PATHOPHYSIOLOGY

Incomplete Spinal Cord Injury

(Central Spinal Cord Syndrome; Mild Disc Bulging in Cervical Spine)

Risk Factors:

Gender (Female 20%) Age (15 – 35 y/o are most

affected) Sports activity/participation

in risky physical activity (7%)

Predisposing Factors:

Sports activity/participation in risky physical activity

Falls (22%) Enough sleep/Rest

Etiology:

Common mechanisms of SCI from traumatic impact include (1) hyperextension, (2) hyper flexion injuries, frequently accompanied by (3) rotational movements, (4) vertical compression, or (5) lateral flexion. Penetrating wounds such a missile trauma or stab wounds are commonplace. Primary and secondary injuries similar to those occurring to the brain can also occur to the spinal cord, including concussion, contusion, hemorrhage, laceration, eschemia, and edema.

Associated vertebral injuries may lead to spinal cord damage in subluxation (incomplete), compression fractures and fracture dislocations and other vertebral injuries. The extent of cord damage in vertebral injury is related to the degree of

Traumatic impact on cervical spine damaging inter vertebral disc

Tears in the annulus (outer rings)

Fluid content of nucleus pulposus leak through some torn annular fibers

Mild inter-vertebral disc bulging on C4-C5, C5-C6

Bulging puts pressure on surrounding ligaments

Intrusion into the spinal canal

Affects spinal function

Impaired/Loss of function, such as mobility or sensation

Fa

Pain

Functions:

C4: Upper body muscles (e.g. Deltoids, Biceps, Trapezius)

C5: (1) Primary Motor: Shoulder Abduction, Elbow Flexion (2) Sensation: Lateral Arm (3) Reflex: Biceps

C6: (1) Primary Motor: Wrist Extension (2) Sensation: Lateral Forearm, Thumb,

C4: Results in significant loss of function at the biceps and shoulders. Also affects function of diaphragm and intercostals muscles which may be obliterated in very severe injuries.

C5 : Full inervation of sternocleidomastoid, trapeziuz and other muscles: therefore neck, scapula and shoulder movement is retained.

C6 : Complete innervations of the rotator muscles of the shoulder is

Weakness in upper extremities > Hemiparesis

Quadriplegia, incomplete 31.2% - Paraplegia, complete 28.2% - Paraplegia, incomplete 23.1% - Quadriplegia, complete 17.5%

An incomplete spinal cord injury is the term used to describe damage to the spinal cord that is not absolute. The incomplete injury will vary enormously from person to person and will be entirely dependant on the way the spinal cord has been compromised.

Central Cord Syndrome: is when the damage is in the centre of the spinal cord. This typically results in he loss of function in the arms, but some leg movement may be preserved. There may also be some control over the bowel and bladder preserved. It is possible for some recovery from this type of injury, usually starting in the legs, gradually progressing upwards. This is a type of incomplete spinal cord injury

Motor strengths and sensory testing

The extent of injury is defined by the ASIA Impairment Scale (modified from the Frankel classification), using the following categories1,2 :

A - Complete: No sensory or motor function is preserved in sacral segments S4-S5.4

B - Incomplete: Sensory, but not motor, function is preserved below the neurologic level and extends through sacral segments S4-S5.

C - Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have muscle grade less than 3.

D - Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have muscle grade greater than or equal to 3.

E - Normal: Sensory and motor functions are normal.