Microscope-Based Augmented Reality: A New Approach in Intraoperative 3D Visualization in Microvascular Decompression?

Neurovascular compression (NVC) syndromes such as trigeminal neuralgia (TN) are causally treated with microvascular decompression (MVD). Semiautomatic segmentation of high-resolution magnetic resonance imaging (MRI) data and constructive interference in steady state (CISS)/time-of-flight (TOF) sequences are utilized for the three-dimensional (3D) visualization of underlying causative vessels at the root entry zones of the relevant cranial nerves. Augmented reality (AR) of neurovascular structures was introduced especially in the resection of brain tumors or aneurysmatic operations. In this report, the potential feasibility of the implementation of microscope-based AR into the intraoperative microsurgical set-up of MVD was investigated. This article recommends the preoperative evaluation of 3D visualization besides the microscopical view of the surgeon. The implementation of multiple imaging data by AR into the operating microscope may afflict the experienced surgeon's view, which should be examined prospectively.

A Case With Twists and Turns: A Report of Vertebrobasilar Dolichoectasia.

Vertebrobasilar dolichoectasia (VBD) is a rare anatomical abnormality of the vertebral artery system, defined as irregular expansion, elongation, and tortuosity of vertebral arteries. Anomalies of the vertebrobasilar artery can have a wide variety of clinical presentations, ranging from simple headaches to debilitating strokes. We present the case of an atypical presentation of VBD which mimicked trigeminal neuralgia by compressing the trigeminal nerve. There are currently no guidelines concerning the management of VBD, nor is there evidence of a definitive cure. This case invoked discussions among the medical team as to whether management should be medically or surgically focused, as well as long-term outcomes for patients with VBD. The superiority of medical versus surgical treatment of this issue is still a debated topic. This patient trialed medical management with dexamethasone and carbamazepine with no improvement in symptoms. He then underwent surgical gamma knife treatment but even this invasive measure was unsuccessful at relieving his symptoms. We hope that by presenting this case, we can display how the therapies available for VBD are limited and often unsuccessful in relieving the disease burden in patients with VBD.

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.

Evaluating Changes in Pulsatile Flow With Endovascular Stents in an In Vitro Blood Vessel Model: Potential Implications for the Future Management of Neurovascular Compression Syndromes.

BACKGROUND: Neurovascular compression syndromes (NVCS), encompassing conditions such as trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia, significantly impair patient quality of life through abnormal vascular compression and micro-pulsation of vasculature on cranial nerves at the Obersteiner-Redlich zone. The modulation of pulsatile flow dynamics via endovascular stents presents a novel research frontier for alleviating these syndromes. AIM: The primary aim of this investigation was to delineate the impact of various endovascular stents on pulsatile flow within an in vitro model of a blood vessel, thereby elucidating their potential applicability in the therapeutic management of NVCS. MATERIALS AND METHODS: A simple in vitro analog of a posterior circulation artery was developed, employing an intravenous pump to replicate cardiac-induced blood flow. Within this model, alterations in pulsatile flow were quantitatively assessed following the introduction of three categorically distinct endovascular stents, varying in size. This assessment was facilitated through the employment of both micro-Doppler and Doppler ultrasound methodologies. RESULTS: The Pipeline 5x35 mm stent (Medtronic, Minneapolis, MN) demonstrated the most significant reductions in peak systolic velocity (Vmax) and pulsatility index (PI), PI especially over the stent, suggesting its potential for drastically altering blood flow dynamics. Similarly, Neuroform Atlas 4.5x30 mm and Neuroform Atlas 4x24 mm stents (Stryker, Kalamazoo, MI) also showed notable decreases in hemodynamic parameters, albeit to different extents. Statistical analysis confirmed that these changes were significantly different from the control (P < 0.0001 for PI and Vmax; P < 0.05 for inter-stent comparisons), except for proximal PI means, which did not significantly differ from the control (P = 0.2777). CONCLUSION: These findings affirm the potential of endovascular stents to substantially modulate arterial pulsatility. The observed decrease in pulsatile flow resultant from endovascular stent application has the potential to attenuate ectopic nerve excitation, a hallmark of NVCS. Consequently, this research highlights the prospective utility of endovascular stents in developing minimally invasive therapeutic approaches for NVCS.

