Intramedullary lesion expansion on magnetic resonance imaging in patients with motor complete cervical spinal cord injury.
OBJECTIVE
The authors performed a study to determine if lesion expansion occurs in humans during the early hours after spinal cord injury (SCI), as has been established in rodent models of SCI, and to identify factors that might predict lesion expansion.


METHODS
The authors studied 42 patients with acute cervical SCI and admission American Spinal Injury Association Impairment Scale Grades A (35 patients) and B (7 patients) in whom 2 consecutive MRI scans were obtained 3-134 hours after trauma. They recorded demographic data, clinical information, Injury Severity Score (ISS), admission MRI-documented spinal canal and cord characteristics, and management strategies.


RESULTS
The characteristics of the cohort were as follows: male/female ratio 37:5; mean age, 34.6 years; and cause of injury, motor vehicle collision, falls, and sport injuries in 40 of 42 cases. The first MRI study was performed 6.8 ±2.7 hours (mean ± SD) after injury, and the second was performed 54.5 ± 32.3 hours after injury. The rostrocaudal intramedullary length of the lesion on the first MRI scan was 59.2 ± 16.1 mm, whereas its length on the second was 88.5 ± 31.9 mm. The principal factors associated with lesion length on the first MRI study were the time between injury and imaging (p = 0.05) and the time to decompression (p = 0.03). The lesion's rate of rostrocaudal intramedullary expansion in the interval between the first and second MRI was 0.9 ± 0.8 mm/hour. The principal factors associated with the rate of expansion were the maximum spinal cord compression (p = 0.03) and the mechanism of injury (p = 0.05).


CONCLUSIONS
Spinal cord injury in humans is characterized by lesion expansion during the hours following trauma. Lesion expansion has a positive relationship with spinal cord compression and may be mitigated by early surgical decompression. Lesion expansion may be a novel surrogate measure by which to assess therapeutic effects in surgical or drug trials.
Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. baarabi@smail.umaryland.edu
Bizhan
B
Aarabi
J Marc
JM
Simard
Joseph A
JA
Kufera
Melvin
M
Alexander
Katie M
KM
Zacherl
Stuart E
SE
Mirvis
Kathirkamanthan
K
Shanmuganathan
Gary
G
Schwartzbauer
Christopher M
CM
Maulucci
Justin
J
Slavin
Khawar
K
Ali
Jennifer
J
Massetti
Howard M
HM
Eisenberg
D000293:Adolescent; D000328:Adult; D002574:Cervical Vertebrae / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D019299:Decompression, Surgical; D005260:Female; D006470:Hemorrhage / Q000473:pathology / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D015601:Injury Severity Score; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011693:Purpura / Q000473:pathology / Q000601:surgery; D013117:Spinal Cord Compression / Q000473:pathology; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult