Search

Abstract: The high frequency stimulation (HFS) model can be used alongside quantitative sensory testing (QST) to assess the sensitisation of central nociceptive pathways. However, the validity and between-session reliability of using QST z -score profiles to measure changes in mechanical and thermal afferent pathways in the HFS model are poorly understood. In this study, 32 healthy participants underwent QST before and after HFS (5× 100 Hz trains; 10× electrical detection threshold) in the same heterotopic skin area across 2 repeated sessions. The only mechanical QST z -score profiles that demonstrated a consistent gain of function across repeated test sessions were mechanical pain threshold (MPT) and mechanical pain sensitivity (MPS), which were associated with moderate and good reliability, respectively. There was no relationship between HFS intensity and MPT and MPS z -score profiles. There was no change in low intensity, but a consistent facilitation of high-intensity pin prick stimuli in the mechanical stimulus response function across repeated test sessions. There was no change in cold pain threshold (CPT) and heat pain threshold (HPT) z -score profiles across session 1 and 2, which were associated with moderate and good reliability, respectively. There were inconsistent changes in the sensitivity to innocuous thermal QST parameters, with cool detection threshold (CDT), warm detection threshold (WDT), and thermal sensory limen (TSL) all producing poor reliability. These data suggest that HFS-induced changes in MPS z -score profiles is a reliable way to assess experimentally induced central sensitisation and associated secondary mechanical hyperalgesia in healthy participants., (Copyright © 2023 International Association for the Study of Pain.)

