Internal Neurolysis Research Articles

Predictive Factors for Herpes Simplex Virus Reactivation in Patients with Trigeminal Neuralgia After Surgery

This study aimed to investigate the predictive factors associated with the reactivation of herpes simplex virus (HSV) in patients with trigeminal neuralgia (TN) after surgery, and to determine whether there is a correlation between reactivation and surgical efficacy. This study included 190 patients who underwent surgery between January 2020 and December 2021. Postoperative HSV reactivation was defined as the presence of perioral or gingival herpes and herpes labialis within 1 week postoperatively. Logistic regression analysis was used to evaluate clinical characteristics as potential predictors of HSV reactivation. Additionally, Spearman's rank correlation coefficient was used to determine any correlation between the postoperative barrow neurological institute (BNI) pain intensity score and HSV reactivation. Of the 190 patients, 56 (29.5%) experienced postoperative HSV reactivation. Both univariate and multivariate analyses identified several significant predictors of HSV reactivation, such as a history of HSV infection, previous trigeminal nerve-damaging surgery, the use of internal neurolysis (IN) as a surgical technique, and an operation time of ≥25 min. No significant correlation was found between HSV reactivation and pain relief, as measured by BNI scores. HSV reactivation was observed in a considerable proportion of patients with TN. Long operative times (≥25 min), the use of IN as a surgical technique, a history of HSV infection, and previous trigeminal nerve-damaging surgery were identified as risk factors. Further research is needed to optimize surgical procedures and develop targeted management protocols to reduce the risk of HSV reactivation.

The choice of method of electroneuromyogaphy in remote consequences of gunshot and mine-blast injuries of limb nerves

Objective. Clarification of the nature of damage and degree of functional disorders in the remote consequences of gunshot and mine-blast injuries of limb nerves using neurophysiological techniques (NP) of functional diagnostics (stimulation and needle electromyography), correlation of these data with the nerve damage characteristics determined during surgical interventions (operative findings). Materials and methods. 480 military personnel and civilians, men aged 18-64 years (average age 33.5 years), with gunshot and mine-blast injuries of limb nerves (LNI) within 1 to 11 months after injury were examined. A total of 1400 EMG studies were conducted. Clinical-neurological methods were used to determine the level, degree, and nature of LNI. Results. Among the examined 480 patients, complete nerve damage was detected in 299, and partial in 181. Causes of nerve damage included: shrapnel, gunshot, mine-blast injuries, nerve rupture due to bone fractures, injuries by sharp objects, iatrogenic damage. In 62.3% of cases of complete LNI surgical interventions were performed using the technique of neurotization using branches of donor nerves. Provided anatomical integrity of nerve structures and presence of conductivity during EMG testing, external or internal neurolysis was performed. Surgical intervention timing: up to 6 months post-injury - 68.1% of cases; up to 3 months - 31.9%. Based on the results of comprehensive clinical-NP research, adapted schemes for assessing NP data corresponding to each pathohistological type of LNI were developed, and NP criteria for classifying consequences of LNI into three degrees of severity of functional deficit - mild, moderate, and severe were proposed. Conclusions. Criteria for choosing the optimal NP diagnostic methodology for the remote consequences of gunshot and mine-blast injuries of limb nerves have been determined. Comprehensive clinical-instrumental diagnostics allows to objectify the level and degree of limb nerve damage, signs of neuromuscular apparatus recovery, provides information for planning of the surgical tactics and subsequent rehabilitation therapy.

A systematic review on the efficacy of adjunctive surgical strategies during microvascular decompression for trigeminal neuralgia without intraoperative evidence of neurovascular conflict.

