Beta activity in human anterior cingulate cortex mediates reward biases.

The rewards that we get from our choices and actions can have a major influence on our future behavior. Understanding how reward biasing of behavior is implemented in the brain is important for many reasons, including the fact that diminution in reward biasing is a hallmark of clinical depression. We hypothesized that reward biasing is mediated by the anterior cingulate cortex (ACC), a cortical hub region associated with the integration of reward and executive control and with the etiology of depression. To test this hypothesis, we recorded neural activity during a biased judgment task in patients undergoing intracranial monitoring for either epilepsy or major depressive disorder. We found that beta (12-30 Hz) oscillations in the ACC predicted both associated reward and the size of the choice bias, and also tracked reward receipt, thereby predicting bias on future trials. We found reduced magnitude of bias in depressed patients, in whom the beta-specific effects were correspondingly reduced. Our findings suggest that ACC beta oscillations may orchestrate the learning of reward information to guide adaptive choice, and, more broadly, suggest a potential biomarker for anhedonia and point to future development of interventions to enhance reward impact for therapeutic benefit.

Default mode network electrophysiological dynamics and causal role in creative thinking.

The default mode network (DMN) is a widely distributed, intrinsic brain network thought to play a crucial role in internally-directed cognition. The present study employs stereo-electroencephalography in 13 human patients, obtaining high resolution neural recordings across multiple canonical DMN regions during two processes that have been associated with creative thinking: spontaneous and divergent thought. We probe these two DMN-associated higher cognitive functions through mind wandering and alternate uses tasks, respectively. Our results reveal DMN recruitment during both tasks, as well as a task-specific dissociation in spatiotemporal response dynamics. When compared to the fronto-parietal network, DMN activity was characterized by a stronger increase in gamma band power (30-70 Hz) coupled with lower theta band power (4-8 Hz). The difference in activity between the two networks was especially strong during the mind wandering task. Within the DMN, we found that the tasks showed different dynamics, with the alternate uses task engaging the DMN more during the initial stage of the task, and mind wandering in the later stage. Gamma power changes were mainly driven by lateral DMN sites, while theta power displayed task-specific effects. During alternate uses task, theta changes did not show spatial differences within the DMN, while mind wandering was associated to an early lateral and late dorsomedial DMN engagement. Furthermore, causal manipulations of DMN regions using direct cortical stimulation preferentially decreased the originality of responses in the alternative uses task, without affecting fluency or mind wandering. Our results suggest that DMN activity is flexibly modulated as a function of specific cognitive processes and supports its causal role in divergent thinking. These findings shed light on the neural constructs supporting different forms of cognition and provide causal evidence for the role of DMN in the generation of original connections among concepts.

Insula uses overlapping codes for emotion in self and others.

In daily life, we must recognize others' emotions so we can respond appropriately. This ability may rely, at least in part, on neural responses similar to those associated with our own emotions. We hypothesized that the insula, a cortical region near the junction of the temporal, parietal, and frontal lobes, may play a key role in this process. We recorded local field potential (LFP) activity in human neurosurgical patients performing two tasks, one focused on identifying their own emotional response and one on identifying facial emotional responses in others. We found matching patterns of gamma- and high-gamma band activity for the two tasks in the insula. Three other regions (MTL, ACC, and OFC) clearly encoded both self- and other-emotions, but used orthogonal activity patterns to do so. These results support the hypothesis that the insula plays a particularly important role in mediating between experienced vs. observed emotions.

Active nerve management for above the knee amputation: A comparison of through the wound versus posterior approach.

Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are used to prevent or treat neuromas in amputees. TMR for above-the-knee amputation (AKA) is most commonly performed through a posterior incision rather than the stump wound because recipient motor nerves are primarily located in the proximal third of the thigh. When preventative TMR is performed with concurrent AKA, a posterior approach requires intraoperative repositioning and an additional incision. The purpose of this study was to evaluate feasibility of TMR and operative times for nerve management performed through the wound compared to a posterior approach in AKA patients to guide surgical decision-making. Patients who underwent AKA with TMR between 2018-2023 were reviewed. Patients were divided into two groups: TMR performed through the wound (Group I) and TMR performed through a posterior approach (Group II). If a nerve was unable to undergo coaptation for TMR due to the lack of suitable donor motor nerves, RPNI was performed. Eighteen patients underwent AKA with nerve management were included from Group I (8 patients) and Group II (10 patients). TMR coaptations performed on distinct nerves was 1.5 ± 0.5 in Group I compared to 2.6 ± 0.5 in Group II (p = 0.001). Operative time for Group I was 200.7 ± 33.4 min compared to 326.5 ± 37.1 min in Group II (p = 0.001). TMR performed through the wound following AKA requires less operative time than a posterior approach. However, since recipient motor nerves are not consistently found near the stump, RPNI may be required with TMR whereas the posterior approach allows for more TMR coaptations.

A biophysically constrained brain connectivity model based on stimulation-evoked potentials.

BACKGROUND: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies. NEW METHOD: Using intracranial electrophysiology data recorded from a single patient undergoing stereo-electroencephalography (sEEG) evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES. C1 components were utilized for a novel topology optimization method, modeling 3D electrical conductivity to infer neural pathways from stimulation sites. Additionally, PEP features were compared with tractography metrics, and model results were analyzed with respect to anatomical features. RESULTS: The proposed optimization model resolved conductivity paths with low error. Specific electrode contacts displaying high error correlated with anatomical complexities. The C1 component strongly correlated with additional PEP features and displayed stable, weak correlations with tractography measures. COMPARISON WITH EXISTING METHOD: Existing methods for estimating neural signal pathways are imaging-based and thus rely on anatomical inferences. CONCLUSIONS: These results demonstrate that informing topology optimization methods with human intracranial SPES data is a feasible method for generating 3D conductivity maps linking electrical pathways with functional neural ensembles. PEP-estimated effective connectivity is correlated with but distinguished from structural connectivity. Modeled conductivity resolves connectivity pathways in the absence of anatomical priors.

Stereo-EEG-guided network modulation for psychiatric disorders: Surgical considerations.

BACKGROUND: Deep brain stimulation (DBS) and other neuromodulatory techniques are being increasingly utilized to treat refractory neurologic and psychiatric disorders. OBJECTIVE: /Hypothesis: To better understand the circuit-level pathophysiology of treatment-resistant depression (TRD) and treat the network-level dysfunction inherent to this challenging disorder, we adopted an approach of inpatient intracranial monitoring borrowed from the epilepsy surgery field. METHODS: We implanted 3 patients with 4 DBS leads (bilateral pair in both the ventral capsule/ventral striatum and subcallosal cingulate) and 10 stereo-electroencephalography (sEEG) electrodes targeting depression-relevant network regions. For surgical planning, we used an interactive, holographic visualization platform to appreciate the 3D anatomy and connectivity. In the initial surgery, we placed the DBS leads and sEEG electrodes using robotic stereotaxy. Subjects were then admitted to an inpatient monitoring unit for depression-specific neurophysiological assessments. Following these investigations, subjects returned to the OR to remove the sEEG electrodes and internalize the DBS leads to implanted pulse generators. RESULTS: Intraoperative testing revealed positive valence responses in all 3 subjects that helped verify targeting. Given the importance of the network-based hypotheses we were testing, we required accurate adherence to the surgical plan (to engage DBS and sEEG targets) and stability of DBS lead rotational position (to ensure that stimulation field estimates of the directional leads used during inpatient monitoring were relevant chronically), both of which we confirmed (mean radial error 1.2±0.9 mm; mean rotation 3.6±2.6°). CONCLUSION: This novel hybrid sEEG-DBS approach allows detailed study of the neurophysiological substrates of complex neuropsychiatric disorders.

A biophysically constrained brain connectivity model based on stimulation-evoked potentials.