Purpose of Review: This review explores the potential of using novel imaging approaches to deepen our understanding of descending modulatory mechanisms in pain, focussing on functional magnetic resonance imaging (fMRI) of the spinal cord and novel approaches to combining molecular and fMRI data. This review sheds light on the neural processes involved in pain modulation, paving the way for the development of targeted treatments., Recent Findings: The reviewed literature demonstrates significant advancements in pain research. Recent studies show the potential of using fMRI to investigate the spinal cord's role in pain modulation. Furthermore, novel analytical approaches integrating molecular and fMRI data show promise in elucidating the complex neurobiological processes underlying pain regulation. The main themes explored here include the identification of neurochemical markers associated with pain modulation and the characterisation of neural circuits involved in descending pain control., Summary: A comprehensive understanding of descending modulatory mechanisms in pain can inform the development of novel treatments, targeting dysfunction of these key pathways. By leveraging spinal fMRI and integrating molecular data into brain fMRI, researchers can identify potential therapeutic targets throughout the neuraxis. These advances may contribute to the development of personalised medicine approaches, allowing for tailored interventions based on individual pain profiles., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The purpose of this study was to evaluate monetary trends in Medicare reimbursement rates for 30 abdominal wall reconstruction surgical procedures over a 20-year period (2000 to 2020)., Methods: The Physician Fee Schedule Look-Up Tool from the Centers for Medicare and Medicaid Services was used for each of the 30 included current CPT codes, and reimbursement data were extracted. Monetary data were adjusted for inflation to 2020 U.S. dollars using changes to the United States consumer price index. The R 2 values for the average annual percentage change and the average total percentage change in reimbursement were calculated based on these adjusted trends for all included procedures., Results: After adjusting for inflation, the average reimbursement for all procedures decreased by 17.1% from 2000 to 2020. The greatest mean decrease was observed for CPT code 49568 (the implantation of mesh or other prosthesis for open incisional or ventral hernia repair or mesh for closure of débridement for necrotizing soft-tissue infection, -34.4%). The only procedure with an increased adjusted reimbursement rate throughout the study period was CPT code 20680 (+3.9%). From 2000 to 2020, the adjusted reimbursement rate for all included procedures decreased by an average of 0.85% each year, with an average R 2 value of 0.78, indicating a stable decline throughout the study period., Conclusions: Reimbursement rates are declining when adjusted for inflation. Increased awareness of these trends is helpful to maintain access to optimal abdominal reconstruction care in the United States., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Background: Research regarding financial trends in craniofacial trauma surgery is limited. Understanding these trends is important to the evolvement of suitable reimbursement models in craniofacial plastic surgery. The purpose of this study was to evaluate the trends in Medicare reimbursement rates for the top 20 most utilized surgical procedures for facial trauma., Methods: The 20 most commonly utilized Current Procedural Terminology (CPT) codes for facial trauma repairs in 2018 were queried from The National Summary Data File from the Centers for Medicare & Medicaid Services (CMS). Reimbursement data for each procedure was then extracted from The Physician Fee Schedule Lookup Tool. Changes to the United States consumer price index (CPI) were used to adjust all gathered data for inflation to 2021 US dollars (USD). The average annual and the total percent change in reimbursement were calculated for the included procedures based on the adjusted trends from the years 2000 to 2021., Results: From 2000 to 2021, the average reimbursement for all procedures decreased by 16.6% after adjusting for inflation. Closed treatment of temporomandibular joint dislocation and closed treatment of nasal bone fractures without manipulation demonstrated the greatest decrease in mean adjusted reimbursement at -48.7% and -48.3%, respectively, while closed treatment of nasal bone fractures without stabilization demonstrated the smallest mean decrease at -1.4% during the study period. Open treatment of nasal septal fractures with or without stabilization demonstrated the greatest increase in mean adjusted reimbursement at 18.9%, while closed treatment of nasal septal fractures with or without stabilization demonstrated the smallest increase at 1.2%. The average reimbursement for all closed procedures in the top 20 decreased by 19.3%, while that for all open procedures decreased by 15.5%. The adjusted reimbursement rate for all top 20 procedures decreased by an average of 0.8% each year., Conclusions: To the best of our knowledge, this is the first study to comprehensively evaluate trends in Medicare reimbursement for facial trauma surgical repairs. Adjusting for inflation, Medicare reimbursement for the top 20 most commonly utilized procedures has largely decreased from 2000 to 2021. Consideration of these trends by surgeons, hospital systems, and policymakers will be important to assure continued access to meaningful surgical facial trauma care in the United States., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Abstract: Chronic pain is a highly debilitating and difficult to treat condition, which affects the structure of the brain. Although the development of chronic pain is moderately heritable, how disease-related alterations at the microscopic genetic architecture drive macroscopic brain abnormalities is currently largely unknown. Here, we examined alterations in morphometric similarity (MS) and applied an integrative imaging transcriptomics approach to identify transcriptional and cellular correlates of these MS changes, in 3 independent small cohorts of patients with distinct chronic pain syndromes (knee osteoarthritis, low back pain, and fibromyalgia) and age-matched and sex-matched pain-free controls. We uncover a novel pattern of cortical MS remodelling involving mostly small-to-medium MS increases in the insula and limbic cortex (none of these changes survived stringent false discovery rate correction for the number of regions tested). This pattern of changes is different from that observed in patients with major depression and cuts across the boundaries of specific pain syndromes. By leveraging transcriptomic data from Allen Human Brain Atlas, we show that cortical MS remodelling in chronic pain spatially correlates with the brain-wide expression of genes related to pain and broadly involved in the glial immune response and neuronal plasticity. Our findings bridge levels to connect genes, cell classes, and biological pathways to in vivo imaging correlates of chronic pain. Although correlational, our data suggest that cortical remodelling in chronic pain might be shaped by multiple elements of the cellular architecture of the brain and identifies several pathways that could be prioritized in future genetic association or drug development studies., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association for the Study of Pain.)