Aim of the present study was to conduct a comprehensive review of surgical strategies that can be offered to patients with trigeminal neuralgia undergoing microvascular decompression (MVD) surgery and without intraoperative evidence of neurovascular conflict, with a high pre-operative suspicion of conflict lacking intraoperative confirmation, or individuals experiencing recurrence after previous treatment. This systematic review followed established guidelines (PRISMA) to identify and critically appraise relevant studies. The review question was formulated according to the PICO (P: patients; I: intervention; C: comparison; O: outcomes) framework as follows. For patients with trigeminal neuralgia (P) undergoing MVD surgery (I) without demonstrable preoperative neurovascular conflict, high suspicion of conflict but no intraoperative confirmation or recurrence after previous treatment (C), do additional surgical techniques (nerve combing, neurapraxia, arachnoid lysis) (O) improve pain relief outcomes (O)? The search of the literature yielded a total of 221 results. Duplicate records were then removed (n = [76]). A total of 143 papers was screened, and 117 records were excluded via title and abstract screening; 26 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 17 articles were included in the review, describing the following techniques; (1) internal neurolysis (n = 6) (2) arachnoid lysis/adhesiolysis (n = 2) (3) neurapraxia (n = 3) (4) partial rhizotomy of the sensory root (n = 4) (5) pontine descending tractotomy (n = 2). The risk of bias was assessed using the ROBINS-I (Risk of Bias in Non-randomized Studies - of Interventions) assessment tool. While the described techniques hold promise, further research is warranted to establish standardized protocols, refine surgical approaches, and comprehensively evaluate long-term outcomes.

Efficacy of Internal Neurolysis for Atypical Facial Pain

Efficacy of Internal Neurolysis for Atypical Facial Pain

Internal Neurolysis for Trigeminal Neuralgia: A Preliminary Single-institution Experience in Japan.

Internal neurolysis (IN) is a surgical procedure in which the trigeminal fibers are separated between the pons and porus trigeminus to relieve trigeminal neuralgia (TN). Recent investigations revealed that the number of nerve bundles made by IN varies, and immediate postoperative hypesthesia exceeded 90% and pain control rate at 1 year was 77%-93.5%. We present the preliminary experience of 18 patients who underwent IN for TN between June 2020 and June 2022. The Barrow Neurological Institute pain scale (BNI-PS) was recorded preoperatively and in June 2023, and the Barrow Neurological Institute hypesthesia scale (BNI-HS) was recorded preoperatively, immediate postoperatively and in June 2023. Intraoperatively, the number of bundles made by IN was reviewed. Preoperative BNI-PS ranged between VI and V. Two patients experienced BNI-HS II due to percutaneous procedure prior to IN. Intraoperatively, 3 bundles were made by IN in 7 patients, 4 bundles in 5, and 5 bundles in 6. Immediate postoperative BNI-HS I was recorded in 6 patients and II in 12 (66.7%). The last follow-up revealed that BNI-PS I and II were recorded in 13 patients (72.2%) and BNI-HS I and II in 6 patients, respectively. Our results demonstrated that the rates of immediate postoperative hypesthesia (66.7%) and pain control (72.2%) at 1 year or later were below those of previous reports. Therefore, we are currently combing to make at least 6 bundles. Detailed surgical technique and cardiac reflex alerts during the procedure are described.

Single-center experience of cubital tunnel syndrome surgery performing transposition or internal neurolysis with external decompression under regional intravenous anesthesia technique

Aims: To share the 7-year experience of a single center in the application of regional intravenous anesthesia (RIVA) for surgical treatment of cubital tunnel syndrome (CTS) caused by compression of the ulnar nerve in the elbow region.
 Methods: A total of 100 patients with CTS who were operated with the RIVA technique at a single center between 2012 and 2019 were retrospectively analyzed. In the RIVA technique, after providing venous drainage in the operated side arm, the double cuff tourniquet was inflated in the upper arm, and anesthesia was provided by administering a 30-40 mL solution of 2% lidocaine (3 mg/kg) diluted in 1% saline through the intravenous catheter. The surgical methods applied (transposition or internal neurolysis with external decompression), demographic data, preoperative and postoperative visual analog scale (VAS) scores for pain were compared.
 Results: Out of 100 patients, 30 patients underwent surgical transposition (group 1) while internal neurolysis with external decompression was performed in 70 patients (group 2). The mean age of patients in groups 1 and 2 was 66.3±12.1 and 60.6±11.7 years, respectively. Women accounted for 73.3% of patients in group 1 and 87.1% of patients in group 2. The left side was affected in 18 (60%) patients in group 1 and 42 (60%) patients in group 2. In group 1, the mean postoperative 3rd-week VAS score (1.96±0.76) was significantly lower than the mean preoperative VAS score (7.46±0.93; p

