Around five years ago when I was 42, I started developing twitchy wrists, close to the spot on the wrist used for taking one's pulse. I also had trouble balancing food on a fork and holding a glass of water steady. My father thought I might be starting to exhibit symptoms Parkinson's.
My father was diagnosed with Parkinson's in 2004 and has been on Carbidopa/Levadopa for over a decade. I never liked how my father was addicted to Parkinson's medication, so I never went to a doctor for that. Instead I stopped sitting down as much as possible. I started using my laptop on top of a pillow that was top of my chest, all while lying down flat on my back. It's not the base of the laptop that rests on the pillow, but the edge of the base of the laptop. So I have to use my left hand to hold the laptop in place, while I type with my right hand. After several months, my twitching went away and I could hold a glass of water steady again. Using a laptop while lying down flat on my back has been my preferred way ever since.
I recently found this article about neurological problems and insufficient brain waste draining:
caringmedical.com/brain-toi...
"The brain drains when you lie down. The brain drains less when you are standing"
"The drainage of the brain through the venous system goes from 614-740 ml/min in the supine position to 280-304 ml/min while upright.(4,5) In the supine position, 75-92% of the venous flow goes through the internal jugular veins but goes down to 25-42% as the venous flow shifts more to the epidural, vertebral, and deep cervical veins while upright."