Suprascapular nerve entrapment caused by a large hematoma of the scapula: a case report.

BACKGROUND: Suprascapular nerve entrapment is a rare disorder that is frequently misdiagnosed as another disease. The suprascapular nerve is commonly entrapped at the following two sites: the suprascapular and spinoglenoid notches. Nerve entrapment at the spinoglenoid notch causes infraspinatus muscle weakness and atrophy. Patients present with posterior shoulder pain and weakness. Magnetic resonance imaging is used to confirm the diagnosis of a spinoglenoid cyst and nerve compression. Open or arthroscopic aspiration or decompression is indicated for patients with cysts in whom conservative treatment has failed and those with cysts associated with suprascapular nerve compression. CASE PRESENTATION: Herein, we describe the case of a 49-year-old man with suprascapular nerve entrapment caused by a large cyst, namely, a hematoma, in the superior scapular and spinoglenoid notches. Open surgical decompression of the suprascapular nerve was performed owing to an intact rotator cuff and glenoid labrum. CONCLUSION: Posterior shoulder pain promptly resolved without complications.

Correlation of Preoperative High-Resolution Neurovascular Imaging and Surgical Success in Neurovascular Compression Syndromes.

BACKGROUND: Neurovascular compression syndromes (NVCSs) are a group of neurological disorders characterized by compression of a cranial nerve and include trigeminal neuralgia (TN), hemifacial spasm, geniculate neuralgia, glossopharyngeal neuralgia, vestibular paroxysmia, and trochlear palsy. The European Academy of Neurology recommends constructive interference in steady-state/fast imaging employing steady-state (CISS/FIESTA) magnetic resonance imaging (MRI) in the evaluation of medically intractable TN, but similar recommendations do not exist for the remaining NVCSs. METHODS: We conducted a retrospective chart review of 300 patients with an NVCS who underwent microvascular decompression (MVD) by a single neurosurgeon from 2004 to 2021. Data were collected on preoperative diagnosis, pre- and postoperative symptoms, presence/absence of preoperative high-spatial-resolution CISS/FIESTA MRI, and intraoperative findings. Rates of symptomatic improvement were used as a correlate of surgical success. RESULTS: The rate of symptomatic improvement in the patients with a preoperative CISS/FIESTA MRI was 5.8% greater than those without preoperative high-spatial-resolution neuroimaging (98.8% vs. 93%, respectively; P = 0.008). Stratified by diagnosis, patients with TN had the greatest difference in surgical success between the 2 groups (99.3% vs. 92.9%, n = 268; P = 0.006). No statistically significant differences were observed in the other NVCSs, although positive trends were noted. CONCLUSIONS: Preoperative CISS/FIESTA MRI correlated with greater rates of surgical success in cases of medically intractable TN; however, definitive conclusions could not be made regarding the remaining NVCSs. We support the recommendation that this imaging modality be included as part of the standard of practice for the evaluation and management of TN and encourage future studies to further elucidate this relationship for the less common NVCSs using a larger cohort.

Is the cochleovestibular nerve function affected in patients with hemifacial spasm?

Hemifacial spasm (HFS) is a motor disorder caused by the vascular compression of the facial nerve in the posterior fossa. The cochleovestibular nerve is close to the facial nerve and shares the same entry to the periphery, also has disorders caused by vascular compression. We evaluated the cochleovestibular nerve function in patients with HFS based on the hypothesis that vascular compression, which causes HFS, can also affect the nearby cochleovestibular nerve function. The medical charts of 49 patients with surgically confirmed HFS were reviewed retrospectively. The results of the pure-tone threshold, auditory brainstem response (ABR), video head impulse test (vHIT), and magnetic resonance imaging were analyzed. In each patient, the HFS side and the unaffected side were compared in the paired manner. The anterior inferior cerebellar artery was the major offending vessel (69.4%). There were no significant differences in the pure-tone threshold, properties of ABR waves, and vHIT gain. There was no evidence of cochleovestibular nerve compression syndrome in all patients. The angulation of the nerve by the offending vessel was more frequently identified in the HFS side than in the unaffected side (p = 0.040). The effect of HFS on cochleovestibular nerve function is limited.

