Atalante Exoskeleton in the Rehabilitation of Patients With Amyotrophic Lateral Sclerosis

Safety and Efficacy of the Atalante Exoskeleton in the Rehabilitation of Patients With Amyotrophic Lateral Sclerosis: Study Protocol for an Open, Uncontrolled Interventional Study, EXALS.

Using a MRI gait motor imagery paradigm in ALS patients in order to study how ALS affects the function of the central neural networks involved in gait function, we showed a reorganization of the motor networks that represents a compensatory response to the dysfunction of the networks involved in gait function. Our main hypothesis is that by providing coherent proprioceptive input to the sensorimotor integration areas, gait training with an exoskeleton may boost compensatory network reorganization and help to maintain function. We hypothesize that this can be achieved through a locomotion training strategy that reproduces normal gait motor patterns and appropriate sensory feedback. Gait training with an exoskeleton can meet these needs. The Atalante exoskeleton offers unique potential thanks to its cutting-edge technological features, hands-free functions and availability in numerous centers across Europe. Evaluation of its safety and efficacy in ALS is of the utmost interest in order to generalize this new approach in ALS.

Current research is mainly focused on evaluating the effect of robotic rehabilitation on locomotion in ALS. In order to understand this approach, it is important to validate its safety and to determine patient's experience with this new rehabilitation concept in ALS. In this study, we aim to evaluate the safety, the participant experience and effectiveness of the training program with the Atalante exoskeleton as a gait training tool for ALS patients, compared with usual care, on walking ability, functional capacity and other symptoms associated with motor disability. The Atalante exoskeleton is the only self-balancing exoskeleton that enables assisted walking without walking aid, reproducing a natural walking pattern and multidirectional movement. EXALS is an interventional, monocentric, prospective, open trial. With a limited number of studies on gait rehabilitation exoskeletons in ALS, this study represents a significant scientific contribution, being the first to explore the benefits of a self-balancing exoskeleton with a rigorous design. In addition to robust outcome measures, this study places importance on participants' perception, motivation, and involvement in decision-making, adding depth and strength to the research.

Inclusion Criteria:

• Patients with amyotrophic lateral sclerosis (defined according to the El Escorial criteria: possible, probable or definite), at the time of diagnosis
• Male or female, between 18 and 70 years of age
• Slowly and moderately evolving patients ∆ ALS Progression rate (FS) ≤ 1.11 (The ALS progression rate was calculated as follows: (48 - ALSFRS-R at screening visit) / (duration from onset to this visit (month)) (Kimura et al., 2006). ALSFRS-R progression will be classified as slow (∆FS ≤ 0.47), intermediate (0.47 ≤ ∆PR ≤1.11) or fast (∆PR > 1.11) (Labra et al., 2016).
• Manual muscle testing ≥ 3 for deltoid muscle and ≥ 4 for neck flexors and extensors muscles
• Ambulatory status: a stable gait deficit with a total score between 3 and 6 on the ALSFRS-R sub-items "walking" and "climbing stairs"
• French speaking patient
• Patient affiliated with the French social security system
• Signed informed consent
• Measurements related to the use of the Atalante exoskeleton:
• Height between 155 and 190 cm
• Weight < 90 kg
• Pelvis width < 46 cm in seated position
• Thigh length between 56.8 and 64.8 cm
• Leg length > 45.7cm or less than:
• 60.7cm if ankle dorsi flexion is ≥16°
• 57.7cm if ankle dorsi flexion is ≥13°and <16°
• 56.7cm if ankle dorsi flexion is>10°and ≤13°
• 55.7cm if ankle dorsi flexion is ≥ 0°and ≤10°
• Joint amplitudes of lower limbs :
• Hip: flexion 90°, extension 5°, medial rotation 10°, lateral rotation 20°, abduction 17°, adduction 10°
• Knee: flexion 5-110°
• Ankle: dorsiflexion (knee straight) 0°, plantarflexion 9°, eversion18°, inversion 18°.

Exclusion Criteria:

• Osteoporosis at the femoral and/or lumbar level (T score ≤ -2.5), confirmed by bone densitometry at both the femoral and lumbar sites.
• Pressure ulcers in areas of contact with the exoskeleton
• Severe spasticity (greater than Ashworth 3) for adductor, hamstring, quadriceps and sural triceps muscles or uncontrolled clonus
• Cardiac or respiratory contraindications to physical effort
• Cognitive impairment that can affect comprehension
• Pregnancy or attempted pregnancy