Background and Purpose: Decompressive hemicraniectomy has been used to treat spontaneous intracerebral hemorrhage, but the benefit of evacuating the hematoma during the procedure is unclear. We aim to evaluate the utility of performing clot evacuation during hemicraniectomy for spontaneous intracerebral hemorrhage., Methods: Retrospective cohort of consecutive patients (2010-2019) treated with decompressive hemicraniectomy for a spontaneous supratentorial intracerebral hemorrhage at the University of Iowa. We compared hemicraniectomy alone to hemicraniectomy plus hematoma evacuation. We analyzed clinical features and hematoma characteristics. The outcomes at 6 months were dichotomized into unfavorable (Glasgow Outcome Scale score 1-3) and favorable (Glasgow Outcome Scale score 4-5)., Results: Eighty-three patients underwent decompressive hemicraniectomy for spontaneous intracerebral hemorrhage, 52 with hematoma evacuation, and 31 without hematoma evacuation. There were no statistically significant differences in clinical and radiographic characteristics between the 2 groups. Evacuating the hematoma in addition to hemicraniectomy did not change the odds of favorable outcome at 6 months ( P =0.806)., Conclusions: In this retrospective study, the performance of hematoma evacuation during decompressive hemicraniectomy for spontaneous intracerebral hemorrhage may not change functional outcomes over performing the hemicraniectomy alone.

Objective: To study the indications and outcomes of lateral sphenoidectomy as part of a combined skull base approach in the treatment of tumors involving Meckel's cave (MC) and cavernous sinus (CS)., Study Design: Retrospective patient series., Setting: Tertiary referral center., Patients: Twenty-two consecutive patients (mean age: 45 yr, range: 16-76) who underwent transzygomatic, extended middle fossa approaches for tumors involving MC and CS., Interventions: Surgical access to MC and CS was achieved via extended middle fossa, trans-clinoid approach. Lateral sphenoidectomy was defined as drill-out of the greater sphenoid wing lateral to foramen rotundum and ovale, decompression of superior orbital fissure, and removal of anterior clinoid process. Reconstruction was achieved using combination of autologous and synthetic materials. Eleven patients (50%) received adjuvant radiation., Main Outcome Measures and Results: Tumor pathologies included meningioma (16 patients), epidermoid cyst (2), trigeminal schwannoma (2), invasive pituitary adenoma (1), and chondrosarcoma (1). Mean (range) preoperative tumor size was 4.0 cm (1.3-9). Mean (range) length of follow-up was 4 years (range 0.1-10). Overall tumor control and gross total resection were achieved in 95 and 23% of patients, respectively. Lateral sphenoidectomy was performed in 16 patients (73%) for enhanced surgical access and/or tumor extension to the infratemporal fossa (6 patients). Postoperatively, cranial nerve deficits occurred in 12 (55%) patients (V-9 patients; III, IV, or VI-4; VII-2; VIII-2). Cerebrospinal fluid leak and hydrocephalus occurred in two and four patients, respectively., Conclusion: In combination with middle fossa-based approaches to tumors involving MC and CS, lateral sphenoidectomy may play a viable role in tumor access and control.

Objective: Define the indications and outcomes for subjects undergoing treatment utilizing the extended middle cranial fossa approach (EMCF)., Study Design: Retrospective records review., Setting: University-based tertiary referral center., Patients: Subjects undergoing treatment of posterior cranial fossa (PCF) lesions., Intervention(s): EMCF exposure and treatment of the indicating PCF lesion., Main Outcome Measure(s): Demographic, audiometric, and cranial nerve functioning variables were assessed., Results: Thirty-five subjects who underwent an EMCF exposure were identified over a 12-year period. The most common indication was meningioma (18; 51%) followed by schwannomas (six, 17%), and vascular lesions (five, 14%). Preoperative cranial nerve complaints were common (32, 94%) as were objective cranial nerve abnormalities on physical examination (21; 60%). Preoperative audiometric data from subjects with hearing demonstrated good functioning including pure-tone average (PTA) (21.7 ± 15.6 dB HL) and word understanding scores (95.1 ± 7.4%). Most (34, 97%) subjects had intact facial nerve function. The average length of stay was 11.6 days (median = 9). Cranial neuropathies were common postoperatively with 27 (79%) subjects demonstrating some objective cranial nerve dysfunction, the most common of which was trigeminal nerve hypesthesia (21, 61.7%). Subjects with identifiable pre- and postoperative audiometric data and preoperative hearing demonstrated small declines in the four-tone average (16.2 dB) and word recognition scores (22.4%). Two subjects (6%) had new profound hearing loss postoperatively., Conclusions: The EMCF approach can provide safe and effective exposure of the anterior PCF.

