Advances in the early diagnosis of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease. Despite rapid disease progression, diagnostic delay of 10-16 months persists, influenced by disease-specific factors and healthcare systems. Reducing it is crucial for early intervention, multidisciplinary care planning, and patient participation in clinical trials. The authors review relevant studies identified through PubMed between from 1990 through to 2024. The article explores factors contributing to diagnostic delay, the importance of early diagnosis, and strategies for improvement, including the role of the diagnostic criteria and biomarkers. Diagnosis of ALS remains clinical, with clinical expertise as the main modifiable factor in the diagnostic delay. Some biomarkers may be useful to speed up diagnosis at an earlier stage of the of the disease and in patients with atypical presentations or co-morbidities. However, the use of biomarkers for ALS diagnosis in clinical practice is far from being established and poses considerable challenges, including the lack of disease-specific biomarkers and the potential for delayed results. Until disease-specific biomarkers become available, early referral to ALS specialists, together with physician education programmes, will remain the main tools to reduce diagnostic delay in the next years.