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ObjectivesSpinal cord stimulation (SCS) is conventionally placed at either cervical or thoracic spinal regions to treat chronic pain. However, for patients with multiarea pain, concomitant cervical and thoracic SCS (ctSCS) may be necessary to provide sufficient coverage. It remains unknown whether ctSCS is effective and safe. Thus, we aimed to survey the existing literature and assess the efficacy and safety of ctSCS.MethodsA systematic review of the literature was performed according to the 2020 PRISMA guidelines to investigate pain, functional, and safety outcomes related to ctSCS. Articles between 1990 and 2022 available through PubMed, Web of Science, Scopus, and Cochrane Library databases were included if they assessed these outcomes in the context of ctSCS. Data extracted from articles included study type, number of ctSCS implantations, stimulation parameters, indications for implantation, complications, and frequency. The Newcastle–Ottawa scale was used to assess risk of bias.ResultsThree primary studies met our inclusion criteria. Overall, ctSCS was effective in providing analgesia. Pain severity was captured with patient‐reported pain scales and changes in analgesic requirements. Various metrics were used to quantify quality of life and functional outcomes. Failed back surgery syndrome was the most common indication for ctSCS implantation. Implanted pulse generator pocket pain was the most common postoperative adverse event.ConclusionsDespite the limited evidence available, ctSCS seems to be effective and generally well tolerated. The dearth of relevant primary literature illustrates a knowledge gap, and future studies are needed to better clarify the efficacy and safety profile of this SCS variant.

OBJECTIVE Stereotactic electroencephalography (sEEG) is an increasingly utilized method for identifying electrophysiological processes underlying sensorimotor, cognitive, and emotional behaviors. In this review, the authors outline current research using sEEG to investigate the neural activity underlying emotional and psychiatric behaviors. Understanding the current structure of intracranial research using sEEG will inform future studies of psychiatric disease and therapeutics for effective neuromodulation. METHODS The authors conducted a comprehensive systematic review of studies according to PRISMA guidelines to investigate behaviors related to psychiatric conditions in patients with epilepsy undergoing monitoring with sEEG. Articles indexed on PubMed between 2010 and 2022 were included if they studied emotions or affective behaviors or met the National Institute of Mental Health Research Domain Criteria positive and negative valence domains. Data extracted from articles included study sample size, paradigms and behavioral tasks employed, cortical and subcortical targets, EEG analysis methods, and identified electrophysiological activity underlying the studied behavior. The Newcastle-Ottawa Scale was used to assess bias risk. RESULTS Thirty-two primary articles met inclusion criteria. Study populations ranged from 3 to 39 patients. The most common structures investigated were the amygdala, insula, orbitofrontal cortex (OFC), hippocampus, and anterior cingulate cortex (ACC). Paradigms, stimuli, and behavioral tasks widely varied. Time-frequency analyses were the most common, followed by connectivity analyses. Multiple oscillations encoded a variety of behaviors related to emotional and psychiatric conditions. High gamma activity was observed in the amygdala and anterior insula in response to aversive audiovisual stimuli and in the OFC in response to reward processing. ACC beta band power increases and hippocampal-amygdala beta coherence variations were predictive of worsening mood states. Insular and amygdalar theta oscillations encoded social pain and fear learning, respectively. Most studies performed passing recordings, allowing for the decoding of affective states and depression symptoms, while other studies utilized direct stimulation, such as in the OFC to improve mood symptoms. CONCLUSIONS Stereotactic EEG in epilepsy has identified multiple corticolimbic structures with specific oscillatory and synchronization activity underlying a diverse range of behaviors related to emotions and affective conditions. Given the heterogeneity of psychiatric conditions, sEEG provides an opportunity to study these neural correlates to develop personalized effective neuromodulatory treatments. Future studies should focus on optimizing paradigms and tasks to investigate a broad range of behavioral phenotypes that overlap across psychiatric conditions.