Microbiological assessment of arterial allografts processed in a tissue bank.

The transmission of microbial infection through tissue allografts is one of the main risks that must be controlled in tissue banks. Therefore, microbiological monitoring controls and validated protocols for the decontamination of tissues during processing have been implemented. This study is based on the evaluation of data from microbiological cultures of arteries (mainly long peripheral arteries) processed in the tissue bank of Valencia (Spain). Donors' profile, pre- and post-disinfection tissue samples were assessed. The presence of residual antibiotics in disinfected tissues was determined and the antimicrobial potential of these tissues was tested. Our overall contamination rate was 23.69%, with a disinfection rate (after antibiotic incubation) of 87.5%. Most (76.09%) of the microbial contaminants were identified as Gram positive. Arterial allografts collected from body sites affected by prior organ removal showed higher risk of contamination. Only vancomycin was detected as tissue release. The antimicrobial effect on Candida albicans was lower than that for bacterial species. Risk assessment for microbial contamination suggested the donor's skin and the environment during tissue collection as the main sources for allograft contamination. Antibiotic-disinfected arterial allografts showed antimicrobial potential.

Electrophysiology in diagnosis and management of neuropathic pain.

Electrophysiological techniques demonstrate abnormalities in somatosensory transmission, hence providing objective evidence of 'somatosensory lesion or disease' which is crucial to the diagnosis of neuropathic pain (NP). Since most instances of NP result from damage to thermo-nociceptive pathways (thin fibres and spino-thalamo-cortical systems), specific activation of these is critical to ensure diagnostic accuracy. This is currently achieved using laser pulses or contact heat stimuli, and in a near future probably also with contact cold and intra-epidermal low-intensity currents. Standard electrical stimuli, although of lesser diagnostic yield, are useful when large and small fibres are affected together. Nociceptive evoked potentials to laser (LEPs) and contact heat (CHEPs) have shown adequate sensitivity and specificity to be of clinical use in the differential diagnosis of NP, in conditions involving Aδ of C-fibres and spino-thalamo-cortical pathways. LEPs have also a role in the detection of patients at risk of developing central post-stroke pain after brainstem, thalamic or cortical injury. Cognitive cortical responses and autonomic reactions (sympathetic skin responses) reflect pain-related arousal and can document objectively positive symptoms such as allodynia and hyperalgesia. They are of help in the differential diagnosis of somatisation disorders, by discriminating conscious simulation (malingering) from conversive sensory loss. The electrophysiological approach to patients suspected, or at risk, of NP is a cost-effective procedure that should never be absent in the diagnostic armamentarium of pain clinics.

Does an observer's empathy influence my pain? Effect of perceived empathetic or unempathetic support on a pain test.

The physiological and behavioural effects of empathy for other's pain have been widely investigated, while the opposite situation, i.e. the influence on one's pain of empathetic feedback from others, remains largely unexplored. Here, we assessed whether and how empathetic and unempathetic comments from observers modulate pain and associated vegetative reactions. In Study 1, conversations between observers of a pain study were recorded by professional actors. Comments were prepared to be perceived as empathetic, unempathetic or neutral, and were validated in 40 subjects. In a subsequent pain experiment (Study 2), changes in subjective pain and heart rate were investigated in 30 naïve participants who could overhear the empathetic or unempathetic conversations pre-recorded in study 1. Subjective pain was significantly attenuated when hearing empathetic comments, as compared to both unempathetic and neutral conditions, while unempathetic comments failed to significantly modulate pain. Heart rate increased when hearing unempathetic remarks and when receiving pain stimuli, but heart acceleration to nociceptive stimulation was not correlated with pain ratings. These results suggest that empathetic feedback from observers has a positive influence on pain appraisal and that this effect may surpass the negative effect of unempathetic remarks. Negative remarks can either trigger feelings of guilt or induce irritation/anger, with antagonistic effects on pain that might explain inter-individual variation. As in basal conditions heart rate and pain perception are positively correlated, their dissociation here suggests that changes in subjective pain were linked to a cognitive bias rather than changes in sensory input.

EAN guidelines on central neurostimulation therapy in chronic pain conditions.

