EMERGENCY:Vascular TOS with acute arm swelling, discolouration, or absent radial pulse is a vascular emergency. Arterial TOS with distal embolisation can cause finger ischaemia. Venous TOS (Paget-Schroetter) requires urgent anticoagulation. —call040-46324365immediately — 24 hours, 7 days— 24/7
Thoracic Outlet Syndrome in Hyderabad: Pain and Numbness From the Neck to the Little Finger That Worsens With Overhead Work — Cervical Rib, Physiotherapy, and Surgery at KIMS
Expert ROOS and Adson's provocation testing, chest X-ray for cervical rib, dedicated MRI brachial plexus, NCS with the sensitive MABC sensory study, EMG of C8–T1 muscles, CT angiography for vascular TOS, structured 12–16 week TOS physiotherapy programme, transaxillary first rib resection, supraclavicular scalenectomy and cervical rib excision, urgent anticoagulation and catheter-directed thrombolysis for Paget-Schroetter, and vascular reconstruction for arterial TOS at KIMS Neuroscience, Secunderabad, Hyderabad.
TOS is compression of the brachial plexus lower trunk (C8–T1), subclavian artery, or subclavian vein in the thoracic outlet — the space between the clavicle and first rib. Three forms: neurogenic TOS (90%): lower trunk compression causing inner arm pain and C8–T1 sensory symptoms; arterial TOS: subclavian artery compression with arm claudication and distal embolisation; venous TOS (Paget-Schroetter): subclavian vein thrombosis in young athletes after vigorous upper limb exercise. Causes: cervical rib (0.5–1% of population, bilateral in 50%), fibrous bands, scalene muscle hypertrophy. The ROOS stress test (3 minutes in the goalpost position) is the most sensitive provocation test. The medial antebrachial cutaneous (MABC) nerve sensory study is the most sensitive electrodiagnostic indicator, more sensitive than standard ulnar/median NCS. Cervical rib is visible on plain chest X-ray. Treatment: TOS physiotherapy (12–16 weeks), first rib resection or scalenectomy.
- The ROOS stress test
- Arms held at 90 degrees abduction and 90 degrees external rotation (goalpost position). Open and close fists for 3 minutes. Positive: arm heaviness, numbness, pain forces the arms down before 3 minutes. The most sensitive provocation test for neurogenic TOS.
- MABC nerve study — the sensitive test
- Medial antebrachial cutaneous (MABC) nerve traverses the thoracic outlet and is the most sensitive electrodiagnostic indicator of lower trunk (C8–T1) compression. Standard median and ulnar NCS are often borderline normal in nTOS. At KIMS, MABC study is performed for all suspected TOS.
- Three forms
- Neurogenic TOS (90%): inner arm and hand pain/tingling, overhead-aggravated · Arterial TOS (rarest): arm claudication, digital ischaemia from subclavian aneurysm embolisation · Venous TOS (Paget-Schroetter): sudden arm swelling in young athlete
- Paget-Schroetter = emergency
- Sudden arm swelling + bluish discolouration in a young athlete after vigorous upper limb exercise = effort thrombosis of subclavian vein. Duplex US immediately. Anticoagulation urgently. Catheter-directed thrombolysis within 7–14 days. First rib resection after anticoagulation.
- Cervical rib
- Present in 0.5–1% of population · Bilateral in ~50% · More symptomatic in women · Visible on plain AP chest X-ray with lower cervical spine · Incidental finding without symptoms = no treatment needed
- Surgery at KIMS
- Transaxillary first rib resection (primary approach) · Supraclavicular scalenectomy + cervical rib excision (when cervical rib is primary compressor) · Infraclavicular (retropectoralis minor decompression) · 70–85% success in selected patients
- Distinguish from cubital tunnel
- nTOS: overhead arm use aggravates · Cubital tunnel: elbow flexion aggravates · Both C8–T1 distribution · MABC NCS + ROOS test distinguishes
| Fact | Details |
|---|---|
| Three forms | Neurogenic (90%): lower trunk C8–T1, inner arm pain · Arterial (rarest): subclavian artery, digital ischaemia · Venous (Paget-Schroetter): subclavian vein thrombosis in young athletes |
| Cervical rib | 0.5–1% population · Bilateral 50% · Visible on plain CXR · Asymptomatic = no treatment · Symptomatic = context of TOS assessment and physiotherapy/surgery |
| ROOS test | 90 degrees abduction + 90 degrees ER (goalpost) for 3 minutes · Positive: arm drop from heaviness/pain/numbness before 3 minutes · Most sensitive nTOS provocation |
| MABC nerve study | Most sensitive NCS for lower trunk TOS · Standard ulnar/median often borderline normal · Slowed or absent MABC = diagnostic support for nTOS |
| Paget-Schroetter | Young athlete + sudden arm swelling + bluish discolouration = emergency · Duplex US + anticoagulation + thrombolysis within 7–14 days + first rib resection |
| Physiotherapy | First-line for neurogenic TOS: scalene stretching + postural correction + pectoralis minor stretch + neural mobilisation · 12–16 weeks · 50–70% achieve adequate control |
| Surgery outcomes | 70–85% significant improvement in selected nTOS patients · 5–10% recurrence from scar · Arterial TOS: vascular reconstruction as indicated |
About This Condition
Thoracic Outlet Syndrome at a Glance
The essential facts that shape how thoracic outlet syndrome is recognised at KIMS — the three anatomical compartments of the outlet, the three clinical forms (neurogenic, arterial, venous), the most common causes and anatomical variants including cervical rib, and the ROOS stress test that defines the clinical diagnosis.
