Stellate ganglion block to mitigate thalamic pain syndrome of an oncological origin.

BACKGROUND: Thalamic pain syndrome (TPS) is an enigmatic and rare condition. Thalamic pain syndrome is under the umbrella of central pain syndrome, which is classically associated with multiple sclerosis, spinal cord injury, postamputation, epilepsy, stroke, tumor, and Parkinson's disease. The mainstay treatment of TPS is polypharmacy. There is uncertainty about the intermediate options to manage medication-resistant TPS before resorting to invasive, and often expensive, intracranial therapies. Stellate ganglion block (SGB) has shown promise in reducing TPS symptoms of the upper extremity and face following a thalamic ischemic event. AIMS: Discuss the effect and potential utility of SGB on ipsilateral headache, facial, and upper extremity neuropathic pain due to thalamic malignancies. MATERIALS AND METHODS: A review of two patient records that underwent SGB for treatment of TPS of oncologic origin. RESULTS: We present two cases of the successful use of SGB for the treatment of oncologic-related TPS for patients who had failed other conservative pharmacologic measures. DISCUSSION: Chronic pain is a complex experience that often simultaneously involves psychosocial, neuropathic, and nociceptive constituents. Among advanced cancer patients, factors such as an individual's spirituality, psychological stressors, and views on their mortality add layers of intricacy in addressing their pain. While TPS has been characterized in both stroke populations and oncologic populations, the treatment of SGB for pain relief in TPS has been limited to the stroke population. Repeated SGB worked to alleviate the ipsilateral headache, facial, and upper extremity pain in these two patients. The benefits of utilization of SGB, with the possibility of pain relief, within the thalamic malignancy population cannot be understated. CONCLUSION: In summary, ultrasound-guided SGB may be considered in patients with TPS due to thalamic cancer, before pursuing more invasive intracranial surgeries to treat pain.

A single-center, retrospective analysis to compare measurement of fibrinogen using the TEG6 analyzer to the Clauss measurement in children undergoing heart surgery.

BACKGROUND: Newer generation viscoelastic tests, TEG6s, offer point-of-care hemostatic therapy in adult patients. However, their efficacy in estimating fibrinogen levels in pediatric patients undergoing cardiac surgery is not well established. AIMS: This study evaluates TEG6s for estimating fibrinogen levels in pediatric cardiac surgery patients and its predictive capability for post-bypass hypofibrinogenemia. METHODS: A single-center, retrospective study on pediatric patients (under 18 years) who underwent cardiac surgery with cardiopulmonary bypass from August 2020 and November 2022. Blood samples for estimated whole blood functional fibrinogen level via TEG6s (Haemonetics Inc.) and concurrent laboratory-measured plasma fibrinogen via von Clauss assay were collected at pre- and post-cardiopulmonary bypass. RESULTS: Paired data for TEG6s estimated functional fibrinogen levels and plasma fibrinogen were analyzed for 432 pediatric patients pre-bypass. It was observed that functional fibrinogen consistently overestimated plasma fibrinogen across all age groups with a mean difference of 138 mg/dL (95% confidence interval [CI]: 128-149 mg/dL). This positive bias in the pre-bypass data was confirmed by Bland-Altman analysis. Post-bypass, functional fibrinogen estimates were comparable to plasma fibrinogen in all patient groups with a mean difference of -6 mg/dL (95% CI: -20-8 mg/dL) except for neonates, where functional fibrinogen levels underestimated plasma fibrinogen with a mean difference of -38 mg/dL (95% CI: -64 to -12 mg/dL). The predictive accuracy of functional fibrinogen for detecting post-bypass hypofibrinogenemia (plasma fibrinogen ≤250 mg/dL) demonstrated overall fair accuracy in all patients, indicated by an area under the curve of 0.73 (95% CI: 0.65-0.80) and good accuracy among infants, with an area under the curve of 0.80 (95% CI: 0.70-0.90). Similar performance was observed in predicting critical post-bypass hypofibrinogenemia (plasma fibrinogen ≤200 mg/dL). Based on these analyses, optimal cutoffs for predicting post-bypass hypofibrinogenemia were established as a functional fibrinogen level ≤270 mg/dL and MAFF ≤15 mm. CONCLUSION: This study demonstrates that whole blood functional fibrinogen, as estimated by TEG6s, tends to overestimate baseline plasma fibrinogen levels in pediatric age groups but aligns more accurately post-cardiopulmonary bypass, particularly in neonates and infants, suggesting its potential as a point-of-care tool in pediatric cardiac surgery. However, the variability in TEG6s performance before and after bypass highlights the need for careful interpretation of its results in clinical decision-making. Despite its contributions to understanding TEG6s in pediatric cardiac surgery, the study's design and inherent biases warrant cautious application of these findings in clinical settings.

