transcranial Direct Current Stimulation (tDCS) on the left posterior parietal cortex and rehabilitative treatment with Smania's training

Placebo stimulation and rehabilitative treatment with Smania's training

Direct current transcranial stimulation will be applied for 20 minutes over the left posterior parietal cortex with an intensity set to 2 mA.

It consists of 24 imitation tests carried out with the fingers, the hand and the limb homolateral to the lesion.

Each gesture is presented up to three times if the production is incorrect, and receives a score of 3 to 0 depending on whether the copy is correct the first, the second, the third time, or never. The test includes 24 gestures, 12 symbolic and 12 non-symbolic, for a total score of 72. Application of the test to over 200 normal subjects showed that the diagnosis of apraxia can be made reliably when the score drops below 53, it's probable, but not certain, for a score between 53 and 62, and it's excluded when the score is greater than 62.

Test for ideomotor apraxia assessment which allows to highlight: 1) the selective deficits for the type of gesture to be imitated and, therefore, specific damage to the two processes underlying the imitation (direct route and semantic pathways) presenting known and new gestures in separate blocks; and 2) deficits of the distal or proximal component of the movements.

By placing in front of the patient one object at a time, he is asked to perform the pantomime of use of the object without touching or holding the object itself, but only by looking at it (visual mode). The examiner will assign 2 points if the execution is correct, 1 point if the execution is correct after repetition of the command and 0 points for always incorrect execution. The objects used are: glass, screwdriver, comb, gun, fork, key, rubber, saw, hammer, fan.

The examiner mimics the 10 bucco-facial movements required by the protocol, and asks the patient to imitate them. If the subject does not perform the task or does not perform it correctly, the therapist repeats the gesture a second time. If, again, the patient does not perform or makes a mistake, the next stimulus is taken. Maximum time for each stimulus is 30 seconds. The gestures to imitate are: show your tongue, whistle, yawn, try to lick your nose, make a partridge, give a kiss, show how your teeth shake when it's cold, snap your tongue making the sound of a galloping horse, blow and scratch your throat. The score is 2 if the execution is accurate on the first attempt, 1 if it is correct on the second attempt and 0 if the gesture is not executed or is not reproduced correctly.