Patients with neuropathic pain commonly present with spontaneous pain, in addition to allodynia and hyperalgesia. Although evoked responses in neuropathic pain models are well characterized, determining the presence of spontaneous pain is more challenging. We determined whether the chronic constriction injury (CCI) model could be used to measure effects of treatment of spontaneous pain, by evaluating dorsal horn neuron (DHN) spontaneous activity and spontaneous pain-related behaviors. We measured conditioned place preference (CPP) to analgesia produced by sciatic nerve block with bupivacaine in rats with established CCI. We undertook another CPP experiment using hind paw incision. We also examined DHN spontaneous activity in CCI rats. Although CCI produced nocifensive responses to mechanical stimuli, CPP to analgesic nerve block was not evident 14 days after injury: Compared with baseline (314 ± 65 seconds), CCI rats did not show a preference for the bupivacaine-paired chamber after conditioning (330 ± 102 seconds). However, sciatic nerve block after hind paw incision produced CPP on postoperative day 1, serving as a positive control. The proportion of spontaneously active DHNs (33%) was not significantly increased in CCI rats compared with the sham (21%). The median rate of spontaneous activity in the CCI group (12.6 impulses per second) was not different from the sham group (9.2 impulses per second). Also, there was no change in DHN spontaneous activity after sciatic nerve block with bupivacaine. Our findings suggest that CCI as a neuropathic pain model should not be used to measure effects of treatment of spontaneous pain driven by the peripheral input.

Nonopioid agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs), are the most commonly used class of analgesics. Increasing evidence suggests that cyclooxygenase (COX) inhibition at both peripheral and central sites can contribute to the antihyperalgesic effects of NSAIDs, with the predominant clinical effect being mediated centrally. In this study, we examined the cerebral response to ibuprofen in presurgical and postsurgical states and looked at the analgesic interaction between surgical state and treatment. We used an established clinical pain model involving third molar extraction, and quantitative arterial spin labelling (ASL) imaging to measure changes in tonic/ongoing neural activity. Concurrent to the ASL scans, we presented visual analogue scales inside the scanner to evaluate the subjective experience of pain. This novel methodology was incorporated into a randomized double-blind placebo-controlled design, with an open method of drug administration. We found that independent of its antinociceptive action, ibuprofen has no effect on regional cerebral blood flow under pain-free conditions (presurgery). However, in the postsurgical state, we observed increased activation of top-down modulatory circuits, which was accompanied by decreases in the areas engaged because of ongoing pain. Our findings demonstrate that ibuprofen has a measurable analgesic response in the human brain, with the subjective effects of pain relief reflected in two distinct brain networks. The observed activation of descending modulatory circuits warrants further investigation, as this may provide new insights into the inhibitory mechanisms of analgesia that might be exploited to improve safety and efficacy in pain management.

Background: The transverse rectus abdominis musculocutaneous (TRAM) flap is the standard in autologous breast reconstruction. The management of local recurrence of breast cancer after TRAM flap breast reconstruction has not been well described. The purpose of this study was to examine the incidence of local recurrence of breast cancer after TRAM flap breast reconstruction, evaluate treatment modalities, and determine outcomes in such cases., Methods: A retrospective review was conducted of all patients who underwent immediate breast reconstruction with a free or pedicled TRAM flap over a 15-year period. Those patients who experienced local breast cancer recurrence were identified. A subset of complete skin-sparing mastectomy patients was also identified for review., Results: From 1987 to 2002, 419 TRAM flap breast reconstructions were performed in 395 patients. Thirty-four (9 percent) were complete skin-sparing mastectomy using a periareolar mastectomy incision only. The mean follow-up time in this study was 4.9 years (range, 1 to 14.7 years). Local recurrence occurred in 16 of 419 patients (3.8 percent), with a mean time to local recurrence of 1.6 years (range, 0.2 to 7.0 years). There were no local recurrences seen in patients following complete skin-sparing mastectomy. Treatment of local recurrence included excision, chemotherapy, radiotherapy, and bone marrow transplant. Only three of the 16 patients (19 percent) required removal of the entire TRAM flap to manage local breast cancer recurrence. Nine of 16 patients (56 percent) with local recurrence died of disease at a mean of 1.2 years after the development of recurrence., Conclusion: Long-term follow-up demonstrated a local recurrence rate after TRAM flap breast reconstruction similar to that reported in the literature. Local recurrence was effectively managed with surgical excision of the involved tissues, chemotherapy, and/or radiation therapy. Removal of the entire TRAM flap was only necessary in the setting of multifocal recurrence or involvement of the flap pedicle with disease. The risk of local recurrence was not increased following complete skin-sparing mastectomy.