Analyzing the risk factors of unilateral trigeminal neuralgia under neurovascular compression.

Background: This study aimed to explore the risk factors and potential causes of unilateral classical or idiopathic trigeminal neuralgia (C-ITN) by comparing patients and healthy controls (HCs) with neurovascular compression (NVC) using machine learning (ML). Methods: A total of 84 C-ITN patients and 78 age- and sex-matched HCs were enrolled. We assessed the trigeminal pons angle and identified the compressing vessels and their location and severity. Machine learning was employed to analyze the cisternal segment of the trigeminal nerve (CN V). Results: Among the C-ITN patients, 53 had NVC on the unaffected side, while 25 HCs exhibited bilateral NVC, and 24 HCs showed unilateral NVC. By comparing the cisternal segment of CN V between C-ITN patients on the affected side and HCs with NVC, we identified the side of NVC, the compressing vessel, and certain texture features as risk factors for C-ITN. Additionally, four texture features differed in the structure of the cisternal segment of CN V between C-ITN patients on the unaffected side and HCs with NVC. Conclusion: Our findings suggest that the side of NVC, the compressing vessel, and the microstructure of the cisternal segment of CN V are associated with the risk of C-ITN. Furthermore, microstructural changes observed in the cisternal segment of CN V on the unaffected side of C-ITN patients with NVC indicate possible indirect effects on the CN V to some extent.

A Case of Trigeminal Neuralgia in an Adult Patient With Lambdoid Synostosis.

Trigeminal neuralgia (TN) is characterized by sudden, brief intense pain in the distribution of the unilateral trigeminal nerve (TGN). Neurovascular compression (NVC) of the TGN is the most common cause of TN. Recent studies have suggested that a structural anomaly of the posterior cranial fossa might be involved in the development of TN, and several studies have documented the association between NVC-related TN and congenital posterior cranial deformities in adults. We present the case of a 56-year-old woman with NVC-related TN and unilateral lambdoid synostosis (ULS), along with a literature review, to investigate the relationship between TN and structural anomalies of the posterior fossa. This is the first report of TN in an adult with ULS. Mild and asymptomatic cases of lambdoid synostosis might have a higher incidence of NVC-related TN in association with posterior cranial fossa deformities.

Benchtop and in Vitro Experiments of Novel Transform Stents for Trigeminal Neuralgia Treatment.

BACKGROUND: Trigeminal neuralgia (TN) is a debilitating condition characterized by sudden, excruciating facial pain due to neurovascular compression of the trigeminal nerve. Stent deployment can change the course of the superior cerebellar artery upwards, possibly releasing the root entry zone of the trigeminal nerve. We developed a novel stent, the Transform stent, for TN treatment, and evaluated its mechanical properties using benchtop and in vitro hemocompatibility tests. METHODS: We compared the performance of Transform and Enterprise stents in treating TN because they share similar self-expanding closed-cell features in the manufacturing process, are derived from nitinol tubes, and are fabricated through a laser-cutting process, but also because only the safety of Enterprise stents deployed in intracranial arteries has been reported clinically. All benchtop measurements, including radial force, trackability, bending stiffness, and conformability, were performed thrice for each stent model, and their average values are presented. RESULTS: Transform stents showed higher radial forces in vessels of diameters ranging from 1.0 mm than Enterprise stents. The trackability of the Transform stent was better than that of the Enterprise stent in a neurovascular model. Bending stiffness was stronger in the Transform stent whereas conformability was superior in the Enterprise stent. No significant thrombogenic issues were observed in the in vitro hemocompatibility tests. CONCLUSIONS: This study demonstrated the Transform stent as a potential option and paved the way for innovative endovascular approaches for the future TN treatment. Namely, the study confirmed that the characteristics of Transform stents at benchtop and in vitro evaluations may be used as a first step for studies such as in vivo pre- and clinical studies.

A Case of Unilateral Facial Spasm With Vulnerable Hearing Function Due to a History of Cisplatin Treatment, Resulting in Intraoperative Hearing Loss.

