The most common site of origin in the head and neck is the masseter muscle, whereas IMH originating from the scalene muscles
are rarely seen.
In 15% of cases, C5 and C6 roots may fuse before piercing the anterior scalene muscle
or C5 root alone can pierce the belly of anterior scalene muscle
, as seen in 13% of cases.
In our patient, the tumor was attached to the supraclavicular fossa and adherent to the scalene muscles
, expanding nearby to involve vital anatomic structures, such as the internal jugular vein and accessory and phrenic nerves.
The US transducer was placed transversally on the neck at the level of the superior pole of the thyroid cartilage and then slightly aligned laterally where the nerve roots were observed between the anterior and middle scalene muscles
at the interscalene groove.
The results revealed increased electromyographic amplitude of the large superficial sternocleidomastoid, and anterior scalene muscles
in patients with neck pain.
At the level of the scalene muscles
, these branches regroup to form the superior, middle and inferior trunks, and when they leave the inter-scalene space, they form anterior and posterior divisions at the supraclavicular level.
The interscalene brachial plexus block was performed in the interscalene groove, between the anterior and middle scalene muscles
It can also occur with TOS, which encompasses three separate disorders involving compression of the subclavian artery, subclavian vein, or brachial plexus in the triangular space bordered by the first rib, clavicle, and scalene muscles
(2,4,6,10,11) Compression of the vein in the thoracic outlet through lateral abduction of the arm or hypertrophy of subclavian or anterior scalene muscles
can cause turbulence in the vein, which is exacerbated by increased venous flow experienced during exercise.
The thoracic outlet is the opening between the scalene muscles
and the rib cage.
The subclavian artery emerges from between the anterior and middle scalene muscles
and becomes the axillary artery as it passes the first rib.
The fascia covering the floor of the posterior triangle was removed by fine dissection and the scalene muscles
, levator scapulae muscle and splenius capitus muscle were exposed and identified.