Administration of Riluzole Oral Suspension During the Different Stages of Amyotrophic Lateral Sclerosis
Résumé
Amyotrophic Lateral Sclerosis (ALS) is a fatal adult-onset neurodegenerative disorder that affects the upper and/or lower motor neurons and is associated with the degeneration of cortical and spinal motor neurons (1, 2).
Dysphagia, a swallowing disorder related to tongue atrophy and dysfunction in the closure of the soft palate and the larynx that progressively inhibit the passage of food or liquid from the mouth through the pharynx into the esophagus, is one of the most severe and debilitating symptoms of ALS (3–5). Even though it has an earlier onset and is more severe in ALS bulbar (3) than in spinal patients, it has been demonstrated that more than 30% of spinal onset patients show dysphagia symptoms at diagnosis, and in the advanced stages of the disease of both phenotypes, more evidently, more than 80% of patients manifest bulbar involvement and dysphagia (3, 5). To preserve oral feeding and postpone the need for percutaneous endoscopic gastrostomy (PEG), the first interventions in patients with dysphagia include postural compensation maneuvers, swallowing techniques, and diet adjustments to adapt the consistency of foods and liquids to the patient's impairment (5).
As reported in a retrospective study (5), the prevalence of dysphagia during a mean follow-up of almost 2 years increased from 35.2% at diagnosis to 73.3% at final follow-up in spinal-onset patients, and from 94.7 to 98.2% in bulbar-onset patients (5). Interestingly, six patients with spinal onset (8%) and dysphagia found by FEES (fiberoptic endoscopic evaluation of swallowing) did not report the disorder as symptomatic (i.e., demonstrated silent aspiration). Furthermore, while at the beginning of the observation period 45% of patients were on a normal diet and no patients needed PEG, at the end of the follow-up 63% of patients had modified food consistency, and 20.7% had undergone a PEG. In particular, patients with bulbar onset ALS were given food with modified consistency and underwent PEG more frequently than patients with spinal onset (5).
According to the European guidelines on the clinical management of ALS, timing of PEG should take into account patient characteristics such as bulbar symptoms, malnutrition (weigh loss ≥ 10%), respiratory function (before forced vital capacity <50% of predicted), and patients' general condition (6). As shown in the study of Pena et al. (7), PEG is inserted more precociously in bulbar-onset than in spinal-onset patients (19.3 vs. 29.7 months from symptom onset) while the median survival after PEG replacement is similar in the two groups of patients (7.9 vs. 7.1 months). Furthermore, bulbar-onset patients presented shorter survival (42 vs. 29 months after disease onset) and diagnostic delay (10.3 vs. 12.2 months).