Evaluating the diagnostic role of magnetic resonance imaging in trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia: A controlled blinded study.

Introduction: Hyperactive dysfunction syndromes (HDS)-including trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia-are typically associated with neurovascular compression (NVC) at the cranial nerve root entry/exit zone. MRI is widely employed to detect NVC, although its diagnostic reliability remains controversial, as NVC may also be observed in asymptomatic individuals, while in some symptomatic patients, radiological evidence can be absent. Research question: Can preoperative MRI reliably identify NVC in HDS patients undergoing microvascular decompression (MVD), and how does clinical information affect diagnostic accuracy? Materials and methods: We retrospectively analyzed preoperative 3 T MRIs from 42 HDS patients treated with MVD (2013-2023) and compared them with scans from age-matched healthy controls. Three experienced raters evaluated the images under five conditions with varying levels of clinical information, to assess how context influenced the detection of NVC. Results: Diagnostic accuracy increased in parallel with the amount of clinical information available. Under fully blinded conditions, correct identification of NVC remained below 50 %. Sensitivity improved when the affected nerve was disclosed (77.7 %) and further increased with full clinical context (83.3 %). Sensitivity decreased to 23.8 % when control scans were introduced without the raters' awareness but rose to 88.9 % when controls were acknowledged. Interrater agreement remained low (k = 0.2-0.3) across all settings. Discussion and conclusion: MRI findings alone may be insufficient to confirm or exclude NVC in HDS. Interpretation should always be integrated with clinical data, and surgical decisions should not be based solely on imaging, particularly in symptomatic patients with negative scans.