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Odd Pet Behavior During SCS Trial—Case Report

High frequency SCS setting causes patient’s cat to avoid him when his stimulator is on.

Up to 40% of patients who undergo lower spine surgery for lower extremity radicular pain experience persistent pain after operation—this is commonly referred to as failed back surgery syndrome.1

Traditional spinal cord stimulation (SCS) has been shown to provide substantial pain relief, increased quality of life, and improved functional capacity in randomized controlled trials.2,3

The use of higher frequency stimulation has been gaining traction for pain due to the improved pain coverage and increased patient satisfaction over traditional SCS.4 This increased satisfaction is due in part to the lack of paresthesia experienced by patients implanted with high frequency stimulators.4

Therefore, it is reasonable to assume that as SCS technology and patient satisfaction continue to improve, these devices will continue to be implanted.

We present a case of a 46-year-old man with a history of persistent post-laminectomy pain despite trials with more conservative approaches to pain management. He underwent successful SCS trial. His only complaint was that his normally very affectionate family pet (cat) would avoid him while the SCS device was turned on, which was very troubling for the patient. Although this phenomenon cannot be considered a side effect, it may present a psychosocial issue not previously discussed to our knowledge. We briefly present this case and the issues it may present with patient satisfaction with SCS.

Case History

The patient underwent laminectomy and fusion in 2005, presenting to our office with recurrent low back pain and severe bilateral radicular leg pain. The patient received conservative treatments with multiple facet joint injections and caudal epidural steroid injections without improvement in his symptoms.

He was presented with the option of SCS therapy, and after lengthy discussion of the risks and benefits, consented to a SCS trial. He underwent uneventful SCS trial implantation with a Medtronic RestoreSensor Surescan dual 8-electrode epidural leads with two setting—low density (100 Hz) and high density (1200 Hz).

The patient reported 75% improvement in his low back and leg pain during the 7-day trial period with both of the trial frequency settings. He also reported improved quality of life (QOL).

His only complaint during the trial period was that his cat would avoid him while the stimulator was functioning at the higher frequency level. This was very troubling to him because his pet was a big part of his life.

Although the impact the stimulator had on his relationship with the cat was concerning, the substantial pain relief he experienced was significant enough that he elected to proceed with permanent SCS implantation. He requested, however, that only the lower frequency stimulation setting be used.

This appears to be the first case report of such a phenomenon occurring between a patient and pet. It remains to be seen if the permanent device will have similar effects on his cat.


A recent multicenter prospective study found that high frequency SCS was superior to conventional SCS in relief of both back and leg pain in patients up to 1 year.4 Given these findings, it is reasonable to assume that these newer devices will be implanted more frequently and may likely replace traditional SCS settings. As these devices become more common, we must explore potential issues with patient satisfaction when they come up.

It is unclear if the behavior of the cat in our case was due to the animal sensing the active stimulator. Cats are able to sense sounds at frequencies three times higher than that of humans (up to 65,000 Hz).5 It may be that these animals are able to sense the high frequency emissions from the SCS device.

Our goal is not to explain the phenomenon presented in this case, but rather bring to light a potential issue with patient satisfaction and the importance of considering the socioeconomic impact SCS devices may present to patients and those involved in their daily living.

We believe it is essential to have the individuals personally involved during the consultation and trial phases of SCS treatment. Remember, the main goal of a trial period is not just to ensure adequate pain coverage, but also bring to light any potential negative confounders to the patient’s SCS experience. When identified, these issues should be carefully discussed to explore possible resolutions and confirm expectations in an attempt to improve outcomes.


SCS is an effective treatment option for patients with failed back surgery syndrome. Recently, high-frequency SCS was found to have advantages over traditional SCS with improved patient satisfaction. This new technology may have unrecognized side effects on patients and their loved ones that need to be recognized and addressed when they occur. We present one such case of a patient’s relationship with his pet cat being negatively affected by an active SCS. It remains to be seen whether this behavior is a coincidence or represents a phenomenon that needs serious consideration.

Last updated on: December 9, 2015
First published on: December 1, 2015
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