My mother died of a disease I had never heard of until her doctor diagnosed it. It was called Progressive Supranuclear Palsy or PSP. As the name indicates, PSP worsens (progressive) and causes weakness (palsy) by damaging parts of the brain above nerve cell clusters called nuclei (supranuclear).

At around 80, my mother showed the first symptoms when she began falling forward and hurting herself. We attributed it to the feebleness of old age. Imagine that your brain communicates with your faculties - hearing, sight, speech, mobility and so on - through cables, the way a phone company connects landline phones. Imagine those cables getting frayed because of a progressive disease. Soon the brain can no longer command the organs, and one by one the faculties begin to shut down.