Spasticity is a frequent and debilitating symptom in patients with cerebral palsy. It can alter the patients' balance, mobility, as well as their quality of life (QoL). The available therapeutic strategies for treating spasticity and related symptoms are usually faced with limited efficacy and numerous side effects. For these reasons, non-invasive stimulation techniques, namely transcutaneous electric nerve stimulation using EXOPULSE Mollii suit, might be of help in this context.

This work will assess the effects of the EXOPULSE Mollii suit, which is an assistance device applying non-invasive transcutaneous electrostimulation. The EXOPULSE Mollii control unit is a class IIa device, CE marked, and therefore compliant with the Medical Device Directive. Its intended use includes relaxing spastic muscles, maintaining or increasing the range of movement, activating and re-educating muscles, delaying or preventing atrophy due to disuse, increasing local blood flow, and symptomatic relief and management of chronic refractory pain.

The available interventions targeting spasticity are faced with some limitations. For instance, botulinum toxin injection does not seem to improve arm and hand capacity, walking, or quality of life. The available oral agents are challenged by their potential side effects, such as sedation, drowsiness, mental confusion, fatigue, ataxia, hallucination, insomnia, nausea, dry mouth, bradycardia, hypotension, and depression, to cite a few. Therefore, developing novel therapies would help to overcome the actual limitations. Transcutaneous Electrical Nerve Stimulation (TENS) has proven some efficacy in spasticity management. However, one should note that practical difficulties could arise when using TENS at home or in clinical practice (i.e., correctly attaching electrodes). To overcome these limitations, the EXOPULSE Mollii suit has been developed by Exoneural Network, a Swedish med-tech company. It represents an innovative approach for non-invasive electro-stimulation to reduce spasticity and improve motor function.

EXOPULSE Mollii suits consist of body Garments (Jacket and Pants) and a control unit. The body Garments (Jacket and Pants) is a suit with 58 embedded electrodes that can stimulate 40 groups of muscles, conductive wires, and connectors to a detachable control unit, whose intended purpose is to transmit electric pulses from the control unit to key nerves and corresponding muscle groups throughout the body. The control unit is a battery-powered electrical device that sends low-intensity electric pulses through connectors to the Body Garments which in turn transmits the pulses from the connectors to key nerves and corresponding muscle groups throughout the body.

EXOPULSE Mollii suit consists of transcutaneously stimulating the spastic antagonist muscles with an electric current (i.e., low frequency ~20 Hz, low intensity~2 mA), aiming to reduce muscle stiffness. This treatment method's theoretical background primarily refers to the concept of reciprocal inhibition, i.e., that sensory input from a muscle may inhibit the activation of an antagonistic muscle. Thus, the application of the EXOPULSE Mollii suit aims to stimulate a muscle, e.g., the anterior tibialis muscle to reduce reflex-mediated over-activity (i.e., spasticity) of calf muscles by inducing reciprocal inhibition.

There is growing evidence now from pilot applications of EXOPULSE Mollii suit indicating beneficial effects of using this suit on activity (i.e., mobility and gross motor function) and participation.

Inclusion Criteria:

• Age between 5 and 12 years.
• Having a clinical diagnosis of unilateral or bilateral spastic cerebral palsy since at least one month.
• Being able to walk freely, with slight limitation or using ancillary equipment's (Gross Motor Function Classification System (GMFCS) score ≤3).
• Having a PBS score < 45.
• Being French speaker, able to understand verbal instructions, and affiliated to the national health insurance (sécurité sociale).
• Having spasticity with a score of at least 1+ on the MAS

Exclusion Criteria:

• Being included in another research protocol during the study period
• Being unable to undergo medical monitor for the study purposes due to geographical or social reasons
• Having contraindications to wearing EXOPULSE Mollii suit (i.e., implanted electronic medical devices or equipments which can be disrupted by magnets including ventriculoperitoneal shunts and intrathecal baclofen pumps, electronic life support equipment or high-frequency operation equipment, as well as well electrocardiography equipment or cardiac stimulator)
• Having a change in the pharmacological therapy over the last three months
• Suffering from other somatic or neuropsychiatric diagnoses (e.g., arrhythmias, uncontrolled epilepsy, diseases causing osteoarticular and muscular pain, skin diseases).
• Suffering from a cutaneous disease
• Using another medical device
• Being part of other protected populations as defined in articles L. 1121-5, L. 1121 6,1121-8 and L. 1122-1-2 of the Public Health Code