Acute Partial Transverse Myelitis:Related Factors For Conversion To Multiple Sclerosis

Objective:To define clinical, laboratory and neuroimaging factors in patients with first-ever acute partial transverse myelitis (APTM) that predict relapses or conversion to multiple sclerosis (MS).Methods:We identified43patients with a first-ever APTM admitted to admitted to the third hospital of JiLin University between January2004and November2010were retrospectively reviewed.we recorded patient demographics, clinical impairment, ancillary tests including cerebrospinal fluid (CSF), magnetic resonance imaging (MRI), recurrent and new symptoms and signs during follow-up. Disability status was defined by the expanded disability status scale (EDSS) score on admission.EDSS≤1.5was considered as mild deficit,1.5<EDSS<2.5as moderate and EDSS score≥2.5as severe. The residual disability status after treatment and recurrent during follow-up were analysed. At follow-up, patients were classified into two subgroups:(1) The’MS group’for patients who converted to definite MS according to McDonald’s criteria.(2)’Monophasic and relapsing APTM’for those who continued to meet criteria for a monophasic APTM or those with recurrent myelitis. We compared the patient demographics, clinical impairment at onset and after treatment, CSF parameters, the risk of recurrent and convertion into MS between groups.For statistical analysis, patients were categorized into two groups based on conversion to definite MS. All statistical analyses were performed using SPSS version13.0software. Count data were compared using Fisher’s exact test or chi-square test. Measurement data were compared using the t-test or the Mann-Whitney test. Differences with a P-value<0.05were considered significant.Results:43patients were brought into our study, who were diagnosed as acute partial transverse myelitis. The mean follow-up time was27months.19patients (44.2%) converted to MS. In the others(55.8%), four patients acquired relapsing myelitis because of a second neurological event consistent of a second episode of spinal cord inflammation. In20patients (46.5%), the initial APTM remained the only neurological event during the study period. In our APTM cohort, patients with one or several relatives suffering from MS were also at an increased risk of conversion to MS (P<0.05). APTM patients who later convert to MS had significantly more severe clinical impairment, i.e. more frequent EDSS scores≥2.5(P<0.05).IgG-index were available for22of43patients.14patients have an abnormal IgGindex.12patients later convert to MS in22. An abnormal IgGindex was detected in63.6%of patients. Patients who converted to MS were more probably to have a higher IgG-index (P<0.05). So we reason that an abnormal IgGindex might are the related factors for conversion to multiple sclerosis.27of43patients had brain MRI scans.14patients had the MS-typical brain lesions. The presence of MS-typical brain lesions was significantly higher in patients who converted to MS (P<0.05).64.2%of those with MS-typical brain lesions had developed MS, but only23.1%of those with normal brain MRI.Conclusion:In this retrospective study patients with a first-ever inflammatory lesion of the spinal cord were followed for an average of almost3.5years. We looked for clinical findings and results from ancillary tests that were associated with conversion to MS. These turned out to be:(1) severe impairment at onset;(2) MS-typical lesions on brain MRI;(3) abnormal IgG-index. In our study we found several clinical and paraclinical factors that indicate high or low likelihood of ongoing inflammation and later conversion to MS.