[Syncope from the viewpoint of a neurologist]. / Synkope aus der Sicht des Neurologen.

Syncope is a pathogenetically diverse syndrome that often requires an interdisciplinary investigation. In addition to cardiovascular reasons of syncope neurological diseases and differential diagnoses have to be considered. In particular, neurodegenerative disorders, such as Parkinson's disease or polyneuropathy may cause orthostatic intolerance and syncope due to a malfunction of autonomic reflexes. Furthermore, important differential diagnoses of syncope, such as epilepsy, drop attacks or circulatory disorders in the territory of the basilar artery are attributed to the neurological field.

[HIV test and prevention]. / HIV-Test und Prävention.

Successful prevention of an HIV epidemic is still a desirable goal. As young people are mainly affected by new infections and AIDS mortality has fallen virtually to zero, the long-term total costs of HIV management are increasing. This report describes how the targeted application of HIV testing can influence the HIV epidemic. The crucial point is the early diagnosis of primary HIV infection in standard situations whereby early diagnosis and counselling result in behavioral modifications preventing new transmission.

The effects of high-frequency jet ventilation (HFJV) on pneumoperitoneum-induced cardiovascular changes during laparoscopic surgery.

BACKGROUND: Standard mechanical ventilation may cause adverse cardiovascular effects in addition to those already related to positive-pressure pneumoperitoneum (PP) during laparoscopic surgery. High-frequency jet ventilation (HFJV) is associated with much less airway pressure, with potentially less influence on venous return, thus potentially it may reduce those effects. The aim of this study was to evaluate the benefits of HFJV to reduce the adverse cardiovascular effects during laparoscopic cholecystectomy. METHODS: We conducted a randomized prospective trial, comparing 12 patients undergoing elective laparoscopic cholecystectomy under conventional mechanical ventilation (control) with 13 similar subjects under HFJV (study). Both groups were categorized as ASA I-II and underwent total intravenous anesthesia. Cardiac functionality was continuously evaluated by analysis of arterial pressure wave changes (Edwards Flo-Trac sensor and Vigileo monitor). RESULTS: There was no significant difference between both groups regarding age, gender, BMI, and general medical condition, as well as hemodynamic stability and blood gases throughout surgery. A significant reduction in cardiac output was noted in the control group under PP during the initiation of anti-Trendelenburg position (from 5.6 to 5.0 l/min, P = 0.049). A reciprocal change was observed regarding stroke volume. Such changes were not noticed under HFJV. Total peripheral resistance was significantly increased during PP, and heart rate was not significantly affected throughout surgery in both groups. Unexpectedly, we did not observe marked adverse hemodynamic changes in the control group during PP without position adjustment. CONCLUSIONS: The use of HFJV in upper laparoscopic surgery can impede the adverse cardiovascular changes that usually occur during induction of PP. We also suggest that the use of total intravenous anesthesia (as used in our study) may also lessen the cardiovascular impairment during PP.

[Interhospital transport of intensive care patients in Lower Saxony : statewide need-based and effective management]. / Intensivverlegung in Niedersachsen : Landesweite bedarfsgerechte und effektive Sicherstellung.

BACKGROUND: Since 2007 interhospital transport of intensive care patients in Lower Saxony appertains to the performance requirements of emergency medical services. Against this background the Working Group for Evaluation of Intensive Care Transport (Arbeitsgemeinschaft Evaluation Intensivverlegung) was established. This group formulated standardized definitions for the requirements of intensive care transport vehicles and a federal statewide monitoring of intensive care transport was implemented to analyze if simultaneously on-call intensive care transport systems (intensive care helicopter and ground based mobile intensive care units) can be deployed need-based and efficiently. METHODS: A prospective follow-up study and evaluation of intensive care transport in Lower Saxony between April 1(st) 2008 and July 31(st) 2010 was carried out. RESULTS: A total of 6,779 data records were evaluated in this study of which 4,941 (72.9%) missions were located in Lower Saxony, 2,928 (43.2%) missions were carried out by helicopters and 3,851 (56.8%) by ground based mobile intensive care units. The mean duration of a mission was 3 h 59min±2 h 25 min, 4 h 39 min±2 h 23 min by ground based mobile intensive care units and 2 h 21 in±30 min by helicopter units. All systems proved to be feasible for intensive care transport. The degree of urgency was estimated correctly in 94.8% of the evaluated missions and 58.0% of the transfers could not be deployed. In 76.8% patients were transferred to hospitals with a higher level of medical care, 51.7% of patients were transferred for intensive care therapy and 40.4% for an operation/intervention. Of the patients 38.2% required mechanical ventilation and in 48.3% invasive monitoring was carried out. CONCLUSION: Interhospital transfer of intensive care patients can be carried out need-based with a limited number of intensive care transport vehicles if the missions are deployed effectively by standardized disposition in accordance with performance requirements.