BACKGROUND AND PURPOSE: Our aim was to update previous European Federation of Neurological Societies guidelines on neurostimulation for neuropathic pain, expanding the search to new techniques and to chronic pain conditions other than neuropathic pain, and assessing the evidence with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. METHODS: A systematic review and meta-analysis of trials published between 2006 and December 2014 was conducted. Pain conditions included neuropathic pain, fibromyalgia, complex regional pain syndrome (CRPS) type I and post-surgical chronic back and leg pain (CBLP). Spinal cord stimulation (SCS), deep brain stimulation (DBS), epidural motor cortex stimulation (MCS), repetitive transcranial magnetic stimulation (rTMS) and transcranial direct electrical stimulation (tDCS) of the primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC) were assessed. The GRADE system was used to assess quality of evidence and propose recommendations. RESULTS: The following recommendations were reached: 'weak' for SCS added to conventional medical management in diabetic painful neuropathy, CBLP and CRPS, for SCS versus reoperation in CBLP, for MCS in neuropathic pain, for rTMS of M1 in neuropathic pain and fibromyalgia and for tDCS of M1 in neuropathic pain; 'inconclusive' for DBS in neuropathic pain, rTMS and tDCS of the DLPFC, and for motor cortex tDCS in fibromyalgia and spinal cord injury pain. CONCLUSIONS: Given the poor to moderate quality of evidence identified by this review, future large-scale multicentre studies of non-invasive and invasive neurostimulation are encouraged. The collection of higher quality evidence of the predictive factors for the efficacy of these techniques, such as the duration, quality and severity of pain, is also recommended.

Model-based operational guidelines of a bioprocess for biological nitrogen removal and complete stabilisation of anaerobically digested sewage sludge.

The concept of one-stage reactor system for biological nitrogen removal over nitrite of ammonium high loaded sidestreams is going to be applied to remove nitrogen from anaerobically digested sewage sludge and to achieve its complete stabilisation. Dealing with sludge, the organic matter needed to denitrify is present in the inflow as particulate substrate, which requires a hydrolysis step. The latter implies high anoxic hydraulic retention time (HRT). During both aerobic and anoxic phases, ammonium is released which implies the need to enlarge aerobic HRT. Both effects lead to a total HRT higher than those for nitrification-denitrification of wastewater with soluble substrate. The purpose of this paper is to define, by computer simulation, a set of theoretical criteria, which will be applied later to the operation of a pilot-scale post-aeration reactor to be located in a Spanish WWTP. These criteria will be defined by simulating the reactor performance under different operating conditions. As a conclusion, some operation guidelines have been established for the above-mentioned scenario in terms of aerobic and anoxic retention time, dissolved oxygen concentration and effluent requirements (NH(4)(+), NO(2)(-) and NO(3)(-)).

Validating the colloid model to optimise the design and operation of both moving-bed biofilm reactor and integrated fixed-film activated sludge systems.

The paper presents a systematic study of simulations, using a previously calibrated Colloid model, from which it was found that: (i) for pure moving-bed biofilm reactor (MBBR) processes with tertiary nitrification conditions (no influent chemical oxygen demand (COD)), dissolved oxygen = 5 mg/L and residual NH4-N > 4 mgN/L, a nitrification rate of 1.2 gN/(m(2)d) was obtained at 10 °C. This rate decreases sharply when residual NH4-N is lower than 2 mgN/L, (ii) for MBBR systems with predenitrification-nitrification zones and COD in the influent (soluble and particulate), the nitrification rate (0.6 gN/(m(2)d)) is half of that in tertiary nitrification due to the effect of influent colloidal XS (particulate slowly biodegradable COD) and (iii) for integrated fixed-film activated sludge (IFAS) processes the nitrification rate in the biofilm (0.72 gN/(m(2)d)) is 20% higher than for the pure MBBR due to the lower effect of influent XS since it is adsorbed onto flocs. However, it is still 40% lower than the tertiary nitrification rate. In the IFAS, the fraction of the nitrification rate in suspension ranges from 10 to 70% when the aerobic solids retention time varies from 1.4 to 6 days.

An approach to the detection of pain from autonomic and cortical correlates.

OBJECTIVE: To assess the value of combining brain and autonomic measures to discriminate the subjective perception of pain from other sensory-cognitive activations. METHODS: 20 healthy individuals received 2 types of tonic painful stimulation delivered to the hand: electrical stimuli and immersion in 10 Celsius degree (°C) water, which were contrasted with non-painful immersion in 15 °C water, and stressful cognitive testing. High-density electroencephalography (EEG) and autonomic measures (pupillary, electrodermal and cardiovascular) were continuously recorded, and the accuracy of pain detection based on combinations of electrophysiological features was assessed using machine learning procedures. RESULTS: Painful stimuli induced a significant decrease in contralateral EEG alpha power. Cardiac, electrodermal and pupillary reactivities occurred in both painful and stressful conditions. Classification models, trained on leave-one-out cross-validation folds, showed low accuracy (61-73%) of cortical and autonomic features taken independently, while their combination significantly improved accuracy to 93% in individual reports. CONCLUSIONS: Changes in cortical oscillations reflecting somatosensory salience and autonomic changes reflecting arousal can be triggered by many activating signals other than pain; conversely, the simultaneous occurrence of somatosensory activation plus strong autonomic arousal has great probability of reflecting pain uniquely. SIGNIFICANCE: Combining changes in cortical and autonomic reactivities appears critical to derive accurate indexes of acute pain perception.

