General
- Disproportionately greater motor deficit in the upper extremities than lower
- Usually results from hyperextension injury in the presence of osteophytic spurs
- Surgery is often employed for ongoing compression, usually on a non-emergency basis except for rare cases of progressive deterioration
Numbers
- Most common type of incomplete spinal cord injuries
4 subgroups of patient
- MRI evidence with no other radiographic abnormality 10%
- Medical management
- Acute disc herniation 20%
- Surgical intervention is recommended for this group.
- Fracture subluxation 30%
- Early re-alignment of the spinal column (closed or open) with spinal cord decompression is recommended.
- Spinal stenosis without evidence of bony or ligamentous injury 40%
- Management remains controversial due to the variable degree of spontaneous recovery of neurological function.
Mechanism
- Elderly
- Previously compromised canal
- Anterior hypertrophic spondylotic disc-osteophyte complex
- Posterior buckled ligamentum flavum
- ± Congenital spinal canal stenosis
- ± Translational movement of one vertebra on another may also contribute
- Minor extension injury mechanisms
- Blow to upper face or forehead
- Fall (Etoh)
- Young
- Sporting injuries
- May occur with
- Cervical fracture or dislocation
- Acute traumatic cervical disc herniation
- Specific medical conditions
- Rheumatoid arthritis
- Spinal cord supply from out to in
- Center most region of the spinal cord is a vascular watershed zone → more susceptible to injury from edema.
- Long tract fibers (spinothalamic tract/Corticospinal tract) passing through the cervical spinal cord are somatotopically organized such that cervical fibers are located more medially than the fibers serving the lower extremities
Clinical presentation
- Similar to syringomyelia
- Motor: weakness upper > lower
- > 10 ASIA motor difference
- Sensory: varying degrees
- Hyperpathia to noxious and non-noxious stimuli
- Especially in the proximal portions of the upper extremities
- Delayed
- Lhermitte sign: 7%
- Found in MS, cervical myelopathy, subacute combined degeneration, radiation myelopathy
- Myelopathic findings
- Sphincter dysfunction (usually urinary retention)
Natural history
- Phase of improvement
- LEs → bladder function → UE strength then returns with finger movements last;
- Return of upper extremity function is less reliable, and patients are often left with deficits in their upper extremity, worse distally, characterized by “clumsy” hands.
- Sensory recovery has no pattern
- Followed by a plateau phase and then late deterioration.
- 90% of patients are able to walk with assistance within 5 days.
- Recovery is usually incomplete, and the amount of recovery is related to the severity of the injury and patient age.
- If CCS results from hematomyelia with cord destruction (instead of cord contusion), then there may be extension (upward or downward)
Evaluation
- C-spine X-rays
- Congenital narrowing of AP diameter of spinal canal, superimposed osteophytic spurs, traumatic fracture-dislocation.
- Cervical CT scan
- Looking for fractures and osteophytic spurs.
- MRI
- Spinal canal compromise
- T2WI may show spinal cord oedema acutely, and can detect hematomyelia.
Treatment
- ICU management
- Especially for those with severe neurologic deficits (because of possible cardiac, pulmonary & BP disturbances)
- Monitoring
- Cardiac
- Hemodynamic
- Respiratory
- Maintainece of MAP 85–90mm Hg (use BP augmentation if necessary) for the 1st week after injury to improve spinal cord perfusion
- Surgery for
- Fracture-dislocation injuries
- Surgical decompression of the compressed spinal cord, particularly if the compression is focal and anterior that correlates with the level of deficit AND
- Persistent significant motor deficit following a varying period of recovery OR
- Deterioration of function OR
- Continued significant dysesthetic pain
- Unresolved
- The role of surgery in ATCCS with long segment cord compression or with spinal stenosis without bony injury
- In the absence of surgical indications
- Bed rest in a soft collar for ≈ 3–4 weeks → gradual mobilization in the same collar for an additional 6 weeks.
- Timing of surgery
- Very controversial.
- Cohort study < 24hrs vs > 24hrs surgery decompression
- Early surgical decompression to be associated with improved recovery in upper limb motor function (mean difference 2.3) 1 year
- No difference in lower limb motor score
- Meta-analysis
- Surgery within 24hrs after injury is safe and effective.
- Insufficient evidence to provide a clear recommendation for surgery < 24hrs
- Latest to surgery within 2 weeks after injury
- Reasons
- Can worsened the deficit.
- Early surgery. (< 24 hrs after injury)
- Arguments for
- The central argument that surgery was bad because the first surgery done involves dural opening, dentate ligament resection, and transdural discectomy which is very different from what we do today → we have better tools and techniques
- Decompressive surgery (without cord manipulation) appears to be safe in medically stable patients, but there is only Class III evidence that it may be helpful (controversial).
- Have reduce pressure in canal and therefore allow better healing → experimental evidence only
- Indicated for
- Improving pt that then deteriorates
- Spinal instability as a result of fractures or ligamentous compromise
- Not a pure CCS: Additional presence of long tract findings (has signs of other types of incomplete SCI)
- Delayed surgery (> 7days)
- Indicated for
- Patients with significant persistent cord compression who consistently fail to progress after an initial period of improvement, surgery is indicated often within 2–3 weeks following the trauma without an arbitrary waiting period.
- Better results occur with decompression within the first few weeks or months rather than very late (e.g. ≥ 1–2 years).
- Arguments for delayed surgery
- Early surgery can worsen deficit in operating in an unstable patient
- Starting 48 hours from the injury and lasting several days to a week due to swelling of the spinal cord which may render it fragile
- Only retrospective studies show some benefit in early surgery
- Technical considerations of surgery
- Multi-level laminectomy
- Most rapid procedure to decompress the cord
- Causes dorsal migration of the spinal cord
- Fuse or not to fuse (Post. Or anterior ACDF)
- In myelopathy, fused patients fare better than those that are just decompressed without fusion.
Prognosis
- Cord contusion without hematomyelia
- 50% will recover enough LE strength and sensation to ambulate independently
- Typically has significant spasticity.
- Recovery of UE function is usually not as good, and fine motor control is usually poor.
- Bowel and bladder control often recover, but bladder spasticity is common.
- Elderly worse than young regardless of treatment
- 41% >50 become ambulatory
- 97% for younger patients
- Dvorak et al 2005
- ASIA Motor Score improved from 58.7 → 92.3 at follow-up.
- Positively correlated with the
- ASIA motor score at injury
- Formal education
- Presence of spasticity at follow-up
- Bowel and bladder continence 81%
- FIM (independent ambulation) was reported by 86%.
- Positively correlated with
- Higher ASIA motor score at injury
- Formal education
- Absence of comorbidities
- Absence of spasticity
- Younger age.