Internal Neurolysis for Trigeminal Neuralgia: Technical Nuances and a Single-Institution Experience

Trigeminal neuralgia is a facial pain syndrome most commonly caused by a neurovascular compression (NVC) of the trigeminal nerve. Microvascular decompression (MVD) is the most durable surgical treatment; however, patients without an NVC are not candidates for this procedure. Alternative treatments such as percutaneous rhizotomy and radiosurgery are effective but with higher recurrence rates. Internal neurolysis (IN) is a less frequently used procedure that aims to provide long-term relief to patients without NVC. We present the surgical techniques for IN developed at our institution. We also discuss the technical nuances related to nerve consistency and present a new classification based on these findings. We provide pain and numbness outcomes for our cohort of patients stratified by the extent of neurolysis and nerve consistency. Patients with medically intractable trigeminal neuralgia eligible for posterior fossa exploration are eligible for MVD and possible IN. If no NVC or a mild NVC is encountered, IN is performed. We have divided the procedure into 4 main steps: opening the outer connective sheath, fascicular dissection, inside-out dissection and the fascicular irrigation technique. Trigeminal nerve consistency has been classified into 3 main types: type 1 is soft and friable; type 2 is intermediate consistency and ideal for neurolysis; and type 3 is firm and presents a more challenging dissection. In the absence of microvascular compression, we advocate for a thorough neurolysis using the techniques described in our article.

Single-surgeon approach in microvascular decompression for trigeminal neuralgia: Lessons from an Indonesian Tertiary-Level Neurological Center

BackgroundMicrovascular decompression (MVD) is effective for refractory trigeminal neuralgia (TN), but its accessibility is often limited in lower-to-middle-income countries (LMICs). This study aims to assess the impact of implementing a single-surgeon policy on MVD for TN in LMICs. MethodsA prospective cohort study was conducted from 2014 to 2020, comparing outcomes between multi-surgeon and single-surgeon policies. Residents were included in MVD procedures starting in 2019. The Barrow Neurological Institute (BNI) pain scale (P), numbness scale (N), and result conclusion scale (P + N) were used to evaluate outcomes (1 week, 1 month, 1 year, and yearly thereafter). Propensity score matching was performed before comparing the groups. Pain-free survival was assessed using Kaplan-Meier and Cox-regression analysis. ResultsWe comprehensively analyzed data from 72 patients with a minimum one-year follow-up. The implementation of the single-surgeon policy had several notable impacts. Firstly, it led to an increased referral rate (p < 0.05) and a reduced duration to surgery (p < 0.05). During MVD, there was a significant increase in the identification of complex compression (p < 0.05) and a reduced frequency of internal neurolysis (p < 0.05). After surgery, the single-surgeon group exhibited a superior pain-control profile (RR 1.9, p < 0.001; ARR 26–36%), higher pain-free survival rate (p < 0.001), lower likelihood of pain recurrence (HR 0.2, p < 0.0001), and fewer additional surgical interventions compared to the multi-surgeon group. Moreover, the involvement of residents did not significantly impact surgical outcomes. ConclusionsImplementing a single-surgeon policy for MVD in LMICs has the potential to improve surgical outcomes, provide social benefits, and offer educational opportunities.

Ultrasound as the main method for diagnosing peripheral nerve injuries in mine blast trauma

