Neurogenic thoracic outlet syndrome (TOS) is a clinical diagnosis based on the reproduction of a patient’s symptoms with a provocation test (arm elevation) after excluding other conditions that might cause similar symptoms. Neurologic symptoms and signs can vary from mild paresthesia and numbness to intrinsic hand muscle atrophy. The main controversy in patients with neurogenic TOS involves neurologic-type complaints of paresthesia, numbness, and pain. However, there is no positive objective test to identify the cause. A 54-year-old female patient presented with numbness and radiating pain in her bilateral arms that occurred every time she bowed her head while shampooing. The patient had a history of two neck sprains due to slipping before the onset of symptoms. In addition to pain and numbness in both arms at arm elevation, pain in the suprascapular and occipital areas was also present. After excluding cervical nerve root lesions and other bone abnormalities, the patient's symptoms disappeared by brachial plexus decompression through a supraclavicular approach. It is difficult to diagnose neurogenic TOS with pain and paresthesia without muscle weakness in the upper extremities. If physicians do not consider the possibility of neurogenic TOS in patients with upper extremity paresthesia and pain, unnecessary multiple treatments may be performed, prolonging patients’ suffering. The exacerbation of pain and paresthesia in both arms and hands can occur immediately after the head is lowered during shampooing. This can be interpreted as a characteristic symptom of a constricted interscalene triangle and brachial plexus compression caused by hyperabduction of the arm.
Thoracic outlet syndrome (TOS) refers to compression of the subclavian vessels and brachial plexus in the region of the superior aperture of the chest, with the most common compression of these structures against the first rib
We want to report a very rare case of paresthesia accompanying arm elevation. It occurred on both arms as the main symptom whenever the head was bowed. A hyperabduction test of the arm on physical examination was helpful for the diagnosis. Subsequent decompression of the brachial plexus via the supraclavicular approach successfully relieved the pain and paresthesia of the neurogenic TOS.
A 54-year-old female patient presented with numbness and radiating pain in her bilateral arms every time she bowed (
In the early stages of pain, the pain that occurred momentarily disappeared immediately. Over time, the duration of pain and numbness accompanied by lowering the head increased. Sometimes, as the momentary pain lasted for more than 5 min, the patient had no choice but to stay still while waiting for the pain to go away. Sometimes numbness occurred in both arms and left upper back when the patient turned her head sideways. At night, numbness occurred in the arms according to the posture of the neck. Six months prior to her presentation, the pain intensified, making the patient's daily life difficult. In particular, when the patient bowed her head while shampooing, the pain in both arms lasted for more than two hours. Along with numbness in both arms when bowing the head, a tightening pain occurred in the left occipital area. Occipital pain was tightening and squeezing in nature. It lasted all day. It radiated to the left temporal and posterolateral neck (
On physical examination, no specific findings were observed except for the surgical scar for cervical fusion on the front neck. It was confirmed that immediate numbness occurred in both arms when the patient bowed her head. Numbness in both arms occurred even when the patient's head was turned to the side a lot. However, limitation of neck motion was not confirmed. Neurological examination revealed that both arms and hands had no motor weakness. Pinch and grip strengths were also found to be normal. The deep tendon reflex was normoactive. Mild hypesthesia was observed in the left supraclavicular region, shoulder, and upper lateral region of the left upper arm. A slight tenderness was found in the left supraclavicular region. However, no paresthesia was induced upon compression.
Percussion of the nerve (Tinel’s sign) was negative in the common nerve entrapment site (carpal tunnel, median nerve forearm, cubital tunnel, and brachial plexus) of the upper extremity. However, hyperabduction of bilateral arm to 180 degrees while keeping wrists and elbows straight for 1 min produced mild paresthesia of bilateral arms and hands, and it was judged to be positive. The Wright hyperabduction and Adson tests were negative. The Spurling’s test was also negative. There were no systemic diseases to cause pain. Laboratory findings showed no abnormalities. Electrodiagnostic tests including electromyography (EMG), nerve conduction test, and SSEP was all normal. Plain radiographs of the chest and cervical spine showed no cervical ribs or other bony abnormalities such as prominent transverse process or old clavicle fractures, or findings of degenerative arthritis, such as instability, osteophytes, or intervertebral disk space narrowing other than C5/6 anterior cervical fusion. Computed tomography (CT) and magnetic resonance imaging (MRI) of the cervical spine showed no evidence of residual stenosis or adjacent segment degeneration after cervical surgery. Hypertrophy of scalene muscles and irregularity of the brachial plexus contour was suspected on brachial plexus MRI (
The supraclavicular approach for decompression of the brachial plexus was performed first on the left side, where the pain was more severe. The operation was performed under general anesthesia and intraoperative neurophysiological monitoring according to the method suggested by Mackinnon et al.
In an interview two weeks after the surgery, no neurological abnormalities were observed in the left arm. The pain in the surgical site was minimal. The patient reported that the numbness in the left arm when the head was bowed no longer occurred, although it was still present in the right arm. The pain in the left occipital area along with the pain in the left arm completely disappeared. The patient requested an expedited surgical schedule for her right arm pain.