What it is
Thoracic outlet syndrome (TOS) is a group of conditions caused by compression of the neurovascular structures — the brachial plexus, subclavian artery, or subclavian vein — as they pass through the thoracic outlet. The thoracic outlet is the space between the clavicle and the first rib, subdivided into three anatomical compartments: the scalene triangle (between the anterior and middle scalene muscles), the costoclavicular space (between the clavicle and first rib), and the retropectoralis minor space (beneath the pectoralis minor tendon). Structures passing through these compartments can be compressed by anatomical variants, muscular hypertrophy, or fibrous bands.
Three forms of TOS
Neurogenic TOS (nTOS): by far the most common (90% of TOS cases). Compression of the lower trunk of the brachial plexus (C8–T1 nerve roots) produces pain, paraesthesia, and weakness in the inner arm and hand (ulnar distribution). True neurogenic TOS (Gilliatt-Sumner hand): a rare, severe form with wasting of the thenar and hypothenar muscles and electrophysiological abnormalities. Disputed neurogenic TOS: the more common clinical syndrome with symptoms but no electrodiagnostic abnormality. Arterial TOS (aTOS): subclavian artery stenosis or aneurysm producing arm claudication, Raynaud's phenomenon, and distal embolisation (cold, painful, white or blue fingers from microemboli). Venous TOS (vTOS): subclavian vein thrombosis (Paget-Schroetter syndrome) producing sudden arm swelling, pain, and discolouration — classically in young, athletic individuals after vigorous upper limb exercise.
Causes and anatomical variants
Cervical rib: a supernumerary rib arising from C7 that projects into the thoracic outlet — present in approximately 0.5–1% of the population, bilateral in approximately 50%, more symptomatic in women. A cervical rib can be seen on plain chest X-ray (AP view including the lower cervical spine). Anomalous fibrous band extending from C7 to the first rib (even without a bony cervical rib). Scalene muscle hypertrophy or anomalous insertion. Clavicle malunion after fracture (reducing the costoclavicular space). Poor posture (rounded shoulders, forward head) chronically narrowing the thoracic outlet.
ROOS stress test — the key provocation
The ROOS (elevated arm stress test) or "challenged abduction external rotation" (AERE) test: the patient holds the arms at 90° abduction and 90° external rotation (the "goalpost" position) and repeatedly opens and closes the fists for 3 minutes. A positive test reproduces the symptoms (arm fatigue, numbness, pain) within 3 minutes and causes the patient to drop the arms. The ROOS test is the most sensitive provocation test for nTOS.
Appointment
040-44885000
The Teacher Whose Arm Went to Sleep on the Blackboard
A 34-year-old schoolteacher in Hyderabad attends KIMS with a 2-year history of pain and tingling in her right arm and hand. The pain originates at the base of the neck, radiates down the inner arm and forearm to the little finger. It is worst when she is writing on the blackboard — her right arm becomes heavy, aching, and numb within 3–4 minutes of overhead writing. It is also bad when drying her hair or reaching overhead shelves. Lying on the right side at night worsens the symptoms; supporting the arm on a cushion provides partial relief. She has been told she has cervical spondylosis and has been on physiotherapy and anti-inflammatory medications for 18 months with limited improvement.
At KIMS, the examination: ROOS stress test is positive at 90 seconds — she cannot maintain the goalpost position for even 2 minutes before severe arm pain and hand tingling force her to lower the arm. Adson's test: radial pulse diminishes on right with head turned to the right and deep inspiration (note: radial pulse reduction during Adson's maneuver can occur in asymptomatic individuals and is not diagnostic of arterial TOS by itself). Tinel's over the brachial plexus at the supraclavicular fossa: reproduces inner arm tingling. No thenar or hypothenar wasting. Neurological examination of the cervical spine: full range of motion; Spurling's test negative. NCS: mild slowing of medial antebrachial cutaneous sensory nerve (MABC — a nerve that traverses the thoracic outlet and is characteristically affected in nTOS); median and ulnar NCS at standard sites: borderline normal.