BACKGROUND: The amount of published data related to peripheral nerve blast injuries is limited.&#x0D; AIM: The study was aimed at determining the accuracy and sensitivity and assessing the specificity of ultrasound in the diagnosis of peripheral nerve injuries in mine blast trauma.&#x0D; METHODS: A total of 159 patients (274 peripheral nerves) were examined. Ultrasound was performed according to the standard technique using a HI VISION Avius HITACHI scanner with an EUP-L74M linear transducer (a frequency range of 513 MHz) and a preset musculoskeletal system ultrasound program. The duration of nerve injuries ranged from 2 to 273 days. All patients were men aged 20 to 48 years. Peripheral nerves were damaged as a result of mine blast trauma. Statistical analysis was used to assess sensitivity, specificity, and diagnostic accuracy. These characteristics were calculated according to the qualitative assessment of surgical intervention, the results of conservative treatment, and the method under study (ultrasound).&#x0D; RESULTS: A total of 274 damaged peripheral nerves were examined. The Group 1 included 93 (34%) nerves that required surgical intervention. In Group 2, consisting of 181 (66%) nerves, conservative treatment was used. Most of the nerves (47 [51%]) in Group 1 were damaged due to the compression effects of scarring in the surrounding tissues. Seventeen (18%) partial violations of the anatomical integrity of nerves with the formation of intramural and marginal neuromas were detected. Multiple and single nerve injuries were observed in 95 (59.7%) and 64 people (40.3%), respectively. Peripheral nerves of the upper extremities were damaged more frequently (185 [67.5%]), whereas nerves of the lower extremities were damaged in 89 (32.5%) cases. Ultrasound showed an increase in the cross-sectional area of nerves, blurred contours, decreased echogenicity, and changes in the bundle structure up to the complete absence of differentiation of individual fascioculi. The formation of neuromas was observed in complete and partial nerve ruptures. All 93 nerves in Group 1 underwent surgical intervention, particularly, external neurolysis (32 [34%]), internal neurolysis (15 [16%]), nerve suture (15 [16%]), excision of neuroma followed by microsurgical epineural suture (18 [19%]), and autoneural plasty (11 [12%]). In 2 (3%) cases, a decision was made to abstain from plasty and perform a tendon transposition due to a pronounced diastasis. All patients of Group 2 were shown to have a wait-and-see approach, and conservative therapy was prescribed. In 179 (99%) cases, complete recovery of sensory and motor activity was observed within 21 days. In 2 (1%) patients, a repeated ultrasound was performed due to no effect of treatment. Compression by scar tissues was revealed, and surgical intervention was made.&#x0D; CONCLUSIONS: In mine-explosive impact, ultrasound is the leading method for diagnosing peripheral nerve injuries. Ultrasound with sensitivity of 97.8% and specificity of 98.8% reveals lesions for which surgical treatment is indicated. The diagnostic accuracy is 98.5%.

Diagnosis and treatment of phrenic nerve hourglass constriction in patients with Parsonage-Turner syndrome.

Phrenic nerve injury can occur anywhere along its course and clinically results in diaphragm paralysis. Although most patients with Parsonage-Turner syndrome and phrenic nerve dysfunction improve without treatment, some patients do not recover spontaneously. In these cases, an initial autoimmune response produces scarring along the affected nerve(s). This scar, known as an hourglass constriction, causes focal compression of the nerve at the site of the scar, which prevents the nerve from spontaneously recovering. Thus, the authors present a unique case of phrenic nerve injury secondary to Parsonage-Turner syndrome that improved with internal neurolysis. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID22105.

Гистоморфометрическая оценка большеберцового нерва и мелких мышц стопы после внутреннего невролиза и аутогенной пластики большеберцовой порции седалищного нерва крыс

Introduction Transformations of the nerves and muscles of the distal extremities after nerve injuries at the level of the proximal segments are critical for the restoration of functions, but have not been sufficiently studied in experimental biological models. Purpose Histomorphometric evaluation of the tibial nerves and plantar interosseous muscles after internal neurolysis and autogenous plasty of the tibial portion of the sciatic nerve (SN) in rats. Materials and methods The study was performed on 21 male Wistar rats, aged 8-10 months. Series 1 (internal SN neurolysis) – n = 6. Series 2 (autogenous SN neuroplasty) – n = 8. Control – 7 intact rats. The rats were euthanized 6 months after the operation. Light microscopy and histomorphometry of transverse semithin sections of the tibial nerve at the level of the middle third of the lower leg and paraffin sections of the plantar interosseous muscles of the foot were performed. Results In series 1, endoneural vessels had increased diameters and wall thickness in the tibial nerve, but a smaller lumen compared to the norm; the dimensional characteristics of the myelinated fiber population were increased due to myelin decompactization and axonal edema; about 10 % of myelinated fibers were destructively changed. In series 2, the numerical density of the endoneural vessels of the tibial nerve was doubled in comparison with the intact one; the numerical and dimensional composition of the regenerated myelinated fibers indicated active but incomplete regeneration. The vascularization index of the plantar interosseous muscles in series 1 was close to normal, in series 2 it decreased twice, the median of muscle fiber diameters was reduced by 12.41 % (p = 0.000) and 20.96 % (p = 0.000), respectively. Muscle fibers with a diameter of more than 30 μm increased in series 2 compared to series 1. Conclusion Internal neurolysis and interfascicular autoplasty of the sciatic nerve cause multidirectional changes in the endoneural vessels of the tibial nerve, which predetermine the multidirectional nature and severity of denervation and reinnervation changes in the nerves of the lower leg and small muscles of the foot.

