True Neurogenic Thoracic Outlet Syndrome Research Articles

True Neurogenic Thoracic Outlet Syndrome with Elongated C7 Transverse Processes in a Hemiplegic Patient: A Case Report

Thoracic outlet syndrome (TOS) is caused by the compression of neurovascular structures in the thoracic cage. TOS can be classified into neurogenic TOS (NTOS) and vascular TOS. Congenital anomalies, such as cervical ribs and elongated C7 transverse processes, may be the cause of NTOS. NTOS can be subcategorized as either disputed NTOS or true NTOS. True NTOS, a very rare disease with a prevalence of about one in a million, is diagnosed by the weakness and atrophy of T1-innervated intrinsic muscles of the hand and corresponding electrodiagnostic abnormalities. We report a case of a 42-year-old patient, who presented with a 5-year history of clumsiness and 1 1-year history of weakness and atrophy in her right hand. The patient was diagnosed with true NTOS during comprehensive rehabilitation, which she received for left hemiplegia due to intracranial hemorrhage. Elongated bilateral C7 transverse processes were found on a radiological evaluation. True NTOS is often overlooked or mistaken for carpal tunnel syndrome, thus delaying the diagnosis and inevitably worsening outcomes. Therefore, an electrodiagnostic study is crucial for detecting true NTOS, rather than typical physical examinations such as the Roos stress test and Adson’s test.

True neurogenic thoracic outlet syndrome: late outcomes from a surgical series.

True neurogenic thoracic outlet syndrome (TNTOS) is rare, and evaluation of surgical treatment is limited to a few studies in the literature. The purpose of this study is to present the results from a surgical series of 21 patients with TNTOS. Retrospective analysis on 21 patients diagnosed with TNTOS who underwent surgery. Demographic data and neurological status were characterized, and patients were classified in accordance with a pre-established scale for assessing the severity of hand impairment before and after surgery. Neuropathic pain was assessed using a visual analogue scale (VAS) and functional disability was quantified using the QuickDASH questionnaire. The results from before and after surgery were compared using the Wilcoxon test, and the significance level was taken to be 5%. There was a significant difference in VAS values from before to after the operation (Wilcoxon test: p = 0.0001; r = 0.86). Most patients (90%) improved after surgery, and in 85% of these patients, the VAS improvement was greater than 50%. Improvement in hand function occurred in seven patients (33.3%), and in most of these cases (28.6%), this improvement was classified as mild. Most patients (93.3%) showed moderate to very severe functional disability at the end of the follow-up. After surgery, only one-third of the cases showed improvement in motor function and most patients had significant functional disability. However, the improvement regarding pain was significant. Surgery to control this symptom should be recommended, even in cases of late presentation and severe motor impairment.

Wasting of the hand is not fate! A case of missed true neurogenic thoracic outlet syndrome

Wasting of the hand is not fate! A case of missed true neurogenic thoracic outlet syndrome

Wasting of the hand is not fate! A case of missed true neurogenic thoracic outlet syndrome.

Wasting of the hand is not fate! A case of missed true neurogenic thoracic outlet syndrome.

The role of congenital malformations of the thoracic outlet in the development of the syndrome.

Thoracic outlet syndrome (TOS) represents a clinical condition caused by compression of the neurovascular structures that cross the thoracic outlet. TOS can be classified in: 1) neurogenic TOS (NTOS), 2) venous TOS (VTOS), 3) arterial TOS (ATOS). Many different causes can determine the syndrome: congenital malformations, traumas, and functional impairments. This manuscript reviews how the congenital malformations play an important role in adult age; however, TOS also affects patients of all ages. Radiological imaging like X-ray (radiography), magnetic resonance and computed tomography can provide useful information to assess TOS causes and decide a potential surgery. 79% of the patients included in the first two stages of nerve, artery, vein (NAV) staging experienced excellent results with kinesiotherapy; whereas patients included in the third and fourth stage of NAV staging were subject to surgery. The treatment of acute forms of TOS involves thrombolysis and anticoagulant therapy; surgery is appropriate for true NTOS, vascular TOS and in some cases when conservative treatment fails.

