E4992. MR Neurography in the Evaluation of Peripheral Trigeminal Neuropathies in the Postoperative Period
  1. Tyler Thornton; University of North Texas Health Science Center
  2. Shuda Xia; UT Southwestern Medical Center
  3. John Zuniga; UT Southwestern Medical Center
  4. Avneesh Chhabra; UT Southwestern Medical Center
Peripheral trigeminal neuropathy (PTN) can lead to significant pain and deleterious effects on quality of life with clinical neurosensory testing (NST) being the current reference standard for the preoperative diagnosis of PTNs. MR neurography (MRN) is useful for earlier diagnosis of PTN than NST, and its ability to classify nerve injuries as per Sunderland classification. There is a lack of literature on imaging of the nerve following surgical repair. This pilot study aims to define the utility of MRN in monitoring structural changes post nerve-repair surgery and its correlation with postsurgical clinical outcomes.

Materials and Methods:
A total of 297 patient records with the chief complaint of PTN were identified from a university database. Of these patients, 70 underwent subsequent nerve repair surgery, and 9/70 underwent a postsurgical MRN. Both the presurgical and postsurgical MRNs were evaluated with use of the neuropathy score reporting and data system (NS-RADS) scoring system. Patients' MRN findings were graded as per injury (I) and postintervention (PI) categories with their respective subcategories (I1-5 and PI1-3). Surgical findings were reviewed to confirm nerve injury severity. Postsurgical clinical changes in general sensation, pain, and taste were evaluated. Clinical changes were categorized as complete resolution, partial improvement, or no change.

There were six women and three men with an age range of 25–73 years. Most injuries resulted from third molar removals (7/9), with an average length of time from inciting event to nerve repair surgery of 6 months. NS-RADS I4 injuries (neuroma-in-continuity) were found in 8/9 patients, and NS-RADS I5 in the remaining; all were confirmed intraoperatively. Of the three patients with expected postsurgical MRN findings (PI I), all experienced either partial improvement or complete resolution of neuropathic symptoms. Of the five patients with postsurgical MRN findings demonstrating persistent or worsening neuropathy (PI II-III), one patient demonstrated partial improvement of general sensation, pain, and taste sensation, and the remaining four demonstrated no improvement or worsening symptoms.

MRN has been shown to be useful for preoperative planning, and this study shows initial validation of its role in postoperative state with follow-up MRNs showing good concordance with clinical outcomes.