Chest X-ray (AP with lower cervical spine): a bilateral cervical rib visible at C7, right larger than left. MRI brachial plexus: no intrinsic nerve pathology; the lower trunk appears compressed at the level of the right cervical rib. The thoracic outlet MRI confirms the anatomical relationship between the cervical rib and the lower plexus trunk.
Management at KIMS: initial 12-week physiotherapy programme specifically for TOS (scalene muscle stretching; postural correction exercises; shoulder girdle strengthening to elevate the clavicle and widen the thoracic outlet). At 12-week review: 40% improvement in symptoms. She returns to most activities but cannot teach for a full day of blackboard writing without significant arm symptoms. Surgical referral is made: first rib resection and cervical rib excision at KIMS. At 6-month post-operative review: arm symptoms fully resolved. She is teaching without restriction.
Book a Consultation
Speak directly with The KIMS Neuroscience team and the KIMS thoracic outlet specialist team — neurosurgery, peripheral nerve and brachial plexus surgery, vascular surgery, clinical neurophysiology (NCS/EMG, MABC), neuroradiology, and TOS-specific physiotherapy coordinated under one roof. No referral required. Monday to Saturday.
040-44885000Emergency (vascular TOS): 040-46324365Clinical Features by TOS Type
The four clinical profiles of TOS at KIMS — neurogenic TOS with C8–T1 inner-arm symptoms aggravated by overhead use, arterial TOS with digital ischaemia from subclavian artery embolisation, venous TOS (Paget-Schroetter) with effort thrombosis in young athletes, and the disputed neurogenic form diagnosed clinically with MABC support.
Neurogenic TOS — inner arm pain and the C8–T1 distribution
The brachial plexus lower trunk (C8–T1) is the structure most commonly compressed in neurogenic TOS. The resulting symptoms are in the C8–T1 distribution: pain along the inner arm and forearm; tingling and numbness in the ring and little fingers and the medial palm; and weakness of the intrinsic hand muscles (grip and pinch). This distribution overlaps significantly with cubital tunnel syndrome (ulnar nerve) and C8 radiculopathy from the cervical spine, making TOS one of the most commonly confused diagnoses in upper limb neurology. Key distinguishing features of nTOS: symptoms aggravated by overhead arm use (reaching up, hair drying, overhead storage); symptoms in the supraclavicular fossa with pressure; and the positive ROOS test at under 3 minutes. Cubital tunnel syndrome worsens with elbow flexion, not overhead arm use.
Arterial TOS — the rarest and most dangerous form
Arterial TOS (aTOS) involves the subclavian artery and typically occurs in the presence of a complete cervical rib that produces a post-stenotic dilatation (aneurysm) of the subclavian artery distal to the compression. This aneurysm can thrombose and embolise distally — producing cold, painful, white or blue fingers from digital ischaemia. The presentation can mimic Raynaud's phenomenon. A reduction in radial pulse during a provocative maneuver (such as Adson's test) may occur in TOS but is not diagnostic by itself — radial pulse reduction can occur in asymptomatic individuals and its diagnostic value in isolation is limited. Arterial TOS should be diagnosed based on compatible vascular symptoms and signs together with appropriate vascular imaging (CTA/MRA showing subclavian artery abnormality). This form requires urgent vascular surgical referral at KIMS — digital ischaemia from embolisation can lead to finger amputation.
Venous TOS (Paget-Schroetter syndrome) — effort thrombosis
Paget-Schroetter syndrome is acute subclavian vein thrombosis in a young, athletic person following vigorous upper limb exercise (weight-lifting, swimming, throwing sports). The vein is acutely compressed in the costoclavicular space and thromboses. Presentation: sudden onset of arm swelling, heaviness, bluish discolouration, and dilated superficial veins over the chest and shoulder on the affected side. Diagnosis: duplex ultrasound of the subclavian vein; venography in selected cases. Treatment at KIMS: urgent anticoagulation (heparin followed by warfarin or DOAC); catheter-directed thrombolysis within 7–14 days of onset for selected young patients with significant residual thrombus; first rib resection after anticoagulation to prevent recurrence.
Disputed neurogenic TOS — the diagnosis without electrodiagnostic confirmation
The majority of TOS patients — those with typical symptoms, positive provocation tests, and relief with TOS-specific physiotherapy, but normal standard NCS and EMG — have "disputed neurogenic TOS". This remains a controversial diagnosis because the electrophysiological confirmation is absent. At KIMS, the medial antebrachial cutaneous (MABC) nerve sensory study is a sensitive adjunct — slowing of MABC conduction is more sensitive than standard ulnar or median NCS for detecting lower trunk compression. In patients with classic history, positive ROOS test, MABC abnormality, and cervical rib on CXR, the clinical diagnosis is made and surgery is considered after physiotherapy failure.