Anterior Interosseous Nerve Syndrome.

Anterior interosseous nerve syndrome (AINS) is a rare form of peripheral neuropathy which involves disruption of the anterior interosseous nerve. The pathophysiology of AINS remains unclear. AINS typically initially presents with forearm pain and may gradually progress to palsy of the deep muscles of the anterior forearm. Diagnosis of AINS requires thorough patient history and physical exam. EMG is the preferred diagnostic study and classically reveals abnormal activity and prolonged latency periods within the evoked action potentials of the FPL and PQ. Due to the self-limiting nature of AINS, there is general agreement that conservative and symptomatic management should be explored for up to 6 months as first line therapy, which usually includes analgesics and nonsteroidal anti-inflammatory drugs, contracture prevention, hand therapy, and hand splinting. Surgical options such as internal neurolysis and minimally invasive endoscopic decompression may be explored if functional recovery from conservative management is limited.

Radial Nerve Fascicular Transfer Preserving Long Head through Anterior Incision for Transhumeral Targeted Muscle Reinnervation

Summary:New developments in targeted muscle reinnervation promise better options for treatment of neuropathic pain and improved prosthetic control. For transhumeral amputations, the traditional approach involves an anterior incision to access the median and ulnar nerves and a second posterior incision to access the radial nerve. This is necessitated as exposure of motor branches of the radial nerve distal to the branch to the long head of the triceps is difficult from the anterior approach. Herein, we describe a technique for transferring the radial nerve proper distal to the long head branch to a motor branch to the medial or lateral head of the triceps through internal neurolysis and fascicular transfer. This allows all surgical steps to be performed through a single incision while preserving native motor branches to the biceps and triceps muscles.

Surgical Treatment for Trigeminal Neuralgia.

Various treatments for trigeminal neuralgia (TN) are known to yield initial satisfactory results; however, the surgical treatment has excellent long-term outcomes and a low recurrence rate. Surgical treatment addresses the challenge of vascular compression, which accounts for 85% of the causes of TN. As for surgical treatment for TN, microvascular decompression (MVD) has become the surgical treatment of choice after Peter J. Jannetta reported the results of MVD surgery in 1996. Since then, many studies have reported a success rate of over 90% for the initial surgical treatment. Most MVDs aim to separate (decompress) the culprit vessel from the trigeminal nerve. To increase the success rate of surgery, accurate indications for MVD and management of the offender vessels without complications are critical. In addition, if there is no vascular compression, partial sensory rhizotomy or internal neurolysis can be performed to improve surgical outcomes.

435 Internal Neurolysis for Trigeminal Neuralgia: Systematic Review

INTRODUCTION: Trigeminal neuralgia (TN) remains a challenging disease with debilitating symptoms and variable efficacy of treatment options. Internal neurolysis (IN) is a technique to dissect out the cisternal portion of the trigeminal nerve into multiple “fascicles”, and has shown potential as a treatment option. METHODS: Studies from 2000-2021 that assessed IN for TN were aggregated and independently reviewed. Outcomes evaluated included post-operative pain scores as defined by the BNI-PS or UCSF-PS, recurrence rates, hypesthesia scores as defined by the BNI-HS, and complications. Outcome were stratified as either excellent (BNI-PS: I or UCSF: excellent), good (BNI-PS: I/II or UCSF: excellent) or fair (BNI-PS: I-III and UCSF: excellent/good). Recurrence rates were considered for any pain recurrence and for significant recurrence defined as BNI-PS I/II transitioning to III-V. Weighted averages for demographics, outcomes and complications were generated. RESULTS: A total of 520 patients in 12 studies were identified with 384 patients undergoing IN. The mean follow-up was 36.5 months (range 12-90 months). Overall, an excellent to good outcome was seen in 83.7% of patients. Pain outcomes at 1 year were excellent: 58-78.4%, good: 77-93.75%, and fair: 80-93.75%. Overall pain outcomes were excellent: 47-82.1%, good: 62.5-87.1% and fair: 80-100%. Hypesthesia following IN was seen in as many as 96% post-operatively, however at follow-up remained in only 1.75-10%. The 1-year and overall recurrence rates of any pain were: 3.92-42% and 3.6-50%. The 1-year and overall rates for significant recurrence of pain were: 3.92-17% and 3.6-25%. CONCLUSION: IN represents a potentially promising approach for the surgical treatment of TN in the absence of vascular compression and cases of recurrence. It may also be an adjunct option to MVD in cases of low grade vascular compression. Further study is required to evaluate the impact of IN.

