Go in for a CT Myelography
to know the condition of the roots. If these are normal then you can be rest assured that the cause is not related to root compression. Also, get a EMG/NCV study of both upper limbs
to find out if there are any abnormalities. A trapped nerve as well as carpal tunnel syndrome
should be evident from these investigations and appropriate management done. If these are normal then the cause for your symptoms lies elsewhere and separate studies like Vitamin B12
levels are advocated.