Diagnosis at KIMS
Diagnosis at KIMS
Thoracic outlet syndrome is diagnosed at KIMS with a staged workflow combining plain imaging, sensitive electrophysiology, dedicated nerve MRI, and provocative- position CT angiography for vascular forms :
Chest X-ray — cervical rib identification
AP chest X-ray with the neck included (lower cervical spine visible) identifies a cervical rib at C7. A well-corticated complete cervical rib articulating with the first rib, a rudimentary cervical rib ending freely, or a unilateral elongated C7 transverse process can all compress the lower plexus trunk. Present in 0.5–1% of the population; visible on plain film.
NCS and EMG — with MABC nerve study
Standard NCS of median and ulnar nerves (usually normal or borderline in most nTOS). Medial antebrachial cutaneous (MABC) sensory NCS: this nerve arises from the medial cord of the brachial plexus (C8–T1) and traverses the thoracic outlet — it is the most sensitive electrodiagnostic indicator of lower plexus compression. Slowed or absent MABC response supports nTOS. EMG: denervation in C8–T1 muscles (intrinsic hand muscles, flexor carpi ulnaris, abductor pollicis brevis) indicates true neurogenic TOS with axon loss.
MRI brachial plexus — nerve imaging
Dedicated MRI brachial plexus with sagittal and coronal oblique sequences identifies compression, oedema, or signal change in the lower trunk as it passes over a cervical rib or fibrous band. Normal MRI does not exclude nTOS. MRI also demonstrates the relationship of the cervical rib to the nerve trunk and helps plan surgery.
CT angiography — for vascular TOS
CTA with arm in provocative position (arms elevated) identifies subclavian artery compression, post-stenotic dilatation, aneurysm, or subclavian vein thrombosis. Essential for any patient with suspected arterial or venous TOS.
Treatment
Treatment at KIMS
The KIMS thoracic outlet syndrome programme is built around four integrated management areas — first-line TOS-specific physiotherapy, surgical decompression with first rib resection and scalenectomy, transparent surgical outcomes and recurrence rates, and the vascular-TOS pathway of anticoagulation, catheter-directed thrombolysis, and rib resection.
Physiotherapy, surgical decompression, outcomes & vascular TOS care at KIMS
Physiotherapy — First Line for Neurogenic TOS: A structured 12–16 week programme of TOS-specific physiotherapy: scalene muscle stretching (the anterior and middle scalenes are the primary compressors in the scalene triangle); postural correction (strengthening the lower trapezius and serratus anterior to elevate the clavicle and open the thoracic outlet); pectoralis minor stretching (reducing retropectoralis minor space compression); and neural mobilisation exercises. Approximately 50–70% of nTOS patients achieve adequate symptom control with physiotherapy alone.
Surgical Decompression — First Rib Resection and Scalenectomy: Surgical decompression of the thoracic outlet at KIMS is indicated for: nTOS failing 3–4 months of physiotherapy; true neurogenic TOS with electrophysiological abnormalities; aTOS (with vascular reconstruction if needed); vTOS after anticoagulation. Approaches: transaxillary first rib resection (resection of the first rib through the axilla — the most common approach for primary thoracic outlet decompression); supraclavicular scalenectomy and cervical rib excision (preferred when a cervical rib is the primary compressor or when the brachial plexus needs to be directly explored); and infraclavicular approach (for retropectoralis minor decompression).
Surgical Outcomes & Recurrence Rates: Outcomes of first rib resection: in carefully selected nTOS patients failing physiotherapy, approximately 70–85% achieve significant symptom improvement after surgery. Recurrence (from scarring around the nerve stump of the resected rib or from residual fibrous band) occurs in approximately 5–10% of cases.
Related Conditions
Thoracic outlet syndrome belongs to the family of peripheral nerve disorders evaluated and managed at KIMS Neuroscience. Explore related peripheral nerve conditions or return to the peripheral nerve disorders hub.
FAQs
Frequently Asked Questions
The arm that goes numb on the blackboard. The swimmer with the swollen blue arm. The cervical rib found on X-ray that explains years of inner arm pain.
Thoracic outlet syndrome is diagnosed at KIMS Neuroscience, Secunderabad, Hyderabad with a dedicated brachial plexus MRI, MABC nerve study, and CT angiography, and treated with TOS physiotherapy or first rib resection and scalenectomy. Emergency (vascular TOS): 040-46324365. Appointments: 040-44885000.
International enquiries: info@kimsneurosciences.com