Clinical StudyLong-term prognostic factors for microvascular decompression for trigeminal neuralgia
Introduction
Trigeminal neuralgia (TN) is a facial pain syndrome characterized by paroxysmal, shock-like pain attacks that are distributed along the trigeminal nerve. Various surgical treatments have been used to treat TN. Among these treatments, microvascular decompression (MVD) has been the most attractive treatment strategy because it provides the highest rates of long-term patient satisfaction and the lowest rates of pain recurrence.1 However, not all patients with TN are cured by MVD. Although reports of initial pain relief after MVD range from 86–98.2%, the recurrence rates range from 15.1–30%.[2], [3], [4] Furthermore, open surgery has a higher mortality rate compared with other techniques used to treat TN including percutaneous techniques or stereotactic radiosurgery.[2], [3]
Most cases of TN are caused by a neurovascular conflict (NVC) at the root entry zone of the trigeminal nerve, and in several analyses, patients with more severe vascular compression of the trigeminal root have reported greater relief of their symptoms after microvascular decompression.[5], [6], [7], [8] Therefore, prediction of NVC severity using preoperative imaging may be useful for predicting long-term success and could help guide patient selection for MVD treatment.
This retrospective study was performed to determine the imaging predictors of pain relief after MVD. In addition, the preoperative patient factors and surgical findings were analyzed. The preoperative imaging studies were compared with the surgical findings to identify imaging findings predictive of success.
Section snippets
Methods
In this study, 153 consecutive patients were treated with MVD for typical TN by a single surgeon (K. Park) at the Samsung Medical Center in Seoul, Korea between January 1998 and March 2010 and were evaluated. Within this group, 12 patients were excluded due to a lack of recorded postoperative results. Therefore, only 141 patients were included in this study.
The prognostic factors were assessed by a review of the medical records and were classified into two categories, specifically, the
Overall outcome after microvascular decompression
The follow-up evaluation period ranged from 6 months to 10 years with a mean of 26.3 months. The Kaplan–Meier curves for success (excellent outcome) and acceptable success (excellent or good outcome) are shown in Fig. 1a, b. An immediate, complete postoperative relief from pain was achieved in 120 patients (85.1%), with immediate good relief being attained in 16 patients (11.3%) and poor relief in five patients (3.6%). Using the Kaplan–Meier analysis, the estimated probability of being pain-free
Discussion
Since Gardner proposed the theory of NVC, a growing body of evidence indicates that compression of the trigeminal nerve root at or near the dorsal root entry zone by a vessel is the major cause of TN.[2], [7], [12], [13], [14], [15] Although autopsy studies have revealed some degree of contact between the trigeminal nerve and a blood vessel in 14–60% of asymptomatic individuals, it is uncommon for arterial contact to produce a distortion or grooving of the nerve.[16], [17], [18], [19]
Conclusion
The presence of a definitive NVC with a single arterial offender at surgery is the most important prognostic factor in MVD for TN, and the preoperative MRI findings of deviation and a CSF rim sign are correlated with a more severe NVC. Due to the limitations of this retrospective study, a thorough prospective study is required to clarify the significance of these positive MRI findings.
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2022, World NeurosurgeryCitation Excerpt :However, clinical practice found that certain patients with TN exhibited unsatisfactory outcomes or recurrence after MVD.4-7 The factors affecting MVD prognosis have often been intricate and complex, manifesting with complicated and obscure relationships between many independent, nonlinear variables, for which favorable predictive results could not be obtained through traditional empirical prognostic judgments or standard linear regression models.5,8-13 With the development of computer technology, artificial neural networks (ANNs) have enabled impressive achievements in the field of disease prognosis prediction for surgical procedures.14-17
Comparison of Prognostic Scoring Systems to Predict Durable Pain Relief After Microvascular Decompression for Trigeminal Neuralgia
2022, World NeurosurgeryCitation Excerpt :Our data suggest that the degree of NVC as defined in the PS is a particularly sensitive marker for durability of pain relief after MVD. There is a well-documented relationship between NVC and symptoms of TN.12,15-18 In particular, previous studies have shown that the degree of NVC is a significant predictor of pain relief after MVD.12,15,16
The Epidemiology, Cause, and Prognosis of Painful Tic Convulsif Syndrome: An Individual Patient Data Analysis of 192 Cases
2021, World NeurosurgeryCitation Excerpt :Forest plots are shown in Figure 3. The comparison among PTC, TN, and HFS in aspects of epidemiology, surgical outcome, and prognosis predictor is summarized in Table 3.6,18-51 In this study IPD from 192 patients with PTC were analyzed, showing that PTC shared many similarities with TN and HFS in terms of epidemiology but may differ in conflicting vessels and prognosis predictors.
Pain-Free Outcomes and Durability of Surgical Intervention for Trigeminal Neuralgia: A Comparison of Gamma Knife and Microvascular Decompression
2018, World NeurosurgeryCitation Excerpt :MVD is unique in that it entirely preserves the integrity of the trigeminal nerve, whereas ablative procedures, such as GKS, partially or totally destroy the nerve to eliminate aberrant action potentials.20,22,36,48,49 Some authors argue that MVD has a higher potential for complications because the procedure requires a craniotomy and often cerebellar retraction to gain access to the trigeminal root entry zone to displace encroaching vasculature.6,10,11,20,50-53 The reported complications from the procedure include facial numbness, nausea, vomiting, wound infection, cerebrospinal fluid leak, headaches, diplopia, facial palsy, meningitis, and hearing loss.5,6,8-10
Flat Posterior Cranial Fossa Affects Outcomes of Microvascular Decompression for Trigeminal Neuralgia
2018, World NeurosurgeryCitation Excerpt :In other words, “flatness” of the PCF was associated with poor outcomes of MVD for primary TN. Numerous prognostic factors of MVD for TN have been investigated and reported to date.4,6,8 The present study demonstrated that atypical type 2 TN, mild NVC, and a flat-shaped PCF were associated with poor outcome of MVD for primary TN.