Can straightening and reversal of curve cause one to lose pain and other sensations in extremities and loss of communication in spine?

No but what is the: Reason for the imaging finding of curve reversal or straightening is either degenerative changes or muscle spasm. So, a tumor, hematoma or blood clot, disc herniation or spinal stenosis or even an infection or pathologic/traumatic fracture or syringomyelia leading to spinal cord compression may be the actual cause of the neurologic findings/signs/ symptoms.