I have hydrocephalus and have had 6 shunt operations in my life. I also had seizures as a child. I get dysphagia whenever I have anything with monosodium glutamate. In fact, I think it is was caused my childhood seizures. I had something over a week ago with monosodium glutamate (not knowingly), but still 9 days later have difficulty swallowing. Could this be a sign of shunt failure?

No, not from shunt failure, but you need to discuss this with your doctor. AND if you can't ingest MSG then you MUST be diligent eating out, ask questions of the kitchen and start reading labels.