Background: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies. New Method: Using intracranial electrophysiology data recorded from a single patient undergoing sEEG evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES. C1 components were utilized for a novel topology optimization method, modeling 3D conductivity propagation from stimulation sites. Additionally, PEP features were compared with tractography metrics, and model results were analyzed with respect to anatomical features. Results: The proposed optimization model resolved conductivity paths with low error. Specific electrode contacts displaying high error correlated with anatomical complexities. The C1 component strongly correlates with additional PEP features and displayed stable, weak correlations with tractography measures. Comparison with existing methods: Existing methods for estimating conductivity propagation are imaging-based and thus rely on anatomical inferences. Conclusions: These results demonstrate that informing topology optimization methods with human intracranial SPES data is a feasible method for generating 3D conductivity maps linking electrical pathways with functional neural ensembles. PEP-estimated effective connectivity is correlated with but distinguished from structural connectivity. Modeled conductivity resolves connectivity pathways in the absence of anatomical priors.

Brain mechanisms underlying the emotion processing bias in treatment-resistant depression.

Depression is associated with a cognitive bias towards negative information and away from positive information. This biased emotion processing may underlie core depression symptoms, including persistent feelings of sadness or low mood and a reduced capacity to experience pleasure. The neural mechanisms responsible for this biased emotion processing remain unknown. Here, we had a unique opportunity to record stereotactic electroencephalography (sEEG) signals in the amygdala and prefrontal cortex (PFC) from 5 treatment-resistant depression (TRD) patients and 12 epilepsy patients (as control) while they participated in an affective bias task in which happy and sad faces were rated. First, compared with the control group, patients with TRD showed increased amygdala responses to sad faces in the early stage (around 300 ms) and decreased amygdala responses to happy faces in the late stage (around 600 ms) following the onset of faces. Further, during the late stage of happy face processing, alpha-band activity in PFC as well as alpha-phase locking between the amygdala and PFC were significantly greater in TRD patients compared to the controls. Second, after deep brain stimulation (DBS) delivered to bilateral subcallosal cingulate (SCC) and ventral capsule/ventral striatum (VC/VS), atypical amygdala and PFC processing of happy faces in TRD patients remitted toward the normative pattern. The increased amygdala activation during the early stage of sad face processing suggests an overactive bottom-up processing system in TRD. Meanwhile, the reduced amygdala response during the late stage of happy face processing could be attributed to inhibition by PFC through alpha-band oscillation, which can be released by DBS in SCC and VC/VS.

Intracranial stimulation and EEG feature analysis reveal affective salience network specialization.

Emotion is represented in limbic and prefrontal brain areas, herein termed the affective salience network (ASN). Within the ASN, there are substantial unknowns about how valence and emotional intensity are processed-specifically, which nodes are associated with affective bias (a phenomenon in which participants interpret emotions in a manner consistent with their own mood). A recently developed feature detection approach ('specparam') was used to select dominant spectral features from human intracranial electrophysiological data, revealing affective specialization within specific nodes of the ASN. Spectral analysis of dominant features at the channel level suggests that dorsal anterior cingulate (dACC), anterior insula and ventral-medial prefrontal cortex (vmPFC) are sensitive to valence and intensity, while the amygdala is primarily sensitive to intensity. Akaike information criterion model comparisons corroborated the spectral analysis findings, suggesting all four nodes are more sensitive to intensity compared to valence. The data also revealed that activity in dACC and vmPFC were predictive of the extent of affective bias in the ratings of facial expressions-a proxy measure of instantaneous mood. To examine causality of the dACC in affective experience, 130 Hz continuous stimulation was applied to dACC while patients viewed and rated emotional faces. Faces were rated significantly happier during stimulation, even after accounting for differences in baseline ratings. Together the data suggest a causal role for dACC during the processing of external affective stimuli.

Contralateral C7 nerve transfer for severe pediatric brachial plexus injuries: donor site morbidity.

