A mixture model for differentiating longitudinal courses of multiple sclerosis.

BACKGROUND: Multiple sclerosis has a broad spectrum of clinical courses. Early identification of patients at greater risk of accumulating disability is essential. OBJECTIVES: Identify groups of patients with similar presentation through a mixture model and predict their trajectories over the years. METHODS: Retrospective study of patients from 1994 to 2019. We performed a latent profile analysis followed by a latent transition analysis based on eight parameters: age, disease duration, EDSS, number of relapses, multi-topographic symptoms, motor impairment, sphincter impairment, and infratentorial lesions. RESULTS: We included 629 patients, regardless of the phenotypical classification. We identified three distinct groups at the beginning and end of the follow-up. The three-classes model disclosed the "No disability regardless disease duration" (NDRDD) class with low EDSS and younger patients, the "Disability within a short disease duration" (DSDD) class with the worse disability besides short illness, and the "Disability within a long disease duration" (DLDD) class that achieved high EDSS over a long disease duration. EDSS, disease duration, and no sphincter impairment had the best entropy to distinguish classes at the initial presentation. Over time, the patients from NDRDD had a 52.1 % probability of changing to DLDD and 7.7 % of changing to DSDD. CONCLUSIONS: We identified three groups of clinical presentations and their evolution over time based on considered prognostic factors. The most likely transition is from NDRDD to DLDD.

Myelopathies in patients older than 50: not to miss inflammatory etiologies.

BACKGROUND: Inflammatory myelopathies are primarily associated with younger age, and there are few studies in the elderly. Longitudinally extensive spinal cord lesions (LECL) are common in inflammatory myelopathies, but when the first event occurs in older age may have a broader differential diagnosis. OBJECTIVES: To identify all non-traumatic myelopathies' etiologies in patients older than 50 years in a tertiary care hospital and to evaluate characteristics that differentiate inflammatory from non-inflammatory etiologies, focusing on the late-onset (≥50 years old) longitudinally extensive spinal cord lesions (LO-LECL) group. METHODS: Retrospective study of patients admitted between 2008 to 2019. Demographic, clinical, laboratory, and magnetic resonance imaging (MRI) data of all patients were analyzed to identify predictors that could more easily identify inflammatory from non-inflammatory etiologies and further identify the etiologies of LO-LECL. RESULTS: One hundred and three patients 50 years or older diagnosed with non-traumatic myelopathy were included, despite the lesion extension. Five were vascular (5%), 10 spondylotic (10%), 16 other etiologies (16%), 22 inflammatory (21%) and 50 neoplastic myelopathies (49%). Among 23 LO-LECL, 3 were vascular (13%), 4 neoplastic (17%), 7 other etiologies (30%) and 9 inflammatory (39%). The inflammatory LO-LECL had the median time to nadir significantly different from the neoplastic and the other etiologies groups and had the median EDSS at last visit (3.5) significantly lower than the non-inflammatory LO-LECL (7.0-7.5). CONCLUSIONS: Inflammatory etiologies are not to be disregarded in older adults with non-traumatic myelopathies. The symptoms' temporal profile is critical to differentiate inflammatory LO-LECL from other etiologies and it has better functional recovery after adequate treatment.