CLINICAL AND NEUROPHYSIOLOGICAL PARALLELS OF THE BRACHIAL PLEXOPATHY IN THE STRUCTURE OF NEUROGENIC THORACIC OUTLET SYNDROME

The aim: Was assessment of the neurophysiological data and features of clinical picture in patients with neurogenic thoracic outlet syndrome (TOS). Materials and methods: 103 patients with upper extremity pain and/or paresthesia or hypotrophy, or a combination of these symptoms were examined. The examination algorithm included: cervical spine radiography, cervical spine and brachial plexuses magnetic resonance imaging (MRI), upper extremity soft tissues and vessels ultrasonic examination, stimulation electroneuromiography with F-waves registration. Results: Neurogenic TOS was diagnosed in 29 patients. A significant relationship between the following complaints and neurophysiological parameters was observed: pain, numbness during physical activity and decreased medial anrebrachial cutaneous nerve response amplitude by ≥25% compared to the contralateral side; hypothenar hypotrophy and decrease of ulnar nerve motor/sensory response amplitude; the 4-5th fingers hypoesthesia and decrease of ulnar nerve sensory response amplitude. Conclusions: Medial antebrachial cutaneous nerve amplitudes asymmetry indices of ≥25% or lack of response may be considered to be a marker of true neurogenic TOS.

Essentials of thoracic outlet syndrome: A narrative review.

Thoracic outlet syndrome (TOS) is a group of diverse disorders involving compression of the nerves and/or blood vessels in the thoracic outlet region. TOS results in pain, numbness, paresthesia, and motor weakness in the affected upper limb. We reviewed the pathophysiology, clinical evaluation, differential diagnoses, and treatment of TOS. TOS is usually classified into three types, neurogenic, venous, and arterial, according to the primarily affected structure. Both true neurogenic and disputed TOS are considered neurogenic TOS. Since identifying the causative lesions is complex, detailed history taking and thorough clinical investigation are needed. Electrodiagnostic and imaging studies are helpful for excluding other possible disorders and confirming the diagnosis of true neurogenic TOS. The existence of a disputed TOS remains controversial. Neuromuscular physicians tend to be skeptical about the existence of disputed TOS, but thoracic surgeons argue that disputed TOS is under-diagnosed. Clinicians who encounter patients with TOS need to understand its key features to avoid misdiagnosis and provide appropriate treatment.

A case of true neurogenic thoracic outlet syndrome diagnosed by dynamic evaluation in symptom-induced limb position using nerve ultrasound

A case of true neurogenic thoracic outlet syndrome diagnosed by dynamic evaluation in symptom-induced limb position using nerve ultrasound

