MeSH definition : Diseases of the eleventh cranial (spinal accessory) nerve. This nerve originates from
motor neurons in the lower medulla (accessory portion of nerve) and upper spinal cord
(spinal portion of nerve). The two components of the nerve join and exit the skull
via the jugular foramen, innervating the sternocleidomastoid and trapezius muscles,
which become weak or paralyzed if the nerve is injured. The nerve is commonly involved
in MOTOR NEURON DISEASE, and may be injured by trauma to the posterior triangle of
the neck.;
Diseases of the eleventh cranial (spinal accessory) nerve. This nerve originates from
motor neurons in the lower medulla (accessory portion of nerve) and upper spinal cord
(spinal portion of nerve). The two components of the nerve join and exit the skull
via the jugular foramen, innervating the sternocleidomastoid and trapezius muscles,
which become weak or paralyzed if the nerve is injured. The nerve is commonly involved
in MOTOR NEURON DISEASE, and may be injured by trauma to the posterior triangle of
the neck.