The term peripheral nerve is synonymous with the peripheral nervous system (PNS). The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs. The PNS is divided into two systems — the autonomic nervous system and the somatic nervous system.
The somatic nervous system is responsible for controlling movement (motor function) and also for receiving sensation input from the periphery (sensory). These sensations include pain signals from the periphery to the spinal cord and ultimately, to the brain. In certain painful conditions such as cancer pain, the pain signals from these nerves can be blocked to provide relief to patients.
The most common reason for peripheral nerve blocks is when pain medication escalation is limited by side-effects. Some patients, however, will benefit from one component of their pain being relieved by a simple peripheral nerve block as part of a comprehensive, multi-pronged plan.
When these nerve blocks are given in combination with other therapy, including pain medications, radiation therapy, and chemotherapy, their use may allow significant relief from pain while avoiding side-effects from escalation of pain medications.
Peripheral nerve blocks can be performed either with the assistance of landmarks that can be easily felt by touch (palpation) or under imaging guidance (a live x-ray or ultrasound machine) to increase the accuracy of this procedure.
Similar to any other procedure or medication, there are low potential risks of infection, bleeding, allergic reaction, and prolonged increases in pain. X-ray guidance and sterile techniques used by your physician throughout the procedure will significantly reduce these risks.