This is high-dose vitamin B-1 therapy. According to Medline the recommended daily thiamine dose for healthy people is 1-2mgs and 300mgs for people with 'severe' thiamine deficiency. The Italian group gave their patients (with normal thiamine blood levels) from 600 to 1,500 mgs of thiamine per day (depending on their body weight). The doctors observed an 'all or nothing' response, with no response being shown until the correct dose was found.
Side effects consisted of tachycardia and insomnia in a few patients which disappeared when the dose was lowered.