The investigators hypothesize a relevant impact of cognitive status over gait performance in patients with amyotrophic lateral sclerosis (ALS), contributing to poor mobility and representing a relevant risk for falls. The present observational, cross-sectional study on ambulatory patients with ALS will evaluate gait performance using different sets of dual-task conditions to demonstrate the importance of cognitive aspects in rehabilitation programs for these patients. The dual-task conditions to be assessed during gait performance will include: counting backwards by 3 (executive simple task); counting backwards by 7 (executive complex task); mnemonic recall of the Rey's Auditory Verbal Learning Test (RAVLT). Patients' performance will be compared with a group of healthy controls with similar age and sex distribution in order to highlight the specific effects of the disease.

Patient inclusion criteria:

• Age ≥ 18 years;
• Clinical diagnosis of ALS or other MND phenotype;
• Able to walk unassisted for at least 1 minute consecutively;
• Oral and written informed consent to study participation.

Healthy control inclusion criteria:

1. Age ≥ 18 years;
2. Age and sex distribution similar to patients (age range: mean age of patients years ± 15 years);
3. Able to walk unassisted for at least 1 minute consecutively;
4. Oral and written informed consent to study participation.

Exclusion Criteria

An individual (either patient or healthy control) who meets any of the following criteria will be excluded from participation in this study:

1. Diagnosis of dementia;
2. Medical conditions or substance abuse that could interfere with cognition;
3. Any (other) major systemic, psychiatric, neurological, visual, and musculoskeletal disturbances or other causes of walking inability.

Based on previous experience and referral rates to the San Raffaele ALS Center (directed by the PI, including the Neurology and Neurorehabilitation wards and outpatient ALS clinic counting 50 new patients/year, 80 second opinion/year; 120 patients in care), the investigators plan to enroll at least 30 patients with ALS or any other MND phenotype, as well as 30 healthy controls with similar age and sex distribution, in line with sample size of previous studies ranging from 11 (Hausdorff et al., 2000) to 42 (Dubbioso et al., 2023). Healthy controls will be recruited by word of mouth, via consenting friends and non-consanguineous relatives who will be accompanying patients for study visits. Subjects will be assessed for suitability from their clinical notes or via a telephone screen. Given the cross-sectional, single-visit design of the present study, the investigators expect all patients to complete the study.