Re: Thoracic ruptures, legs falling asleep when lying down????
I can't really comment on the thoracic disc issues, but whenever there are signs of legs falling asleep, or becoming slightly numb, it is a sign that a spinal nerve is being pinched or compressed. There are nerves that exit the spine at each vertebra, on either side. When the discs break down, the space between vertebrae lessens and this can allow for a nerve to be compressed.
Changing position sometimes allows the vertebrae to shift slightly, enough to open up enough space so the nerve can fully function again.
You might want to consult with the doctor who is managing your thoracic problems if this is a new symptom, or if it is worsening.