A 51-year-old man with a history of cisplatin treatment for a right testicular tumor underwent microvascular decompression for hemifacial spasm. At an early stage in the surgical procedure, the intraoperative auditory brainstem response (ABR) was diminished despite a relatively minimally invasive approach, resulting in irreversible hearing loss. Cisplatin is known to cause dose-dependent hearing impairment primarily affecting the cochlea, but it can also induce neurotoxicity. In the present case, prior cisplatin administration may have caused fragility of the cochlear nerve as well. Patients with a history of ototoxic and neurotoxic drugs such as cisplatin require more careful manipulation and thorough intraoperative auditory monitoring during neurosurgical procedures that may affect hearing, such as those for hemifacial spasms.

Radiological characteristics predicting early poor drug response in patients with hemifacial spasm.

OBJECTIVES: Patients with hemifacial spasm (HFS) often resort to botulinum toxin injections or microvascular decompression surgery when medication exhibits limited effectiveness. This study aimed to identify MRI and demographic factors associated with poor drug response at an early stage in patients with HFS. METHODS: We retrospectively included patients with HFS who underwent pre-therapeutic MRI examination. The presence, location, severity, and the offending vessels of neurovascular compression were blindly evaluated using MRI. Drug responses and clinical data were obtained from the medical notes or phone follow-ups. Logistic regression analysis was performed to identify potential factors. RESULTS: A total of 116 patients were included, with an average age at the time of first examination of 50.4 years and a median duration of onset of 18 months. Forty-nine (42.2%) patients reported no symptom relief. Thirty-seven (31.9%) patients reported poor symptom relief. Twenty-two (19.0%) patients reported partial symptom relief. Eight (6.9%) patients achieved complete symptom relief. The factors that were statistically significant associated with poor drug responses were contact in the attach segment of the facial nerve and aged 70 and above, with an odds ratio of 7.772 (p = 0.002) and 0.160 (p = 0.028), respectively. CONCLUSIONS: This study revealed that mild compression in the attach segment of the facial nerve in pre-therapeutic MRI increases the risk of poor drug responses in patients with HFS, while patients aged 70 and above showed a decreased risk. These findings may assist clinician to choose optimal treatment at an early stage.

Microvascular decompression for hemifacial spasm after Bell's palsy: a retrospective clinical study.

OBJECTIVE: This study aimed to investigate the clinical characteristics of hemifacial spasm (HFS) after Bell's palsy and to evaluate the therapeutic efficacy of microvascular decompression (MVD). METHODS: A retrospective analysis was conducted on 18 patients who underwent MVD for HFS after Bell's palsy at our institution between January 1, 2017, and December 31, 2021. Clinical presentations, intraoperative findings, postoperative outcomes, and complications were comprehensively assessed. RESULTS: Neurovascular compression (NVC) was identified in all the 18 patients. The offending vessels included anterior inferior cerebellar artery (AICA) in 6 patients (33.3%), posterior inferior cerebellar artery (PICA) in 7 patients (38.9%), vertebral artery (VA) combined with AICA in 3 patients (16.7%), and VA alongside PICA in 2 patients (11.1%). Notably, marked arachnoid membrane adhesion was evident in 11 patients (61.1%). 15(83.3%) patients were cured immediately after MVD, delayed relief was found in 3 (16.7%) patients. During the follow-up period, recurrence was not documented. Surgical complications were limited to facial paralysis in 3 patients and auditory impairment in 1 patient. No additional surgical complications were recorded. CONCLUSIONS: In patients manifesting HFS after Bell's palsy, NVC predominantly underlies the etiology. MVD is a reliably safe and efficacious therapeutic intervention.

Evaluating magnetic resonance imaging characteristics and risk factors for hemifacial spasm.