Treatment of redo-microvascular decompression or internal neurolysis plus microvascular decompression for recurrent trigeminal neuralgia: a review of long-term effectiveness and safety.

ObjectiveWe examined the clinical characteristics and outcomes of patients with recurrent trigeminal neuralgia (TN) and assessed the long-term efficacy and safety of microvascular decompression (MVD) to treat typical recurrent TN.MethodsWe identified 3024 patients who underwent MVD for treatment of TN at the China-Japan Friendship Hospital from March 2009 to December 2020. We retrospectively analyzed the data and outcomes of 137 patients who underwent redo-MVD and 74 patients who did not undergo redo-MVD as the control group. These outcomes were evaluated using the Barrow Neurological Institute scoring system.ResultsRecurrence in 68 of the 137 patients was due to incomplete or absent decompression or new responsible vessels. To ensure thorough pain relief, redo-MVD should include decompression of both the trigeminal root entry zone and the peripheral nerve segments, where blood vessels can cause symptoms. Factors associated with reduced effectiveness of redo-MVD were no period of initial pain relief after the first MVD and a longer duration of symptoms before the first MVD.ConclusionsRedo-MVD should not be excluded as a treatment option for patients with refractory TN who develop recurrent pain after a first MVD procedure.

Schwannoma of the digital nerve

Schwannomas are the most common benign tumours affecting the peripheral nervous system. They represent a benign proliferation of Schwann cells. Schwannomas and other peripheral nerve sheath tumours are common in the head and neck, spine, thorax, abdominal wall, and retroperitoneum. However, localization in hand is exceptional. We present a 22-years-old female patient diagnosed and operated on for schwannoma of the digital nerve (dorsal cutaneous branch originating from the palmar cutaneous branch of ulnar nerve). In the case of a palpable hand mass, one of the possible diagnoses is schwannoma, and since the operative technique is somewhat specific with tumour enucleation and internal neurolysis, it is necessary to preoperatively keep in mind schwannoma in the differential diagnosis.

Interfascicular Anatomy of the Motor Branch of the Ulnar Nerve: A Cadaveric Study

The motor branch of the ulnar nerve contains fascicles that innervate the intrinsic musculature of the hand. This cadaveric study aimed to describe the organization and consistency of the internal topography of the motor branch of the ulnar nerve. Five fresh-frozen cadaveric specimens with an average age of 74 years (range, 65-88 years) were dissected. The ulnar nerve was exposed and transfixed to the underlying tissues to maintain its orientation throughout the dissection. The dorsal cutaneous branch (DCB) and the volar sensory branch were identified and reflected to expose the motor branch. The fascicles to the first dorsal interosseus (FDI), flexor pollicis brevis, and abductor digiti minimi (ADM) were identified. Internal neurolysis was performed distal to proximal to identify the interfascicular arrangement of these fascicles within the motor branch. The organization of these fascicles was noted, and the branch points of the DCB, FDI, and ADM were measured relative to the pisiform using a handheld electronic caliper. The internal topography of the motor branch was consistent among all specimens. Proximal to the pisiform, the arrangement from radial to ulnar was as follows: volar sensory branch, flexor pollicis brevis, FDI/intrinsic muscles, ADM, and DCB. The position of these branches remained consistent as the deep motor branch curved radially within the palm and traveled to the terminal musculature. The locations of the average branch points of the FDI, ADM, and DCB with respect to the pisiform were as follows: FDI, 4.6 cm distal (range, 4.1-4.9 cm), 4.5 cm radial (range, 4.1-4.9 cm); ADM, 0.65 cm distal (range, 0.3-1.1 cm), 0.7 cm radial (range, 0.3-1.1 cm), DCB, 7.7 cm proximal (range, 4.2-10.1 cm), and 0.4 cm ulnar (range, 0.3-0.8 cm). The internal topography of the ulnar nerve motor branch was consistent among the specimens studied. The topography of the motor branches was maintained as the motor branch turns radially within the palm. This study provides further understanding of the internal topography of the ulnar nerve motor branch at the wrist level.

