hi, thank you for providing the brief history of you. A thorough clinical examination is advised. as you have already performed all the test and came out negative I feel this could be a neurological issue. Like the nerve pinching. As nerve carries the functions of the sensory system any disruption in the nerve route may lead to such symptoms. I will advice you to perform core stability exercises and also spine muscle Strengthening exercises by which the nerve pinch can be removed and the symptoms will be reduced as well. Since it is a harmless and no sideffects are there I will advice you to do exercises. Many cases in my clinical experience has responded well to physical therapy alone with exercises for the spine stability. Regards Jay Indravadan Patel