First of all blood sugar control - in case of elevated glucosae decrease gradually, avoiding sudden drop, second - Blood pressure control in the range of 140 mm Hg systolic and 80 mmHg diastolic. Numbing indicates neuropathy, that is why to activate metabolism it is advocated intramuscular injectiones of SOLCOSERYL ( Switzerland) 5 cc each other day 5 injectiones ans Nycergoline 5 mg once a day before meal 2 weeks.
Too low details. Such symptoms have many reasons. Numbing can be related to DM or unrelated. Where is the numbing? Whole upper limb? only hand? What are the reflexes? Waht is the muscle power? Probable causes: cervical discopathy (check X-ray of C), neuropathy also. It need more diagnosis. Write more details.