BACKGROUND: Pediatric brachial plexus injuries (BPI) can have a devastating impact on upper extremity function. With localized lesions, nerve grafting and transfers are well-described. However, reconstruction of pan-plexus (C5-T1) injuries (PPI) requires donor nerves outside of the brachial plexus. The cross C7 (CC7) nerve transfer extended with sural nerve grafts to the contralateral recipient nerve offers the advantage of supplying robust donor axons. Though controversial in the West, CC7 transfer is routine in many Asian centers. We present a case series of pediatric patients who underwent CC7 transfer for BPI. Our objective was to catalog donor site morbidity incurred by transferring the C7 nerve root. METHODS: This retrospective study was approved by the Institutional Review Board of our university. INCLUSION CRITERIA: patients under 18 years old that underwent CC7 nerve transfer for BPI at our health system between 2021 and 2022. A chart review was completed to collect demographic and outcomes data. RESULTS: Three patients underwent a complete CC7 transfer between 2021 and 2022 for BPI reconstruction. All patients underwent concomitant additional nerve transfers. Post-operative donor site sensory deficits were minimal and transient in all but one patient, who reported mild but persistent paresthesia of the donor side hand with movement of recipient side digits; however, no patients suffered donor site motor deficits (Table 1). CONCLUSIONS: We conclude that CC7 nerve transfer is a safe surgical option to provide additional donor motor axons for PPI in pediatric patients.

Decoding Depression Severity From Intracranial Neural Activity.

BACKGROUND: Disorders of mood and cognition are prevalent, disabling, and notoriously difficult to treat. Fueling this challenge in treatment is a significant gap in our understanding of their neurophysiological basis. METHODS: We recorded high-density neural activity from intracranial electrodes implanted in depression-relevant prefrontal cortical regions in 3 human subjects with severe depression. Neural recordings were labeled with depression severity scores across a wide dynamic range using an adaptive assessment that allowed sampling with a temporal frequency greater than that possible with typical rating scales. We modeled these data using regularized regression techniques with region selection to decode depression severity from the prefrontal recordings. RESULTS: Across prefrontal regions, we found that reduced depression severity is associated with decreased low-frequency neural activity and increased high-frequency activity. When constraining our model to decode using a single region, spectral changes in the anterior cingulate cortex best predicted depression severity in all 3 subjects. Relaxing this constraint revealed unique, individual-specific sets of spatiospectral features predictive of symptom severity, reflecting the heterogeneous nature of depression. CONCLUSIONS: The ability to decode depression severity from neural activity increases our fundamental understanding of how depression manifests in the human brain and provides a target neural signature for personalized neuromodulation therapies.

Outcomes after Anterior Interosseous Nerve to Ulnar Motor Nerve Transfer.

Background Ulnar nerve lesions proximal to the elbow can result in loss of intrinsic muscle function of the hand. The anterior interosseous nerve (AIN) to deep motor branch of the ulnar nerve (DBUN) transfer has been demonstrated to provide intrinsic muscle reinnervation, thereby preventing clawing and improving pinch and grip strength. The purpose of this study was to evaluate the efficacy of the AIN to DBUN transfer in restoring intrinsic muscle function for patients with traumatic ulnar nerve lesions. Methods We performed a prospective, multi-institutional study of outcomes following AIN to DBUN transfer for high ulnar nerve injuries. Twelve patients were identified, nine of which were enrolled in the study. The mean time from injury to surgery was 15 weeks. Results At final follow-up (mean postoperative follow-up 18 months + 15.5), clawing was observed in all nine patients with metacarpophalangeal joint hyperextension of the ring finger averaging 8.9 degrees (+ 10.8) and small finger averaging 14.6 degrees (+ 12.5). Grip strength of the affected hand was 27% of the unaffected extremity. Pinch strength of the affected hand was 29% of the unaffected extremity. None of our patients experienced claw prevention after either end-to-end ( n = 4) or end-to-side ( n = 5) AIN to DBUN transfer. Conclusion We conclude that, in traumatic high ulnar nerve injuries, the AIN to DBUN transfer does not provide adequate intrinsic muscle reinnervation to prevent clawing and normalize grip and pinch strength.

