Manual Dexterity Control After Cerebellar Stimulation

Assessment of Cerebellar Stimulation Effect on Motor Learning in Ageing Population and Stroke Patients

This study will assess the putative advantages of cerebellar stimulation on motor learning abilities of stroke patients. In order to have a control group to refer to, the effect of cerebellar stimulation on healthy young and old participants will also be assessed.

Cerebrovascular accidents (CVA) are the first cause of acquired disability in France. Despite rehabilitation interventions, a great proportion of patients suffers from motor disability in the upper limb. Recently, several studies have shown that post CVA patients exhibit great neural plasticity as a direct consequence of their condition.

Interestingly, the transcranial direct current stimulation (tDCS) is a non-invasive electro stimulation technique that allows for a modulation of cerebral activity. It has been shown that when applied to the cerebellum, tDCS increases learning performances of healthy subjects. Yet, motor rehabilitation after a CVA highly relies on motor (re)learning. The cerebellar tDCS thus appear as a promising method to enhance the performance of post-CVA motor learning and consequently the benefits of post-CVA rehabilitation.

The current study aims to promote the post CVA neural plasticity by using the tDCS in order to enhance motor learning of the upper limb.

Inclusion Criteria:

• Right-handed
• Affiliated to the French health insurance or similar organisation
• Signed informed consent
• Clinical examination

For "Post-AVC patients" :

• at least 18 years old
• completed the Moberg Pick-up test with a minimum score of 20 secondes For "Young healthy" group
• 18 = or > years = or <30 For "Older healthy" group
• 50 > or = years = or < 80

Exclusion Criteria:

• Metallic implant in the head
• Pacemaker, or other electronic implanted devices
• Other central neurological disease
• Pregnancy, breast feeding
• Previous history of neurosurgery or seizures or 1st degree relative with history of seizures
• History of medical neurological or psychiatric disorders
• Participation to another study using cerebral stimulation
• History of bi-polar or recurring depressive disorders
• Planned carotid revascularization, severe caridac disease
• Kidney failure (transaminase > 2 times normal value)
• Other invalidating condition or deficiency interfering with the study

For "Post-AVC patients" :

• NIHSS score > 20
• Cerebellar ischemic CVA