Microstructural abnormalities of the trigeminal nerve correlate with pain severity and concomitant emotional dysfunctions in idiopathic trigeminal neuralgia: A randomized, prospective, double-blind study.

OBJECTIVE: To compare cross-sectional area (CSA) and volume (V) between the trigeminal nerves (TGNs) of the affected side and the unaffected side in patients with idiopathic trigeminal neuralgia (ITN), and both nerves in normal controls, and to correlate these morphological data with degree of facial pain and emotional disorder severity in ITN patients. METHODS: Forty ITN patients and 40 matched healthy volunteers underwent three-dimensional fast imaging employing steady state acquisition (3D-FIESTA) and time-of-flight magnetic resonance angiography (TOF-MRA) focusing on CSA and V of the TGN cisternal segment. Correlations between the morphological results and scores of visual analogue scale (VAS), Hamilton Depression Rating Scale (HAMD), and Hamilton Anxiety Rating Scale (HAMA) were analyzed in two groups. RESULTS: CSA and V of the affected TGN were significantly smaller than in the unaffected TGN and both sides in controls. No statistical differences were observed between morphological data of the unaffected TGN and control TGNs. CSA and V of the affected TGN were significantly associated with VAS scores in ITN patients, and intermediate correlations were detected with HAMD and HAMA scores. CONCLUSION: Degree of atrophy in the affected TGN can be effective for evaluating facial pain and assessing emotional deficits in ITN patients.