Supraclavicular Approach to the Brachial Plexus.

The brachial plexus consists of an intricate array of nerves originating from the C5-T1 ventral rami of the spinal cord. Their course is complex and can be substantially distorted after injury. Thus, dissection of the brachial plexus can be difficult. Here, we present a practical approach to the supraclavicular dissection of the brachial plexus, with emphasis on relevant anatomy and surgical landmarks. Methods: This anatomical review was prepared using intraoperative surgical imaging. In addition, illustrations are used to display the images in schematic form. We present a stepwise surgical approach to the supraclavicular dissection of the brachial plexus. We highlight the differences between pre- and postganglionic nerve root injuries, and also relevant anatomical variants of the brachial plexus. Results: Eleven steps are recommended to facilitate the supraclavicular approach to the brachial plexus. Conclusion: The supraclavicular dissection of the brachial plexus is reliable with consistent landmarks and can be carried out in a stepwise fashion.

The Association of Insurance Status and Complications After Carpal Tunnel Release.

BACKGROUND: Carpal tunnel release (CTR) is one of the most commonly performed procedures in hand surgery. Complications from surgery are a rare but significant patient dissatisfier. The purpose of this study was to determine whether insurance status is independently associated with complications after CTR. METHODS: We retrospectively identified all patients undergoing CTR between 2008 and 2018 using the Indiana Network for Patient Care, a state-wide health information exchange, and built a database that included patient demographics and comorbidities. Patients were followed for 90 days to determine whether a postoperative complication occurred. To minimize dropout, only patients with 1 year of encounters after surgery were included. RESULTS: Of the 26 151 patients who met inclusion criteria, 2662 (10.2%) had Medicare, 7027 (26.9%) had Medicaid, and 16 462 (62.9%) had commercial insurance. Compared with Medicare, Medicaid status (P < .001) and commercial insurance status (P < .001) were independently associated with postoperative CTR complications. The overall complication rate was 2.23%, with infection, wound breakdown, and complex regional pain syndrome being the most common complications. Younger age, alcohol use, diabetes mellitus, hypertension, and depression were also independently associated with complications. CONCLUSIONS: The incidence of complications after CTR is low. Insurance status, patient demographics, and medical comorbidities, however, should be evaluated preoperatively to appropriately risk stratify patients. Furthermore, surgeons can use these data to initiate preventive measures such as working to manage current comorbidities and lifestyle choices, and to optimize insurance coverage.

Parent Perspectives for Type B Ulnar Polydactyly Management.

BACKGROUND: Type B ulnar polydactyly is one of the most commonly encountered congenital hand differences and can be treated with ligation or excision. The purpose of this study was to determine what factors families consider in selecting treatment for their child with type B ulnar polydactyly. METHODS: We reviewed treatment outcomes and administered a survey by telephone to parents of children with type B ulnar polydactyly treated at a pediatric hospital between 2015 and 2020. We assessed satisfaction, reasons for choosing treatment, and post-management complications. RESULTS: The families of 70 of the 156 consecutive treated patients were successfully contacted and agreed to participate (45% response rate). The mean follow-up was 27 months. Twenty-eight chose in-office suture ligation and 42 chose excision. Rapid treatment was prioritized by those who opted for in-office ligation (P = .044). The complication rate for suture ligation was significantly higher than excision (P < .0001), with the most common complication being a residual remnant (nubbin or neuroma stump) (64%). Respondents with residual remnant reported significantly less satisfaction with the appearance of their child's hand (P < .001) and with treatment outcomes (P = .028) compared to those without residual remnants. CONCLUSIONS: Factors considered by parents in choosing type of treatment for type B ulnar polydactyly vary and may be significantly influenced by the surgeon. Although the majority of parents remain extremely satisfied with their child's outcome regardless of management type, time to treatment plays a determinative role in parents opting for ligation rather than excision in the operating room.

