Neurapraxia in patients with trigeminal neuralgia but no identifiable neurovascular conflict during microvascular decompression: a retrospective analysis of 26 cases

Background Microvascular decompression (MVD) is the first choice in patients with classic trigeminal neuralgia (TGN) that could not be sufficiently controlled by pharmacological treatment. However, neurovascular conflict (NVC) could not be identified during MVD in all patients. To describe the efficacy and safety of treatment with aneurysm clips in these situations. Methods A total of 205 patients underwent MVD for classic TGN at our center from January 1, 2015 to December 31, 2019. In patients without identifiable NVC upon dissection of the entire trigeminal nerve root, neurapraxia was performed using a Yasargil temporary titanium aneurysm clip (force: 90 g) for 40 s (or a total of 60 s if the process must be suspended temporarily due to bradycardia or hypertension). Results A total of 26 patients (median age: 64 years; 15 women) underwent neurapraxia. Five out of the 26 patients received prior MVD but relapsed. Immediate complete pain relief was achieved in all 26 cases. Within a median follow-up of 3 years (range: 1.0–6.0), recurrence was noted in 3 cases (11.5%). Postoperative complications included hemifacial numbness, herpes labialis, masseter weakness; most were transient and dissipated within 3–6 months. Conclusions Neurapraxia using aneurysm clip is safe and effective in patients with classic TGN but no identifiable NVC during MVD. Whether this method could be developed into a standardizable method needs further investigation.

Prognostic factors for long-term outcomes of microvascular decompression in the treatment of glossopharyngeal neuralgia: a retrospective analysis of 97 patients

OBJECTIVE The authors aimed to investigate predictors of postoperative outcomes of microvascular decompression (MVD) for the treatment of glossopharyngeal neuralgia (GPN). METHODS A cohort of 97 patients with medically refractory GPN who underwent MVD at the authors’ institution between January 2010 and July 2019 was retrospectively reviewed. Univariate and multivariate regression models were used to identify predictors of long-term outcome in patients after MVD. RESULTS Eighty-nine patients (91.8%) reported immediate and complete relief of pain after the procedure. Of the remaining 8 patients (8.2%), 6 achieved partial pain relief and pain gradually diminished within 2 weeks after surgery, and 2 did not experience postoperative pain relief. In univariate Cox regression analysis, venous compression of the glossopharyngeal nerve root entry zone (HR 3.591, 95% CI 1.660–7.767, p = 0.001) and lower degree of neurovascular conflict (HR 2.449, 95% CI 1.177–5.096, p = 0.017) were significantly associated with worse pain-free survival. In multivariate Cox regression analysis, venous compression (HR 8.192, 95% CI 2.960–22.669, p < 0.001) and lower degree of neurovascular conflict (HR 5.450, 95% CI 2.069–14.356, p = 0.001) remained independently associated with worse pain-free survival. CONCLUSIONS Venous compression of the glossopharyngeal nerve root entry zone and lower degree of neurovascular conflict were significantly correlated with shorter pain-free survival in patients who underwent MVD for GPN. Microvascular decompression is a safe, feasible, and durable approach with a low complication rate for the treatment of GPN.

Microvascular decompression in trigeminal neuralgia: predictors of pain relief, complication avoidance, and lessons learned