Background: There are an increasing number of elderly patients requiring free tissue transfer. The risks of complex reconstructions in this patient population remain largely unknown. Therefore, the authors' reason for conducting this study was to review their experience with free tissue transfer in patients aged 70 years or older., Methods: A retrospective review of all free tissue transfers performed over a 10-year period at Memorial Sloan-Kettering Cancer Center was performed and all patients aged 70 years or older were identified. Medical records and the authors' prospectively maintained database were analyzed with respect to comorbidities and postoperative complications., Results: Two hundred eleven patients aged 70 years or older (70 to 79 years, n = 184; 80+ years, n = 27) were identified during the study period. Of these, 197 (70 to 79 years, n = 170; 80+ years, n = 27) patients had complete charts for review. Flap survival was 100 percent in the 80+ group and 97 percent in the 70 to 79 group. The overall complication rate was 59.3 percent in the 80+ group and 35.3 percent in the 70 to 79 group (p = 0.030). The medical complication rate was 40.7 percent in octogenarians and 11.8 percent in septuagenarians (p = 0.0004). Overall surgical complications were similar in the two groups. Univariate analysis demonstrated that age was associated with medical complications but not surgical complications. Using multivariate analysis, the authors found that alcohol use and coronary artery disease were independent predictors of overall, medical, and surgical complications., Conclusions: Free tissue transfer may be performed in patients over age 70 with a high degree of technical success. The procedure, however, carries a distinct risk of perioperative mortality and morbidity, particularly in patients over the age of 80. Comorbidities significantly associated with complications include age, alcohol use, coronary disease, and hypertension. This study suggests that prolonged survival may be achieved in some patients; however, a selective approach is required.

Among the potential complications associated with the use of breast implants are the risks of periprosthetic infection and device extrusion. There is little published information about the effective management of these situations. Conservative recommendations include antibiotic therapy and removal of the implant until resolution of the infection or until the wound has healed. A retrospective review identified patients with periprosthetic infection or threatened or actual device exposure treated by the senior author. Twenty-four patients encompassing 26 affected prostheses were available for review and were classified into seven groups based on initial presentation as follows: group 1, mild infection (n = 8); group 2, severe infection (n = 4); group 3, threatened exposure without infection (n = 3); group 4, threatened exposure with mild infection (n = 3); group 5, threatened exposure with severe infection (n = 1); group 6, actual exposure without clinical infection (n = 5); and group 7, actual exposure with infection (n = 2). To salvage the prosthesis in these patients, various treatment strategies were utilized. All patients with a suspected infection or device exposure were started immediately on appropriate antibiotic therapy (oral antibiotics for mild infections and parenteral antibiotics for severe infections). Salvage methods included one or more of the following: antibiotic therapy, débridement, curettage, pulse lavage, capsulectomy, device exchange, primary closure, and/or flap coverage. Twenty (76.9 percent) of 26 threatened implants with infection or threatened or actual prosthesis exposure were salvaged after aggressive intervention. The presence of severe infection adversely affected the salvage rate in this series. A statistically significant difference exists among those patients without infection or with mild infection only (groups 1, 3, 4, and 6); successful salvage was achieved in 18 (94.7 percent) of 19 patients, whereas only two of seven of those implants with severe infection (groups 2, 5, and 7) were salvaged (p = 0.0017). Ten (90.9 percent) of 11 devices with threatened or actual exposure, not complicated by severe infection (groups 3, 4, and 6), were salvaged. Several treatment strategies were developed for periprosthetic infection and for threatened or actual implant exposure. Patients with infection were placed on oral or intravenous antibiotics; those who responded completely required no further treatment. For persistent mild infection or threatened or actual exposure, operative intervention was required, including some or all of the following steps: implant removal, pocket curettage, partial or total capsulectomy, débridement, site change, placement of a new implant, and/or flap coverage; the menu of options varied with the precise circumstances. No immediate salvage was attempted in five cases, due to either severe infection, nonresponding infection with gross purulence, marginal tissues, or lack of options for healthy tissue coverage. Based on the authors' experience, salvage attempts for periprosthetic infection and prosthesis exposure may be successful, except in cases of overwhelming infection or deficient soft-tissue coverage. Although an attempt at implant salvage may be offered to a patient, device removal and delayed reinsertion will always remain a more conservative and predictable option.