Magnetic Resonance Imaging Findings in Patients with Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome (TTS) is a common entrapment syndrome whose diagnosis can be difficult. We compared preoperative magnetic resonance imaging (MRI) and operative findings in 23 consecutive TTS patients (28 sides) whose mean age was 74.5 years. The 1.5T MRI sequence was 3D T2* fat suppression. We compared the MRI findings with surgical records and intraoperative videos to evaluate them. MRI- and surgical findings revealed that a ganglion was involved on one side (3.6%), and the other 27 sides were diagnosed with idiopathic TTS. MRI visualized the nerve compression point on 23 sides (82.1%) but failed to reveal details required for surgical planning. During surgery of the other five sides (17.9%), three involved varices, and on one side each, there was connective tissue entrapment or nerve compression due to small vascular branch strangulation. MRI studies were useful for nerve compression due to a mass lesion or idiopathic factors. Although MRI revealed the compression site, it failed to identify the specific involvement of varices and small vessel branches and the presence of connective tissue entrapment.

A case for ultrasound-guided peripheral nerve stimulation in intractable anterior cutaneous nerve entrapment syndrome.

Aim: This case report documents the use of peripheral nerve stimulation in the setting of entrapment of the anterior cutaneous branches of the intercostal nerves, with pain rated by the patient as severe during exacerbation episodes. Materials & methods: Under ultrasound guidance, two permanent leads were implanted caudad to cephalad, along and superficial to the lateral aspect of the rectus abdominis, distal to the umbilicus (1 lead per side). Results: At the 6 month follow-up, the patient reported near complete resolution of baseline pain, as well as fewer, sporadic pain exacerbation episodes, rated as mild-to-moderate. Conclusion: This case report suggests that peripheral nerve stimulation might be a valuable treatment option for previously intractable abdominal pain due to entrapment of the anterior cutaneous branches.

Anterior cutaneous nerve entrapment syndrome is a peculiar, a largely disregarded pain condition. Current management algorithms rely mostly on local injections followed by surgical anterior neurectomy. This case report presents a case of longstanding, anterior cutaneous nerve entrapment syndrome, unresponsive to first-line treatment, that was successfully treated with peripheral nerve stimulation technology targeting the anterior cutaneous branches.

Ultrasound Guided Nerve Blocks for Anterior Cutaneous Nerve Entrapment Syndrome an Overlooked Cause of Chronic Abdominal Pain: A Case Series.

Entrapment abdominal neuropathy is not a common diagnosis in our context. Chronic Abdominal wall pain is often mistaken for gastritis, gynecological issue, thoracic spinal radiculopathy, rectus sheath hematoma, abdominal muscle injury or psychiatric disorder. Anterior cutaneous nerve entrapment syndrome is one of the frequent causes of abdominal wall pain occurring due to trapped thoracic intercostal nerves between abdominal muscles. History and bedside Carnett's sign can elicit the diagnosis. Injection of the local anesthetics with steroids in the junction between the rectus sheath and abdominal muscle under ultrasound guidance can provide sustained pain relief. We should consider Anterior cutaneous nerve entrapment syndrome as a differential diagnosis while evaluating the abdominal wall pain. Keywords: ACENE; carnett's test; chronic abdominal pain; entrapment neuropathy; hydrodissection.

US for Traumatic Nerve Injury, Entrapment Neuropathy, and Imaging-guided Perineural Injection.

