Hi again Lauren,
I really think your more likely dealing with a seasonal related trigger,the Fall season being the right time of year to set it off. Migraines actually do have an association with the Fall season and your combination of symptoms (including all peripheral limb tingling) are commonly related to migraines, so seasonal migraine is an idea to consider.....
Generally the higher the spinal cord lesions or spinal cord damage the more problems occur below it, a T-spine lesion is unlikely to explain all the symptoms you experience, it's also bilaterally both upper and lower neurons so it would have to be high enough and large enough to cut off the cord and bilaterally effect arms and legs, i really don't think a T-spine cord lesion(s) or structural issue would account for it, there's still the Fall season connection you have too.
"...The cervical cord innervates the deltoids (C4), biceps (C4-5), wrist extensors (C6), triceps (C7), wrist extensors (C8), and hand muscles (C8-T1).
The Thoracic Cord. The thoracic vertebral segments are defined by those that have a rib. These vertebral segments are also very special because they form the back wall of the pulmonary cavity and the ribs. The spinal roots form the intercostal (between the ribs) nerves that run on the bottom side of the ribs and connect to the intercostal muscles and associated dermatomes.
The Lumbosacral Cord. The lumbosacral vertebra form the remainder of the segments below the vertebrae of the thorax. The lumbosacral spinal cord, however, starts at about T9 and continues only to L2. It contains most of the segments that innervate the hip and legs, as well as the buttocks and anal regions."
http://www.travisroyfoundation.org/sci/resources/spinal-cord-injury-levels-classification/
"In the thoracic spine, unlike the lumbar or cervical spine, the anatomy is somewhat different and that changes the way the mechanics of the spine are responsible for the injury or the pain that comes from that region. So, the thoracic spine is different because it has the rib cage. The rib cage provides rigidity and reduces motion. Now, because of that, the injury to that region is quite different than it is for higher-mobile regions, such as cervical spine or lumbar spine.
That's why the disc herniations that are common in the lumbar and cervical spine are not as common. In fact, they are very uncommon in the thoracic spine. So, the more common causes of upper back pain is caused by either a joint dysfunction or the muscle and connective tissue irritation."
http://www.spine-health.com/video/causes-upper-back-pain-video
A potential rational behind your neuro not running the T-spine is that disc issues are very uncommon in this location, and it's true that 'all peripherals' are one of the MS red flags, it's more commonly related to the peripheral nervous system than the central which is MS. Bilateral is uncommon in MS though it does happen if the lesion is big enough to cut the cord like TM lesions do, bilaterally upper and lower limbs are honestly less like to be caused by a neurological condition like MS.
Hope that helps........JJ
I neglected to complete the sentence about about the brain MRIs which were negative.