What Causes Prolonged Numbness In Arms, Legs And Face?

Venous Lake on MRI of brain, they feel it is more likely to be that over arachnoid granulation. I am 36 years old, female. I got the MRI due to numbness in arms, legs and face for over a year. Dr. said to check for MS. I also had blood work that showed B12 was low and an EMG that was normal. I started taking B12 with no relief of symptoms. Now I am scheduled to go to a neurologist because my Dr. was not sure what the venous lakes really ment for me. Any ideas?