The Prevalence of Elevated Impedances and Magnetic Resonance Imaging Ineligibility Following Implantation of 10 kHz Spinal Cord Stimulation Devices: A Retrospective Review

OBJECTIVES

Spinal cord stimulation (SCS) is increasingly utilized in the treatment of multiple chronic pain conditions. However, patients will continue to experience other medical issues and the potential for future magnetic resonance imaging (MRI) needs must not be overlooked. SCS devices have device-specific MRI conditional labeling and if impedances are elevated the patient may not be able to obtain an MRI. With 10 kHz SCS devices specifically, an impedance value above 10,000 ohms (Ω) is MRI ineligible. The primary objective of this article was to report the incidence of elevated impedances with a multilumen lead design per electrode, per lead, and to describe the total number of MRI ineligible patients due to elevated impedances using 10 kHz SCS cutoff values. The secondary objective was to determine whether certain patient demographics or surgery characteristics put patients at increased risk of elevated impedances.

MATERIALS AND METHODS

We performed a retrospective review of 327 patients who were implanted with a 10 kHz SCS device between January 2015 and November 2020. Regression models were fitted to determine associations between MRI ineligibility status with clinical characteristics including age, sex, BMI, lead location, implantable pulse generator (IPG) location, and time since implant.

RESULTS

We found elevated impedances with subsequent MRI ineligibility in 13 patients (4.0%). Regression analysis did not identify any associations with MRI ineligibility and patient risk factors including age, sex, body mass index, lead location, IPG location, and follow-up time since implant.

CONCLUSION

We found the prevalence of elevated impedances above 10,000 Ω to be 4% of implanted patients. This information is important for patients and physicians alike and should be considered when device selection is occurring in the pre-operative visits.

The Historical Struggles of Modified Electroconvulsive Therapy: How Anesthesia Came to the Rescue

The complicated history of modified electroconvulsive therapy (ECT) started back before anesthesia was incorporated when unmodified electroconvulsive therapy was not considered humane. When anesthesiologists started working with psychiatrists, ECT gradually regained acceptance by decreasing the obstacles inherent to this therapy despite the complexities of the anesthetics. However, the sociopolitical and medicolegal factors negatively impacted the use of modified ECT leading to a period of time when it was banned from use in the United States. Fortunately, as advances in anesthesia and technology continued to develop, anesthesiologists helped ECT regain widespread usage improving the safety profile, cost effectiveness, quicker onset of seizures, and ease of control despite its stained past. This allowed more accessibility, especially for high-risk medical patients, to a relatively safe and effective treatment for psychiatric diseases.

Burns and injuries resulting from the use of gel candles

Scented gel candles are common decorative household items composed of gelled mineral oil, fragrances, and dye. Like traditional wax candles, they have an open flame. Because of defective design, there have been several burns and injuries caused by these products. Here we report our experience with a scald burn from a gel candle and describe 34 additional injuries attributed to gel candles previously unreported in the medical literature.