Diagnostic Accuracy of Clinical Tests for Neurogenic and Vascular Thoracic Outlet Syndrome: A Systematic Review.

OBJECTIVE: To summarize the evidence on the accuracy of clinical tests to help confirm or refute a diagnosis of thoracic outlet syndrome (TOS). METHODS: We searched 10 databases (January 1990 to February 2016) using relevant key words and medical subject headings terms. We considered diagnostic test accuracy studies comparing clinical tests for the diagnosis of TOS against a reference test. Cross-sectional, cohort, and case-control studies and randomized controlled trials were included. Risk of bias was appraised using QUADAS-2 and the Quality Appraisal of Reliability Studies checklist. We performed a qualitative synthesis of scientifically admissible studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was used to report findings. RESULTS: A total of 3932 articles were retrieved. After removal of duplicates, 1767 articles were screened for titles and abstract, leaving 494 articles for full-text review. Ten studies met the eligibility criteria and were assessed for risk of bias, 4 of which were included in the review. None of the included studies used the same index tests when comparing with a gold standard, and quality was poor. High clinical heterogeneity and the use of different comparators prevented from pooling results. Findings suggest that prescribing magnetic resonance imaging during provocative positioning to confirm a diagnosis of TOS may be useful. However, this is associated with a high false-positive rate of venous compression. CONCLUSION: Little evidence currently supports the validity of clinical tests for the diagnosis of TOS. Future diagnostic accuracy studies should aim to use established methodological criteria and appropriate reporting guidelines to help validate clinical tests for diagnosing patients with TOS.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome: Executive summary.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

Thoracic outlet and pectoralis minor syndromes.

Compression of the neurovascular bundle to the upper extremity can occur above or below the clavicle; thoracic outlet syndrome (TOS) is above the clavicle and pectoralis minor syndrome is below. More than 90% of cases involve the brachial plexus, 5% involve venous obstruction, and 1% are associate with arterial obstruction. The clinical presentation, including symptoms, physical examination, pathology, etiology, and treatment differences among neurogenic, venous, and arterial TOS syndromes. This review details the diagnostic testing required to differentiate among the associated conditions and recommends appropriate medical or surgical treatment for each compression syndrome. The long-term outcomes of patients with TOS and pectoralis minor syndrome also vary and depend on duration of symptoms before initiation of physical therapy and surgical intervention. Overall, it can be expected that >80% of patients with these compression syndromes can experience functional improvement of their upper extremity; higher for arterial and venous TOS than for neurogenic compression.

A review of thoracic outlet syndrome and the possible role of botulinum toxin in the treatment of this syndrome.

The objective of this paper is to discuss the classification, diagnosis, pathophysiology and management of Thoracic outlet syndrome (TOS). Thoracic outlet syndrome (TOS) is a complex entity that is characterized by different neurovascular signs and symptoms involving the upper limb. TOS is defined as upper extremity symptoms due to compression of the neurovascular bundle in the area of the neck just above the first rib. Compression is thought to occur at one or more of the three anatomical compartments: the interscalene triangle, the costoclavicular space and the retropectoralis minor spaces. The clinical presentation can include both neurogenic and vascular symptoms. TOS can be difficult to diagnose because there is no standardized objective test that can be used and the clinician must rely on history and several positive findings on physical exam. The medial antebrachial cutaneous nerve conduction may be a sensitive way to detect pathology in the lower trunks of the brachial plexus which is promising for future research. Treatment options continue to be conservative and surgical. However, for those who have failed physical therapy there is research to suggest that botulinum toxin may help with symptom relief. However, given that there has been conflicting evidence, further research is required using randomized controlled trials.

The thoracic outlet syndromes.

The term thoracic outlet syndrome (TOS) refers to a heterogeneous group of disorders, all of which have in common compression of one or more neurovascular elements at some point within the thoracic outlet. Of the five disorders comprising this group, four have all of the features expected of a syndrome-a recognized constellation of clinical features; an anatomic derangement accounting for these features; and a method of testing that identifies the anatomic derangement. Consequently, their recognition and management are relatively straightforward. Conversely, one of these five disorders (nonspecific TOS) lacks these correlations, which has generated considerable debate in the literature and caused some experts to doubt its existence altogether. The primary focus in this study is on the neurologic forms of TOS. However, for completeness and a better understanding of these neurologic manifestations, the vascular forms are also reviewed.

Provocative F wave in the diagnosis of nonspecific neurogenic-type thoracic outlet syndrome.

