Idiopathic acute transverse myelitis: a clinical study and prognostic markers in 45 cases

Objective The Transverse Myelitis Consortium Working Group has proposed new diagnostic criteria for idiopathic acute transverse myelitis (ATM). We reviewed patients admitted to our center diagnosed with myelitis with two objectives: (i) to evaluate the usefulness of these criteria in distinguishing between myelitis as the first episode of multiple sclerosis (MS) and idiopathic ATM; and (ii) to analyse the clinical and laboratory variables that may be used as functional prognostic markers.

Methods We selected patients who met the criteria. We recorded clinical epidemiological data, patients treated with methylprednisolone, maximal disability reached and disability at final follow-up. We also recorded cerebrospinal fluid (CSF) data and the number of levels affected in the spinal magnetic resonance imaging (MRI).

Results Twenty-four patients fulfilled the criteria for definite ATM and 21 for possible ATM. Five patients converted to MS. Mean follow-up time was 3.5 years. There was an association between younger patients and female patients with conversion to MS. The highest Rankin score reached and increased CSF glucose levels were associated with a poor outcome. In multivariate analysis, only the admission Rankin score was associated with outcome.

Conclusions (i) About 10% of patients who met the criteria may convert to MS; and (ii) admission Rankin score was the only independent prognostic factor found.