Participants in this study will have already been enrolled in another research study: Combining Stellate Ganglion Block with Prolonged Exposure for PTSD, NCT05889741. The investigators are using a Sleep Profiler, EEG headband to monitor a participants brainwaves while they sleep to see what effects the Stellate Ganglion Block injection has on their sleep. Participants will wear the headband for 3 nights before the injection and then 3 nights after the injection. Participants will also complete self-report questionnaires regarding their sleep prior to the injection and following the injection. Approximately 40 participants will be included in this study. This study is a nested observational study whereby participants in the parent study who elect to participate will have their sleep assessed using the EEG headband device and self-reported sleep measures performed.