Prefrontal network engagement by deep brain stimulation in limbic hubs.

Prefrontal circuits in the human brain play an important role in cognitive and affective processing. Neuromodulation therapies delivered to certain key hubs within these circuits are being used with increasing frequency to treat a host of neuropsychiatric disorders. However, the detailed neurophysiological effects of stimulation to these hubs are largely unknown. Here, we performed intracranial recordings across prefrontal networks while delivering electrical stimulation to two well-established white matter hubs involved in cognitive regulation and depression: the subcallosal cingulate (SCC) and ventral capsule/ventral striatum (VC/VS). We demonstrate a shared frontotemporal circuit consisting of the ventromedial prefrontal cortex, amygdala, and lateral orbitofrontal cortex where gamma oscillations are differentially modulated by stimulation target. Additionally, we found participant-specific responses to stimulation in the dorsal anterior cingulate cortex and demonstrate the capacity for further tuning of neural activity using current-steered stimulation. Our findings indicate a potential neurophysiological mechanism for the dissociable therapeutic effects seen across the SCC and VC/VS targets for psychiatric neuromodulation and our results lay the groundwork for personalized, network-guided neurostimulation therapy.

Emergency Department Utilization After Administration of Peripheral Nerve Blocks for Upper Extremity Surgery.

BACKGROUND: The purpose of this study was to determine the impact of upper extremity peripheral nerve blocks on emergency department (ED) utilization after hand and upper extremity surgery. METHODS: We reviewed all outpatient upper extremity surgeries performed in a single Midwestern state between January 2009 and June 2019 using the Indiana Network for Patient Care. These encounters were used to develop a database of patient demographics, comorbidities, concurrent procedures, and postoperative ED visit utilization data. We performed univariate, bivariate, and multivariate logistic regression analyses. RESULTS: Among 108 451 outpatient surgical patients, 9079 (8.4%) received blocks. Within 1 week of surgery, a greater proportion of patients who received peripheral nerve blocks (1.4%) presented to the ED than patients who did not (0.9%) (P < .001). The greatest risk was in the first 2 postoperative days (relative risk, 1.78; P < .001). Pain was the principal reason for ED utilization in the block cohort (53.6%) compared with those who did not undergo a block (35.1%) (P < .001). When controlling for comorbidities and demographics, only peripheral nerve blocks (adjusted odds ratio [OR], 1.71; P = 0.007) and preprocedural opioid use (adjusted OR, 1.43; P = .020) conferred an independently increased risk of ED utilization within the first 2 postoperative days. CONCLUSIONS: Peripheral nerve blocks used for upper extremity surgery are associated with a higher risk of unplanned ED utilization, most likely related to rebound pain. Through proper patient education and pain management, we can minimize this unnecessary resource utilization.

Automated optimization of deep brain stimulation parameters for modulating neuroimaging-based targets.

Objective.Therapeutic efficacy of deep brain stimulation (DBS) in both established and emerging indications, is highly dependent on accurate lead placement and optimized clinical programming. The latter relies on clinicians' experience to search among available sets of stimulation parameters and can be limited by the time constraints of clinical practice. Recent innovations in device technology have expanded the number of possible electrode configurations and parameter sets available to clinicians, amplifying the challenge of time constraints. We hypothesize that patient specific neuroimaging data can effectively assist the clinical programming using automated algorithms.Approach.This paper introduces the DBS Illumina 3D algorithm as a tool which uses patient-specific imaging to find stimulation settings that optimizes activating a target area while minimizing the stimulation of areas outside the target that could result in unknown or undesired side effects. This approach utilizes preoperative neuroimaging data paired with the postoperative reconstruction of the lead trajectory to search the available stimulation space and identify optimized stimulation parameters. We describe the application of this algorithm in three patients with treatment-resistant depression who underwent bilateral implantation of DBS in subcallosal cingulate cortex and ventral capsule/ventral striatum using tractography optimized targeting with an imaging defined target previously described.Main results.Compared to the stimulation settings selected by the clinicians (informed by anatomy), stimulation settings produced by the algorithm that achieved similar or greater target coverage, produced a significantly smaller stimulation area that spilled outside the target (P= 0.002).Significance. The DBS Illumina 3D algorithm is seamlessly integrated with the clinician programmer software and effectively and rapidly assists clinicians with the analysis of image based anatomy, and provides a starting point to search the highly complex stimulation parameter space and arrive at the stimulation settings that optimize activating a target area.