OBJECTIVE: Thoracic outlet syndrome (TOS) is defined as a constellation of clinical symptoms caused by the entrapment of neurovascular structures (subclavian vessels and the brachial plexus) en route to the upper limb via the superior thoracic outlet. Nonspecific neurogenic TOS is not easy to diagnose because there is no investigational technique that has proven to be the diagnostic gold standard. DESIGN: In this study, our aim was to investigate the role of provocative F response in the diagnosis of nonspecific neurogenic TOS. F wave analysis of median and ulnar nerves in neutral and provocative maneuvers was carried out in 21 patients with a clinical diagnosis of nonspecific neurogenic TOS and in 15 healthy volunteers. RESULTS: All findings were within reference range in both groups, and no statistical difference was noted among subject groups, with or without provocative maneuvers. CONCLUSIONS: We conclude that the nonspecific neurogenic TOS is a temporary compression process that does not result in a structural damage on the nerve; therefore, significant electrophysiologic changes are not elicited.

Thoracic outlet syndrome: a review.

BACKGROUND: : Arterial and venous thoracic outlet syndrome (TOS) were recognized in the late 1800s and neurogenic TOS in the early 1900s. Diagnosis and treatment of the 2 vascular forms of TOS are generally accepted in all medical circles. On the other hand, neurogenic TOS is more difficult to diagnose because there is no standard objective test to confirm clinical impressions. REVIEW SUMMARY: : The clinical features of arterial, venous, and neurogenic TOS are described. Because neurogenic TOS is by far the most common type, the pathology, pathophysiology, diagnostic tests, differential and associate diagnoses, and treatment are detailed and discussed. The controversial area of objective and subjective diagnostic criteria is addressed. CONCLUSION: : Arterial and venous TOS are usually not difficult to recognize and the diagnosis can be confirmed by angiography. The diagnosis of neurogenic TOS is more challenging because its symptoms of nerve compression are not unique. The clinical diagnosis relies on documenting several positive findings on physical examination. To date there is still no reliable objective test to confirm the diagnosis, but measurements of the medial antebrachial cutaneous nerve appear promising.

["True neurologic thoracic outlet syndrome" -- anatomical features and electrophysiological long-term follow-up of lateral thenar atrophy]. / "True Neurologic Thoracic Outlet Syndrome" -- Anatomie und elektrophysiologischer Langzeitverlauf bei lateraler Thenaratrophie.

Atrophies of the intrinsic muscles of the hand are considered to be a typical symptom of the "true neurologic" form of thoracic outlet syndrome (TOS). The classical form of this entity was described as early as 1970, consisting of a cervical rib or a prolonged transverse process of C7, complete with a fibrous band to the first thoracic rib, resulting in atrophy of the intrinsic muscles of the hand. All our TOS patients presenting with such atrophy displayed anatomical findings consistent with this definition. Based on this observation, the TOS classification currently in clinical use, which differentiates between "disputed" and "true neurologic" subgroups of the neurologic form, is reviewed. In all cases of "true neurologic TOS" with atrophy of the intrinsic muscles of the hand, the lateral thenar muscles are affected first. We present the electrophysiological long-term results of such thenar atrophies of seven patients with eight operated extremities after brachial plexus decompression. The amplitude of the neurographically measured potential over the opponens pollicis and the abductor pollicis brevis muscle, respectively, was defined as quantitative parameter for muscles atrophy. Neither distinct reinnervation nor progressive denervation was evident in any of the cases after a follow-up period, on average, of more than five years post surgery. These findings are in conflict with clinical observations reporting a major postoperative improvement of the motor deficits.

TOS pathophysiology and clinical features.

The authors present 280 patients operated on for thoracic outlet syndrome (TOS). In a first group of patients anatomical variants were the striking findings. The underlying factor for TOS development is therefore a well defined structural condition and its pathogenetic mechanism is known to be a nerve fibre compression. In a second group there was no specific salient finding but a postural deviation. The unique pathological features were adhesions of the brachial plexus to the scalenus muscle. Consequently its pathogenetic mechanism is generally recognized as nerve fibre distraction. In all patients neurological, vascular and myofascial pain symptoms were observed before the operation. Neurological and vascular pain disappeared after surgery, while the myofascial pain remained. The authors believe that especially in the second, larger group of patients enhancement of the pain-immobility-fibrosis loop is the central pathogenetic factor on which surgical therapy is successful, and that myofascial hemisyndrome--probably arising from a long-standing postural deviation--is not a TOS dependent symptom. In TOS, therefore, there is a pain loop that cannot be resolved by surgical therapy alone. The connection between myofascial pain syndrome and TOS might explain the many controversial opinions regarding frequency, results and surgical possibilities of this lesion.

Whiplash injury. TOS and double crush syndrome. Forensic medical aspects.

