Regional anatomy - case studies of the spinal region

Authors Avatar by junjunjunjoon (student)

Jun Wang

NAECM2011-118007

Regional Anatomy Lab –Assignment 1

Case 1

Case Summary:

Lymph node biopsy was performed on a patient to obtain a sample of her left deep cervical nodes. Following the surgery, the patient complained of weakness in her left shoulder, which is then closely examined to confirm her inability to raise the point of her shoulder. However, the patient’s new symptom was not associated with numbness in her shoulder, back or neck.

Terms:

Lymph node biopsy: Lymph nodes are part of the body's immune system, where produce and harbor infection-fighting white blood cells (lymphocytes) that attack and can be attacked by both infectious agents and cancer cells. For that reason, physicians do a needle biopsy to remove a portion of a lymph node and examine under the microscope to find evidence of these problems.

Deep cervical nodes: are a group of lymph nodes situated around or near the internal jugular vein. Includes two groups, superior and inferior, based on the point where the omohyoid muscle crosses the vein.

Case Discussion:

In class, our group discussed about Case 1. Our first question was to identify which nerve has been cut during the biopsy that would cause the symptoms developed. After looking up the anatomical location of both deep cervical lymph nodes and all the major nerves neighboring, we were able to determine it was the Accessory nerve (CN XI) that was damaged by the biopsy.  

The dorsal primary rami provide only motor innervation to deep back motor muscle, and sympathetic/ general sensory innervation to the skin of the back. All muscles of the upper and lower limbs (e.g., the one responsible for raising the shoulder) are innervated by nerves that are branches of the ventral primary rami. Based on that, the spinal accessory nerve innervates the sternocleidomastoid and the trapezius muscles. It exits the skull through the jugular foramen, and travels deep to the sterocleidomastoid muscle (SCM), which it innervates. As the accessory nerve emerges from under the SCM, it is very superficial, and adjacent to cervical lymph nodes. That made the accessory nerve extremely vulnerable to the accidental injury by the needle puncturing through for the biopsy of the deep cervical lymph nodes. The nerve is then traverses the posterior triangle obliquely to innervate the trapezius muscle, which is the only muscle that can elevate the tip of the shoulder (the acromion). Typically, the sternocleidomastoid is normal, since the injury is to the nerve after the branch to the SCM has originated. Other symptoms that suggest the impairment of Accessory never are:

  • Limitation of shoulder abduction to about 80 degrees.
  • Pain, particularly with weight-bearing with an extended shoulder.
  • Winging of the upper border of the scapula with lateral abduction of the shoulder.
  • Limitation of abduction

Other nerve impairments that were eliminated as the possible damage cause are: greater occipital nerve, spinal nerve C3, dorsal scapular nerve and cutaneous never of the back (dorsal primary rami).

Join now!
  • The greater occipital nerve innervates posterior neck muscles and the skin of the posterior surface of the scalp. Damage to this nerve does not explain the patient's inability to raise her shoulder and would also manifest itself as numbness in the skin of the posterior surface of the scalp.
  • The spinal nerve C3 is formed by the dorsal and ventral roots of C3. Although branches from the ventral primary rami of both C3 and C4 combine with the accessory n. to form the subtrapezial plexus, C3 and C4 provide only proprioception to the trapezius muscle. Damage to either ...

This is a preview of the whole essay