Are persistent tingling in arms and legs for a few weeks an abnormal neurological finding? does it warrant a mri scan of the brain? brain tumour?

Many causes: Systemic tingling may suggest something is going on the sensory nervous system. What I found with some of my patients at your age is iron deficiency. Pts will have odd sensations what you are describing including restless legs at night. Have your doc run some iron studies including ferritin. Otherwise a neurology referral could be helpful. Good luck.

Yes : Numbness and tingling of arms and feet requires medical evaluation . You need to see your primary care physician to some blood work first to rule out any metabolic reason for your symptoms . These will include test for thyroid disease , vitamin B12 deficiency , a metabolic panel and bold count . If all is negative , then a Neuro evaluation maybe needed . I doubt that you will need an MRI ,