[Translated article] Electromyographic axillary nerve injury in fractures of the proximal humerus: Prospective, observational study, analysing the fracture pattern.

OBJECTIVE: Description and analysis of the relation between the proximal humerus fracture patterns and the traumatic injury of the axillary nerve. MATERIAL AND METHOD: Prospective, observational study of a consecutive case series that analysed proximal humerus fractures. Radiographic evaluation was performed, and AO (Arbeitsgemeinshaft für Osteosynsthesefragen) system was used to classify the fractures. Electromyography was used to diagnose the axillary nerve injury. RESULTS: Thirty-one patients on 105 who had a proximal humerus fracture met inclusion criteria. Eighty-six percent of the patients included were women and 14% men. The mean age was 71.8 years (30-96 years). Of the patients included in the study, 58% had normal or mild axonotmesis EMG, 23% had axillary nerve neuropathy without muscle denervation and 19% had injury with axillary nerve denervation. Patients who suffered complex fractures of the proximal humerus (AO11B and AO11C) had a higher risk of presenting axillary neuropathy type lesions with muscle denervation in the EMG, this relationship being statistically significant (p<0.001). CONCLUSION: Patients who have more risk on presenting axillary nerve neuropathy with muscle denervation in electromyography are those who present complex proximal humerus fractures AO11B and AO11C (p<0.001).

Electromyographic axillary nerve injury in fractures of the proximal humerus: Prospective, observational study, analysing the fracture pattern. / Lesión electromiográfica del nervio axilar en fracturas del extremo proximal del húmero. Estudio prospectivo, observacional, analizando el patrón de fractura.

OBJECTIVE: Description and analysis of the relation between the proximal humerus fracture patterns and the traumatic injury of the axillary nerve. MATERIAL AND METHOD: Prospective, observational study of a consecutive case series that analyzed proximal humerus fractures. Radiographic evaluation was performed, and AO (Arbeitsgemeinshaft für Osteosynsthesefragen) system was used to classify the fractures. Electromyography was used to diagnose the axillary nerve injury. RESULTS: Thirty-one patients on 105 who had a proximal humerus fracture met inclusion criteria. Eighty-six percent of the patients included were women and 14% men. The mean age was 71.8 years (30-96 years). Of the patients included in the study, 58% had normal or mild axonotmesis EMG, 23% had axillary nerve neuropathy without muscle denervation and 19% had injury with axillary nerve denervation. Patients who suffered complex fractures of the proximal humerus (AO11B and AO11C) had a higher risk of presenting axillary neuropathy type lesions with muscle denervation in the EMG, this relationship being statistically significant (p<0.001). CONCLUSION: Patients who have more risk on presenting axillary nerve neuropathy with muscle denervation in electromyography are those who present complex proximal humerus fractures AO11B and AO11C (p<0.001).

Modulation of the spinal N13 SEP component by high- and low-frequency electrical stimulation. Experimental pain models matter.

OBJECTIVE: The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of cervical dorsal horn neurons. Neurophysiological studies in healthy participants showed that capsaicin-induced central sensitization causes an increase of the N13 SEP amplitude. Consequently, in human research, this spinal component may serve as a valuable readout of central sensitization. In this study, we wanted to verify if the sensitivity of the N13 SEP for detecting central sensitization is consistent across different experimental pain models inducing central sensitization and secondary hyperalgesia, namely high and low-frequency electrical stimulation (HFS and LFS). METHODS: In 18 healthy participants, we recorded SEP after bilateral ulnar nerve stimulation before and after secondary hyperalgesia was induced through HFS and LFS applied on the ulnar nerve territory of the hand of one side. The area of secondary hyperalgesia was mapped with a calibrated 128-mN pinprick probe, and the mechanical pain sensitivity with three calibrated 16-64-256-mN pinprick probes. RESULTS: Although both HFS and LFS successfully induced secondary hyperalgesia only LFS increased the amplitude of the N13 SEP. CONCLUSIONS: These findings suggest that the sensitivity of the N13 SEP for detecting dorsal horn excitability changes may critically depend on the different experimental pain models. SIGNIFICANCE: Our results indicate that LFS and HFS could trigger central sensitization at the dorsal horn level through distinct mechanisms, however this still needs confirmation by replication studies.