Follow-up of advanced diabetic neuropathy: useful variables and possible pitfalls.

BACKGROUND: The course of advanced diabetic neuropathy (DN) is largely unknown. AIM: To find variables allowing the follow-up of late stages of DN. METHODS: Thirty diabetic patients with DN were observed. Patients were examined at intervals of 6 months over a period of 2 years. The compound muscle action potentials (CMAPs) were recorded in extensor digitorum brevis (EDB) and flexor hallucis brevis (FHB) muscles. Clinical severity of DN, nerve conduction studies (NCS), quantitative sensory testing (QST) and heart rate variability (HRV) were evaluated. The data were compared with age- and sex-matched controls. RESULTS: All measures were sensitive to the detection of DN. Significant deterioration during follow-up was exclusively found in CMAP analysis of the EDB (p<0.05) and FHB muscles (p<0.03). NCS, QST and HRV remained unchanged within the 2 years of observation. Coincidental changes might occur, if only two time points are chosen for followup. CONCLUSION: Our results indicate that ongoing axonopathy predominates in advanced DN. Repeated testing helps to minimize the impact of coincidental or chance changes in DN follow-up studies.

Power spectral analysis of heart rate variability during helium pneumoperitoneum: The mechanism of increased cardiac sympathetic activity and its clinical significance.

BACKGROUND: Carbon dioxide pneumoperitoneum (PP) is known to induce increased cardiac sympathetic expression. The role of the insufflated gas involved in this mechanism should be elucidated in an attempt to eliminate its possible serious consequences. METHODS: Twenty-five patients undergoing elective laparoscopic cholecystectomy were prospectively analyzed for cardiac autonomic nervous activity by spectral heart rate variability. In 15 patients, helium was used as CO(2) substitution for abdominal insufflation (study group). Four frequency bands of interest were obtained from the power spectrum of R-R intervals, as well as the ratio between the low and high frequency (LF/HF), using the fast Fourier transformation algorithm to characterize the synergy of both autonomic branches during PP. RESULTS: Significantly increased values of the power spectrum related to the LF and VLF bands (from 130 to 377 msec(2)/Hz and from 145 to 516 msec(2)/Hz, respectively) were inspected during CO(2) PP, as well as increased LF/LH ratio (2.1). Using helium as CO(2) substitution has eliminated the significant changes in the power spectrum that reflect increased cardiac sympathetic activity. CONCLUSIONS: The elimination of sympathetic predominance by helium PP indicates the central role of CO(2) in establishing this phenomena. Considering this information and its other known advantages, helium should be considered for use during prolonged laparoscopic procedures for high-risk patients.

Assessment of the neurogenic flare reaction in small-fiber neuropathies.

To improve sensitivity of the analysis of axon reflex flare reaction, the authors used a laser Doppler scanner and analyzed flare intensity and size induced by histamine iontophoresis simultaneously at the foot and thigh in patients with small-fiber neuropathy (n = 10) and controls (n = 9). Flare size, but not laser Doppler flux, clearly distinguished patients from controls at both locations (p < 0.01) and may be useful for evaluation of small-fiber neuropathies.

Density of sympathetic axons in sural nerve biopsies of neuropathy patients is related to painfulness.