Background and Purpose: These studies evaluated whether gene transfer of inducible nitric oxide synthase (iNOS) is a sufficient stimulus to produce vascular dysfunction in cerebral arteries., Methods: Intracranial (pial) arteries were dissected from human brain tissue obtained during elective surgery. Isolated human arteries were incubated in vitro with adenovirus containing iNOS (AdiNOS) or a nonexpressive transgene (control, AdBglII) (500 micro L, 3x10(9) plaque-forming units per milliliter), and vascular function was examined 24 hours later. In anesthetized rabbits, AdiNOS or AdBglII (300 microL 1x10(10)) was injected into the cisterna magna. Three days later, the basilar artery was removed, and reactivity was examined ex vivo., Results: In submaximally precontracted vessels, we observed impairment of NO-dependent relaxation in human cerebral arteries after gene transfer of iNOS. Maximum relaxation to bradykinin (1 micromol/L, an endothelium-dependent agonist) was 77+/-11% (mean+/-SE) after AdBglII and 31+/-22% (P<0.05) after AdiNOS. After AdiNOS, responses to nitroprusside (an endothelium-independent NO donor) also were impaired. Responses to both nitroprusside and bradykinin were improved by aminoguanidine (300 micromol/L), an inhibitor of iNOS. AdiNOS produced no change in vasoconstrictor responses to U46619. In basilar arteries from rabbits examined in vitro after gene transfer in vivo, responses to histamine, serotonin, and nitroprusside all were similar after AdiNOS or AdBglII. In contrast, relaxation to acetylcholine was significantly depressed after AdiNOS. Maximum relaxation to acetylcholine (10 micromol/L) was 90+/-3% after AdBglII and 68+/-5% (P<0.05) after AdiNOS. Relaxation of arteries after AdiNOS was improved by aminoguanidine., Conclusions: These studies suggest that expression of iNOS may impair NO-dependent relaxation in both human and rabbit cerebral arteries.