Internal Neurolysis for the Treatment of Trigeminal Neuralgia: A Systematic Review

Trigeminal neuralgia (TN) remains a challenging disease with debilitating symptoms and variable efficacy in terms of treatment options. Microvascular decompression (MVD) with internal neurolysis (IN) is an alternative treatment that might benefit patients but has limited understanding. We performed a systematic review of IN for the treatment of TN. Studies from 2000 to 2021 that had assessed IN for TN were aggregated and independently reviewed. A total of 520 patients in 12 studies were identified, with 384 who had undergone IN (mean age, 53.8 years; range, 46-61.4 years; mean follow-up, 36.5 months). Preoperative symptoms had been present for ∼55.0 months before treatment, and pain was predominantly in V2 and V3 (26.8%), followed by other distributions. Of the patients, 83.7% (range, 72%-93.8%) had had an excellent to good outcome (Barrow Neurological Institute pain scale score [BNI-PS], I-II). The pain outcomes at 1 year were excellent for 58%-78.4%, good or better for 77%-93.75%, and fair or better for 80%-93.75% of the patients. On average, facial numbness after IN was experienced by 96% of the patients. However, at follow-up, facial numbness remained in only 1.75%-10%. Most of the remaining numbness was not significantly distressing to the patients. Subgroup comparisons of IN versus recurrent MVD, IN versus radiofrequency ablation, the effects of IN in the absence of vascular compression, and IN with and without MVD were also evaluated. IN represents a promising surgical intervention for TN in the absence of vascular compression and for potential cases of recurrence. Complications were limited in general but require further study.

Long Time Efficacy and Safety of Microvascular Decompression Combined with Internal Neurolysis for Recurrent Trigeminal Neuralgia.

ObjectiveTo explore the clinical efficacy and safety of microvascular decompression (MVD) combined with internal neurolysis (IN) in the treatment of recurrent trigeminal neuralgia (TN) after MVD. MethodsSixty-four patients with recurrent TN admitted to the hospital from January 2014 to December 2017 were divided into two groups according to the surgical method. Twenty-nine patients, admitted from January 2014 to December 2015, were treated with MVD alone, whereas 35 admitted from January 2016 to December 2017 were treated with MVD+IN. The postoperative efficacy, complications, and pain recurrence rate of the two groups were analyzed.ResultsThe efficacy of the MVD+IN and MVD groups were 88.6% and 86.2%, and the cure rates were 77.1% and 65.5% respectively. There was no statistically significant difference between the two groups (p>0.05). The cure rate (83.3%) of patients in the MVD+IN group, who were only found thickened arachnoid adhesions during the operation that could not be fully released, was significantly higher than that of the MVD group (30.0%) (p<0.05), while the efficacy (91.7% vs. 70%) of the two groups was not statistically different (p>0.05). For patients whose arachnoid adhesions were completely released, there had no significant difference (p>0.05) in the efficacy (87% vs. 94.7%) and recurrence rate (5.0% vs. 11.1%). The incidence of postoperative facial numbness (88.6%) in the MVD+IN group was higher than that in the MVD group (10.3%) (p<0.01). The long-term incidence of facial numbness was not statistically significant (p>0.05). In the 18–36 months follow-up, the recurrence rate of patients in the MVD+IN group (9.7%) and in the MVD group (16%) were not statistically different (p>0.05). ConclusionA retrospective comparison of patients with recurrent TN showed that both MVD and MVD combined with IN can effectively treat recurrent TN. Compared with MVD alone, MVD combined with IN can effectively improve the pain cure rate of patients with recurrent TN who have only severe arachnoid adhesions. The combination does not increase the incidence of long-term facial numbness and other complications.