Functional exploration for neuropathic pain.

Neuropathic pain (NP) may become refractory to conservative medical management, necessitating neurosurgical procedures in carefully selected cases. In this context, the functional neurosurgeon must have suitable knowledge of the disease he or she intends to treat, especially its pathophysiology. This latter factor has been studied thanks to advances in the functional exploration of NP, which will be detailed in this review. The study of the flexion reflex is a useful tool for clinical and pharmacological pain assessment and for exploring the mechanisms of pain at multiple levels. The main use of evoked potentials is to confirm clinical, or detect subclinical, dysfunction in peripheral and central somato-sensory pain pathways. LEP and SEP techniques are especially useful when used in combination, allowing the exploration of both pain and somato-sensory pathways. PET scans and fMRI documented rCBF increases to noxious stimuli. In patients with chronic NP, a decreased resting rCBF is observed in the contralateral thalamus, which may be reversed using analgesic procedures. Abnormal pain evoked by innocuous stimuli (allodynia) has been associated with amplification of the thalamic, insular and SII responses, concomitant to a paradoxical CBF decrease in ACC. Multiple PET studies showed that endogenous opioid secretion is very likely to occur as a reaction to pain. In addition, brain opioid receptors (OR) remain relatively untouched in peripheral NP, while a loss of ORs is most likely to occur in central NP, within the medial nociceptive pathways. PET receptor studies have also proved that antalgic Motor Cortex Stimulation (MCS), indicated in severe refractory NP, induces endogenous opioid secretion in key areas of the endogenous opioid system, which may explain one of the mechanisms of action of this procedure, since the secretion is proportional to the analgesic effect.

Theta-burst versus 20 Hz repetitive transcranial magnetic stimulation in neuropathic pain: A head-to-head comparison.

OBJECTIVE: High-frequency repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce neuropathic pain, but intermittent "theta-burst" stimulation (iTBS) could be a better alternative because of shorter duration and greater ability to induce cortical plasticity. Here we compared head-to-head the pain-relieving efficacy of the two modalities when applied daily for 5 days to patients with neuropathic pain. METHODS: Forty-six patients received 20 Hz-rTMS and/or iTBS protocols and 39 of them underwent the full two procedures in a random cross-over design. They rated pain intensity, sleep quality, fatigue and general health status daily during 5 consecutive weeks. RESULTS: Pain relief during the month following stimulation was superior after 20 Hz-rTMS relative to iTBS (F(1,38) = 4.645; p = 0.037). Correlation between respective levels of maximal relief showed a significant deviation toward the 20 Hz-rTMS effect. A greater proportion of individuals responded to 20 Hz-rTMS (52% vs 32%, 95 %CI[0.095-3.27]; p = 0.06), and reports of fatigue significantly improved after 20 Hz-rTMS relative to iTBS (p = 0.01). General health and sleep quality scores did not differentiate both techniques. CONCLUSIONS: High-frequency rTMS appeared superior to iTBS for neuropathic pain relief. SIGNIFICANCE: Adequate matching between the oscillatory activity of motor cortex and that of rTMS may increase synaptic efficacy, thus enhancing functional connectivity of motor cortex with distant structures involved in pain regulation.

How different experimental models of secondary hyperalgesia change the nociceptive flexion reflex.

OBJECTIVE: In this neurophysiological study in healthy humans, we assessed how central sensitization induced by either high-frequency stimulation (HFS) or topical capsaicin application modulates features of the RIII reflex response. The ability of these stimuli to engage the endogenous pain modulatory system was also tested. METHODS: In 26 healthy participants we elicited an RIII reflex using suprathreshold stimulation of the sural nerve. Subsequently HFS or capsaicin were applied to the foot and the RIII reflex repeated after 15 minutes. Contact heating of the volar forearm served as the heterotopic test stimulus to probe activation of the endogenous pain modulatory system. RESULTS: HFS significantly reduced the pain threshold by 29% and the RIII reflex threshold by 20%. Capsaicin significantly reduced the pain threshold by 17% and the RIII reflex threshold by 18%. Both HFS and capsaicin left RIII reflex size unaffected. Numerical Rating Scale (NRS) pain scores elicited by the heterotopic noxious heat stimulus were unaffected by capsaicin and slightly increased by HFS. CONCLUSIONS: HFS and capsaicin similarly modulated the pain threshold and RIII reflex threshold, without a concomitant inhibitory effect of the endogenous pain modulatory system. SIGNIFICANCE: Our neurophysiological study supports the use of the RIII reflex in investigating central sensitization in humans.