In this study, differences of unmyelinated nerve fiber density in sural nerve biopsy material from patients suffering from neuropathies of unknown origin with (n=14) or without pain (n=13) were analyzed. Immunocytochemistry was applied to differentiate afferent sensory and efferent sympathetic nerve fibers. All patients were evaluated for deficits of small fiber function with thermotesting, quantitative sudomotor-axon reflex-testing and testing of painfulness of mechanical stimuli before performing the biopsy. No difference was found between patients with and without pain concerning clinical deficits or results in any of the neurophysiological examinations. There were also no histopathological differences concerning the density of afferent C-fibers. However, absolute and relative density of efferent sympathetic nerve fibers was significantly higher in patients with painful neuropathy (P<0.001), although none of the patients demonstrated clinical sympathetic abnormalities. We conclude that an imbalance between afferent and sympathetic nerve fiber density in the periphery may contribute to neuropathic pain even in those patients without obvious clinical autonomic disturbances.

Effects of antihyperalgesic drugs on experimentally induced hyperalgesia in man.

In a double-blind, cross-over study, ibuprofen (600 mg), a peripherally-acting selective kappa-opioid receptor agonist (7.5 mg), or placebo were given orally in experiments on healthy volunteers 1 h before assessment of pain thresholds to radiant heat and of pain ratings to controlled mechanical impact stimuli. Mechanical and thermal hyperalgesia had been induced 24 h before by irradiating skin patches on the ventral side of the upper leg. UVB irradiation induced mechanical and thermal hyperalgesia at radiation dosages of three times the minimal erythema dose. UVA irradiation resulted in an immediate erythema and a delayed tanning of the skin, however, no hyperalgesia was observed. For comparison another model of mechanical hyperalgesia was applied in the same experiments which has been previously proven sensitive to non-steroidal anti-inflammatory drugs (NSAIDs). In this model hyperalgesia was assessed, which develops during repetitive pinching of skin folds (pinch model). Ibuprofen significantly diminished heat and mechanical hyperalgesia induced by UVB, but had no effect on pain responses obtained from untreated skin. It also had an antihyperalgesic effect in the pinch stimulus paradigm. In contrast, the kappa-agonist showed no antihyperalgesic efficacy in the chosen models. It is concluded that the UVB model, as the pinch model, is suitable for establishing antihyperalgesic effects of NSAIDs, but probably not of kappa-receptor agonists, in healthy human volunteers. Compared to the pinch stimulus model, the UVB model offers additional advantages: (a) drugs may be tested after induction of the skin trauma by UV and this situation is more similar to the clinical use of antihyperalgesic drugs. (b) Since mechanical and thermal hyperalgesia is induced by UVB, drug effects can be tested upon both forms of hyperalgesia.

Clinical and morphological phenotype of HMSN 1A mosaicism.

Clinical, neurophysiological and morphological studies on a patient with mosaicism of the 17p11.2 duplication were performed in detail for the first time. Since duplication occurs during paternal meiosis, a somatic reversion is suggested, leading to mosaicism. The proportion of nuclei with duplication varied markedly between 49% in blood cells and 74% in tissue from the sural nerve. Clinically, mild symptoms of a motor and sensory neuropathy were present. However, neurophysiological changes and findings in the sural nerve biopsy were consistent with a typical hereditary motor and sensory neuropathy type 1 (HMSN 1). Differing clinical findings in patients with mosaicism of the 17p11.2 duplication may be explained by a varying degree and/or time of reversion.

Early oral feeding following removal of nasogastric tube in gastrointestinal operations. A randomized prospective study.

A study was conducted over a 23-month period to determine the possibility of early postoperative oral feeding after removal of a nasogastric tube in patients undergoing gastrointestinal operations. One hundred seventy-one patients were prospectively randomized into two groups. The first group began liquid oral intake 4 hours after removal of the tube. The second group began an ordinary solid intake soon after nasogastric tube removal. The criterion to remove the tube was based on normal bowel sounds heard by at least two senior surgeons. There was no significant difference between both groups concerning the occurrence of gastrointestinal disturbances following tube removal. Most of the disorders were observed after lower intestinal tract operations. Nine patients in the first group and seven patients in the second group required reinsertion of a nasogastric tube. We suggest that early solid intake immediately after nasogastric tube removal can safely be used in gastrointestinal operations.