Right Hand Dominant Musician With Right Hand Weakness

HPI: EM is a RHD 19yF musician presenting with insidious onset, progressive RH weakness worsening over the last 1-2 years. No trauma. She has difficulty with pincer grasping. Weakness is constant but exacerbated when playing guitar or flute for long periods of time. No numbness, pain, tingling or swelling of the RUE. Denies any fevers, chills, recent URI, polyarthralgia. No family history of neurologic or autoimmune disease. PE: No notable muscle atrophy or TTP in the RUE. Full ROM in neck, shoulder, elbow and wrist. 4/5 strength in pincer grip on right, 5/5 strength in right rotator cuff muscles, tricep, bicep, wrist flexion/extension. +Median nerve weakness, radial and ulnar nerve intact. Normal sensation and RUE reflexes. Positive Adson’s. Negative Spurling, Roos tests., Hoffman, Negative Tinel’s and Phalen’s at the wrist. DDX: Radial neuropathy, Carpal tunnel syndrome, Paget Schroetter Syndrome, Thoracic outlet syndrome, Parsonage-Turner syndrome TEST AND RESULTS: Labs: Within normal limits EMG: Results consistent with a significant True Neurogenic Thoracic Outlet Syndrome on the right. There is also electrodiagnostic evidence of a mild right ulnar mononeuropathy at the ulnar groove. Xray cervical spine: Enlarged transverse processes bilaterally at C7, larger on the right. Partial fusion at C3-4 with 2 mm retrolisthesis of C4 on C5 in extension that reduces with flexion. MRI Brachial plexus: Right cervical rib (at C7), with a hyperintense C8 spinal nerve coursing through this area, as are the medial cord, and visualized proximal ulnar nerve and possibly of the median nerve, likely attributable to mass effect from the cervical rib and/or an accompanying fibrous band. RUE vascular study: negative FINAL WORKING DIAGNOSIS: Neurogenic Thoracic Outlet Syndrome TREATMENT AND OUTCOMES: Initial EMG pointed to neurogenic TOS. Subsequently, patient completed cervical spine xrays and MRI of the brachial plexus, revealing cervical ribs with likely brachial plexus compression. Patient attended physical therapy to focus on posture while playing instruments, stretching of scalene muscles and strengthening scapular stabilizers. Unfortunately, she did not improve with conservative management. She has been seen by orthopedics and vascular surgery and is currently awaiting cervical rib resection surgery.

Clinical, electrodiagnostic and imaging features of true neurogenic thoracic outlet syndrome: Experience at a tertiary referral center

ObjectiveTrue neurogenic thoracic outlet syndrome (TN-TOS) is an extremely rare neuromuscular disease. We report clinical, electrodiagnostic and radiologic features of patients with TN-TOS. MethodsRetrospective chart review of patients satisfying criteria was done. Nerve conduction study (NCS) and needle electromyography (EMG) of upper extremity were reviewed. Brachial plexus MRI and computed tomography angiography (CTA) were also reviewed. ResultsThirteen TN-TOS patients were identified. The most common neurologic signs were hypesthesia in the medial forearm or ulnar digits and weakness of the abductor pollicis brevis (APB) muscle. In NCS, medial antebrachial cutaneous (MABC) sensory nerve action potential amplitude was decreased in all tested patients. The APB muscle was most commonly involved in EMG. Among radiologic criteria, focal stenosis of subclavian artery in CTA was the most common finding. ConclusionWe confirmed that TN-TOS is T1 predominant lower roots/trunk brachial plexopathy with clinical and electrodiagnostic features. Radiologic studies may be used to detect structural abnormalities. SignificanceAs MABC NCS showed abnormal results in all tested patients, it should be added to electrodiagnostic study as screening method. If present, structural abnormalities might be confirmed with radiologic studies.

Thoracic outlet syndromes. The so-called “neurogenic types”

Neurogenic thoracic outlet syndrome (TOS) is one of the most controversial pain syndromes of the upper limbs. The controversies revolve around both the diagnosis and treatment of the non-specific or subjective subtypes. Their diagnosis rests on a combination of history, suggestive symptoms and clinical examination. Proximal pain is primarily muscular in origin, while distal symptoms may be the result of intermittent nerve compression and/or myofascial pain syndrome. Stringent clinical criteria are required to confirm the diagnosis of subjective TOS. In reality, multiple factors can be entangled, with TOS being one element within a multifactorial pain disorder; any musculotendinous pathology of the upper limb and any peripheral nerve entrapment require screening for potential concomitant TOS. Surgery is indicated in most cases of true neurogenic TOS, whereas rehabilitation is the standard treatment for subjective TOS.

