Those individuals sustaining damage to the spinal cord due to nontraumatic causes are often treated in specialized inpatient SCI rehabilitation centres more commonly associated with those with SCI due to traumatic etiologies. Various reports have estimated that one-quarter to one half of all cases seen in specialized SCI rehabilitation centers are associated with nontraumatic etiologies (Muslumanoglu et al. 1997; McKinley et al. 1999b; van der Putten et al. 2001). Despite these significant numbers, relatively little systematic research is directed at nontraumatic SCI (van der Putten et al. 2001; McKinley et al. 2002). Common causes of nontraumatic SCI includes space occupying lesions such as tumours or prolapsed intervertebral discs, spondylosis such as that seen with degenerative spinal changes resulting in compression of the spinal cord, vascular ischemia as in arteriovenous malformations or spinal infarction, inflammation (e.g., idiopathic transverse myelitis, tropical spastic paraparesis, sarcoid) and those associated with congenital or familial etiologies (Adams & Salam-Adams 1991; McKinley et al. 1999b; McKinley et al. 2001). Although estimates of the incidence of nontraumatic SCI have been provided (e.g., 8 per 100,000) (Kurtzke 1975), it is difficult to ensure accuracy given the heterogeneous nature of nontraumatic SCI and the variety of facilities and programs where these patients may receive care.
Studies comparing those with damage to the spinal cord due to nontraumatic vs. traumatic etiologies have demonstrated a variety of systematic differences between these 2 patient groups. In general, those with nontraumatic SCI are more likely to be older, female, have paraplegia and have an incomplete injury than those with traumatic SCI (McKinley et al. 1996; McKinley et al. 2001; McKinley et al. 2002; New 2005). In the present section, we review the studies characterizing rehabilitation outcomes between those with SCI due to nontraumatic vs traumatic causes.
Studies examining nontraumatic SCI typically make use of retrospective case series designs describing rehabilitation outcomes directly (Citterio et al. 2004; McKinley et al. 1996; van der Putten et al. 2001; New et al. 2005; New 2006) or involve case control designs employing matching techniques to make comparisons with traumatic SCI while controlling for such things as age and level and completeness of injury (McKinley et al. 1999; McKinley et al. 2001; McKinley et al. 2002, 2008). As noted above, those with nontraumatic SCI were more likely to be older, female, have paraplegia and have an incomplete injury than those with traumatic SCI (McKinley et al. 1996; McKinley et al. 2001; McKinley et al. 2002; New 2005). No difference in age, marriage, education, socioeconomic factors, LoS and functional outcome was reported for a case control analysis originating from India (Gupta et al 2008, N=76)
Patients with nontraumatic SCI were primarily discharged home after rehabilitation (Citterio et al. 2004; McKinley et al. 1996). Citterio et al. (2004) found that discharge to home was predicted by many factors including: marital status, completeness of injury, clinical improvement, efficient bowel and bladder management, and absence of pressure ulcers. Another important predictor was shown to be a longer length of stay. This was due to the finding that there is an increased probability of functional and neurological improvement after longer hospital stay.
Ones et al. (2007) and Yokoyama et al. (2006) showed no significant difference in LOS between individuals with traumatic vs. nontraumatic spinal cord injury. Conversely, when direct comparisons of traumatic and nontraumatic SCI of various etiologies have been conducted using matching procedures, it is clear that shorter rehabilitation LOS was seen for those with nontraumatic SCI (McKinley et al. 2001; Osterthum et al 2009). In addition, this shorter LOS was associated with reduced hospital charges for both an overall and a per diem basis (McKinley et al. 2001). These findings were replicated with similar studies examining subsets of those with nontraumatic SCI including those with stenosis (McKinley et al. 2002) and those with neoplastic cord compression (McKinley et al. 1999) although this was not the case for a review involving infection-based SCI (McKinley et al. 2008). Most of these findings have been established with data from the US Model Systems, although at least two reports from other jurisdictions have reported longer rehabilitation LOS (van der Putten et al. 2001; New 2005).
