Clinical prognostic indicators in multiple system atrophy

Area of Science:

• Neurology
• Neurodegenerative Diseases
• Clinical Prognostics

Background:

• Multiple System Atrophy (MSA) is a rare neurodegenerative disorder with variable survival rates (6-10 years typically), complicating patient management and clinical trial stratification.
• Previous prognostication studies in MSA have yielded conflicting results, potentially due to diagnostic inaccuracies and limited sample sizes.
• Accurate prediction of MSA progression is crucial for patient care, resource allocation, and designing effective therapeutic trials.

Purpose of the Study:

• To identify and validate survival prognostic factors in a large cohort of Multiple System Atrophy (MSA) patients.
• To investigate the time-dependent nature of prognostic factors in MSA.
• To improve clinical trial stratification and patient care through enhanced MSA prognostication.

Main Methods:

• Survival analysis was conducted on a combined cohort of 555 MSA patients from the Queen Square Brain Bank and the PROSPECT-M-UK study.
• Methods included counting process Cox proportionate hazards modelling, Kaplan-Meier log-rank testing, and landmark survival analysis to address guarantee-time bias.
• Clinical data, including disease onset, specific MSA subtypes (MSA-P, MSA-C, mixed), clinical milestones (wheelchair use, gastrostomy, speech intelligibility), and Unified Multiple System Atrophy Rating Scale (UMSARS) scores, were analyzed.

Main Results:

• Later disease onset was associated with shorter survival (HR=1.04, P<0.001).
• Key late-stage disease markers with median survival <1.5 years included indoor wheelchair use, gastrostomy insertion, and unintelligible speech.
• At 3 years post-onset, negative prognostic factors included recurrent falls, unintelligible speech, and catheter/orthostatic hypotension medication use (all P<0.05). At 5 years, mobility milestones became more significant than dysautonomia markers.
• Higher baseline UMSARS scores and faster UMSARS progression rates were significant negative prognostic factors (HR=1.03 and 1.07, P<0.001).

Conclusions:

• In-clinic rating scales and clinical milestone assessments are valuable tools for aiding Multiple System Atrophy (MSA) prognostication.
• Prognostic factors in MSA exhibit time-dependent variability, explaining heterogeneity in previous studies and highlighting the need for dynamic assessment.
• This improved understanding of MSA prognostication is vital for personalized patient care and for the rational stratification of patients in future clinical trials.