[Imaging Assessment of Thoracic Outlet Syndrome

Bone Abnormalities

Skeletal and bone abnormalities include cervical ribs, elongated transverse process of C7, exostosis of the first rib or clavicle, and excessive callus of the clavicle or first rib.

and a bit more down the page
Elongated Transverse Process of C7.—A C7 transverse process is considered elongated if it extends beyond the tip of the T1 process immediately below it, as seen on cervical radiographs (Fig 9). Like a cervical rib, an elongated C7 transverse process can lead either directly or indirectly to neurovascular compression, in association with a fibrous band or an abnormal middle scalene muscle. ]
http://radiographics.rsna.org/content/26/6/1735.full



I don't know if the C7 issue will cause cognitive problems , but I do know spasms can affect the vertebral artery by pulling on it.
I definitely had some major cog function issues for awhile.
I was also on Lipitor during that same time frame and stopped it at the same time as I got some very good PT- so i can't 100% say which one or what % of the cog fog was TOS or Lipitor caused.