The variable morphology of suprascapular nerve and vessels at suprascapular notch: a proposal for classification and its potential clinical implications.

PURPOSE: The most common place for suprascapular nerve entrapment is the suprascapular notch. The aim of the study was to determine the morphological variation of the location of the suprascapular nerve, artery and vein, and measure the reduction in size of the suprascapular opening in each type of the passage. METHODS: A total of 106 human formalin-fixed cadaveric shoulders were included in the study. After dissection of the suprascapular region, the topography of the suprascapular nerve, artery and vein was evaluated. Additionally, the area of the suprascapular opening was measured using professional image analysis software. RESULTS: Four arrangements of the suprascapular vein, artery and nerve were distinguished with regard to the superior transverse scapular ligament: type I (61.3 %) (suprascapular artery was running above ligament, while suprascapular vein and nerve below it), type II (17 %) (both vessels pass above ligament, while nerve passes under it), type III (12.3 %) (suprascapular vessels and nerve lie under ligament) and type IV (9.4 %), which comprises the other variants of these structures. Statistically significant differences regarding the suprascapular opening were observed between the specimens with types II and III. Anterior coracoscapular ligaments were present in 55 from 106 shoulders. CONCLUSION: The morphological variations described in this study are necessary to better understand the possible anatomical conditions which may promote suprascapular nerve entrapment (especially type III). They may be useful during open and endoscopic procedures at the suprascapular notch to prevent such complications as unexpected bleeding.

Preoperative evaluation of the neurovascular compression using magnetic resonance tomographic angiography: our radiologic indications for microvascular decompression to treat trigeminal neuralgia.

PURPOSE: The aim of this study was to introduce our classification of the neurovascular compression (NVC) in trigeminal neuralgia and the radiologic indications for microvascular decompression (MVD) based on magnetic resonance tomographic angiography. METHODS: From 2003 to 2011, 322 patients with primary trigeminal neuralgia were treated with MVD. The score of NVC was from 0 to 3. Three scores, separately from axial, oblique sagittal, and coronal images, were added together. The degree of NVC was classified as follows: grade 0 (0-1), grade 1 (2-3), grade 2 (4-6), and grade 3 (7-9). RESULTS: In summary, 88.3% (182/206) patients with absolute indication, 78.3% (65/83) patients with relative indication, and 90.9% (30/33) without indication showed excellent results. Among the 27 patients with good result, 13 patients (48.1%) were in grade 1, and 3 (11.1%) were in grade 0. Among the 18 patients with poor result, 5 patients (27.8%) were in grade 1 preoperatively. Five patients with severe complications were all in grade 0 with vague NVC. CONCLUSION: The patients with grades 2 and 3 (absolute indications) NVC were recommended with MVD.

Interventions in the disturbances in the motor and sensory environment.

Treatment of peripheral nervous system (PNS) pathology presents intervention challenges to every therapist. Many of the current and future interventions will be directed at restoring the normal anatomy, function, and biomechanical properties of the PNS, restoring normal neural physiology and ultimately patient function and quality of life. Present interventions use mechanical (movement) or electrical procedures to affect various properties of the peripheral nerve. The purpose of this article was to apply basic science to clinical practice. The pathology and accompanying structural and biomechanical changes in the PNS will be presented in three specific areas commonly encountered in the clinic: nerve injury and laceration; compression neuropathies; and neuropathic pain and neural tension dysfunction. The intent is to address possible interventions exploring the clinical reasoning process that combines basic science and evidence-based best practice. The current lack of literature to support any one intervention requires a strong foundation and understanding of the PNSs' structure and function to refine current and develop new intervention strategies. Current evidence will be presented and linked with future considerations for intervention and research. During this interlude of development and refinement, best practice will rely on sound clinical reasoning skills that incorporate basic science to achieve a successful outcome when treating these challenging patients.

Compressive neuropathies of the upper extremity: update on pathophysiology, classification, and electrodiagnostic findings.

