Prognostic Implications of Microstructural Changes in Patients with Idiopathic Trigeminal Neuralgia

Saturday, May 4, 2024

2:43 PM – 2:48 PM CT

Location: N427d

Presenting Author(s)

Margaret Tugend, BA

Medical Student
Department of Neurological Surgery, Columbia University Irving Medical Center
New York, NY, US

Co-Author(s)

RB

Raviteja Bethamcharla, BS

Medical Student
Department of Neurological Surgery, Columbia University Irving Medical Center, New York Presbyterian Hospital
Philadelphia, Pennsylvania, United States
YC

Yue-Fang Chang, PhD

Research Associate Professor
Department of Radiology, University of Pittsburgh Medical Center, United States
SM

Stine Maarbjerg, MD, PhD

Neurology Resident
Danish Headache Centre, Department of Neurology, United States
RS

Raymond Sekula, MD, MBA

Professor
Department of Neurological Surgery, Columbia University Irving Medical Center
New York, New York, United States
KT

Katie Traylor, DO

Assistant Professor
Department of Radiology, University of Pittsburgh Medical Center, United States
Margaret Tugend, BA

Medical Student
Department of Neurological Surgery, Columbia University Irving Medical Center
New York, NY, US

Disclosure(s):

Margaret Tugend, BA: No financial relationships to disclose

Introduction: A variety of biomarkers other than degree of neurovascular compression (e.g., ox/carbamazepine responsiveness, type of TN) have been used to estimate the likelihood of long-term pain-freedom after MVD. In this study we report the prognostic implications of microstructural changes found in idiopathic trigeminal neuralgia patients with neurovascular contact involving an arterial contact without morphological changes.

Methods: We evaluated patients aged 18 years or older who underwent microvascular decompression (MVD) as their initial surgical procedure for iTN with arterial contact without morphological changes between March 2013 and December 2021. Mean diffusivity, radial diffusivity, axial diffusivity, and fractional anisotropy (i.e., MD, RD, AD, FA) were extracted from the cisternal segment of the trigeminal nerve immediately adjacent to its root entry point (REP). We compared the symptomatic and asymptomatic side and the symptomatic side in responders vs. non-responders to MVD.

Results: The MD was significantly increased in the symptomatic trigeminal nerve (1.9 x 10-3 mm2/s ± 5.5 x 10-5 mm2/s) when compared to the asymptomatic trigeminal nerve (1.6 x 10-3 mm2/s ± 6.5 x 10-5 mm2/s, q = 0.00047). The RD was significantly increased in the symptomatic trigeminal nerve (1.6 x 10-3 mm2/s ± 9.8 x 10-5 mm2/s) when compared to the asymptomatic trigeminal nerve (1.2 x 10-3 mm2/s ± 8.3 x 10-5 mm2/s, q = 0.0000066). The FA was significantly decreased in the symptomatic trigeminal nerve (0.37 ± 0.013) when compared to the asymptomatic trigeminal nerve (0.45 ± 0.015, q = 0.0000054). FA was significantly decreased in treatment non-responders (0.33 ± 0.012) when compared to treatment responders (0.38 ± 0.016, q = 0.0056).

Conclusion : FA has potential to pre-operatively identify iTN patients with arterial contact without morphological changes that will respond to MVD. This study identifies a subset of iTN patients who are not truly idiopathic.