Neurological Signs and Symptoms of True Neurogenic Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a well-known disorder, but many aspects of its pathology, including its definition, has been disputed. True neurogenic TOS (TN-TOS) is a rare but well-defined clinical condition. TN-TOS results from the compression of the C8/T1 roots (dominant for the T1 root) or the proximal lower trunk of the brachial plexus by a fibrous band. The band extends from the first rib to either the tip of an elongated C7 transverse process or a rudimentary cervical rib. The most common presenting symptoms of TN-TOS are insidious-onset atrophy and weakness of the intrinsic hand muscles, predominantly in the thenar eminence and radial digit flexors. Nerve conduction studies demonstrate pathognomonic findings: severely attenuated compound muscle action potential of the abductor pollicis brevis muscle, and usually, loss of the sensory nerve action potential of the medial antebrachial cutaneous nerve. Numbness and sensory loss are typically observed, mainly in the medial forearm, although they are usually mild, and may be absent in some patients. Severe pain or paresthesia proximal to the elbow is not observed. The classical concept of TOS underlie nonspecific neurogenic TOS. It has been primarily diagnosed using provocative maneuvers. However, there is controversy regarding its pathological conceptualization and existence, as objective evidence of the disease is still lacking.

C8 and T1 innervation of forearm muscles

ObjectiveC8-dominant innervation of ulnar-innervated and T1-dominant innervation of median-innervated intrinsic hand muscles have been suggested, although less is known regarding forearm muscles. We aimed to determine myotomal innervation of the forearm muscles based on the clinical and electromyographial findings of patients with C8 or T1 lesions. MethodsMedical Research Council scale and EMG findings were retrospectively reviewed in 16 patients with C8 lesions (2 postmedian sternotomy C8 plexopathy and 14 C8 radiculopathy) and 9 patients with T1-dominant lesions (8 true neurogenic thoracic outlet syndrome and 1 T1 radiculopathy). ResultsClinical and EMG findings revealed T1-dominant innervation of the flexor digitorum superficialis, flexor digitorum profundus of the index finger, abductor pollicis brevis, and flexor pollicis longus muscles, and C8-dominant innervation of the flexor carpi ulnaris, flexor digitorum profundus of the little finger, and digit extensors innervated by the posterior interosseous nerve. The first dorsal interosseous, and abductor digiti minimi muscles seem to be innervated by both C8 and T1 roots. ConclusionsC8-dominant innervation of ulnar-innervated muscles and T1-dominant innervation of median-innervated muscles are also evident for forearm flexor muscles. SignificanceSuch an additional evidence for myotomal innervation will improve localization in clinical as well as electrophysiological diagnoses.

True neurogenic thoracic outlet syndrome (TOS) の臨床的・電気生理学的特徴

True neurogenic thoracic outlet syndrome (TOS) の臨床的・電気生理学的特徴

Electrodiagnostic features of true neurogenic thoracic outlet syndrome

We report the electrodiagnostic (EDX) features of 32 patients with surgically verified true neurogenic thoracic outlet syndrome (TN-TOS). Retrospective record review. We found uniform EDX evidence of a chronic axon loss process that affected the lower portion of the brachial plexus and disproportionately involved the T1 more than the C8 sensory and motor fibers. Because of this relationship, the medial antebrachial cutaneous sensory nerve (T1) and median motor (T1 > C8) study combination was abnormal in 89%, whereas response combinations that primarily assessed the C8 fibers were less frequently affected. The characteristic EDX features of TN-TOS are T1 > C8 nerve fiber involvement. A comprehensive EDX examination of the lower plexus with contralateral comparison studies is imperative to diagnose this disorder accurately.

Sonographic diagnosis of true neurogenic thoracic outlet syndrome

A 32-year-old woman presented with a 5-year history of left shoulder pain, medial hand and forearm numbness, and progressive hand weakness and atrophy. Electrodiagnostic studies were characteristic of true neurogenic thoracic outlet syndrome,1 and a chest X-ray showed bilateral elongated C7 transverse processes. High-resolution ultrasound studies revealed compression of the left lower trunk (LT) between a fibrous band and artery (figure, A). Magnetic resonance neurography (figure, B) and operative exploration (figure, C) confirmed the ultrasound findings. Clinical improvement was noted following surgical neurolysis of the LT. High-resolution ultrasound may be a useful and quick bedside tool to identify causative structural pathology in this classic neuromuscular disorder.

