Case-control cohort study.
To evaluate 1) the hematologic abnormalities within the first week following isolated acute cervical spine trauma or spinal cord injury (SCI); and 2) the influence of age, sex, and severity of SCI on these hematologic abnormalities.
Given that autonomic nervous system has a critical role in the regulation of the hematopoietic system, we sought to evaluate the potential association between hematologic abnormalities within the first week posttrauma and the severity of SCI.
All consecutive individuals with isolated acute cervical spine trauma admitted to our institution from 1998 to 2000 were reviewed. Exclusion criteria included preexisting medical comorbidities and polytrauma. The study population was divided into a SCI group and a control group (individuals with spine trauma without neurologic impairment). The SCI group was subdivided into patients with motor complete SCI (American Spinal Injury Association [ASIA] Grades A/B) and individuals with motor incomplete SCI (ASIA Grades C/D).
There were 21 SCI individuals (15 male, 6 female; ages 17–83 years; mean, 57 years) and 11 controls (6 male, 5 female; ages 18–75 years; mean, 41 years). When controlled for age, SCI individuals showed a significantly higher frequency of reduced hemoglobin concentration (RHC), leukocytosis, lymphopenia, and thrombocytopenia than controls within the first week posttrauma. Blood hemoglobin concentration, lymphocyte, and platelet counts in the SCI group were significant lower than the controls. The SCI group showed a significant higher leukocyte count than the controls. The degree of RHC and lymphopenia was significantly correlated with the severity of SCI.
Our results indicate that patients with isolated cervical SCI have significantly greater frequency of RHC, leukocytosis, lymphopenia, and thrombocytopenia than controls during the first week posttrauma. The degree of RHC and lymphopenia was significantly associated with the severity of SCI. While the mechanisms underlying these clinically important hematologic consequences of SCI remain undetermined, evidence from the literature suggests that acute autonomic denervation of the hematopoietic system could play a key role.
This study indicates that patients with isolated cervical SCI have significantly greater frequency of reduced hemoglobin concentration, leukocytosis, lymphopenia, and thrombocytopenia than patients with isolated cervical spine trauma without neurologic impairment. Additionally, the degree of reduced hemoglobin concentration and lymphopenia was significantly associated with the severity of SCI. While numerous potential mechanisms could account for these findings, our results suggest that acute autonomic dysfunction could account for many of the changes.
From the Department of Surgery, Division of Neurosurgery, University of Toronto; Spinal Program, Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network; and Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada.
Acknowledgment date: October 25, 2005. First revision date: December 6, 2005. Acceptance date: January 23, 2006.
Supported by funds from the Lawson Fellow-Neurology from the Toronto General & Western Hospital Foundation (to J.C.F.), the Krembil Chair in Neural Repair and Regeneration (to M.G.F.), Heart and Stroke Foundation of Ontario (Grant No. NA4951), and Christopher Reeve Paralysis Foundation (Grant No. KB2-0003-1).
The manuscript submitted does not contain information about medical device(s)/drug(s).
Foundation funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Address correspondence and reprint requests to Michael G. Fehlings, MD, PhD, FRCSC, Spinal Program, Krembil Neuroscience Centre, Toronto Western Hospital, Department of Surgery, Division of Neurosurgery, University of Toronto, 399 Bathurst Street, 4W449, Toronto, Ontario, Canada, M5T 2S8; E-mail: Michael.Fehlings@uhn.on.ca