Preoperative demonstration of neurovascular compression in trigeminal neuralgia with contrast - enhanced 3D - SPGR sequence

Objective To assess the value of contrast - enhanced three - dimensional spoiled gradient recalled (3D - SPGR ) sequence in the preoperative visualization of neurovascular compression (NVC) in patients with trigeminal neuralgia(TN) and to evaluate the relationship between clinical symptoms of neuralgia related to trigeminal branches and the sites of trigeminal nerve compression.Method Thirty -seven patients(21 males,16 females; the age ranged from 26 to 81 years with a mean age of 55.3 years) with unilateral typical TN underwent preoperative contrast - enhanced 3D - SPGR sequence.The vascular contact with the trigeminal nerve at the root entry zone (REZ) was reviewed by an experienced neuroradiologist,who was blinded to the clinical details.The imaging results were compared with the operative findings and clinical symptoms related to trigeminal branches in patients.Results In 37 patients with TN,contrast - enhanced 3D - SPGR sequence identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves.Based on surgical findings,the sensitivity of MR imaging was 97.2％ and the specificity 100％.Agreement between the position ( medial,lateral,cranial,and caudal) of the compressing vessel relative to the trigeminal nerve defined by MR imaging and findings at surgery was good( K =0.81 ;95％ confidence interval,0.56 ～ 1.00).Twelve(85.7％ ) of 14 patients with symptoms related to the maxillary division had their NVC at the medial site of the REZ.Thirteen(81.3％ ) of 16 patients with symptoms related to the mandibular division had their NVC at the lateral site of the REZ.A statistically significant difference was observed between the NVC site and the clinically manifested symptoms in the branches of the trigeminal nerve( P ＜ 0.001 ).Conclusions Contrast - enhanced 3D - SPGR sequence is useful in detection of NVC in patients with TN.Anatomic relationships defined by this method may be useful in predicting surgical findings. Key words: Magnetic resonance imaging;  Microvascular decompression;  Neurovascular compression;  Trigeminal neuralgia;  Comparative studies