Objective To analyze characteristics associated with long-term pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TGN). Description of associated morbidity and complication avoidance. Methods One hundred sixty-five patients with TGN underwent 171 MVD surgeries at the authors’ institution. Patient characteristics and magnetic resonance imaging (MRI) datasets were obtained through the hospital’s archiving system. Patients provided information about pre- and post-operative pain characteristics and neurologic outcome. Favorable outcome was defined as a Barrow Neurological Institute (BNI) pain intensity score of I to III with post-operative improvement of I grade. Results Type of TGN pain with purely paroxysmal pain (p = 0.0202*) and TGN classification with classical TGN (p = 0.0372*) were the only significant predictors for long-term pain relief. Immediate pain relief occurred in 90.6% of patients with a recurrence rate of 39.4% after 3.5 ± 4.6 years. MRI reporting of a neurovascular conflict had a low negative predictive value of 39.6%. Mortality was 0% with major complications observed in 8.2% of patients. Older age was associated with lower complication rates (p = 0.0009***). Re-MVD surgeries showed improved long-term pain relief in four out of five cases. Conclusions MVD is a safe and effective procedure even in the elderly. It has the unique potential to cure TGN if performed on a regular basis, and if key surgical steps are respected. Early MVD should be offered in case of medical treatment failure and paroxysmal pain symptoms. The presence of a neurovascular conflict on MRI is not mandatory. In case of recurrence, re-MVD is a good treatment option that should be discussed with patients. Highlights • Long-term analysis of pain relief after MVD. • Positive predictors for outcome: classical TGN and purely paroxysmal pain. • Presence of neurovascular conflict in MRI is not mandatory for MVD surgery. • Analysis of complications and surgical nuances for avoidance. • MVD is a safe procedure also in the elderly.

Refractory cluster-tic syndrome: The Hickam’s dictum

A 50-year-old man debuted with right trigeminal neuralgia. In the following years, it became refractory to medical treatment and ipsilateral cluster headache appeared. He was diagnosed with cluster-tic syndrome. A brain magnetic resonance with high-spatialresolution 3D T2 sequences (FIESTA) excluded the existence of neurovascular conflict, but a surgical exploration was indicated due to its torpid evolution. A venous contact with the right trigeminal nerve was confirmed in the surgery and microvascular decompression was performed. The patient’s evolution was favorable, improving the trigeminal neuralgia as well as the cluster headache. Keywords: Trigeminal neuralgia; cluster headache; cluster-tic syndrome; microvascular decompression.

Trigeminal neuralgia: a practical guide

Trigeminal neuralgia (TN) is a highly disabling disorder characterised by very severe, brief and electric shock like recurrent episodes of facial pain. New diagnostic criteria, which subclassify TN on the basis of presence of trigeminal neurovascular conflict or an underlying neurological disorder, should be used as they allow better characterisation of patients and help in decision-making regarding medical and surgical treatments. MR, including high-resolution trigeminal sequences, should be performed as part of the diagnostic work-up. Carbamazepine and oxcarbazepine are drugs of first choice. Lamotrigine, gabapentin, pregabalin, botulinum toxin type A and baclofen can be used either alone or as add-on therapy. Surgery should be considered if the pain is poorly controlled or the medical treatments are poorly tolerated. Trigeminal microvascular decompression is the first-line surgery in patients with trigeminal neurovascular conflict while neuroablative surgical treatments can be offered if MR does not show any neurovascular contact or where patients are considered too frail for microvascular decompression or do not wish to take the risk.

Paroxysmal otalgia treated with microvascular decompression of the intermediate nerve: illustrative case

BACKGROUND Intermediate nerve neuralgia is a rare type of cranial neuralgia that causes clinical, therapeutic, and diagnostic challenges. Studies have described pharmacological and surgical treatment options. Surgical treatment ranges from sectioning of neural structures to microvascular decompression. Given the rareness of the disease, there are no clear recommendations concerning treatment. OBSERVATIONS Reported is the case of a patient with typical intermediate nerve neuralgia. In this particular case, decision-making toward surgical decompression in an earlier stage of the disease could have been beneficial. The authors found excellent results using only microvascular decompression without sectioning of neural structures. LESSONS Knowledge of intermediate nerve anatomy is essential to understand this complex pain syndrome. This case illustrates that surgery should not only be regarded as a last resort in case of failure of conservative treatment but also should be considered early in the disease course, especially in the case of a clear neurovascular conflict. When no evident cause is found, surgery could be considered as an exploratory option to depict a neurovascular conflict intraoperatively. Microvascular decompression of the intermediate nerve without sectioning of neural structures can obtain excellent results. Since neural structures are saved, postoperative sequelae can be limited.