None of the studies employing matching procedures noted differences in discharge destinations for those with nontraumatic SCI as compared to those with traumatic SCI (McKinley et al. 1999; McKinley et al. 2001; McKinley et al. 2002). although New et al. (2005) did note that within nontraumatic subjects, those individuals male, younger, more mobile, more independent with bowel and bladder function and having less severe AIS grades were more likely to be discharged home. In addition, the relatively poor prognosis and low survival rate of those with neoplastic cord compression has specific implications for discharge disposition (McKinley et al. 1996) although no specific differences were noted in a matched comparison (McKinley et al. 1999).
Comparing the rehabilitation of individuals with traumatic SCI with or without concomitant TBI, Bradbury et al (2008) reported no significant differences in LOS and FIM change score. However the presence of dual diagnoses was deemed to result in clinical but not statistically significantly greater costs associated with the FIM change score.
All studies reviewed employed the FIM to assess the functional status of individuals and generally demonstrated improved function with rehabilitation. Typically, motor FIM scores were employed or in the event total FIM scores were used it was acknowledged that changes were due primarily to the motor FIM subscale given a ceiling effect associated with the cognitive FIM subscale (McKinley et al. 1999; New 2005). There was conflicting evidence in admission and discharge FIM scores between traumatic and nontraumatic SCI groups. A study by Ones et al. (2007) found patients with traumatic SCI had significantly lower admission FIM scores than those with nontraumatic SCI. However, other studies found no such trend (McKinely et al. 1999; McKinely et al. 2001). FIM discharge scores were shown to be lower in the nontraumatic SCI population than traumatic (McKinely et al. 1999; McKinely et al. 2001) while Ones et al (2007) showed no such difference. When examining only those with stenosis vs those with traumatic SCI, those with nontraumatic SCI had higher FIM scores on admission, similar scores on discharge, resulting in reduced change scores and lower efficiency (McKinley et al. 2002). On the other hand, those with neoplastic cord compression demonstrated similar FIM scores on admission, reduced scores on discharge, resulting in reduced change scores but no difference in efficiency (McKinley et al. 1999).
McKinely et al. (1999) and McKinely et al. (2001) found no significant difference between traumatic vs. nontraumatic SCI populations in FIM efficiency. However, Ones et al. (2007) showed a significantly higher FIM efficiency for persons with a traumatic as compared to a nontraumatic etiology. Given this and other conflicting findings in these studies it seems that it is especially important to appreciate the heterogeneity inherent in rehabilitation outcomes of persons with nontraumatic etiologies. In particular, much variation might be expected, especially between centre-based reports with relatively small sample sizes and which include various nontraumatic etiologies within a single nontraumatic grouping. Future research should focus on large scale, case control methodologies employing subject matching strategies that control for potential confounding variables or that examine the effect of potential mediating variables. It is also important to consider logical subgroups based on specific etiologies of nontraumatic SCI.
Van der Putten (2001) assessed a variety of factors using multiple linear regression techniques in order to predict those most associated with increases in FIM motor scores during rehabilitation. They included 100 consecutively admitted patients with nontraumatic SCI with rehabilitation periods of > 1 week. The primary factors associated with improved motor FIM scores accounting for 54% of the variance were having a lower score on admission and reduced time between symptom onset to admission. Age, specific diagnostic subgroup (i.e., space-occupying, vascular, spondylosis, inflammation or hereditary), or lesion level did not improve the prediction significantly.
There is level 4 evidence that those with nontraumatic SCI are more likely to be older, female, have paraplegia and have an incomplete injury as compared to those with traumatic SCI.
There is level 3 evidence that those with nontraumatic SCI have generally reduced rehabilitation LOS, reduced hospital charges but similar discharge destinations as compared to those with traumatic SCI.
There is conflicting level 3 evidence that individuals with nontraumatic SCI have lower FIM efficiencies than those with traumatic SCI, although many studies are comparing persons with different etiologies of nontraumatic SCI.
There is level 3 evidence that individuals with traumatic SCI with or without concomitant TBI have similar LoS and achieve similar FIM motor scores, but associated costs were higher in those with dual diagnosis.