Etiology of SCI Flashcards
Non-Traumatic Spinal Paralysis
development
structural deformities
congenital malformations
familial paralysis
Non-Traumatic Spinal Paralysis
Development
Development: incomplete closure of the spinal cord: spina bifida with meningocele, meningomyelocele (amount of excrusion through cord and skin)
Non-Traumatic Spinal Paralysis
Structural deformities
- scoliosis, kyphosis, spondylolisthesis,
- ankylosing spondilitis (bamboo spine, i.e. fixed flexed position, spine looses elasticity and the spine doesn’t move and lack of movement can lead to spinal compression)
- Non traumatic, can compromise the spine
Non-Traumatic Spinal Paralysis
Congenital malformation
- –Kippel-Feil Syndrome: hemivertebrae and fusion with adjacent vertebral compression and increased SCI risk.
1. Half the vertebrae fuses with the adjacent vertebrae, this leads to cord compression at that level and a SCI
—Sacralization of the 5th lumbar vertebrae.
Non-Traumatic Spinal Paralysis
Familial Paralysis
Fredrick’s Ataxia (familial paralysis), Spinal Cord Agenesis (spinal cord doesn’t grow in utero or stops growing after birth)
Acquired Spinal Paralysis
- infective
- degenerative
- neoplastic
- vascular
- iatrogenic
- idiopathic
- psychological
Acquired Spinal Paralysis
Infective (4)
1—Bacterial abscess (due to bacterial meningitis)
2—Tubercular Spine = Pott’s Disease (destucction of vertebrae, can damage spine if protrudes inward onto spine)
3—Viral: polio, herpes [neurosyphilis) (can damage spine)
4—Transverse Mylelitis: inflammatory demyelination of a cord segment (often due to infection)
Acquired Spinal Paralysis
Degenerative (3)
1—Disc herniation [disc can herniate into the spinal cord itself lead to damage]
2—Ankylosing spondylitis [degenerative disease]
3—Multiple sclerosis*** [can present just like a spinal cord injury, a spinal cord like syndrome caused by MS differs in fatigue, normally we push patients with SCI but this wont work well in a patient with MS]
Acquired Spinal Paralysis
Neoplastic:
2 types
1—Benign-meningioma, neurofibroma, osteosarcoma [if on the spine can injure cord]
2—Malignant: glioma [cancerous growth of glial cells which are connective tissue of the CNS, it permeates throughout the cord], metastatic myeloma [ie of the vertebral bodies and metastasize into the spine]
Extramedullary SC tumor: Intradural SC tumor: Extradural SC Tumor: Cauda Equina Tumor: Metastatic Tumor: Gliomas: Syringomyelia:
Extramedullary SC tumor:
outside cord
Intradural SC tumor
in dura
Extradural SC Tumor:
outside dura mater, compress the cord
Metastatic Tumor:
can metastisize to the spinal cord
Gliomas:
connective tissue in CNS
Syringomyelia:
hollowed out section of the cord, cavity
Acquired Spinal Paralysis
Vascular: (2)
stroke in spinal cord, need vascular supply—if compromised lead to spinal damage
- AV malformation (arterio-venous malformation), angioma, dissecting aneurysm, spontaneous anterior artery thrombosis
- Embolism, hemophilia, and hemorrhage
Acquired Spinal Paralysis
Iatrogenic: (5)
caused by a medical procedure itself
1. Radiation—ie cancer treatment, especially if the spinal cord itself
- s/p surgery –complications ie of back surgery
- s/p injection—ie for pain medication injection
- vaccination
- skull calipers—reduce dislocation with traction of the spine through calipers which are then distracted, sometimes too aggressive and leads to further
Acquired Spinal Paralysis
Idiopathic: (2)
- Syringomyelia: cavity in the cord, can occur in healthy cord spontaneously and damage cord, it is a risk if pre-existing traumatic SCI a srynx can form in the cord
- Multiple Sclerosis**: don’t know the cause of MS
Acquired Spinal Paralysis
Psychological: (3)
- Conversion reaction, hysterical paralysis
- Anxiety and neurosis “converts” into paralysis
- Secondary gain
Traumatic Spinal Paralysis (7)
- Direct vs. indirect forces
