Hi Mr Joseph,
Thank you for posting your query. I must admit, you have provided a very good description of your problems.
Your symptoms are most likely, what we refer to as, Lhermitte's sign or symptom, and it is suggestive of injury to cervical spinal cord
MRI of the cervical spine
would be useful in evaluation of the same, especially to look for injury to a bundle of nerve fibres, called as posterior columns (located in the spinal cord).
Improvement may occur with medications such as pregabalin
Please consult a neurologist
Wishing you good health,
Dr Sudhir Kumar MD DM (Neurology)