Predictors of severity and outcome of multiple sclerosis relapses

Background: Multiple Sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). The most common type of MS is the relapsing-remitting MS (RRMS) where relapses are the main component of the disease course. However, the relationship between the characteristics of the relapses on one hand and their severity and outcome on the other hand has not been fully characterized.

Objectives: To explore the characteristics of relapses among a cohort of Egyptian MS patients and their relation to the severity and outcome of the disease.

Subjects and methods: We analyzed 300 attacks from 223 patients in a retrospective study to identify demographic, clinical and paraclinical (laboratory and radiological) factors affecting: 1- Severity of relapses (the difference between the EDSS at the day of maximum worsening and the EDSS before the onset of the attack). 2- Outcome of relapses (the difference between the EDSS at the day of maximum improvement and the EDSS before the onset of the relapse).

Results: Severe attacks were most likely to occur in patients who are males, single, presenting with poly-symptomatic presentation, slower tempo of evolution of attack symptoms, longer duration of the attack, absence of DMTs at the time of the attack. The risk of having a severe relapse is more than 3 times when the patient is single. Regarding attack outcome, poorly recovered attacks were more common in patients with older age at disease onset and at attack onset, male sex, higher number of relapses, longer duration of illness prior to the attack, severe relapses, polysymptomatic presentation, associated cognitive symptoms, slower tempo of symptom evolution, longer duration of the attack, patients on OCPs, smoking, and presence of black holes in brain MRI. The risk of having relapses with partial or no recovery is more than five times when the patient has black holes in brain MRI and more than 4 times when the patient is a smoker.

Conclusion: Bearing in mind the demographic characteristics as well as the clinical and paraclinical characteristics of each attack and their relation to attack severity and outcome are a key to understanding the individual disease course of every patient and hence tailoring the best therapeutic plan suitable for his individual needs. In other words, prompt, rapid intervention in male patients, polysymptomatic attacks, slower tempo of evolution of attack symptoms and longer duration of the attack should be adopted since these factors are predictive of severe relapses as well as poor relapse outcome.