Dermatomal somatosensory evoked potentials and electrical perception thresholds during recovery from cervical spinal cord injury

BACKGROUND: .Dermatomal somatosensory evoked potentials (dSSEPs) not only provide a neurophysiological readout comparable with conventional SSEPs but also provide an opportunity to track changes in sensory function corresponding to individual dermatomes (ie, a single spinal segment) above, at, and below the level of spinal cord injury (SCI). OBJECTIVES: .This study aimed to determine the reliability and responsiveness of dSSEPs and electrical perception thresholds (EPTs) to monitor changes in sensory function after cervical SCI. METHODS: . Initial and follow-up dSSEPs and EPTs were recorded from cervical dermatomes (C4-C8) of patients with traumatic tetraplegia (C3-C8; ASIA Impairment Scale A-D) during recovery after SCI (n = 18). RESULTS: . Follow-up examination of 74 initial dSSEPs unaffected by SCI (n = 18) revealed no significant change in latency (Delta = 0.0 +/- 1.4 ms; P = .9) or EPT sensitivity (Delta = 0.1 +/- 0.8 mA; P = .3). In 41 dSSEPs initially delayed after SCI (n = 14), latencies significantly decreased on follow-up examination (Delta = -3.1 +/- 2.9 ms; P < .01) without a corresponding increase in sensitivity of the EPT (Delta = 0.2 +/- 3.4 mA; P = .7). dSSEPs that were not measurable initially were subsequently recorded in 11 dermatomes (n = 5) on follow-up examination.This conversion of abolished-to-recordable dSSEPs was often preceded by the perception of an initial EPT and associated with a concomitant recovery of EPT at follow-up. CONCLUSION: . dSSEPs and EPT can be reliably recorded to monitor changes in sensory function for each individual spinal segment after cervical SCI. dSSEPs may be potentially useful to monitor the safety of a therapeutic drug or cell transplant in early-phase (I/II) clinical trials as well as document the potential efficacy of interventions where the standard neurological assessment might not detect subtle therapeutic effects

Validity of estimated cardiorespiratory fitness in patients with primary breast cancer

Background: Estimated peak oxygen consumption (Vo2peak) is widely used in oncology; however, estimated Vo2peak equations were developed in noncancer settings. Objectives: The aim of this study was to evaluate the validity of estimated Vo2peak in women with primary breast cancer and to develop oncology-specific estimated Vo2peak equations. Methods: Vo2peak was directly measured (TrueOne 2400, Parvo Medics) during 380 cardiopulmonary exercise tests in women previously treated for breast cancer (mean age: 59 ± 10 years; 3.1 ± 1.2 years post-therapy). The American College of Sports Medicine (ACSM), the Fitness Registry and the Importance of Exercise National Database (FRIEND), and heart failure (HF)-FRIEND equations were used to estimate Vo2peak. New equations were developed using patient and peak (Oncpeak) or submaximal (Oncsub) exercise test characteristics. Results: The median differences between measured and estimated Vo2peak were 7.0 mL O2·kg−1·min−1, 3.9 mL O2·kg−1·min−1, and −0.2 mL O2·kg−1·min−1 for ACSM, FRIEND, and HF-FRIEND, respectively. The number of estimated Vo2peak values within ±3.5 mL O2·kg−1·min−1 of the measured values was 70 (18%), 164 (43%), and 306 (81%) for ACSM, FRIEND, and HF-FRIEND, respectively. The Oncpeak and OncSub models included body mass index, age, a history of chemotherapy or radiation, the peak measured heart rate, and the treadmill grade and/or speed. The median differences between measured and estimated Vo2peak were 0.02 mL O2·kg−1·min−1 (Oncpeak) and −0.2 mL O2·kg−1·min−1 (Oncsub). Eighty-six percent (n = 325) and 76% (n = 283) estimated Vo2peak values were within ±3.5 mL O2·kg−1·min−1 of the measured Vo2peak values for Oncpeak and Oncsub, respectively. Conclusions: HF-FRIEND or oncology-specific equations could be applied to estimate Vo2peak in patients previously treated for breast cancer in settings where cardiopulmonary exercise tests are not available. (Trial Comparing the Effects of Linear Versus Nonlinear Aerobic Training in Women With Operable Breast Cancer [EXCITE]; NCT0118636