Effects and Mechanisms of Sensory Afferent Electrostimulation on Upper Limb Function in Patients With Hemiparesis

The goal for this project is to investigate the effects of a 5-week SAES therapy in addition to conventional therapy on both behavioural (sensory and motor) and neurological measures and the underlying mechanisms of treatment response.

The goal of this project to investigate the effects of a 5-week SAES therapy in addition to conventional therapy.

The aim is to investigate whether SAES is more effective than conventional therapy alone in children with hemiparesis. The investigators will assess the efficacy of SAES using novel clinical assessment such as kinematic evaluations and modern neurophysiological measures, namely transcranial magnetic stimulation (TMS) and resting-state functional MRI (rs-fMRI).

It will be expected a benefit for children with hemiparesis after SAES training which may lead to improved bimanual and unimanual functions. Benefits have been reported in adults and in preliminary studies also in children.

Type of study: Randomised controlled clinical trial

Participants with hemiparesis will be included in the study. The study group will receive the SAES training with a glove or adhesive electrodes as a home-based training during 30 minutes per day, 5x/week, for 5 weeks, combined with conventional occupation therapy.

Researchers will compare the SAES group with a group of patients with comparable conditions who receive the prescribed conventional occupational therapy and/or physiotherapy (treatment as usual, TAU)

Children with hemiparesis present with sensory and motor deficits, which negatively affect quality of life and decrease participation in everyday life. To date, no treatment is yet effective to decrease these impairments. A recent systematic review confirms that unimanual and bimanual trainings effectively improve upper limb function in children with hemiparesis. However, it is still challenging to find the best individual training method for children with hemiparesis, as there is much variability in treatment response.

In the present study, the effects and mechanisms of non-invasive electrostimulation of the hand, called Sensory Afferent Electrostimulation (SAES) will be investigated. SAES triggers action potentials in afferent nerve fibres leading to increased sensory afferent input in the sensorimotor regions of the brain. Through this, SAES can enhance excitability of the motor cortex and of upper limb performance. While proven effective in adults after stroke, SAES is safe with promising positive results in a very small study in children with hemiparesis. However, the investigation of efficacy of SAES on sensory and motor functions was so far neglected. Modern stimulation and imaging methods revealed that, whole-hand SAES induced increased strength of corticospinal projections and intracortical change (measured with transcranial magnetic stimulation), which may indicate long-term potentiation mechanisms. Furthermore, in a functional MRI study, SAES induced increased motor cortex activity. Hence, resting state fMRI will allow to understand the efficacy of SAES on the topographically connectivity of the motor and sensorimotor network at rest.

The experimental intervention consists of SAES with a glove or adhesive electrodes (e.g. Cefar Reha X2) at 20Hz, 300µs, intensity between 2-10mA, during 30 minutes per day, 5x/week, for 5 weeks, combined with conventional occupation therapy. The subsequent therapy sessions will take place at home, with in-between telephone checks.

The control intervention (treatment as usual, TAU) consists of the prescribed conventional occupational therapy and/or physiotherapy. The evaluation of the UL sensory and motor function will be conducted at the University Children's Hospital in Bern by blind assessors, expert in the clinical measures, and will take place before and after each intervention period and at 12-weeks follow-up.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of hemiparesis
* Upper limb deficits.
* Written informed consent by participant and / or parent.

Exclusion criteria:

* Botulinum toxin injections in the last 6 months
* Hand surgery in the last 2 years
* UL trauma in the last year, medical conditions preventing UL training
* Participation in another UL training.

For children who additionally undergo MRI and TMS measurements, the exclusion criteria contain MRI or TMS or contraindications such as implanted metal and an active epilepsy.