The Effect of Metformin on Vestibular Schwannoma Growth: A Systematic Review and Meta-analysis.

OBJECTIVES: To systematically review and evaluate metformin's potential impact on vestibular schwannoma (VS) growth. DATA SOURCES: PubMed, Cochrane Library, and Embase. REVIEW METHODS: A retrospective cohort study was performed on sporadic VS patients undergoing initial observation who had at least two magnetic resonance imaging studies. Patients were stratified by metformin use during the observation period. Primary endpoint was VS growth, defined as at least a 2 mm increase in diameter. Survival free of tumor growth was evaluated between groups. Systematic review and meta-analysis were performed to produce a pooled odds ratio [OR]. Study heterogeneity was assessed and post-hoc power analysis was performed. RESULTS: A total of 123 patients were included, of which 17% were taking metformin. Median patient age was 56.6 years (range, 25.1-84.5). There were no statistically significant differences between the groups. Survival analysis did not demonstrate a statistically significant difference in time to VS growth between groups (hazard ratio = 0.61, 95% confidence interval [CI] = 0.29-1.29). Furthermore, logistic regression analysis did not demonstrate a statistically significant difference between groups in the odds of VS growth (OR = 0.46, 95% CI = 0.17-1.27). Systematic review identified 3 studies. Meta-analysis suggested that metformin reduces the odds of developing VS growth (pooled OR = 0.45, 95% CI = 0.29-0.71). Studies demonstrated low between-study heterogeneity. Power analysis demonstrated a sample size of 220 patients with equal randomization would be required to prospectively identify a true difference with 80% power. CONCLUSIONS: Metformin use may reduce the odds of VS growth. A randomized trial would be ideal to identify an unbiased estimate of metformin's effect on VS growth. Laryngoscope, 133:2066-2072, 2023.

Survival Outcomes of Patients with Mycosis Fungoides Involving the External Ear and Ear Canal.

OBJECTIVES/HYPOTHESIS: Mycosis Fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma. Disease involvement of specific locations may be more significant than simply the symptoms associated with that site; it is possible that involvement of certain sites could be associated with poor prognosis. We aimed to evaluate the outcomes of patients with MF with documented involvement of the EAC and external ear. STUDY DESIGN: Retrospective analysis. METHODS: We retrospectively reviewed 40 patients with MF that were treated by otologists between 2012 and 2021. RESULTS: We report the largest series of patients with MF involving the external ear and EAC. Of the 40 patients included in this study, 17 presented with Mycosis Fungoides in the otologic region (MFO). Of these 17 MFO patients, 2/17 had involvement of the external ear only, 3/17 of the EAC only, 11/17 of both the external ear and EAC, and 1/17 of the periauricular skin. Of note, 11/14 (79%) patients presenting with EAC disease died compared to11/26 (42%) of patients without involvement. In addition, eight of the 13 (62%) patients with external ear involvement died compared to 14/27 (52%) of patients without involvement. Ear canal involvement was associated with a statistically significant shorter overall survival duration in patients with MF (p = 0.03). Furthermore, disease in the EAC was found to have a hazard ratio value of 2.565 (CI 1.102-5.970). CONCLUSIONS: Involvement of the EAC by MF portends a poor prognosis. This finding highlights the need for a more in-depth otologic evaluation of patients with MF. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1486-1491, 2023.

Phase effects in masking: within- versus across-channel processes.

The effects of bandwidth and component phase on masking were investigated using 200-ms narrowband (1-ERB(N)) and broadband (5-ERB(N)) cosine-phase (CP) and random-phase (RP) harmonic complex maskers, centered at 1 or 6 kHz. A continuous notched-noise was used to restrict off-frequency listening. The masker fundamental frequency (F0) was 25 Hz. In experiment 1, thresholds were measured for sinusoidal signals at 1 and 6 kHz, gated with the maskers. Thresholds were lower in the CP than in the RP masker, for both bandwidths, but the effect was markedly greater for the wider bandwidth. For the CP maskers, thresholds were markedly lower for the 5-ERB(N) than for the 1-ERB(N) bandwidth; for the RP maskers, there was a small effect in the opposite direction. Experiment 2 used 1- and 6-kHz CP maskers. The masker components in the ERB(N) around the signal frequency were presented to one ear, and the remaining components were presented contralaterally. Thresholds were much higher than when all components were presented to the same ear, and were higher than for the 1-ERB(N) masker alone, suggesting that the low thresholds for broadband monaural presentation do not depend on "high level" across-channel comparisons. Simultaneous masked thresholds could be predicted well using a model based on a simulated auditory filter, a level-dependent compressive nonlinearity, and a sliding temporal integrator; it was not necessary to assume the involvement of across-channel processes or of selective listening in the masker dips.