Implanted Spinal Cord Stimulator Dysfunction After Electrical Shock

Abstract

Spinal cord stimulation (SCS) has played a significant role in chronic pain since its inception during the late 1960s. There are several proposed mechanisms for SCS, one of which works via electrical pulses that target the dorsal horn of the spinal cord to inhibit afferent pain signals to achieve analgesia (Gate Control Theory). This can lead to an overall improvement in pain control when pharmacologic therapy is inadequate or ineffective. SCS also reduces pharmacologic needs, and hence alleviates side effects associated with opioids and other medications. We present the case of a 44-year-old male with chronic pain and an implanted SCS in place who presented to our university institution pain clinic for lumbar back pain with bilateral radiculopathy. He had suffered from back pain since 1996 and an implanted SCS was placed in June 2013. Three years after the SCS placement, the patient suffered an alternating (60 Hz) current 120-volt electrical shock while working on kitchen appliances resulting in SCS dysfunction. Prior to the electrocution event, the SCS was operating normally with a battery life registering three-fourths full. The stimulator was turned on one day prior to the incident. At the time of the electrical shock, the SCS was not actively stimulating. Following the incident, the patient tried to turn on the stimulator without success. Implantable devices, including pacemakers and neuromodulators, have a circuit protective mode which should prevent this type of occurrence. Using the physician programmer, we were unable to detect, connect, or interrogate his stimulator. With the help of a device representative, we attempted a physician mode recharge (PMR) for 10 minutes while in office. We were then able to pair the patient’s charger with the stimulator, and enter into the normal feedback-enabled charge mode. His charger display screen indicated a drained battery. After approximately 25 minutes of recharging, a second attempt to interrogate the device was successful. We hope this encourages all current and future SCS manufacturers to perform further device testing, quality control development, and research and development to make subsequent SCS even more reliable and resistant to damage or premature failure. Key words: Spinal cord stimulator (SCS), spinal cord generator, power-on reset (POR), SCS malfunction, electrical shock, dysfunction