Risk for Persistent Peripheral Neuropathy After Repair of Brachial Artery Injuries.

Background Brachial artery lacerations are limb-threatening injuries requiring emergent repair. Concomitant peripheral nerve symptoms are often only identified postoperatively. This study evaluated the prevalence of peripheral nerve deficits among this population as the indications for early nerve exploration have not been definitively established. Methods We reviewed all patients sustaining a brachial artery injury at one pediatric and two adult Level I Trauma Centers between January 1, 2007, and December 31, 2017. We recorded patient demographics, comorbidities, intoxication status, injury mechanism, concomitant injuries, type of repair, and intraoperative peripheral nerve exploration findings. Pre-and post-operative and long-term peripheral nerve function examination findings were analyzed. Differences between categorical variables were determined with Chi-square and Fisher's exact tests. Results Thirty-four patients sustained traumatic brachial artery lacerations requiring operative repair. Injury mechanisms included tidy (clean cut) laceration (n=11, 32%), gunshot wound (n=9, 26%), blunt trauma (n=8, 24%), and untidy laceration (n=6, 18%). Preoperatively, 15% had a normal peripheral nerve examination, 26% had localizable symptoms, 38% had non-localizable symptoms, and 21% were taken to the operating room without formal nerve assessment. Thirty-two percent underwent formal nerve exploration, and 81% underwent nerve repair. At an average follow-up of 2.5 years, 27% of patients underwent exploration, and 39% did not have localizable peripheral nerve deficits (p=0.705). Conclusions Brachial artery injuries are associated with a clinically significant risk for long-term peripheral nerve symptoms. Early nerve exploration in patients with peripheral nerve symptoms after a brachial artery injury may be warranted, although there is no statistically significant likelihood for improved peripheral neurological outcomes.

The Effects of Postoperative Physician Phone Calls for Hand and Wrist Fractures: A Prospective, Randomized Controlled Trial.

Background In this study, we sought to determine if postoperative physician phone calls following hand and wrist fracture surgery improve patient outcomes, satisfaction, and treatment adherence. Methodology We prospectively enrolled 24 consecutive adult patients who underwent outpatient surgery for isolated hand and wrist fractures at a single, metropolitan, safety-net hospital over one year to receive an additional physician phone call starting on postoperative day one. We measured preoperative and postoperative Brief Michigan Hand Questionnaire (bMHQ) composite score, overall satisfaction on a five-point Likert scale, compliance with treatment recommendations, presence of complications, discharge instructions reading level, and clarity of discharge and follow-up instructions. The surgical team was blinded to the treatment arm. Results The bMHQ score improved 26% after surgery; however, there was no difference in absolute score change between groups (12.2 vs. 6.5, p = 0.69). Most patients were satisfied throughout all stages of care, but postoperative satisfaction did not differ between groups (1.4 vs. 2.5, p = 0.21). There was a stronger correlation between patient hand function and satisfaction starting one month after surgery (R2 = 0.502, p = 0.002) than preoperatively (R2 = 0.252, p = 0.029). Immediately following surgery, most patients stated that discharge instructions were clear, and the average readability was below the average patient education level. Despite this, 13% removed their splint or Kirschner wires, 67% did not follow up within a week of recommendation, 62% did not complete postoperative treatment, and 33% had complications. Conclusions Postoperative phone calls by physicians did not improve compliance with recommendations, patient-rated outcome measures, or clinical outcomes among our hand and wrist fracture patient population.