Thoracic outlet syndrome in 3T MR neurography—fibrous bands causing discernible lesions of the lower brachial plexus

To investigate whether targeted magnetic resonance neurography (MRN) of the brachial plexus can visualise fibrous bands compressing the brachial plexus and directly detect injury in plexus nerve fascicles. High-resolution MRN was employed in 30 patients with clinical suspicion of either true neurogenic thoracic outlet syndrome (TOS) or non-specific TOS. The protocol for the brachial plexus included a SPACE (3D turbo spin echo with variable flip angle) STIR (short tau inversion recovery), a sagittal-oblique T2-weighted (T2W) SPAIR (spectral adiabatic inversion recovery) and a 3D PDW (proton density weighted) SPACE. Images were evaluated for anatomical anomalies compressing the brachial plexus and for abnormal T2W signal within plexus elements. Patients with abnormal MR imaging findings underwent surgical exploration. Seven out of 30 patients were identified with unambiguous morphological correlates of TOS. These were verified by surgical exploration. Correlates included fibrous bands (n = 5) and pseudarthrosis or synostosis of ribs (n = 2). Increased T2W signal was detected within compressed plexus portion (C8 spinal nerve, inferior trunk, or medial cord) and confirmed the diagnosis. The clinical suspicion of TOS can be diagnostically confirmed by MRN. Entrapment of plexus structures by subtle anatomical anomalies such as fibrous bands can be visualised and relevant compression can be confirmed by increased T2W signal of compromised plexus elements. • MR neurography (MRN) can aid the diagnosis of thoracic outlet syndrome (TOS). • Identifiable causes of TOS in MRN include fibrous bands and bony anomalies. • Increased T2W signal within brachial plexus elements indicate relevant nerve compression. • High positive predictive value allows confident and targeted indication for surgery.

True Neurogenic Thoracic Outlet Syndrome Following Hyperabduction during Sleep - A Case Report -

True neurogenic thoracic outlet syndrome (TOS) is an uncommon disease and is difficult to diagnose at the early stage and then completely cure. We experienced a case of true neurogenic TOS with typical clinical symptoms and electrophysiologic findings as a result of repetitive habitual sleep posture. A 31-year-old woman who had complained of progressive tingling sensation on the 4th and 5th fingers with shoulder pain was diagnosed of brachial plexopathy at the lower trunk level by electrodiagnostic studies. There was no other cause of brachial plexopathy except her habit of hyperabduction of shoulder during sleep. This case demonstrated that the habitual abnormal posture can be the only major cause of neurogenic TOS. It is of importance to consider TOS with the habitual cause because simple correction of the posture could stabilize or even reverse disease progress.

Fibrotendinous band causing neurogenic Thoracic Outlet Syndrome in adolescent with bilateral cervical ribs

Thoracic Outlet Syndrome (TOS) describes a variety of symptoms caused by the compression of the neurovascular structures in the cervicoaxillary region as they leave the thorax toward the upper limbs. Causes of TOS are vascular and neurogenic, with neurogenic symptoms being the most common presentation (95% of patients). Symptoms related to neurogenic TOS include intrinsic hand muscle and thenar region atrophy and weakness, as well as medial hand and forearm numbness, which are all suggestive of lower trunk involvement. This condition is very rare in the pediatric population. We are reporting a case of true neurogenic TOS caused by a fibrotendinous band in an adolescent with bilateral cervical ribs who was submitted for surgical treatment at the right side.

A Case of True Neurogenic Thoracic Outlet Syndrome, Electrophysiologic Findings and Long-term Outcome After Surgery

A Case of True Neurogenic Thoracic Outlet Syndrome, Electrophysiologic Findings and Long-term Outcome After Surgery