Animated at right:
Open MRI Image
Guided Injection of Anterior Scalene Muscle
Patients with thoracic outlet
syndrome (TOS) typically experience heaviness and
weakness of the arm and hand with pain affecting the
neck, shoulder arm and hand. Ofter the ring finder
and little finger (4th and 5th digit are most affected
in the hand.
Among the most common causes
of TOS is compression of the arm nerves (the brachial
plexus) between the anterior and middle scalene muscles.
Often the diagnosis of TOS can be confirmed by image
guided injections of the scalene muscle. The injection
introduces a long acting anesthetic into the muscle,
relaxing it so that pressure on the nerves is relieved.
In some cases, injections of this type can actually
cure the condition. Injection of botulinum toxin into
the scalene muscle is also very effective in some
patients.
Unfortunately, the scalene muscle
is a small structure surrounded by the jugular vein,
the carotid artery, the top of the lung, the thoracic
duct, and by all of the nerves for your arm and hand
as well as nerves for breathing and even nerves for
the pupil of the eye and the eyelid. It cannot be
reliably felt through the skin as it is beneath several
other muscles. Safe, successful injection of the scalene
muscle has been a great obstacle to many patients
and physicians who find this treatment option medically
necessary. X-ray fluoroscopic guidance is not very
helpful as there are no 'X-ray visible' landmarks
near the scalene muscle. Excessive radiation from
X-rays are a risk for the radiation-sensitive thryoid
gland.
Now, Open MRI guided injection
for the scalene muscles has greatly transformed treatment
for TOS. With the Open MRI guidance procedure developed
by Dr. Aaron Filler at the Institute for Nerve Medicine,
the physician has a detailed real time view of the
scalene muscles and all of the sensitive structures
around it. This makes the procedure extraordinarily
safe and reliable. In addition it becomes possible
to reliably identify and inject other muscles in the
region that may become involved such as the levator
scapula, the middle scalene, the trapezius, the rhomboids,
and the sternocleidomastoid mucles.
In the coronal image (A),
the arrow indicates a darkened area caused by the
injectate within the anterior scalene muscle.
In the axial image (B),
the titanium needle is seen passing into the anterior
scalene muscle. The injectate has expanded the muscle,
however the failure of injectate to flow in to the
more posterior portions of the muscle suggests fibrosis
within the muscle.
