A neuromonitoring system comprises a plurality of needle electrodes, a ground electrode, a monopolar stimulating probe having an electrode tip and configured to be coupled to a cable, and a stimulating probe sleeve. The sleeve is adapted and configured to be removably coupled to the monopolar stimulating probe. The sleeve has a slot and is configured and adapted to coaxially slide relative to the monopolar stimulating probe between a first retracted position and a second advanced position. The electrode tip generates an omnidirectional signal when in use while the sleeve is in the retracted position or in an uncoupled position. The electrode tip generates a unidirectional signal when in use while the sleeve is in the advanced position.