Although many of the health and safety issues associated with breast augmentation have been thoroughly discussed over the past decade, the literature is remarkably silent regarding postmastectomy reconstruction of the previously augmented breast. A retrospective review of the senior author's reconstructive practice was performed for the years 1983 through March of 1999, revealing 21 women who underwent postmastectomy breast reconstruction after previous breast augmentation. For purposes of measuring aesthetic results, these 21 patients were matched to a carefully selected control group of 15 patients. They were also compared with other, larger populations, including 777 of the senior author's other breast reconstructions, the breast cancer registry at the Lombardi Cancer Center in Washington, D.C., and several large, published epidemiologic studies. The interval between the previous augmentation and the diagnosis of breast cancer ranged from 9 months to 18 years, with a mean of 9.3 years. None of the previous augmentation implants was ruptured at the time of mastectomy. Of the nine patients with previous subpectoral augmentation, cancer was detected mammographically in five (56 percent), whereas of the 12 patients with previous subglandular augmentation, cancer was first detected mammographically in only three (25 percent). This difference was not statistically significant (p = 0.2). Overall, eight of the study patients' tumors (38 percent) were first detected mammographically, which is similar to other published reports of breast cancer patients in the general population. Seventy-one percent of the 21 study patients were node-negative, which also compares favorably with other published series. Sixteen of the women with previous augmentation (76 percent) had purely prosthetic reconstructions. Flaps were used in the other five reconstructions (23 percent): three latissimus dorsi flaps (14 percent) and two transverse rectus abdominis musculocutaneous flaps (9 percent). All five flaps were used in patients who had undergone radiation therapy. Throughout the senior author's entire reconstructive practice history, transverse rectus abdominis musculocutaneous flaps were more frequently used [282 of 777 nonaugmented reconstructions (36 percent)], whereas latissimus dorsi flaps were less frequently used [17 of 777 nonaugmented reconstructions (2.2 percent)] (p < 0.001). The cosmetic results of the breast reconstructions in the previously augmented study group were generally good-to-excellent, with a mean score by blinded observers of 3.35 of a possible 4.0. These results were comparable to or better than those in the matched controls, who scored a mean of 3.0.

In this study we report a convergence of behavioural and neuroanatomical evidence in support of an amygdala hypothesis of autism. We find that people with high-functioning autism (HFA) show neuropsychological profiles characteristic of the effects of amygdala damage, in particular selective impairment in the recognition of facial expressions of fear, perception of eye-gaze direction, and recognition memory for faces. Using quantitative magnetic resonance (MR) image analysis techniques, we find that the same individuals also show abnormalities of medial temporal lobe (MTL) brain structure, notably bilaterally enlarged amygdala volumes. These results combine to suggest that developmental malformation of the amygdala may underlie the social-cognitive impairments characteristic of HFA. This malformation may reflect incomplete neuronal pruning in early development.

An ELISA using a panel of specific monoclonal antibodies was developed to identify all alpha and flaviviruses isolated from mosquitoes caught throughout Australia. This technique is sensitive and rapid and is more specific than the traditional methods used to identify flaviviruses. The ability to identify unknown virus isolates from field-caught mosquitoes quickly and accurately improves the efficiency of arbovirus surveillance programs and allows health authorities to give an early warning of an increased health risk from a mosquito-borne virus in a particular region.

Objective: To compare the hemodynamics of closed-chest cardiac massage vs. open-chest cardiac massage in patients resuscitated from cardiac arrest that occurred outside of the hospital., Design: Prospective, non-outcome, case series., Setting: Large urban emergency department., Patients: Ten adult, normothermic, nontraumatic, out-of-hospital, cardiac arrest patients who failed advanced cardiac life support (ACLS) therapy., Interventions: Patients presenting to the hospital in cardiac arrest were managed according to the ACLS protocol at the clinician's discretion. Proximal aortic and central venous pressure catheters were placed to measure arteriovenous compression- and relaxation-phase pressure gradients. After 5 mins of baseline measurements during closed-chest cardiac massage, patients underwent a left lateral thoracotomy, and open-chest cardiac massage was performed for 5 mins., Measurements and Main Results: The mean coronary perfusion pressure and compression-phase pressure gradients were 7.3 +/- 5.7 and 6.2 +/- 5.4 mm Hg, respectively, during closed-chest cardiac massage, while increasing to 32.6 +/- 17.8 and 32.6 +/- 29.9 mm Hg, respectively, during open-chest cardiac massage. The differences between both measurements were statistically significant (p < .05)., Conclusions: Open-chest cardiac massage is superior to closed-chest cardiac massage in providing relaxation-phase and compression-phase pressure gradients during cardiac arrest in patients failing current ACLS protocols. During open-chest cardiac massage, all patients exceeded the minimum coronary perfusion pressure of 15 mm Hg, which is recommended to obtain a return of spontaneous circulation. Further outcome studies are needed to determine the timeliness and appropriate indications for open-chest cardiac massage.