Multiple sclerosis (MS) is a chronic neurological disease, which affects young adults at a time when they have to make most of their personal and professional choices. predicting the long-term disability of MS is therefore very important for patients as well as neurologists. it has become even more crucial nowadays with more and more treatment options becoming available.Several prognostic factors of long-term irreversible disability have been described in MS: 1) at onset: ethnicity, sex, age, type of symptoms, and initial course and 2) later on, they include recovery from the initial symptoms, delay to the second neurologic episode, number of relapses in the first few years, and clinical characteristics in the early phase of the disease.1 recent studies have also suggested that brainstem involvement is an important predictor of future disability.2,3 these studies have shown that the presence of at least one brainstem lesion increases both the risk of conversion and disability, 2 and that two ABSTRACT: Background/Aims: the aim of the present study was to determine the optimum method to detect brainstem lesions in patients with Multiple Sclerosis (MS). Methods: 72 patients with the diagnosis of relapsing-remitting MS were prospectively included. brainstem functional system score (bSfS) (part of the expanded disability status scale (edSS) evaluating brainstem symptomatology) was calculated. Magnetic resonance imaging (Mri) was performed on 1.5t and t1, t2, pd and fluid-attenuated inversion recovery (flair) sequences were analyzed for presence of brainstem lesions. auditory evoked potentials (aep) and ocular and cervical vestibular evoked myogenic potentials (oVeMp and cVeMp) were performed according to the standardized protocol. Results: from 72 patients, 18 (25%) had clinical involvement of the brainstem. Mri showed brainstem involvement in 29 (40%) patients. of the neurophysiological tests, aep showed pathological result in 16 (22%) patients, oVeMp in 36 (50%) patients, cVeMp in 18 (25%) patients, and VeMp (combination of oVeMp and cVeMp) in 45 (63%) patients. VeMp detected brainstem lesions in higher percentage than clinical examination, Mri and aep, which was statistically significant (< 0.0001, 0.012 and < 0.0001, respectively). Conclusions: results of the present study have shown that VeMps are the optimal method to detect brainstem lesions in multiple sclerosis and that they detect them significantly better than clinical examination, aep or Mri.RÉSUMÉ: Évaluation de l'atteinte du tronc cérébral dans la sclérose en plaques. Contexte/Objectifs : le but de cette étude était de déterminer quel est le meilleur moyen de détection des lésions du tronc cérébral chez les patients atteints de sclérose en plaques (Sp). Méthode : Soixante-douze patients, chez qui un diagnostic de Sp récurrente rémittante avait été posé, ont été inclus dans l'étude de façon prospective. le score à l'exploration fonctionnelle du tronc cérébral (bSfS), la partie de l'edSS qui évalue la symptomatologie du tronc cérébral, a été calculé. l'ir...