The treatment methods of TN-MS include drugs, gamma knife, balloon compression, MVD and PSR, but the treatment effects are different. Giulia Di Stefano [8] summarized the articles published in recent years on drug treatment of TN-MS and proposed that patient cannot tolerate the central sedation and exercise side effects of carbamazepine, oxcarbazepine, lamotrigine, gabapentin, and pregabalin, and most patients cannot obtain satisfactory curative effects. Further development of new selective and well tolerated sodium channel blockers is still necessary. Zakrzewska[9] are conducting a randomized clinical trial of a new selective sodium channel blocker, hoping that the drug will have a good therapeutic effect and fewer side effects, and alleviate the suffering of patients.
Helis [10] reported a group of cases of gamma knife treatment of TN-MS, 82% of patients had a good pain relief rate after surgery. The average relief time was about 1.1 years. After 1 year, 3 years, and 5 years follow-up, the average remission rate is 51%, 39%, 29%, the recurrence rate is high, and the long-term effect is poor performance. Alvarez-Pinzon 11] believe that the minimal invasiveness and satisfying results of GKRS support its use as the first-line treatment of TN in patients with MS。However, most of the therapeutic effects of the gamma knife are gradually effective half a year after the operation, and most patients cannot tolerate the pain during this period.
Pinzon[11] believes that the effectiveness of PBC is confirmed in treatment TN-MS. Asplund[12] reported a group of cases, 66 TN-MS patients underwent 111 trigeminal nerve semilunar segment microballoon compression, the immediate postoperative effective rate was 67%, and the average recurrence time was 8 months. Martin[13] reported 17 cases, and the immediate postoperative effective rate was 82%。Nicola Montano[14] reported 21 cases, 17 cases were relieved after PBC treatment, the effective rate was 80.95%, the pear-like shape of the balloon at the operation were associated to higher pain-free survival, which is consistent with our experience。However, Baabor[15] reported that patients with classic TN who received PBC had an immediate postoperative effective rate of 93% and an overall effective rate of 99%, indicating that PBC is not as effective as typical TN in treating TN-MS. From my perspective, the inconsistent results may be related to technology, case selection, and sample size, however, its efficacy is not as good as that of typical TN. In our center, TN-MS patients who have failed medical treatment are more inclined to undergo PBC surgery, because the surgical trauma is not more obvious than the gamma knife, and it is effective immediately after the operation.
MVD is the best treatment for classic TN with responsible vascular compression, which has become a consensus, but the role of responsible vascular in TN-MS and the therapeutic effect of MVD are still not fully understood. Truini[16] believes that a dual concurrent mechanism explains trigeminal neuralgia in patients with multiple sclerosis. But Noory[17] has different opinion on it, he believes that neurovascular contact plays no role in trigeminal neuralgia secondary to MS. Paulo [18] reported 33 cases of MVD in the treatment of TN-MS, and a follow-up of 53.5 months after surgery indicated that the pain relief rate was 67%. They believed that although MVD is not as effective as classic TN in the treatment of TN-MS, it can still be recommended Choose, and the more severe the preoperative pain, the worse the surgical effect. We do not do much discussion here about regarding MVD and TN-MS.
Trigeminal nerve sensory root cut was first proposed by Dandy in the 1920s. At first, it was completely cut, and later, to preserve the sense of touch, it was changed to partial cut, that is, PSR operation. Later, it was gradually applied to patients who did not have a clear responsibility vessel in the REZ area during MVD surgery and those who were ineffective or recurred after MVD surgery. The follow-up effect was good. Yin Liu[19] believe that in the postmenstrual fossa MVD surgery, there is no obvious vascular compression, the decompression effect is not satisfactory, and the patient’s age is more than 60 years old. It is appropriate to adopt PSR surgery, and its effective rate is the same as that of MVD. The tolerance for numbness is much greater than pain. Terrier[3] reported a group of cases, the postoperative pain relief rate was 86.4%, and the 5-year follow-up recurrence rate was 31.5%. Recently, Bigder[20] proposed that PSR can prolong pain recurrence time and reduce pain score more than other methods in the treatment of TN-MS.
In this group of cases, 8 of them are male (38%), 13 of them are female (62%), 10 were left (47.6%), 9 were right (42.8%), and 2 were bilateral (9.5%). The history of MS is 6-11 years, with an average of 7.76±1.48 years; the history of TN is 5-8 years, with an average of 5.95±1.09 years, which is not consistent with the results of Cruccu[5], which may be due to our small sample size. This study showed that the pain relief rate on the first day after PSR was 100%, the follow-up 6M, 12M, and 18M relief rates were 100%, 95%, 81%, and the recurrence rates were 0, 5%, and 19%, respectively. The effect is better than the 86.4% reported by Terrier[3], but not as good as non-TN-MS, may be related to the history of PBC surgery in this group of patients and the degree of trigeminal nerve cut during the operation, and the long-term prognosis still needs further observation. The comparison of the two treatment methods before and after shows that PSR has a better VAS score drop and lower recurrence rate than PBC; all patients have facial sensation after surgery, but it is tolerable, and experienced significantly better than pain, and no corneal reflex attenuation, which did not affect life; 1 case of intracranial infection, but there are no serious complications such as intracranial hemorrhage, facial paralysis, cerebrospinal fluid leakage after PSR; 7 cases of chewing function decline after PBC, but they are completely improved after half a year. This is because PBC destroys trigeminal semilunar ganglion, motor nerves are affected, and PSR only selectively cuts off part of the sensory root. But at the same time, PSR also has its drawbacks, because the craniotomy is very traumatic. Although there were no serious complications in these 21 patients, it did not mean that they would not occur, probably because the sample size was too small. It has been reported that the mortality rate of MVD is 0.4% [21]. And the average length of stay and cost of PSR is higher than that of PBC. Zakrzewska[22] conducted a systematic retrospective analysis and concluded that the treatment effect of TN-MS is poor compared with classic TN. The 2-year recurrence rate of various surgical treatments is approximately 50%. There is no evidence that medications or early surgery are effective, but we believe that TN-MS patients who relapse after PBC should still be actively treated. PSR can be determined as a recommended treatment.