Decompression of the right brachial plexus was performed one and a half months after the operation on the left. It was performed in the same manner as in the first left surgery (
TOS is a constellation of clinical manifestations in the neck, shoulder, and upper extremities caused by compression of neurovascular structures in the thoracic outlet region
Neurogenic TOS is thought to result from a combination of a congenial anatomical predisposition and trauma to the neck
TOS typically occurs in young and middle-aged adults. It occurs in women three times more frequently than in man
The brachial plexus has a course between the anterior and middle scalene muscles. It continues distal deep to the clavicle and superior to the first rib. This opening is anatomically referred to as the thoracic inlet and clinically as the thoracic outlet
The anterior scalene muscle originates from the anterior tubercles of the transverse processes of the third through sixth cervical vertebrae. It inserts onto the scalene tubercle of the first rib. The middle scalene originates from the posterior tubercles of transverse processes of the second through seventh cervical vertebrae. It inserts onto a more posterior portion of the first rib. The subclavian artery and the brachial plexus pass through the space posterior to the anterior scalene muscle called scalene triangle or interscalene space. This space is bounded by the anterior scalene muscle anteriorly, the middle scalene muscle posteriorly, and the first rib inferiorly. It has some overlap with the posterior space of the costoclavicular space
The diagnosis of TOS is based on findings of clinical evaluation, particularly if symptoms can be reproduced when various dynamic maneuvers including elevation of the arm are undertaken
The onset of symptoms of TOS may be insidious or follow trauma
It is important to distinguish between the more common cervical spine diseases and TOS
Among several provocative maneuvers of neurogenic TOS, hyperabduction test described by Novak et al.
Imaging tests such as CT and MRI are needed to investigate congenital or other organic causes of TOS such as tumors or other space-occupying soft tissue lesions
CT and MRI might be helpful in the identification of soft tissue abnormalities associated with TOS. Several anatomical variations of the scalene muscles have been suggested to be responsible for TOS
Electrodiagnostic studies are typically normal in patients with TOS unless TOS is associated with cubital or carpal tunnel syndrome
It is known that 50% to 80% of patients with neurogenic TOS improve through physioptherapy
For thoracic outlet decompression, several surgical approaches have been proposed, including high posterior thoracoplasty, anterior approach, and transaxillary approach
Diagnosis and treatment of TOS remain controversial and difficult, particularly in patients with neurogenic TOS without muscle atrophy. In these patients, the diagnosis of neurogenic TOS can be made by provocative testing after excluding other potentially causative conditions. Most patients improve with conservative management, including activity, posture modification, and physical therapy. Those with persistent significant symptoms are candidates for surgical decompression with a supraclavicular approach.
No potential conflict of interest relevant to this article was reported.
Distribution of bilateral arm pain and radiologic findings. (A) Distribution of pain and paresthesia (hatched area) in the bilateral arms and hands. The gray area indicates the distribution of the aching pain associated with arm paresthesia. (B) Distribution of aching and tightening pain in the left occipital area. It radiated to the temporoparietal vertex and posterolateral neck. (C) Sagittal T2-weighted magnetic resonance imaging of the cervical spine showing no abnormality, except for prior C5/6 anterior cervical discectomy fusion (arrow). (D) A coronal T2-weighted, enhanced, short tau inversion recovery image of the brachial plexus showing suspected hypertrophy of the anterior scalene muscle (white arrows) and interdigitation of the contour of the brachial plexus (black arrows). Deviation in the course of the lower trunk of the right brachial plexus (white arrow) was noted. (E) A sagittal T2-weighted image of the left brachial plexus shows the left brachial plexus (white arrow) leaving the interscalene triangle between the anterior (black arrow) and middle (white arrowhead) scalene muscles. The back arrowhead indicates the subclavian artery.
Intraoperative photographic findings of neurogenic thoracic outlet syndrome during decompression surgery via the supraclavicular approach. (A) An intraoperative photograph showing the upper trunk (black arrows) of the left brachial plexus. The upper trunk was found to be impinged between the anterior (white arrows) and middle (white arrowhead) scalene muscles. The white star indicates the left phrenic nerve, branching from the upper trunk. (B) An intraoperative photograph showing decompression of the left brachial plexus. Indentation and distortion of the course of middle and lower trunks of the brachial plexus medial to the upper trunk (black arrows) were found between cut edges of the anterior (white arrow) and middle (white arrowhead) scalene muscles. The white star indicates the left phrenic nerve. The black arrowhead indicates the long thoracic nerve. (C) An intraoperative photograph showing the upper trunk (black arrows) of the right brachial plexus. The upper trunk was swollen and fixed between the tense anterior (white arrows) and posterior (white arrowhead) scalene muscles. The white star indicates the left phrenic nerve overlying the anterior scalene muscle. (D) An intraoperative photograph showing completed decompression of the right brachial plexus (black arrows). Indentations of the lower and middle trunks of the right brachial plexus were observed medial to the upper trunks (black arrows) between cut edges of the anterior (white arrow) and middle (white arrowhead) scalene muscles. The long thoracic nerve (black arrowhead) was isolated from the middle scalene muscle.