I never thought of Tourette's syndrome, but "structured" chorea because those movements are so organised, consist of neck rotations, shoulder shrugs etc., in sequence, that people may think he is actually doing exercise.
Lately he said he is able to control when to begin and stop the movements.
Just googled to find out the correlation between Sydenham's chorea and streptococcal rheumatic fever, which further convince me that his self exercise "gift" may be related with his earlier fever cough. Wonder if doctor prescripts steroids and antibiotics. Anyway hope he is getting better, not like Cali's progression:
Ah, now I know why she is taking CoQ10 supplement, which is good for heart.