PURPOSE: The specific neurovascular compression (NVC) event responsible for the symptomatic manifestation of hemifacial spasm (HFS) remains difficult to assess accurately using magnetic resonance imaging (MRI). We aim to evaluate the MRI characteristics of HFS. METHOD: We retrospectively included patients with HFS and divided them into a test group (n = 186) and a validation group (n = 28). The presence, severity, and offending vessel type of NVC in each portion, and the orientation of the offending vessel around the facial nerve, were recorded. Conditional logistic regression analyses were performed to evaluate correlations using test group. The validation group was used to verify whether our findings improved diagnostic performance. RESULTS: Deformity in the proximal cisternal segment was significantly correlated with HFS occurrence (odds ratio [OR]: 256.58, p = .002), whereas contact was not (p = .233). Both contact and deformity in the root detachment point (OR: 19.98 and 37.22, p < .001 and p = .013, respectively) or attached segment (OR: 4.99 and 252.52, p = .001 and p < .001, respectively) were significantly correlated with HFS occurrence. Our findings improved specificity, positive predictive value, and accuracy of diagnosis than conventional diagnostic methods. The vertebral artery predominantly compress the facial nerve in the inferior-anterior position, the anterior inferior cerebellar artery predominantly in the inferior position, the posterior inferior cerebellar artery predominantly in the inferior position, vein predominantly in the posterior-superior position. CONCLUSIONS: This study further demonstrates that within the susceptible portion of facial nerve, different portions of the nerve respond differently to NVC. Each offending vessel has its own preferred conflict orientation. Our study offers reference for neurosurgeons in diagnosis and treatment.

The Anterior Inferior Cerebral Artery Variability in the Context of Neurovascular Compression Syndromes: A Narrative Review.

The anterior inferior cerebellar artery (AICA) is situated within the posterior cranial fossa and typically arises from the basilar artery, usually at the pontomedullary junction. AICA is implicated in various clinical conditions, encompassing the development of aneurysms, thrombus formation, and the manifestation of lateral pontine syndrome. Furthermore, owing to its close proximity to cranial nerves within the middle cerebellopontine angle, AICA's pulsatile compression at the root entry/exit zone of cranial nerves may give rise to specific neurovascular compression syndromes (NVCs), including hemifacial spasm (HFS) and geniculate neuralgia concurrent with HFS. In this narrative review, we undertake an examination of the influence of anatomical variations in AICA on the occurrence of NVCs. Significant methodological disparities between cadaveric and radiological studies (CTA, MRA, and DSA) were found, particularly in diagnosing AICA's absence, which was more common in radiological studies (up to 36.1%) compared to cadaver studies (less than 5%). Other observed variations included atypical origins from the vertebral artery and basilar-vertebral junction, as well as the AICA-and-PICA common trunk. Single cases of arterial triplication or fenestration have also been documented. Specifically, in relation to HFS, AICA variants that compress the facial nerve at its root entry/exit zone include parabola-shaped loops, dominant segments proximal to the REZ, and anchor-shaped bifurcations impacting the nerve's cisternal portion.

Role of Lifestyle in Thoracic Outlet Syndrome: A Narrative Review.

INTRODUCTION: The presence of a positional compression of the neurovascular bundle in the outlet between the thorax and the upper limb during arm movements (mainly abduction) is common but remains asymptomatic in most adults. Nevertheless, a certain number of subjects with thoracic outlet positional compression will develop incapacitating symptoms or clinical complications as a result of this condition. Symptomatic forms of positional neurovascular bundle compression are referred to as "thoracic outlet syndrome" (TOS). MATERIALS AND METHODS: This paper aims to review the literature and discuss the interactions between aspects of patients' lifestyles in TOS. The manuscript will be organized to report (1) the historical importance of lifestyle evolution on TOS; (2) the evaluation of lifestyle in the clinical routine of TOS-suspected patients, with a description of both the methods for lifestyle evaluation in the clinical routine and the role of lifestyle in the occurrence and characteristics of TOS; and (3) the influence of lifestyle on the treatment options of TOS, with a description of both the treatment of TOS through lifestyle changes and the influence of lifestyle on the invasive treatment options of TOS. RESULTS: We report that in patients with TOS, lifestyle (1) is closely related to anatomical changes with human evolution; (2) is poorly evaluated by questionnaires and is one of the factors that may induce symptoms; (3) influences the sex ratio in symptomatic athletes and likely explains why so many people with positional compression remain asymptomatic; and (4) can sometimes be modified to improve symptoms and potentially alter the range of interventional treatment options available. CONCLUSIONS: Detailed descriptions of the lifestyles of patients with suspected TOS should be carefully analysed and reported.