US is commonly performed to help diagnose traumatic peripheral nerve injury and entrapment neuropathy, particularly with superficial nerves, where higher spatial resolution provides an advantage over MRI. Other advantages of US include dynamic evaluation, easy contralateral comparison, fewer implant contraindications, less artifact from ferromagnetic debris, and facile needle guidance for perineural injections. The authors review peripheral nerve US for traumatic peripheral nerve injury with an emphasis on injury grading and entrapment neuropathy and describe best-practice techniques for US-guided perineural injections while highlighting specific techniques and indications. Online supplemental material is available for this article. ©RSNA, 2022.

Does the Suprascapular Nerve Move within the Suprascapular Notch? Biomechanical Perspective Using the Finite Element Method.

PURPOSE: We aimed to analyze changes in suprascapular nerve (SSN) position within the suprascapular notch during in vivo shoulder abduction. MATERIALS AND METHODS: Three-dimensional models of the shoulder complex were constructed based on magnetic resonance imaging of the brachial plexus (BP-MR) in a patient diagnosed with SSN dysfunction but normal scapular movement. Using BP-MR in neutral position and computed tomography data on shoulder abduction, shoulder abduction was simulated as the transition between two positions of the shoulder complex with overlapping of a neutral and abducted scapula. SSN movement during abduction was evaluated using the finite element method. Contact stress on the SSN was measured in the presence and absence of the transverse scapular ligament (TSL). RESULTS: In the neutral position, the SSN ran almost parallel to the front of the TSL until entering the suprascapular notch and slightly contacted the anterior-inferior border of the TSL. As shoulder abduction progressed, contact stress decreased due to gradual loss of contact with the TSL. In the TSL-free scapula, there was no contact stress on the SSN in the neutral position. Towards the end of shoulder abduction, contact stress increased again as the SSN began to contact the base of the suprascapular notch in both TSL conditions. CONCLUSION: We identified changes in the position of the SSN path within the suprascapular notch during shoulder abduction. The SSN starts in contact with the TSL and moves toward the base of the suprascapular notch with secondary contact. These findings may provide rationale for TSL release in SSN entrapment.

Accuracy of suprascapular notch cross-sectional area by MRI in the diagnosis of suprascapular nerve entrapment syndrome: a retrospective pilot study.

BACKGROUND: Previous studies have demonstrated that morphological changes in the suprascapular notch are closely associated with suprascapular nerve entrapment syndrome (SNES). Thus, we hypothesized that the suprascapular notch cross-sectional area (SSNCSA) could be a good diagnostic parameter to assess SNES. METHODS: We acquired suprascapular notch data from 10 patients with SNES and 10 healthy individuals who had undergone shoulder magnetic resonance imaging (S-MRI) and had no evidence of SNES. T2-weighted coronal magnetic resonance images were acquired from the shoulder. We analyzed the SSNCSA at the shoulder on S-MRI using our image-analysis program (INFINITT PACS). The SSNCSA was measured as the suprascapular notch, which was the most affected site in coronal S-MRI images. RESULTS: The mean SSNCSA was 64.50 ± 8.93 mm2 in the control group and 44.94 ± 10.40 mm2 in the SNES group. Patients with SNES had significantly lower SSNCSA (P < 0.01) than those in the control group. Receiver operating curve analysis showed that the best cut-off of the SSNCSA was 57.49 mm2, with 80.0% sensitivity, 80.0% specificity, and an area under the curve of 0.92 (95% CI [0.79, 1.00]). CONCLUSIONS: The SSNCSA was found to have acceptable diagnostic properties for detecting SNES. We hope that these results will help diagnose SNES objectively.

Entrapment Neuropathies of the Shoulder.

Entrapment neuropathies of the shoulder most commonly involve the suprascapular or axillary nerves, and they primarily affect the younger, athletic patient population. The extremes of shoulder mobility required for competitive overhead athletes, particularly in the position of abduction and external rotation, place this cohort at particular risk. Anatomically, the suprascapular nerve is most prone to entrapment at the level of the suprascapular or spinoglenoid notch; the axillary nerve is most prone to entrapment as it traverses the confines of the quadrilateral space.Radiographs should be ordered as a primary imaging study to evaluate for obvious pathology occurring along the course of the nerves or for pathology predisposing the patient to nerve injury. Magnetic resonance imaging plays a role in not only identifying any mass-compressing lesion along the course of the nerve, but also in identifying muscle signal changes typical for denervation and/or fatty atrophy in the distribution of the involved nerve.