Posttraumatic autotransplantation of spleen tissue.

Clinical and laboratory studies have documented high susceptibility to pneumococcal infection in asplenic humans and animals. Splenic autotransplantation has been suggested as a method of preserving function. Autotransplantation of irreparably damaged spleens in humans preserved splenic functions. Ten patients operated on for blunt abdominal trauma required unavoidable splenectomy. In each, autotransplantation of the removed spleen (roughly 50 g) was performed. Postoperative studies of splenic functions revealed disappearance of Howell-Jolly bodies from peripheral blood. Levels of IgM, which were initially significantly depressed, returned to normal and there were normal technetium Tc 99m sulfur colloid scans ten weeks after surgery. All patients are alive and healthy. Our data suggest that autotransplantation of spleen is a safe alternative method for preserving splenic function when total splenectomy is mandatory for hemostasis.

The laparoscopic approach to abdominal hydatid cysts: a prospective nonselective study using the isolated hypobaric technique.

HYPOTHESIS: The laparoscopic isolated hypobaric technique that we developed and use is safe and feasible for almost all kinds of hepatic and extrahepatic abdominal hydatid cysts. DESIGN: A case series. PATIENTS: Between August 1992 and December 1999, 31 patients with no selection criteria underwent 32 consecutive laparoscopic operations for 52 symptomatic hydatid cysts located in the liver (49), spleen (1), and pelvis (2). Eleven patients underwent surgery for between 2 to 5 cysts. INTERVENTIONS: The main surgical maneuvers (puncture, parasite neutralization, and complete evacuation) were performed through an assembled transparent cannula, in which a vacuum was created, while its tip adhered firmly to the cyst wall. Following evacuation of the cyst contents, we attempted to perform partial pericystectomy, omentoplasty, and closed-suction drainage. MAIN OUTCOME MEASURES: Surgical complications and postoperative disease recurrence. RESULTS: Mean cyst diameter was 8.4 cm (range, 3.5-25 cm). Seven cysts were subdiaphragmatic, and 6 were on the posterior (hidden) aspect of the liver. Mean postoperative follow-up was 49 months. Forty-one cysts contained live parasites, and 11 were secondarily infected. Twenty-four cysts were complex. Perioperative complications occurred in 5 patients, including 1 patient who died 1 month after surgery owing to Candida sepsis. Mean hospital stay was 6 days. No evidence of recurrence was recorded during follow-up. CONCLUSIONS: The isolated hypobaric laparoscopic technique described provides a safe and efficacious approach to almost all types of abdominal hydatid cysts and takes advantage of the recognized benefits of the laparoscopic approach.

Plasma extravasation and neuropeptide release in human skin as measured by intradermal microdialysis.

Time course of plasma extravasation in neurogenic inflammation elicited by histamine iontophoresis and topical capsaicin application was measured in vivo by a modified intradermal microdialysis technique in humans. Single linear plasmapheresis fibers were inserted intracutaneously at the volar forearm and perfused with Ringer's solution (4 microl/min) with one microdialysis fiber located at the planned stimulation site and a second inside the axon reflex area. Protein concentration in the dialysate increased by 300% in the histamine wheal but no increase was found in the surrounding flare area. There was no protein extravasation in the skin treated with capsaicin nor in the surrounding flare region. Inside the histamine-induced flare reaction a significant increase of calcitonin gene related peptide (CGRP) was found, whereas the increase of substance P (SP) was not significant.

Inhibition of proliferation of human cerebral meningioma cells by suramin: effects on cell growth, cell cycle phases, extracellular growth factors, and PDGF-BB autocrine growth loop.

