Prognostic factors for outcome of microvascular decompression in trigeminal neuralgia: A prospective systematic study using independent assessors

Abstract

Introduction There is a lack of high-quality prospective, systematic studies using independent assessors of outcome of microvascular decompression as treatment for trigeminal neuralgia. Methods Clinical characteristics and outcome data were recorded prospectively from consecutive classical trigeminal neuralgia patients, using standardized interviews. Degree of neurovascular contact was evaluated by a 3.0 Tesla MRI blinded to symptomatic side. Patients were assessed before and 12 months after surgery by a neurologist. Results Twenty-six men and 33 women completed 12 months follow-up. Forty-one patients (69%) had an excellent outcome (no pain, no medication). Ten (18%) patients had a good outcome. Eight (12%) patients had no improvement or had worsening of pain. MRI showed neurovascular contact with morphological changes in 34 patients (58%). Odds ratio between neurovascular contact with morphological changes and excellent outcome was 4.4 (Cl 1.16-16.26), p = 0.029. Odds ratio between male sex and excellent outcome was 11.38 (Cl 2.12-59.52), p = 0.004. No significant association was found between excellent outcome and concomitant persistent pain, current age or disease duration. Conclusion Neurovascular contact with morphological changes and male sex are positive predictive factors for outcome of microvascular decompression. The findings enable clinicians to better inform patients before surgery.

MRI-derived neurovascular compression score provides the indication of surgical treatment of patients with primary trigeminal neuralgia: A validated multi-center study

“…MVD is the primary option and carry a low risk of requiring a secondary procedure and facial numbness after surgery (13,14). A recent prospective study investigating the outcomes of MVD in patients with TN has found that male gender and NVC with morphological changes on preoperative MRI images, where distortion, dislocation, and distension were observed, predicted the excellent outcomes (15). This study and earlier studies have reported that the severity degree of NVC was signi cantly associated with surgical outcomes (16,17).…”

“…The underlying mechanism may due to the fact that the demyelinated trigeminal nerve root remyelinates after MVD and the neuroedema at the symptomatic NVC were released (3,18). Therefore, the preoperative neurological imaging assessment of NVC severity is important in predicting patients' outcomes beyond diagnosis (15,19).…”

“…More recent studies have further developed the NVC evaluation system, particularly focusing on the morphological changes of the trigeminal nerve. Tone Bruvik Heinskou's group has graded the NVC contact as simple contact, displacement (displacement or distortion), and atrophy with a reduced volume of the nerve (15). The present study also included the morphological changes and adapted a scoring system in describing the NVC degree in a quantitative manner but in more detail (12).…”

Recent advances in understanding/managing trigeminal neuralgia

“…NVC causing atrophy or displacement of the nerve (or both) was highly associated with pain on the symptomatic side of patients with classic TN in contrast to NVC in general, according to this study 17 . A more recent study reported that neurovascular contact with morphological changes to the nerve as detected by 3-Tesla MRI and male gender was associated with better outcome following microvascular decompression surgery 18 . Excellent outcome and concomitant persistent pain, current age, or disease duration were not correlated 18 .…”

European Academy of Neurology guideline on trigeminal neuralgia

“…In a recent prospective study using independent assessors of outcome, it was demonstrated that patients with classical TN have a higher chance of a successful outcome after microvascular decompression (MVD) compared to idiopathic TN patients . However, a significant proportion of patients with idiopathic TN also had good pain relief after MVD . Thus, it seems that an NVC without morphological changes does play a role in some idiopathic TN patients who are therefore not truly ‘idiopathic'.…”