Clinical examination and electrodiagnostic studies remain the gold standard for diagnosis of nerve injuries. Diagnosis of chronic nerve compression (CNC) injuries can be difficult in patients with confounding factors such as diabetes. The treatment of nerve entrapment ranges from medical to surgical management, depending on the nerve involved and on the severity and duration of compression. Considerable insights have been made at the molecular level, differentiating between nerve crush injuries and CNC injuries. Although the myelin changes after CNC injury were previously thought to be a mild form of Wallerian degeneration, recent evidence points to a distinct pathophysiology involving Schwann cell mechanosensitivity. Future areas of research include Schwann cell transplantation in the treatment regimen, the correlation between demyelination and the onset of pain, and the role of Schwann cell integrins in transducing the mechanical forces involved in nerve compression injuries to Schwann cells.

Oblique Sagittal Images Prevent Underestimation of the Neuroforaminal Stenosis Grade Caused by Disc Herniation in Cervical Spine MRI.

PURPOSE: To identify whether standard sagittal MRI images result in underestimation of the neuroforaminal stenosis grade compared to oblique sagittal MRI images in patients with cervical spine disc herniation. MATERIALS AND METHODS: 74 patients with a total of 104 cervical disc herniations compromising the corresponding nerve root were evaluated. Neuroforaminal stenosis grades were evaluated in standard and oblique sagittal images by one senior and one resident radiologist experienced in musculoskeletal imaging. Oblique images were angled 30° towards the standard sagittal plane. Neuroforaminal stenosis grades were classified from 0 (no stenosis) to 3 (high grade stenosis). RESULTS: Average neuroforaminal stenosis grades of both readers were significantly lower in standard compared to oblique sagittal images (p < 0.001). For 47.1 % of the cases, one or both readers reported a stenosis grade, which was at least 1 grade lower in standard compared to oblique sagittal images. There was also a significant difference when looking at patients who had neurological symptoms (p = 0.002) or underwent cervical spine surgery subsequently (p = 0.004). Interreader reliability, as measured by kappa value, and accordance rates were better for oblique sagittal images (0.94 vs. 0.88 and 99 % vs. 93 %). CONCLUSION: Standard sagittal images tend to underestimate neuroforaminal stenosis grades compared to oblique sagittal images and are less reliable in the evaluation of disc herniations within the cervical spine MRI. In order to assess the potential therapeutic consequence, oblique images should therefore be considered as a valuable adjunct to the standard MRI protocol for patients with a radiculopathy. KEY POINTS: · Neuroforaminal stenosis grades are underestimated in standard compared to oblique sagittal images. · Interreader reliability is higher for oblique sagittal images. · Oblique sagittal images should be performed in patients with a cervical radiculopathy. CITATION FORMAT: · Kintzele L, Rehnitz C, Kauczor H et al. Oblique Sagittal Images Prevent Underestimation of the Neuroforaminal Stenosis Grade Caused by Disc Herniation in Cervical Spine MRI. Fortschr Röntgenstr 2018; 190: 946 - 954.

Cranial Neuralgias.

Advances in diagnostic modalities have improved the understanding of the pathophysiology of neuropathic pain involving head and face. Recent updates in nomenclature of cranial neuralgias and facial pain have rationalized accurate diagnosis. Clear diagnosis and localization of pain generators are paramount, leading to better use of medical and targeted surgical treatments.

Accurate nomenclature for forefoot nerve entrapment: a historical perspective.

Current medical nomenclature is often based on the early history of the condition, when the true etiology of the disease or condition was not known. Sadly, this incorrect terminology can become inextricably woven into the lexicon of mainstream medicine. More important, when this is the case, the terminology itself can become integrated into current clinical decision making and ultimately into surgical intervention for the condition. "Morton's neuroma" is perhaps the most striking example of this nomenclature problem in foot and ankle surgery. We aimed to delineate the historical impetus for the terminology still being used today for this condition and to suggest appropriate terminology based on our current understanding of its pathogenesis. We concluded that this symptom complex should be given the diagnosis of nerve compression and be further distinguished by naming the involved nerve, such as compression of the interdigital nerve to the third web space or compression of the third common plantar digital nerve. Although the nomenclature becomes longer, the pathogenesis is correct, and treatment decisions can be made accordingly.

Anatomical relations between anterior coracoscapular ligament and suprascapular neurovascular structures and a proposal for classification.