The growth of human cerebral meningiomas depends on various growth factors, including epidermal growth factor (EGF), transforming growth factor (TGF)-alpha and TGF-beta, platelet-derived growth factor (PDGF)-BB, insulin-like growth factor (IGF)-I and IGF-II, and acidic and basic fibroblast growth factors. The latter three have been shown to form autocrine loops that are thought to be a major component of uncontrolled growth in meningioma tissue. Suramin is known to prevent binding of a variety of growth factors to their receptors in mammalian tissue, thus abolishing para- and/or autocrine-mediated cell growth. The authors therefore tested the effect of suramin on the proliferation of cultured human meningioma cells. Suramin (10(-5) to 10(-4) M) significantly inhibited the growth of meningioma cells in culture. The maximum effect observed was with the higher dose (10(-4) M), which resulted in a 40% to 70% reduction in cellular proliferation. This effect was observed in all 15 tumor samples studied and was confirmed by [3H]thymidine uptake. In studies using DNA flow cytometry, suramin inhibited meningioma cell proliferation in five tumor samples by arresting cells in the S and G2/M phases of the cell cycle. Growth factor (EGF, IGF-I, and PDGF-BB)-induced cell proliferation was completely abolished in five tumor samples when 10(-4) M suramin was applied to meningioma cells. Western blot analysis of three tumor samples showed that the intracellular PDGF-BB content of meningioma cells was significantly reduced after treating the cells with 10(-4) M suramin. Binding of iodinated growth factors (that is, [125I]EGF, [125I]IGF-I, and [125I]PDGF-BB) to their receptor sites was prevented by suramin in a dose-dependent manner in 10 meningioma membrane fractions. Lowering of the intracellular PDGF content and prevention of extracellular growth factor receptor binding demonstrates that suramin disrupts autocrine loops and paracrine growth stimulation in meningioma tissue. These data provide evidence that growth of cerebral meningiomas in culture is strongly inhibited by suramin at a concentration of 10(-4) M. Suramin acts as a scavenger neutralizing exogenous growth factors; thus it can interrupt autocrine loops and paracrine stimulation of human meningioma cell growth. The evidence favors suramin as a therapeutic option for controlling meningioma proliferation in patients with inoperable and recurrent high-grade meningiomas.

The impact of patient delay and physician delay on the outcome of laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: Laparoscopic cholecystectomy is now used in the management of acute cholecystitis. Under these circumstances unfavorable conditions may result in conversion and complications. Information about these conditions may help in planning the laparoscopic approach or in proceeding directly to open cholecystectomy. This study was initiated to evaluate perioperative factors associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis. Special attention was paid to the duration of complaints until surgery, to the delay on the part of the patient, and to the delay on the part of the physician. METHODS: Between January 1994 and December 1997, we attempted to perform laparoscopic cholecystectomy on 348 patients with acute cholecystitis. All perioperative data were collected on standardized forms. RESULTS: There were 182 cases (52%) of acute uncomplicated cholecystitis, 90 (26%) of gangrenous cholecystitis, 33 of hydrops (9.5%), and 43 of empyema of the gallbladder (12.5%). Seventy six patients (22%) needed conversion to open cholecystectomy and complications occurred in 57 cases. Advanced cholecystitis was associated with significant patient delay (P = 0.01), and it had a significantly higher conversion rate (39%) compared with early cholecystitis (14.5%); (P <0.00001). Conversion rates were also associated with male gender (P = 0.0017), a history of biliary disease (P = 0.0085), and a patient delay of >48 hours (P = 0.028). The total and infectious complication rates were associated with an age older than 60 years (P = 0.023 and 0.007, respectively) and male gender (P = 0.026 and 0.014, respectively). CONCLUSIONS: In acute cholecystitis, patient delay is associated with a high conversion rate. Early timing of laparoscopic cholecystectomy tends to reduce the conversion rate, as well as the total and the infectious complication rates. Male gender, a history of biliary disease, and advanced cholecystitis are associated with conversion. Male and older patients are associated with a high total and infectious complication rates.

