Encyclopedia of Health and Medicine

284 The Nervous System
that support survival such as respiration, BLOOD
PRESSURE, and HEART RATE. COMPUTED TOMOGRAPHY
(CT) SCAN or MAGNETIC RESONANCE IMAGING (MRI) can
show the full extent of the injury.
Treatment Options and Outlook
The standard of care is to administer an intravenous
corticosteroid medication, methylprednisolone,
within eight hours of a spinal cord. The
methylprednisolone reduces the body’s natural
inflammatory response, lessening the risk for
added pressure within the spinal canal and the
direct damage to neurons that INFLAMMATION
causes. Other treatment options may include surgery
to stabilize the spine and remove any BONE
fragments or debris from the spinal canal or using
braces to immobilize the spine. Supportive measures
such as MECHANICAL VENTILATION may be necessary,
depending on the level of the injury.
Ongoing treatment typically includes early and
aggressive PHYSICAL THERAPY, OCCUPATIONAL THERAPY,
and other rehabilitation approaches to maintain
MUSCLE tone and STRENGTH as well as to restore as
much independence as possible. Much of this
treatment may take place at an inpatient rehabilitation
center that specializes in spinal cord
injuries. Many people are able to recover to a reasonable
level of function through the use of
mobility aids and assistive devices. When the
injury is incomplete, full recovery is sometimes
possible. However, it is difficult for neurologists to
predict what level of recovery is likely. An individual’s
general health condition, motivation, and
persistence are important influences.
Risk Factors and Preventive Measures
Measures that reduce the risks for spinal cord
injury are those that lower the likelihood of motor
vehicle accidents. Many of these risks are behaviors
such as excessive speed, driving while intoxicated,
and failure to wear seat belts. Proper
technique and equipment for athletic activities
such as horseback riding, downhill skiing, bicycling,
and contact sports help improve the safety
of participating in these events.
See also CORTICOSTEROID MEDICATIONS; NEURON;
NEUROTRANSMITTER; QUALITY OF LIFE; TRAUMATIC BRAIN
INJURY (TBI).
spinal nerves The 31 paired nerves that branch
from the SPINAL CORD, extending into the body to
form the PERIPHERAL NERVES. The spinal nerves and
the CRANIAL NERVES together make up the PERIPH-
ERAL NERVOUS SYSTEM. The spinal nerves emerge
from the gray matter of the spinal cord in two
roots. The ventral (anterior or front) spinal NERVE
root is the motor portion of the spinal nerve that
carries nerve impulses from the BRAIN and spinal
cord to the peripheral body. The dorsal (posterior
or back) spinal nerve root is the sensory portion of
the spinal nerve that carries nerve impulses from
the body to the spinal cord and brain. Each spinal
nerve root immediately branches into several
rootlets, which subsequently give rise to the
peripheral nerves that serve the body (excluding
the head and face).
SPINAL NERVE PAIRS
cervical: 8 pairs, designated C1 through C8
thoracic: 12 pairs, designated T1 through T12
lumbar: 5 pairs, designated L1 through L5
sacral: 5 pairs, designated S1 through S5
coccygeal: 1 pair, designated CO1
Spinal nerve pairs C1 through C4 serve the neck
and are collectively referred to as the cervical
plexus. Spinal nerve pairs C5 through T1 serve the
upper extremities and main trunk and are collectively
known as the thoracic plexus. Spinal nerve
pairs L1 through L5 (the dorsal roots of L4 and L5)
serve the lower back and legs and are collectively
referred to as the lumbar plexus. Spinal nerve pairs
L4 (the ventral roots of L4 and L5) through S3
serve the structures of the lower abdomen and are
collectively known as the sacral plexus. Spinal
nerve pairs S4, S5, and CO1 serve the structures of
the pelvis, including the genitals, and are collectively
known as the pudendal plexus.
For further discussion of the spinal nerves
within the context of the structures and functions
of the nervous system, please see the overview
section “The Nervous System.”
See also MULTIPLE SCLEROSIS; SPINA BIFIDA; SPINAL
CORD INJURY.
stupor A state in which a person is unaware of
and does not interact with the external environ-