Cord Injury has many
causes and the resulting disability can take many forms.
Spinal Cord Injury (SCI) is damage to the spinal cord that results
in a loss of function such as mobility or feeling. Frequent
causes of damage
are trauma (car accident, gunshot, sports accidents, falls, etc.)
or disease (polio, spina bifida, spinal tumours, etc.). The spinal
cord does not have to be severed in order for a loss of function
to occur. In fact, in most people with SCI, the spinal cord is intact,
but the damage to it results in loss of functioning. SCI is very
different from other back injuries such as ruptured disks, or pinched
nerves, or even broken vertebrae.
A person can "break their back or neck" yet not sustain a spinal
cord injury if only the bones around the spinal cord (the vertebrae)
are damaged, but the spinal cord is not affected. In these situations,
the individual may not experience paralysis after the bones are
stabilized. Whilst recovery from broken bones is not without complications,
if the spinal cord wasn't compromised at the time of injury then
with the right post injury treatment there should be a full recovery.
If you have broken your neck or your back and not affected the spinal
cord then you are extremely fortunate. Damage to the spinal
cord and the resultant loss of function is usually permanent and
will mean a varying degree of 'lifelong' disability dependant on
where and how seriously the cord was affected. All too
often everyone who has broken their neck or back are thought of
in the same category and recoveries are often compared. It
comes down the the single fact that if the spinal cord has been
damaged in any way, the outcome of the injury / illness will be
a lot different to someone has just broken vertebrae. The
late Barry Sheene, a British motorcyclist broke virtually every
vertebrae in his neck and back during his career. Somehow
he managed to get away without damaging his spinal cord on any occasion
and made a full neurological recovery from his injuries i.e. No
permanent loss of movement or body functioning. Someone else
may have a far more trivial accident and remain completely paralysed
because of damage sustained to the spinal cord.
The spinal cord is the largest nerve in the body and an extension
of the brain. Nerve fibers are responsible for the communication
systems of the body -- sensory, motor and autonomic functions. All
the information going from the brain to the limbs travels through
the spinal cord.
spinal cord is surrounded by rings of bone called vertebra. These
bones constitute the spinal column (back bones). In general, the
higher in the spinal column the injury occurs, the more dysfunction
a person will experience. The vertebra are named according to their
location. The eight vertebra in the neck are called the Cervical
Vertebra. The top vertebra is called C-1, the next is C-2, etc.
Cervical SCI's usually cause loss of function in the arms and legs,
resulting in tetraplegia or
quadriplegia. The twelve vertebra
in the chest are called the Thoracic Vertebra. The first thoracic
vertebra, T-1, is the vertebra where the top rib attaches.
Injuries in the thoracic region usually affect the chest and the
legs and result in paraplegia. The
vertebra in the lower back between the thoracic vertebra, where
the ribs attach, and the pelvis (hip bone), are the Lumbar Vertebra.
The sacral vertebra run from the Pelvis to the end of the spinal
column. Injuries to the five Lumbar vertebra (L-1 thru L-5) and
similarly to the five Sacral Vertebra (S-1 thru S-5) generally result
in some loss of functioning in the hips and legs.
The spinal cord is about 18 inches long. It starts at the base of
the brain, and extends to about the waist. Because the spinal cord
is such an important part of the nervous system, it is surrounded
and protected by bones called vertebrae. The spinal cord is the
first relay station for sensory information on its way to the various
centres of the brain. The spinal cord has many fibers that carry
these messages between the brain and different parts of the body.
The messages may:
tell a body part to move; send and receive messages of sensation
from the body, such as pain, heat, or cold; or control the involuntary
activities of the body, such as body temperature.
Damage to the spinal cord can occur from a traumatic injury. The
backbone may pinch the spinal cord, causing it to bruise or swell,
or the injury may tear the spinal cord and its nerve fibers. After
a spinal cord injury, all the nerves above the level of injury keep
working like they always have. However, at the point of injury and
below, the spinal cord nerves cannot send messages between the brain
and parts of the body. Sensory functions, bladder functions, and
movement are all dependent on information that travels up and down
the spinal cord. Interruption of spinal cord function by a traumatic
injury may result in a loss of feeling and motor function.
The anatomy of the spinal column is extremely well designed to serve
many functions. All of the elements of the spinal column and vertebrae
serve the purpose of protecting the spinal cord, which provides
communication to the brain, mobility and sensation in the body through
the complex interaction of bones, ligaments and muscle structures
of the back and the nerves that surround it. The back is also the
powerhouse for the entire body, supporting our trunks and making
all of the movements of our head, arms, and legs possible.
The nerves that lie within the spinal cord are upper motor neurons
(UMNs) and their function is to carry the messages back and forth
from the brain to the spinal nerves along the spinal tract. The
spinal nerves that branch out from the spinal cord to the other
parts of the body are called lower motor neurons (LMNs). These spinal
nerves exit and enter at each vertebral level and communicate with
specific areas of the body. The sensory portions of the LMN's carry
messages about sensation from the skin and other body parts and
organs to the brain. The motor portions of the LMN's send messages
from the brain to the various body parts to initiate actions such
as muscle movement.
spinal cord is the major bundle of nerves that carry nerve impulses
to and from the brain to the rest of the body. The brain and the
spinal cord constitute the Central Nervous System. Motor and sensory
nerves outside the central nervous system constitute the Peripheral
Nervous System, and another diffuse system of nerves that control
involuntary functions such as blood pressure and temperature regulation
are the Sympathetic and Parasympathetic Nervous Systems.
Effects Of Spinal
There are two classifications of spinal cord injury
(also called quadraplegia) and
The effects of SCI depend on the type of injury and the level of
the injury. SCI can be divided into two types of injury -
complete injury means that there
is no function below the level of the injury; no sensation and no
voluntary movement. Both sides of the body are equally affected.
An incomplete injury means
that there is some functioning below the primary level of the injury.
A person with an incomplete
injury may be able to move one limb more than another, may be
able to feel parts of the body that cannot be moved, or may have
more functioning on one side of the body than the other. With the
advances in acute
treatment of SCI, incomplete injuries are becoming more common.
The level of injury is very helpful in predicting what parts of
the body might be affected by paralysis and loss of function. Remember
that in incomplete injuries there will be some variation in these
prognoses. Most incomplete
injuries are unique in presentation and eventual outcome (recovery).
Of course every individual case is treated on its merits.
See below for further categories of SCI.
Complete SCI -
Incomplete SCI -
Causes of SCI -