What could cause constant parethesia in various areas for months? brain/neck mri are normal and so is blood work.. b 12 is normal! also dizzy!

Nerve issues: These symptoms could represent peripheral nerve issues, even the small fibre variant. Although ms is demonstrated on MRI studies, sometimes early on these may be normal and only spinal fluid studies may detect. A number of chemical or metabolic, or even toxic causes may be responsible. Some medicines cause paresthesias, such as topirimate.