My Friend Has Fibromyalgia And Was Recently Hospitalized With Salmonella....the

My friend has fibromyalgia and was recently hospitalized with salmonella....the strange thing is that before she even knew/had symptoms of salmonella she lost most of the strength in her legs, and a lot in her arms. She has recovered from salmonella but is at a rehab centre trying to get enough strength in legs and arms to come home. What could have brought on this sudden limb weakness?