OBJECTIVE: Although suprascapular nerve entrapment is rare, the most common site of compression is the suprascapular notch. The anterior coracoscapular ligament (ACSL), which lies inferior to the superior transverse scapular ligament (STSL), may also be a cause of entrapment. We aimed to investigate the presence of ACSL and its relations to the suprascapular nerve and vessels. METHODS: We dissected 50 shoulders of 26 cadavers. We excluded 2 shoulders due to previous shoulder surgery. We observed the course of the suprascapular nerve, artery, and vein(s), and examined whether they passed between STSL and ACSL or under ACSL. We classified the anatomical relations between neurovascular structures, STSL, and ACSL. In Type I, the suprascapular nerve passed between STSL and ACSL; in Type Iia, the suprascapular nerve and a single suprascapular vein passed between STSL and ACSL; in Type Iib, a suprascapular vein passed under ACSL and the suprascapular nerve passed between STSL and ACSL; in Type III, the suprascapular artery, vein, and nerve passed between STSL and ACSL. RESULTS: ACSL was present in 16 shoulders (32%). The suprascapular nerve passed between STSL and ACSL in all cases. We observed Type I, Type Iia, Type Iib, and Type III anatomical relations in 14%, 12%, 2%, and 4% of cases, respectively. CONCLUSION: Vascular structures that pass under STSL may cause suprascapular nerve entrapment. Presence of ACSL with vessel(s) passing under it and/or between it and STSL may increase the risk of nerve entrapment.

Implant-related nerve injuries.

Injuries to branches of the trigeminal nerves are a known complication during dental implant placement. These injuries tend to be more severe than those experienced during other dentoalveolar procedures. This article reviews the types of nerve injuries and areas and situations of which clinicians should be cognizant when placing dental implants. Strategies to avoid injuries, and a management algorithm for suspected nerve injuries, are also discussed.

Quadrilateral space syndrome: the Mayo Clinic experience with a new classification system and case series.

Quadrilateral space syndrome (QSS) arises from compression or mechanical injury to the axillary nerve or the posterior circumflex humeral artery (PCHA) as they pass through the quadrilateral space (QS). Quadrilateral space syndrome is an uncommon cause of paresthesia and an underdiagnosed cause of digital ischemia in overhead athletes. Quadrilateral space syndrome can present with neurogenic symptoms (pain and weakness) secondary to axillary nerve compression. In addition, repeated abduction and external rotation of the arm is felt to lead to injury of the PCHA within the QSS. This often results in PCHA thrombosis and aneurysm formation, with distal emboli. Because of relative infrequency, QSS is rarely diagnosed on evaluation of athletes with such symptoms. We report on 9 patients who presented at Mayo Clinic with QSS. Differential diagnosis, a new classification system, and the management of QSS are discussed, with a comprehensive literature review. The following search terms were used on PubMed: axillary nerve, posterior circumflex humeral artery, quadrilateral space, and quadrangular space. Articles were selected if they described patients with symptoms from axillary nerve entrapment or PCHA thrombosis, or if related screening or imaging methods were assessed. References available within the obtained articles were also pursued. There was no date or language restriction for article inclusion; 5 studies in languages besides English were reported in German, French, Spanish, Turkish, and Chinese.

Prevalence of peripheral neuropathy in the Parsi community of Bombay.

We carried out a door-to-door survey to screen for neurologic diseases, including peripheral neuropathy, in a community of 14,010 Parsis living in housing colonies in Bombay, India. The most common neurologic disorder was peripheral neuropathy with 334 cases (2,384 cases/100,000 population). The most common neuropathy was compressive, with diabetes the most common noncompressive etiology. There was no leprosy, and nutritional neuropathies were rare.

Shoulder-arm pain from cervical bands and scalene muscle anomalies.

Fourteen patients were identified with (1) pain and sensory changes in a brachial plexus distribution, (2) aggravation of pain with use of the affected extremity, and (3) pain on palpation over the brachial plexus. All patients had minimal or no intrinsic hand muscle atrophy. Only one patient had cervical ribs. Nerve conduction studies were normal, and electromyography (EMG) showed mild chronic neuropathic changes in 2 patients. None of the patients responded to conservative therapy over a prolonged period (7-12 months). A compressive brachial plexopathy from abnormally attached or enlarged scalene muscles that affected both upper and lower trunks of the brachial plexus was found at surgery in all patients. In 13 patients, at least one fibrous band compressed the lower trunk of the brachial plexus. Therefore, neurogenic thoracic outlet syndrome can occur from cervical bands and scalene muscle anomalies without intrinsic hand muscle atrophy, cervical ribs, enlarged C7 transverse processes, or EMG abnormalities.

