Hi, noted that your mother is a diabetic. The long standing diabetic patients sometimes suffers from nerve pain called Diabetic Peripheral Neuropathy. But majority of the neck pain plus shoulder pain symptoms comes form the nerve compression in the vertebra (the central bones containing the spinal cord and other nerves)- these are usually posture related as well seen in certain other conditions. Mainstay of this kind of treatment is Physiotherapy. So consult your primary care physician or your diabetic doctor and understand what likely reason for the pain is. Also consult physiotherapist which will be definitely helpful.