- Retrohyperflexion-hyperextension (traumatic usually combined pressure with hyperextension/flexion with or without rotation)
- Ventro-hyperflexion-anterior flexion
- Flexion and rotation
- Vertical stress
- Lateral flexion
- Direct injury
Retrohyperflexion-hyperextension
what level most common for
what ligament torn
what can happen
what causes the injury
most common
- Most common at C4-C6
- Usually tear Anterior Longitudinal Ligament
- Can get avulsion fx where ALL (anterior longitudinal ligament) attaches to vertebral bodies
- Separation of anterior body of anterior vertebral body and adjacent disc
- Acceleration injury, ie car rear-ended: head jerk forward and powerfully backwards, puts a big force on the posterior aspect of vertebrae, force on posterior vertebrae, spinous processes pushed together and fractured, loss of that articulation and its stability, tear ALL (as head jerks back), avulsion fracture of where the ALL attached to the vertebral bodies (can get seperation of anterior vertebral body and disc adjacent)
Ventrohyperflexion/anterior flexion:
what kind of situation causes it
what ligament torn
where fx
how can this affect the cord
- Deceleration injury-anterior force strikes you (ie hits car) and the head whips forwards into forward flexion
An anterior force hits car and head whips rapidly forward and get compression fx of anterior vertebrae, tear of PLL and tears of supraspinatus and infraspinous ligaments harder to hold head up - PLL (posterior longitudinal ligament), supraspinous ligament, infraspinous ligament tear (need to hold head up)
- Anterior compression and fractures
- – Stability between vertebrae is impaired–>fracture and dislocation [loss of stability between vertebrae]
- -Osteophyte or broken boney fragment can pierce the cord itself
Flexion with Rotation
what part of bone is injured
what part of column is injured
what happens to stability
(go forward with rotation to side)
Anterior bone disruption, a greater failure of the facet joints – lateral translation
Anterior and posterior columns can be disrupted, this is an unstable injury with loss of bony ligamentous and capsular integrity
Lose bony stability because of rotate one facet joint over another, loss of ligamentous stability, loss of joint capsule integrity
Vertical stress:
what situation causes
what happens to vertebrae
what happens to spinal cord
Divers fracture-land on their head–Land hard on feet (lumbar/thoracic)
vertebral body can burst depending on amount of force result in “burst” fracture or compression fractures
bony fragments and disk matter are sent in all directions including into the spinal canal—therefore the hard and protective material of bone can enter the cord itself
tear and compress the spinal cord
Lateral and Rotational Stress:
what causes it
what mechanism of injury
what is injured
Motor vehicle accident or trauma to side of head (T boning accident)
Lateral flexion of the cervical spine is accompanied by axial rotation
Rotational forces may stretch and rupture the posterior ligaments, dislocate the facets, and may cause compression fracture of the bony structure
Types of Cord Injury:
Type 1:
wedge compression fracture with teardrop chip, no real damage to cord
SCI Type 2:
half vertebral body is damaged, no actual damage to cord (just to vertebrae, less cord stability, pain, loose bone chips have potential of pierce cord, but type one and two more likely to cause pain than neurological damage)
Both type one and type two do not damage cord, only damage vertebra so lose stability of cord and have pain and lose bone chips can get into intervetebral foremen etc but type 1 and 2 distal or lateral to cord more cause pain than neurological damage
SCI
Type 3
direct: can lead to compression and loss of vascularization to the spinal cord
SCI
Type 4
direct: can lead to compression and loss of vascularization to the spinal cord
Less frequent to get direct injury to the cord