Nerve Entrapments in the Pelvis and Hip.

Clinical symptoms of pelvic entrapment neuropathies are widely variable and frequently nonspecific, thus rendering it difficult to localize and diagnose. Magnetic resonance imaging (MRI), and in particular MR neurography, has become increasingly important in the work-up of entrapment neuropathies involving the pelvic and hip nerves of the lumbosacral plexus. The major sensory and motor peripheral nerves of the pelvis and hip include the sciatic nerve, superior and inferior gluteal nerves, femoral nerve, lateral femoral cutaneous nerve, obturator nerve, and pudendal nerve. Familiarity with the anatomy and imaging appearance of normal and pathologic nerves in combination with clinical presentation is crucial in the diagnosis of entrapment neuropathies.

Imaging of Entrapment Neuropathies in the Ankle.

Entrapment neuropathies of the ankle and foot pose a major diagnostic challenge and thus remain underdiagnosed. Recent advancements in imaging modalities, including magnetic resonance neurography (MRN), have resulted in considerable improvement in the anatomical localization and identification of pathologies leading to nerve entrapment. MRN supplements clinical examination and electrophysiologic studies in the diagnosis of neuropathies, aids in assessing disease severity, and helps formulate management strategies. A comprehensive understanding of the anatomy and imaging features of the ankle is essential to diagnose and manage entrapment neuropathies accurately. Advancements in imaging and their appropriate utilization will ultimately lead to better diagnoses and improved patient outcomes.

[Diagnosis and treatment of paralysis following intrafascicular peripheral nerve torsion: two clinical observations and a literature review]. / Diagnostika i lechenie paralicha, vyzvannogo intrafastsikulyarnym perekrutom perifericheskogo nerva: dva klinicheskikh nablyudeniya i obzor literatury.

BACKGROUND: Intrafascicular nerve torsion is a rare and poorly studied type of nerve compression. This disease can be assigned to compression-induced neuropathies, but it has a distinctive feature. It is a spontaneous intrafascicular compression following internal local spiral deformation and compression of the nerve outside routine tunnels due to its torsion around its own axis. Understanding the pathogenesis of such spiral compression is essential in diagnosis, prognosis and treatment of these patients. OBJECTIVE: To assess the effectiveness of various diagnostic techniques, the possibility and effectiveness of surgical treatment of patients with spiral intrafascicular nerve deformation. MATERIAL AND METHODS: The authors report 2 patients (45-year-old man and 38-year-old woman) who were examined for progressive radial neuropathy of unknown etiology. Ultrasound of the radial nerve and electroneuromyography were performed. These data made it possible to diagnose nerve lesion in both cases. These findings justified external and internal radial nerve decompression. RESULTS: Ultrasound was valuable to establish localization and cause of radial nerve lesion (local hourglass-shaped deformation). Electroneuromyography confirmed conduction disturbances along the altered segment of radial nerve in both patients. Intraoperatively, intrafascicular nerve torsion as a cause of functional disorders was confirmed in both cases. Both patients required external and internal nerve decompression with restoration of linear orientation of the nerve and its fixation within the epineurium. Positive effect was noted immediately after surgery. Control survey after 3 and 6 months revealed significant regression of symptoms (increase in muscle strength and motion amplitude) and high satisfaction with treatment outcomes. CONCLUSION: Clinical manifestations of intrafascicular radial nerve torsion imitate typical compression-induced neuropathy. However, this lesion is characterized by another unclear pathogenesis, localization far from natural tunnels, typical ultrasound and intraoperative patterns. Surgical treatment has certain features, and its effectiveness depends on surgical technique and ranges from 60% to 90%.