What is the ruling on the prayer of a person afflicted with Tourette's Syndrome who experiences severe involuntary movements and vocalizations, and temporary paralysis (freeze tic) during prayer, which sometimes prevents him from completing it?

Tourette's Syndrome is a hereditary neurological disorder that affects men more than women, with its most prominent symptoms being involuntary movements and sounds. A patient with this syndrome is treated according to its effect on their mind: if it affects them completely, they are not held accountable (for religious duties); if partially, they are required to fulfill duties only when they are aware; and if it does not affect their mind, prayer is not waived for them. They must pray according to their ability, and their prayer is not invalidated by involuntary movements or sounds. They should pray sitting or by gesturing if they are unable. Prayer is not waived for a sane person, no matter how severe their inability.