Spine Topics Flashcards
What % of pts with major spine injury will have second spine injury at another level?
- 20%
- These pts often have simultaneous but unrelated injury (eg chest trauma)
Injuries directly associated with spinal cord injuries
-Arterial dissections (carotid and/or vertebral)
Def of Spinal Stability
Conceptual definition (from White and Punjabi): the ability of the spine under physiologic loads to limit displacement so as to prevent injury or irritation of the spinal cord and nerve roots (including cuada equina) and, to prevent incapacitating deformity or pain due to structural changes
Biomechanical stability
Ability of spine ex vivo to resist forces
Def of Level of Injury
Some disagreement here:
- Lowest level of completely normal function, vs
- Most caudal segment with motor function that is at least 3/5 and if pain and temp sensation is present
Incomplete lesion
Definition: any residual motor or sensory function more than 3 segments below the level of injury; look for signs of preserved long tract function
Signs of incomplete lesion:
-Sensation (including position sense) or voluntary movement in LEs
-Sacral sparing: preserved sensation around the anus, voluntary rectal sphincter contraction, or voluntary toe flexion
-Note, injury does NOT qualify as incomplete with preserved sacral reflexes alone
Types of incomplete lesions
- Central cord syndrome
- Brown-Sequard syndrome (cord hemisection)
- Anterior cord syndrome
- Posterior cord Syndrome
Complete Lesion
Def: no preservation of any motor and/or sensory function more than 3 segments below the level of injury
-Recovery is essentially zero if the spinal cord injury remains complete beyond 72 hrs
What % of pts with complete injury on initial exam will develop some recovery within 24 hrs
-Approx 3% of pts with complete injuries on initial exam will develop some recovery within 24 hours
Hemodynamic shock after SCI
Hypotension (usually SBP < 80) following SCI caused by variety of reasons
1) Inturruption of sympathetics (implies SCI above T1)
- Loss of vascular tone (vasoconstrictors) below the level of injury
- Leaves parasympathetics relatively unopposed causing bradycardia
2) Loss of muscle tone due to skeletal muscle paralysis below level of injury results in venous pooling and thus relative hypovolemia
3) Blood loss from associated wound may cause true hypovolemia
“Spinal Shock”
Description: transient loss of all neurologic function (including segmental and polysynaptic reflex activity and autonomic function) below level of SCI
- Causes flaccid paralysis and areflexia lasting varying periods (usually 1-2 weeks, occasionally several months, sometimes permanent)
- Resolution yields anticipated spasticity below the level of the lesion (a poor prognostic sign)
- Spinal cord reflexes immediately above the injury may also be depressed on the basis of the Schiff-Sherrington phenomenon
Schiff-Sherrington Phenomenon
- When the spinal cord is transected in the midthoracic region or a little lower, the stretch and other postural reflexes of the upper extremity become exaggerated; if the transection is made in the sacral cord, a similar effect is observed in the lower limbs
- The effect is regarded as a release phenomenon, release from an inhibitory influence normally exerted by the spinal segments below the transection
Whiplash
Previously a lay term, but currently defined as:
-Traumatic injury to soft tissue structures in region of the c-spine (including cervical muscles, ligaments, intervertebral discs, facet joints) due to hyperflexion, hyperextension, or rotational injury to neck in the absence of fractures, dislocations, or intervertebral disc herniation
-The most common non-fatal automobile injury
S/Sx: may start immediately, but are most commonly delayed several hrs to days; include symptoms related to C-spine, headaches, cognitive impairment, and low back pain
Dx: use WAD classification system
Clinical Grading of WAD Severity
0: No complaints, no signs (not whiplash)
1: neck pain or stiffness or tenderness, no signs
2: above symptoms with reduced ROM or point tenderness
3: above symptoms with weakness, sensory deficit, or absent DTRs
4: above symptoms with fracture or dislocation (not whiplash)
Work up based on WAD
Grade 1: pt with normal mental status and physical exam do not require plain radiographs on presentation
Grade 2 & 3: C-spine x-rays, possibly with flexion/extension views; special imaging (CT, MRI, myelography) not indicated
Grade 3 & 4: should be managed as suspected SCI