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

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. CONCLUSIONS: In the absence of microvascular compression, we advocate for a thorough neurolysis using the techniques described in our article.

Application of Sequential Thresholding-Based Automated Reconstruction of the Trigeminal Nerve in Trigeminal Neuralgia.

OBJECTIVE: High-resolution magnetic resonance imaging (MRI) of the trigeminal nerve is indispensable for workup of trigeminal neuralgia (TN) before microvascular decompression; however, the evaluation is often subjective and prone to variability. We aim to develop and assess sequential thresholding-based automated reconstruction of the trigeminal nerve (STAR-TN) as an algorithm for segmenting the trigeminal nerve and contacting structures that will allow for a structured method for assessing neurovascular conflict. METHODS: A total of 42 patients with TN who underwent high-resolution MRI before microvascular decompression in 2022 were included in our study. Segmentation of the trigeminal nerve and contacting structures was performed on preoperative MRI scans using STAR-TN. The segmentations were then evaluated for neurovascular conflict and compared to the preoperative radiology and operative notes. Geometric features, including the area of contact and distance to conflict, were extracted. RESULTS: Of the 42 patients, 32 (76.2%) were found to show neurovascular conflict based solely on their STAR-TN segmentations and 10 (23.8%) were found to not show neurovascular conflict. Compared with the intraoperative findings, this resulted in a sensitivity of 78.0% and specificity of 100%. In contrast, assessments of neurovascular conflict by radiologists using only 2-dimensional MRI views had a sensitivity of 68.3% and specificity of 100%. Of the 32 patients with neurovascular conflict, 29 (90.9%) had conflict within the root entry zone. Overall, the patients had a median area of contact of 10.66 mm2. CONCLUSIONS: STAR-TN allows for 3-dimensional visualization and identification of neurovascular conflict with improved sensitivity compared with neuroradiologist assessments from MRI slices.

Microvascular decompression for trigeminal neuralgia: A retrospective analysis of long-term outcomes and prognostic factors / Descompresión microvascular en la neuralgia del trigémino: análisis retrospectivo de los resultados a largo plazo e identificación de factores pronósticos

Introduction: Microvascular decompression is considered to be the most effective and onlyetiological surgical treatment for classical trigeminal neuralgia, relieving the neurovascularcompression found in up to 95% of cases. This study aims to report the long-term outcomesand to identify prognostic factors in a series of patients with trigeminal neuralgia treated bymicrovascular decompression. Methods: A retrospective observational study of 152 consecutive patients operated bymicrovascular decompression with at least six months of follow-up. The surgical results, includ-ing pain relief according to the Barrow Neurological Institute pain scale, complications and themedical treatment during the follow-up period were reviewed. Binary regression analysis wasperformed to identify factors associated with a good long-term outcome. Results: A total of 152 patients with a mean age of 60 years and a mean follow-up of 43 monthswere included. At the final follow-up visit, 83% of the patients had achieved significant reliefof the pain and 63% could reduce the absolute drug doses by 50% or more. The most frequentcomplications were wound infection (4.5%) and CSF fistula (7%). Being over 70 years of age andhaving paroxysmal pain were associated with a long-term pain relief.(AU)

Introducción: La descompresión microvascular se considera el tratamiento quirúrgico etiológico más eficaz de la neuralgia clásica del trigémino, dirigido a aliviar la compresión neurovascular identificada hasta en un 95% de casos. Este estudio tiene como objetivo analizar los resultados quirúrgicos y la evolución a largo plazo de una serie de pacientes con neuralgia del trigémino tratados mediante descompresión microvascular, así como identificar factores pronósticos. Métodos: Estudio observacional retrospectivo de 152 pacientes consecutivos sometidos a descompresión microvascular y con un seguimiento posquirúrgico mínimo de seis meses. Analizamos los resultados quirúrgicos, clasificando el grado de dolor según la escala del Instituto Neurológico de Barrow, las complicaciones y el tratamiento médico requerido durante el período de seguimiento. Realizamos un análisis de regresión binaria para identificar factores asociados con un buen resultado a largo plazo. Resultados: Incluimos 152 pacientes con una edad media de 60 años y un seguimiento medio de 43 meses. En la última visita de seguimiento, el 83% de los pacientes había logrado un alivio significativo del dolor y el 63% pudo reducir la dosis absoluta de fármacos para la neuralgia en un 50% o más. Las complicaciones más frecuentes fueron infección de la herida (4,5%) y fístula de LCR (7%). La edad superior a 70 años y el dolor de predominio paroxístico se asociaron con un mejor pronóstico. Conclusiones: Nuestros resultados apoyan que la descompresión microvascular es una terapia efectiva y segura en pacientes con neuralgia del trigémino. La cirugía temprana puede ser beneficiosa en pacientes refractarios al tratamiento farmacológico.(AU)

