Temporal patterns of spinal cord stimulation for chronic pain in rat model

Study Purpose: The purpose of this study was to design patterns of dual frequency spinal cord stimulation and test their ability to alleviate chronic pain in a rat model. Specifically, we sought to evaluate their performance relative to traditional, single frequency spinal cord stimulation.

Data Collection: We used a biophysically validated computational model of the dorsal horn of the spinal cord to find dual frequency pairs that were likely to improve over single frequency counterparts and that the improvement was robust to pain progression and dorsal column fibers recruited. We tested these patterns in a spared nerve injured rat by recording paw withdrawal thresholds during stimulation.

Primary Conclusion: Dual frequency spinal cord stimulation in the spared nerve injury model of chronic pain increases responder rates to spinal cord stimulation over traditional single frequency stimulation.

Curator's Notes

Experimental Design: Dual-frequency spinal cord stimulation was tested in 10 spared nerve-injured rats using two electrode pair configurations. For each rat, the data includes paw withdrawal thresholds obtained at the study baseline, after a spared nerve injury, x-rays for electrode location confirmation, and paw withdrawal thresholds for each stimulation condition. Six stimulation patterns were delivered in two different configurations, resulting in 12 different stimulation conditions (sham, 2-2 Hz, 54-54 Hz, 25-40 Hz, 54-2 Hz, 2-54 Hz, across medial-lateral and rostral-caudal contact pairs). The six stimulation patterns for a given contact pair orientation were delivered randomly over six days of testing at the same time of day (either morning or afternoon, with start times separated by 5 hours). In each cohort of up to 4 animals, half received medial-lateral stimulation in the morning and rostral-caudal stimulation in the afternoon, while the other half received the opposite.

Completeness: This dataset is complete.

Subjects & Samples: Male (n=10) adult Sprague-Dawley rats (RRID:RGD_734476) were used in this study.

Primary vs derivative data: Primary folder is organized by the subject ID and the type of stimulation condition received (perf-) and contains recording paw withdrawal thresholds in .xlsx files.

Code Availability: The code folder contains the dorsal horn model source code (src) and model neuron responses to simulations (model-output). The model-derivative folder contains calculated spike times used to select the best frequency pairs to be tested in the rodent model. Each spatial configuration folder is named for the number of center then surround fibers receiving frequency 1-both frequencies-no stimulation-frequency 2. Within each individual folder are the modified model inputs to create that simulation and a zip file with the output of the four neuron model neurons in response to each of the 5041 possible frequency pairs. The base model is open source and can be found here: https://modeldb.science/168414?tab=1