How does a person afflicted with multiple sclerosis pray and purify himself?

Multiple Sclerosis (MS) affects the nervous system and impacts the functions of organs and the brain, with the degree of damage varying from person to person. For someone afflicted with it, if the disease does not affect their mind to the extent of abrogating their religious obligations, they must perform their prayers to the best of their ability. They should perform whatever purification and prayer they are capable of, and what they are unable to do is waived for them, as Allah Almighty says: ﴿Allah does not burden a soul beyond its capacity.﴾

Regarding purification: They should strive to purify themselves to the best of their ability. If they are unable to perform ghusl (definition) (ritual bath) and wudu (ablution) and tayammum (definition) (dry ablution) is an option, then they should perform tayammum. If they are unable to perform tayammum and wudu, they should pray in their current state and not delay the prayer beyond its prescribed time.

Regarding prayer: They should pray to the best of their ability. If they are unable to stand, they should pray sitting, in whatever posture is easiest for them. If they are unable to sit, they should pray lying down, and it is preferable to lie on their right side if both sides are equally comfortable. If they pray lying on their back with their feet towards the Qiblah, this is not valid if they are able to lie on their side. If they are lying down, they should motion for rukoo' (bowing) and sujood (prostration) with their head towards their chest. If they are unable to motion, the actions are waived, and the verbal recitations remain. If they are unable to perform both verbal recitations and actions, they are waived, and only the intention remains; they should intend that they are in prayer and intend the recitation, bowing, prostration, standing, and sitting.