Microvascular decompression for trigeminal neuralgia: A retrospective analysis of long-term outcomes and prognostic factors.

INTRODUCTION: Microvascular decompression is considered to be the most effective and only etiological surgical treatment for classical trigeminal neuralgia, relieving the neurovascular compression found in up to 95% of cases. This study aims to report the long-term outcomes and to identify prognostic factors in a series of patients with trigeminal neuralgia treated by microvascular decompression. METHODS: A retrospective observational study of 152 consecutive patients operated by microvascular decompression with at least six months of follow-up. The surgical results, including pain relief according to the Barrow Neurological Institute pain scale, complications and the medical treatment during the follow-up period were reviewed. Binary regression analysis was performed to identify factors associated with a good long-term outcome. RESULTS: A total of 152 patients with a mean age of 60 years and a mean follow-up of 43 months were included. At the final follow-up visit, 83% of the patients had achieved significant relief of the pain and 63% could reduce the absolute drug doses by 50% or more. The most frequent complications were wound infection (4.5%) and CSF fistula (7%). Being over 70 years of age and having paroxysmal pain were associated with a long-term pain relief. CONCLUSIONS: Our results support the notion that microvascular decompression is an effective and safe therapy in patients with trigeminal neuralgia. A multidisciplinary approach with an early referral to a neurosurgical unit many be beneficial in patients who are refractory to pharmacological treatment.

Outcomes after Microvascular Decompression for Hemifacial Spasm without Definite Radiological Neurovascular Compression at the Root Exit Zone.

The purpose of this study was to investigate the outcome of microvascular decompression (MVD) in patients with hemifacial spasm (HFS) who have no definite radiological neurovascular compression (NVC). Sixteen HFS patients without radiological NVC on preoperative MRI underwent MVD surgery. The symptoms were left-sided in fourteen (87.5%) and right-sided in two patients (12.5%). Intraoperatively, the most common vessel compressing the facial nerve was the AICA (8, 44.4%), followed by arterioles (5, 27.8%), veins (4, 22.2%), and the PICA (1, 5.6%). The most common compression site was the cisternal portion (13, 76.5%) of the facial nerve, followed by the REZ (4, 23.5%). One patient (6.3%) was found to have multiple NVC sites. Arachnoid type (7, 50%) was the most common compressive pattern, followed by perforator type (4, 28.6%), sandwich type (2, 14.3%), and loop type (1, 7.1%). A pure venous compression was seen in two patients, while a combined venous-arterial "sandwich" compression was detected in two patients. Symptom improvement was observed in all of the patients. Only one patient experienced recurrence after improvement. Based on our experience, MVD surgery can be effective for primary HFS patients with no definite radiological NVC. MVD can be considered if the patient shows typical HFS features, although NVC is not evident on MRI.

A very rare case of a thoracobrachialis muscle.

The anterior arm compartment includes the biceps brachii muscle, brachialis muscle, and coracobrachialis muscle, and they are characterized by different morphological variations. During standard anatomical dissection of right upper limb, an variant muscle was found. It originated from the fascia covering the long head of biceps brachii and from the tendon of pectoralis major muscle. It also connected to the brachial fascia. It also demonstrated a long thin tendon which was distally attached to the medial epicondyle of humerus. Knowledge about the morphological variations in this region is clinically important because of their direct correlation with neurovascular structures, which may lead to pathologies such as tingling, muscle weakness, paresthesia, and loss of sensation.

The Superior Cerebellar Artery: Variability and Clinical Significance.

The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.