If a patient experiences decreased PTN responses, what is the best initial step?

The best initial step when a patient experiences decreased PTN (posterior tibial nerve) responses is to notify the neurosurgeon. This action is crucial because decreased sensory responses can indicate potential complications related to the surgical procedure, such as nerve injury, ischemia, or changes in blood flow. By alerting the neurosurgeon, they can assess the situation quickly and take any necessary actions to protect the patient's neural structures.

Monitoring during surgery, especially neurophysiological monitoring, is crucial for ensuring patient safety and effective intervention when changes in evoked potentials occur. While checking for equipment malfunction and other options may be necessary later, the priority must be to bring the issue to the surgeon’s attention immediately so they can make informed decisions about continuing the procedure or making adjustments to safeguard the patient's neurophysiological integrity.