I followed up with Dr A Costantini regarding his following research:
He explained as follows:
"we use thiamine hydrocloride intramuscular phials or
tablets taken by mouth. Generally, with the oral therapy we start with
2 grams each day to be taken once a day in the morning, in order to
increase the dose later consequently to the results obtained. The oral
therapy is as effective as the intramuscular one. Some follow-ups of
the results are always necessary"