Numbness And Decreased Strength With Inability To Twist Fingers And Wrist At The Age Of 57

My daughter age 57 is having numbness and decreased strength and inability to twist fingers and wrist (as in unscrewing a lid ) and writing has changed. No pain associated. Dr. has been consulted. Low risk for stroke, MRI of brain negative, carotid artery ok. . She is a professional. A volunteer director of a huge Hospice company in Omaha. Early Melanoma lesion excised from right side of face in 2012. Face has healed well although a large incisiong and deep. No neuro concerns other than as expected. Now, twitching of area beside nose and under eye on the right. The Melanoma involved a large area on the right face--cheekbone to chin bone. We are waiting on lab tests but not sure what all her doctor ordered. He is checking her thyroid. She has no history of a fall or illness in the recent past. She expresses the numbness like "I could feel the pin pricks and I can feel touch but it doesn't feel right like it is numb underneath." Wondering if surgery on face could have a bearing on these symptoms (1 year past) or what sort of thing could this be. Thanks so much.