CLINICAL PRESENTATION

This website emphasises immediate recognition of the presenting signs of the three subsets of TOS, as the condition is commonly misdiagnosed in practice. Understanding the presentation of TOS is pivotal to preventing long-term consequences, particularly chronic upper extremity pain, and severe disability due to nerve entrapment. Each subset of TOS presents differently, and knowing what to look out for will guide diagnosis (Rizzo et al., 2024).

Presentation of NTOS

nTOS is commonly depicted in young, healthy individuals who participate involving repeated overhead motions (e.g., throwing in baseball and grabbing a rebound in basketball). Manual labourers (e.g., factory workers and construction workers) who are constantly lifting heavy items, causing strain on the shoulder and neck, and people with sustained poor postures in their daily life (e.g., office workers and students) (Jones et al., 2019). The diagnosis of nTOS is constructed upon a history of presenting symptoms and subsequent clinical findings. The main presenting symptom of nTOS is a depressed scapula at rest, which is also commonly depicted during shoulder abduction and flexion causing nerve irritation and compression at the thoracic outlet (Watson et al., 2010).

nTOS can present in a true or disputed nature. True nTOS is only provided as a diagnosis if there are findings of objective, verifiable neurological deficits. These include positive nerve conduction or electromyography studies depicting abnormalities in the C8-T1 roots of the brachial plexus. Furthermore, muscle wastage and weakness in the hand and thenar eminence muscles (abductor pollicis brevis, flexor pollicis brevis and opponens pollicis) are commonly identified in advanced cases of true nTOS (Lee et al., 2011).

Disputed nTOS is characterised by symptoms of nerve compression without clear objective neurological defects. Electrodiagnostic tests often depict normal results, with no observable abnormalities on imaging. Diagnosis is based on clinical presentation, patients generally present with vague and widespread symptoms, complaining of fatigue, discomfort, and sensory changes in the upper limb (Panther et al., 2022).

Other common symptoms of disputed nTOS include pain in the trapezius muscles, occipital headaches, and supraclavicular pain (Sanders et al., 2008). Pain is also diffused throughout the posterior aspect of the anterior shoulder with a referral down the inner aspect of the arm following the ulnar nerve distribution (Jones et al., 2019).

A: Normal depiction of the shoulder girdle

B: The presentation of a depressed scapula causing a constriction of the structures in the thoracic outlet

(Watson et al., 2010)

PRESENTATION OF VTOS

vTOS also occurs in physically active individuals between the ages of 15-45, who participate in occupations or recreational activities involving heavy lifting, and repeated upper limb movements.

The clinical presentation of vTOS generally consists of acute upper limb swelling, usually after prolonged and/or forceful activity, as well as heaviness and aching during or after using the arm above the head. Distended veins may also be visible on the affected arm, shoulder, neck, or chest as a result of impaired blood drainage. Pain is depicted in the upper arm and shoulder region, and is generally described as a dull ache (Habibollahi et al., 2021).

Distended veins, common in patients with vTOS (Thompson et al., 2011).

PRESENTATION OF ATOS

aTOS patients typically present with cold upper extremities, numbness, and pallor during activities that require above head movements. Other symptoms may include cyanosis, weak or absent radial pulse in the affected limb as well as pain, cramping, and fatigue in the arm and shoulder (Jones et al., 2019).

(Vidyasri, 2022).