This retrospective observational study will analyze de-identified clinical data from patients with amyotrophic lateral sclerosis (ALS) collected at multiple centers over 7 years. The primary objective is to describe disease progression using the ALS Functional Rating Scale-Revised (ALSFRS-R). Secondary objectives include evaluating survival, ventilatory decline, and correlations between available biomarkers (e.g., neurofilament light chain, cytokines) and disease trajectory. No new interventions or patient contact will occur.

Inclusion Criteria:

1. Diagnosis of amyotrophic lateral sclerosis (ALS) or motor neuron disease confirmed.
2. Age ≥18 years.
3. Availability of at least one ALS Functional Rating Scale-Revised (ALSFRS-R) score.
4. Availability of longitudinal follow-up data.

Exclusion Criteria:

1. Patients with alternative diagnoses that mimic ALS (e.g., multifocal motor neuropathy, cervical myelopathy, myasthenia gravis).
2. Absence of medical records

People aged ≥18 with ALS