In this article the author wants to specify that the whiplash syndrome is underestimated, even by the specialists. In particular the complications aren't taken into correct consideration, above all if they concern the brachial plexus, especially regarding the TOS syndrome and double-crush syndrome. This is a problem also among the experts who have to make an evaluation in the field of insurance.

Vascular Thoracic Outlet Syndrome staging and treatment.

Thoracic Outlet Syndrome (TOS) is a well known lesion. Sophisticated imaging techniques can clearly highlight any anatomical damage and a wide range of therapeutic choices are available. It would seem obvious that any given patient should obtain the same treatment irrespective of the medical institution he contacts, but this is not the case. Instead each specialist may recommend different treatments: physiatrist, neurologist, surgeons (thoracic, vascular, neuro, orthopedic). Everyone preserves his specific language and there is no univocal treatment plan consensus for this complex syndrome. Evidently, the correct staging of TOS is still an unresolved question. In order to solve this problem, we collected all clinical and instrumental aspects of the syndrome into a clear, precise classification. Similar to TNM staging of malignant diseases, we used a grouping model based on the three mainly involved anatomical structures: N (= Nerves; brachial plexus and sympathetic fibers), A (= Artery; subclavian-axillary), V (= Vein; subclavian-axillary). We named it the NAV staging of TOS. A retrospective examination of our case records confirmed a valid and useful correlation between the proposed NAV staging and the therapeutic procedures that were actually applied. It is now essential to perform a multi-centre study to extend the validity of our staging.

[Thoracic outlet syndrome: clinical staging]. / Sindrome dello stretto toracico superiore: stadiazione clinica.

The clinical and instrumental manifestations of thoracic outlet syndrome are well known but the therapeutic choices frequently differ in relation to the physician's experience. Thus, there is no univocal opinion regarding the therapy of this complex syndrome. To solve this problem we have attempted to bring together the clinical and instrumental pictures in a single classification that includes the three fundamental aspects of the syndrome, namely nerve, artery and vein injury (NAV). Our goal was to achieve a universally accepted therapy-oriented staging system, as is the case with the TNM system for malignant tumours. From 1984 to 2002, in our institution 156 patients with thoracic outlet syndrome were evaluated. These were grouped in 4 stages depending on their NAV status. Subsequent therapy was in accordance with stage. Our results confirmed the accuracy of NAV. On the basis of our preliminary experience, the NAV staging system is useful for correct patient grouping. Now a prospective multicentre study is needed for universal scientific validation.

Thermal asymmetry of the upper extremity in scalenus anticus syndrome, leg-length inequality and response to chiropractic adjustment.

OBJECTIVE: To describe a case of a vasomotor, vascular form of thoracic outlet syndrome that causes upper extremity thermal asymmetry, and to discuss a single subject case study (N-of-1) comparing the correlation of a subjective test for putative atlas vertebral subluxation complex (supine leg-length inequality) with a single blinded objective measurement [temperature differential (delta degree T)] on the dorsum of the hands. CLINICAL FEATURES: A 71-yr-old woman with a cold, painful right hand and chronic neck pain sought chiropractic evaluation. There was a left head tilt and muscular hypertonicity with fibrous bands in the opposite scalenes and sternocleidomastoid. Thermographic examination revealed a large temperature differential (12 degrees F) between the dorsum of the right and left hands, with the superficial veins on the dorsum of the cold hand collapsed. Thoracic outlet provocation tests were negative. A left-side leg-length inequality potentially indicative of putative upper cervical subluxation was also noted. A diagnosis of presumptive thoracic outlet syndrome with vasomotor vascular complications subsequent to altered cervical biomechanics was made. INTERVENTION AND OUTCOME: Treatment was limited to chiropractic, upper cervical, vectored, linear adjustment of the atlas vertebra. Temperature differential between the hands improved significantly after individual atlas adjustment(s) and in the long term. CONCLUSION: Scalenus anticus syndrome and upper extremity thermal asymmetry may result from altered cervical biomechanics caused by atlas vertebral subluxation complex. Furthermore, the supine leg check may be of value in determining the necessity of atlas adjustment.

Factors prolonging disability in work-related cumulative trauma disorders.

Workers' compensation costs for management of soft tissue disorders continue to increase. The complexity of medical management of these cases has increased due to social factors. The purpose of this study is to improve the physician's ability to recognize nonmedical issues that prevent a rapid return to employment. A classification system is presented that will allow the clinician to identify administrative and pyschosocial issues that prolong disability. Additionally, the patients' job demands were classified by known ergonomic risk factors. The system was applied retrospectively to 50 random cases referred to two occupational hand clinics over a 1-year period. The results indicated that the psychosocial classification of the patient and the current employment status are the most important factors in prolonging disability workers.