SYMPTOMS OF TOS

What are the symptoms of the thoracic outlet syndrome?

Symptoms of thoracic outlet syndrome depend on the type of TOS yet most of them overlap in various forms of disease. 

Neurogenic TOS – nTOS. There are three cardinal symptoms of n-TOS – pain, sensory and motor disturbances. Pain is by far the most frequent and consistent symptom. It is usually located in the shoulder and radiates to head, neck, back, armpit, chest, arm, hand and fingers. Pain may be constant or intermittent. 

Sometimes chest pain may mimic heart attack and patients may mimic heart attact and some patients might undergo coronary angiography for suspected myocardial infarction. Pain is exasperated by physical activity and raising the affected arm. One of the typical finding is avoiding to hold the phone  on the affected side due to early arm fatigue and pain. Headache located at the back of the head is very common. In addition, to pain patients frequently develop arm and hand numbness and tingling. Numbness may be constant or intermittent and is usually accompanied with sensation of pins and needles in the affected area. Motor deficits or simply muscle weakness is initially present as early fatigue, but later progresses to significant weakness and wasting (atrophy) especially in the hand (Gilliatt-Sumner hand). 

Venous TOS – vTOS. Pain, cyanosis (bluish discoloration) and edema (fluid accumulation) are the presenting symptoms. Symptoms may diminish when the arm is raised up so blood easily flows back. In some cases, subclavian vein is thrombosed resulting in significant compromise of blood flow – Paget-Schroetter disease. In some cases, network of collateral veins is visible in the shoulder and upper chest. Pain is usually accompanied by tingling sensation in hands and finges. 

Arterial TOS – aTOS. Pain, tingling, paleness, early fatigue, and coldness are presenting symptoms. In some cases subclavian artery may get thrombosed and result in sudden loss of blood flow to the arm. Such acute cases require immediate intervention to avoid arm gangrene. Chronic cases may be misdiagnosed as Raynaud syndrome.

Combined symptoms. Vascular symptoms may be combined with neurogenic. In these cases, a combination of above mentioned symptoms may be present. 

There is growing evidence that thoracic outlet syndrome may impede with brain blood supply. It is believed to develop due to insufficient blood flow in the vertebral artery. Two vertebral arteries are among four vessels proving blood supply for the brain (the other two are carotid arteries). It is a branch of subclavian artery and any impairment of flow in parent (subclavian) vessel may cause disturbance in the daughter (vertebral) resulting in  the insufficient blood supply to the brain. Although, the mechanism of vertebral (or vertebrobasilar) insufficiency is poorly understood, the permanent of temporary impairment of brain blood flow in TOS is well documented. In extreme cases, the patient may present with stroke due  to significant brain blood flow impairment. However, in the vast majority of cases symptoms are not so severe and tend to be temporary. Exercise induced symtoms are quite typical. Since vertebral arteries supply the brainstem, cerebellum and the back part of the brain insufficient blood supply may result in disturbance of these brain regions. Symptoms may inlcude dizziness, tinnitus, visual disturbances, and gait problems.