Power spectral analysis of heart rate variability during positive pressure pneumoperitoneum: the significance of increased cardiac sympathetic expression.

BACKGROUND: Positive pressure pneumoperitoneum (PPP) effects on the autonomic nervous system (ANS) might be of clinical importance, as imbalance in the autonomic cardiac control might lead to serious consequences. METHODS: Fifteen healthy patients undergoing elective laparoscopic cholecystectomy were analyzed for cardiac autonomic nervous activity by spectral heart rate variability, during awake state, before and after intubation, during CO2 PPP (14 mmHg), and after CO2 evacuation. The very low, low, high and very high frequency (VLF, LF, HF, VHF respectively) bands of the spectral density of the heart rate variability (HRV) and their normalized values, as well as the LF/HF ratio, were obtained from the power spectra of R-R intervals, using the fast-Fourier transformation algorithm. RESULTS: Using Friedman's nonparametric test, only the difference between the power of LF during anesthesia (median 30.74) and the middle of PPP (median 195.66) was found to be significant (p<0.012). Such change was recorded in 14 patients (p = 0.001, sign test). CONCLUSIONS: Increased LF power reflects sympathetic cardiac activation. As the LF range accounts for regulation of blood pressure and baroreflex, several mechanisms may explain this activation. This in turn may predispose patients who suffer from cardiac disease to higher risk of developing ventricular arrhythmias, besides the possible adverse hemodynamic consequences of PPP.

Neuropeptide content of peripheral nerve in relation to nerve function in neuropathy.

OBJECTIVE: In this study an APAAP (alcalic-phophatase-anti-alcalic-phosphatase) technique was used to distinguish afferent (calcitonin-gene-related-peptide (CGRP) or substance-P-(SP) positive) and autonomic (tyrosin-hydroxylase (TH), neuropeptide Y (NPY) or vasoactive-intestinal-polypeptide- (VIP) positive) nerve fibers in sural nerve biopsy material from patients with moderate sensory neuropathy. A panneuronal marker against protein-gene-product 9.5 (PGP 9.5) was used for detection of the total amount of nerve fibers. Second aim was to analyze possible correlations between the impairment in tests for the function of unmyelinated fibers (i.e. thermal threshold testings, sensitivity to painful mechanical stimulation, axon reflex-mediated flare reaction and sudomotor activity) and nerve pathology. RESULTS: A high correlation between CGRP and SP (p < 0.00003) and between TH and NPY, respectively, (p < 0.004) was found, but not between afferent and autonomic markers or between specific markers and PGP 9.5. While no correlations between sensory neuropeptides (CGRP and SP) and specific testings of afferent fiber function or between neuropeptide content and clinical data could be demonstrated, there was a significant correlation between the TH content of the sural nerve and the sweat output, stimulated by acetylcholine iontophoresis at the level of the foot (p = 0.019) and upper leg (p = 0.011). CONCLUSION: This study demonstrates the possibility of visualizing subgroups of unmyelinated nerve fibers in sural nerve biopsies selectively with this technique. The density of TH-positive sympathetic nerve fibers, but not the density of afferent c-fibers, is correlated with corresponding results in specific tests of c-fiber function.

Use of tissue adhesives in the repair of lacerations in children.

During the last 5 years, over 1,500 minor lacerations in children were treated in the emergency room of Nahariya Regional Hospital, by the adhesive "Hystoacryl Blue," with gratifying results. The method, its advantages, and special precautions are described.

Low-grade B cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in the gallbladder.

Mucosa-associated lymphoid tissue (MALT) lymphomas arise in most cases in the gastrointestinal tract, and are usually of low-grade B cell origin. MALT lymphomas may rarely occur in organs where lymphoid tissue is sparse, especially following inflammatory conditions. Primary lymphomas of the gallbladder are extremely rare, and MALT lymphoma has been reported only twice. We herein describe the third case of low-grade MALT lymphoma of the gallbladder, which exhibits an unusual clinical behavior. The exceptionally advanced stage of the disease stresses the importance of early operation when cholecystectomy is indicated.