraocular muscles (EOM).
Introduction
Hypertrophic pachymeningitis (HP) is a rare chronic inflammatory condition characterized by fibrous thickening of the cerebral and/or spinal dura mater [1].HP is classified into two types based on its etiology: primary (idiopathic) HP, which has no identifiable cause, and secondary HP.
Materials and Methods
This retrospective study included twenty-two idiopathic HP patients diagnosed and underwent 3T MRI between 2017–2021 in the ophthalmology and neurology department at Siriraj Hospital. The study fully complied with the Declaration of Helsinki.
Results
Clinical and demographic data for the idiopathic HP patients and HC are presented in Table 1. Twenty-two idiopathic HP patients, including 8 males and 14 females (mean age 51.50 ± 15.41 years), and 22 healthy controls in the sex-matched and age-matched groups (mean age 51.41 ± 15.30 years) were included for analysis.
Discussion
Hypertrophic pachymeningitis (HP) is a rare fibrosing inflammatory disorder characterized by thickening of the dura mater, either focal or diffuse. The diagnosis of idiopathic HP is made by excluding various infectious, autoimmune, and neoplastic diseases.
Conclusion
In idiopathic HP, patients have significantly larger EOM volumes, particularly in the left IR and both MR muscles. This could be due to the diffuse infiltrative histopathology that potentially involves microstructural changes in the EOM.
Citation: Kitkamolwat S, Soonthornpusit S, Eiamsamarng A, Rattanathamsakul N, Chirapapaisan N, Ngamsombat C (2025) Analysis of extraocular muscle volumes in idiopathic hypertrophic pachymeningitis patients. PLoS One 20(4): e0309638. https://doi.org/10.1371/journal.pone.0309638
Editor: Atakan Orscelik, UCSF: University of California San Francisco, UNITED STATES OF AMERICA
Received: August 30, 2024; Accepted: February 24, 2025; Published: April 29, 2025
Copyright: © 2025 Kitkamolwat et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Data cannot be shared publicly because of confidential patient data. Data are available from the Faculty of Medicine, Siriraj Hospital, Mahidol University Institutional Data Access / Ethics Committee (contact via siethics@mahidol.ac.th) for researchers who meet the criteria for access to confidential data.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors declare no competing interests.
