Question

During a family vacation, the Densmores were struck by a transfer truck which destroyed
their car. Luckily, the family survived with what seemed like superficial wounds, except for Mrs.
Densmore who appeared to suffer from ‘whiplash injury’. As the days passed, Mrs. Densmore
began to suffer neuromuscular symptoms. She exhibited a profound tilting of the head to the
right side of her body. Other tests by an orthopedic physician indicated partial paralysis of the
right sternocleidomastoid muscle. Subsequent x-rays revealed two displaced cervical vertebrae
that were placing pressure on the rootlets of one of her cranial nerves. After surgery to realign
the vertebrae and physical therapy, the symptoms partially disappeared within weeks and were
almost entirely reversed within a few weeks.

question:

4.   In Case Study 4, Mrs. Densmore only suffered issues to her sternocleidomastoid muscle. What other problems might be seen in someone with damage to that nerve?

Answer 1

Here, the nerve affected is the spinal root of accessory nerve (11th cranial nerve). Since sternocleidomastoid muscle is also supplied by C2 and C3 spinal nerves, there is only partial paralysis of patient's right sternocleidomastoid muscle due to injury of spinal accessory nerve caused by two displaced cervical vertebrae.

Lesions of spinal accessory nerve by fracture base of skull through jugular foramen or stab wounds in neck or during surgical removal of cervical lymph nodes can lead to:

• ipsilateral paralysis of sternocleidomastoid, with result that patient is unable to tilt his head towards ipsilateral shoulder and unable to turn his face towards opposite side.
• paralysis of trapezius, with result that patient is unable to shrug his shoulder against resistance.

Irritative central lesions of spinal accessory nerve cause spasmodic torticollis characterized by clonic spasms of sternocleidomastoid muscle.