T4 syndrome is a relatively uncommon condition in which spinal injury at the T4 vertebra causes a set of symptoms including diffuse arm pain and pins and needles or numbness in the upper arm.
T4 syndrome affects three times as many women as men, and is less common in the young and the old. Children are more flexible, and older people don't rotate so easily.
The upper back (thoracic spine) consists of 12 thoracic vertebrae named T1 to T12 from top to bottom. These vertebrae are connected to their neighbors with joints and discs which support body weight and enable the spine to flex. Near to these joints are nerves which can be damaged or irritated if a particular joint or disc is injured.
Certain types of movement produce forces that stretch or compress the joints and disc at the T4 level. For example, bending, lifting, arching, or twisting movements – or even just poor posture. Traumatic, excessive, repetitive or prolonged force can cause injury and result in irritation or damage to the nerve root at T4. Segments T2 through T7 can also be involved.
Risk factors include:
T4 syndrome produces a complex pattern of painful symptoms which may develop suddenly during the activity that causes the nerve damage, or appear gradually. Symptoms usually occur only on one side of the body, but may appear on both sides. They include:
Symptoms typically worsen at night and are also made worse by activities that involve twisting, lifting, arching backwards, bending forwards or sideways, prolonged sitting, laughing, coughing or sneezing, taking a deep breath, or activities that involve extending the arms in front of the body, such as driving.
T4 syndrome is rare, so it's usually a diagnosis of exclusion in which myelopathy, cardiac pain, thoracic outlet syndrome, systemic illness, thoracic tumor, polyneuritis, fibromyalgia, nerve root compression, and complex regional pain syndrome should be ruled out.
An analysis of patient history and symptoms combined with physical examination is often sufficient to diagnose T4 syndrome. X-ray, MRI or CT scan can confirm diagnosis but these imaging techniques can sometimes produce false positives.
In cases where physiotherapy doesn't resolve the problem, specialists may use X-ray, CT scan or MRI for further assessment. NSAIDs or a corticosteroid injection into the T4 joints may alleviate symptoms.
After treatment, the patient should return to normal activity levels gradually.
Recovery time varies between a few days and a few weeks, depending on the severity of the injury and how well the patient follows the physiotherapist's advice. However, the body does require a few more weeks to completely repair the damage, so the patient should not return to regular activity levels immediately. In severe cases, or cases where advice is not followed, symptoms can continue for months or years.