Abstract
Stupor is a diagnostic challenge at emergency department. Differential diagnosis includes idiopathic recurrent stupor, formerly attributed to "endozepine-4" accumulation. This condition has been recently questioned because many suspected cases resulted in exogenous benzodiazepine intake that eludes the conventional toxicological assay. In case of unexplained recurrent stupor, to extend the benzodiazepine search in nonconventional matrices can allow unmasking of hidden toxic behavior.