Inerferon & Ribavirin Treatment - Symptoms

My 80 year old mother had Inerferon & Ribavirin Treatment in 2002 for Hep C as a result of a contaminated blood transfusion in 1969.

Over the last few years she has developed intermittent issues with the inability to walk forward but no issue walking sidewards or backward. ( very strange) These episode last between 12-24 hours) over the last 2 months or so thes episodes are becoming more frequent.

Could these intermittent foot symptoms be a sign of peripheral neuropathy caused by the Interferon or Ribavirin?"

Are these coming-and-going sensations a typical side effect of this treatment combination, or could they indicate a different underlying issue?

She mas been to numerous doctors and nurologists and is struggling to find and answer or solution.

HAs anyone in here experienced similar symptoms, or have any suggestions