Uncommon nerve compression syndromes of the upper extremity.

Nerve compression syndromes are a common cause of pain, sensory disturbance, and motor weakness in both the upper and the lower extremities. Although carpal tunnel syndrome is frequently diagnosed and treated surgically with success, other compression syndromes are less common and are often best treated nonsurgically. Understanding the anatomy of the major peripheral nerves with respect to intermuscular septa, fibrous bands, muscle margins, and internervous planes is crucial to understanding how and where peripheral nerve compression can occur. Some conditions, such as anterior interosseous nerve syndrome, respond well to nonoperative treatment; others, such as posterior interosseous nerve syndrome, are better treated by surgical intervention. The authors discuss the anatomic and pathologic causes for compression syndromes, as well as guidelines for treatment and outcomes.

Anatomical classification of sites of compression of the palmar cutaneous branch of the median nerve.

The anatomical course of the palmar cutaneous nerve was studied in ten cadavers and classified into six zones or sites. The literature on entrapment neuropathy of the palmar cutaneous nerve was then reviewed and the cases were classified according to the anatomical site of compression.

Neurolysis in compressive neuropathies.

The application of microsurgical neurolytic techniques in cases of peripheral nerve entrapments offers greater advantages than other techniques, as it allows a better understanding of the neural alterations. In most cases, a longitudinal epineurectomy is necessary to free the fascicles of the epineural fibrosis. Less frequently, internal neurolysis is needed for removal of interfascicular scarring. Fifty cases of elbow ulnar neuropathy and 58 of the carpal tunnel syndrome were treated with this technique: 72% of the results were satisfactory.

[Definition and systematization of compression-ischemic neuropathies]. / Opredelenie i sistematizatsiia kompressionno-ishemicheskikh nevropatii.

The authors give a definition of tunnel neuropathies which makes it possible to differentiate them from neurites (of the infectious nature), and to differentiate compression ischemic lesions of the nervous trunks from compression ischemic vertebrogenic radicular involvements (radiculitis) and from other lesions and diseases of the peripheral nervous system. The working classification of compression ischemic neuropathies is built on topographic principles of the arrangement of nerves and their correlations with compressed structures with due consideration for clinical and pathogenetic manifestations.

[Foot entrapment syndromes]. / Syndromes canalaires du pied.

Foot's entrapment syndromes are frequent and often ignored cause of pain. Many clinical descriptions are presented, but diagnostic and therapeutic proceeding is univocal, depending upon to find the conflictual zone (Tinel's sign, electrophysiology, infiltrate test) and to pay attention to the different etiologic factors (static troubles, traumatism, foot/shoe conflict...).

Tardy posterior interosseous nerve palsy following total elbow arthroplasty: report of a case, literature review and a classification system.

We present an unusual case of tardy posterior interosseous nerve palsy in a female patient following total elbow arthroplasty for rheumatoid arthritis. The patient was neurologically intact immediately following surgery but developed loss of active finger and thumb extension within 12 hours following surgery. Expectant management was adapted. The palsy recovered fully without the need of surgical intervention. A literature review is presented and a classification system proposed.

Peripheral nerve entrapments of the lower leg, ankle, and foot.

Peripheral nerve entrapments are a relatively rare and heterogeneous group of nerve disorders encompassing a wide variety of etiologies and clinical presentations. These conditions can present significant diagnostic challenges, owing to both the variety of symptoms these patients display, along with the anatomic variation that exists between individuals. Precise knowledge of the anatomic course, the common motor and sensory distributions of each of the peripheral nerves, and judicious use of imaging or electrodiagnostic testing can greatly assist in arriving at a correct diagnosis. In this article, we discuss in detail the anatomy, clinical presentation, diagnosis, and treatment options for peripheral nerve entrapments of the lower extremity involving the sural, saphenous and common, superficial, and deep peroneal nerves.