The invention relates to the use of a compound of formula :for the preparation of pharmaceutical compositions for increasing the circulating, cellular and extracellular levels of TGF-\u03b21. Said method is applied to central nervous system diseases, preferably to Multiple Sclerosis. A switch is operatively connected to the input terminal, and an offset sampling capacitor is operatively connected to the switch. The technique of the invention thus desirably reduces the required level of charging or discharging of the battery, which is triggered by a response delay of the engine. The transient recorder, in one embodiment, includes an analog-to-digital converter and a voltage threshold detector.