Calcitonin gene-related peptide immunoreactivity in chronic human spinal cord injury.
METHODS
Histopathological study of the human spinal cord.


METHODS
International Collaboration on Repair Discoveries, Vancouver, BC, Canada.


BACKGROUND
In animals, primary dorsal root afferent fibers, which are immunoreactive for calcitonin gene-related peptide (CGRP), sprout following spinal cord injury (SCI) into deeper laminas of the dorsal horn below the level of injury. It has been suggested that this aberrant sprouting plays a role in altering cardiovascular control after SCI and could be responsible for life-threatening episodes of autonomic dysreflexia (AD).


OBJECTIVE
To observe the changes of CGRP distribution after SCI and compare the differences between normal and injured human spinal cord.


METHODS
Upper thoracic segments from individuals with chronic cervical SCI (n=4) and individuals with intact spinal cords (n=5) were processed immunocytochemically to identify CGRP fibers and histologically to identify the severity of degeneration.


RESULTS
Semiquantitative analysis showed a significant increase in CGRP immunoreactivity in the dorsal horns of individuals with chronic SCI (P<0.001). Furthermore, one of the SCI individuals in this study displaying significant CGRP sprouting had well documented episodes of AD.


CONCLUSIONS
Our observations suggest that SCI in humans results in significant sprouting of CGRP fibers. This aberrant sprouting of sensory fibers could contribute to the abnormal cardiovascular control and pain commonly observed following chronic human SCI.
Ackery
A D
AD
International Collaboration on Repair Discovery, Division of Physical Medicine and Rehabilitation, Department of Medicine, School of Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada.
Norenberg
M D
MD
Krassioukov
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020211:Autonomic Dysreflexia / Q000209:etiology / Q000503:physiopathology; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology; D009416:Nerve Regeneration / Q000502:physiology; D013119:Spinal Cord Injuries / Q000150:complications / Q000378:metabolism* / Q000473:pathology*
D015740:Calcitonin Gene-Related Peptide