Modulation of the N13 component of the somatosensory evoked potentials in an experimental model of central sensitization in humans.

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.

EFNS guidelines on neuropathic pain assessment: revised 2009.

BACKGROUND AND PURPOSE: We have revised the previous EFNS guidelines on neuropathic pain (NP) assessment, which aimed to provide recommendations for the diagnostic process, screening tools and questionnaires, quantitative sensory testing (QST), microneurography, pain-related reflexes and evoked potentials, functional neuroimaging and skin biopsy. METHODS: We have checked and rated the literature published in the period 2004-2009, according to the EFNS method of classification for diagnostic procedures. RESULTS: Most of the previous recommendations were reinforced by the new studies. The main revisions relate to: (i) the new definition of NP and a diagnostic grading system; (ii) several new validated clinical screening tools that identify NP components, and questionnaires which assess the different types of NP; (iii) recent high-quality studies on laser-evoked potentials (LEPs) and skin biopsy. CONCLUSIONS: History and bedside examination are still fundamental to a correct diagnosis, whilst screening tools and questionnaires are useful in indicating probable NP; QST is also useful for indicating the latter, and to assess provoked pains and treatment response. Amongst laboratory tests, LEPs are the best tool for assessing Adelta pathway dysfunction, and skin biopsy for assessing neuropathies with distal loss of unmyelinated nerve fibres.

Extended mixed-culture biofilms (MCB) model to describe integrated fixed film/activated sludge (IFAS) process behaviour.

This paper presents how, in a calibration process, different assumptions regarding the standard Mixed-Culture Biofilms (MCB) model were able to match the average results at a continuous Johannesburg pilot plant (comprising two aerobic reactors, AE1 and AE2), but failed to match the batch test results of either the rate of endogenous carbonaceous oxygen uptake (OUR) or the rate of nitrate production (NPR). Under the first assumption, where attachment and diffusion of particulate components were not used, the OUR in the biofilm of the first aerobic reactor (AE1) was too low due to the absence of slowly biodegradable COD (X(S)) attachment flux. In a second assumption, where high diffusion and attachment coefficients were used, the NPR in the biofilm of the AE1 reactor exceeded the experimental value due to the high attachment flux used for nitrifiers (X(A)) and the low competition for space from X(S) and heterotrophic bacteria (X(H)). The only way to match all the experimental results was through the use of a higher attachment coefficient for X(S) in the first reactor (AE1), but this was considered unreasonable. Hence, an extended model was developed where a colloidal state, which interacts at the same time with the flocs and the biofilm through attachment-detachment processes, is distinguished. This model allowed the experimental results to be matched, but using the same value for the attachment coefficients of all particulate components.

Prison infrastructure, the right to health and a suitable environment for the inmates of the Women's Annex in Chorrillos Prison (Peru).

OBJECTIVES: Decide how prison infrastructure guarantees health's right a suitable environment of Establecimiento Penitenciario Anexo de Mujeres de Chorrillos (EPAMCh) prisoners. MATERIAL AND METHOD: For the materials was used an interview guide addressed to 10 specialist and interview guide addressed to 30 prisoners. About the method, it was selected the qualitative approach, the applied type with the phenomenological design. RESULTS: The interview experts said that Establecimiento Penitenciario Anexo de Mujeres de Chorrillos current infrastructure and don´t give minima sanitary services. In the polls, the prisoners unanimously answered that conditions were precarious, but mostly said that they were willing to incorporate to a health education program and bet for a preventive medicine without forget the curative. DISCUSSION: Is Important foment the preventive medicine in order to get a strong health education in jails. To reverse this reality would mean change a guarantee in their health rights and a suitable environment.

Lesión electromiográfica del nervio axilar en fracturas del extremo proximal del húmero. Estudio prospectivo, observacional, analizando el patrón de fractura / Electromyographic axillary nerve injury in fractures of the proximal humerus: Prospective, observational study, analysing the fracture pattern

Objetivo: Descripción y análisis de la relación entre las fracturas de húmero proximal y la lesión traumática del nervio axilar circunflejo. Material y método: Estudio prospectivo, observacional, de una serie de casos consecutivos de fracturas de extremo proximal de húmero. Se realizó valoración radiográfica, clasificando las fracturas según el sistema AO (Arbeitsgemeinshaft für Osteosynsthesefragen, Asociación de Grupo de Trabajo para el Estudio de la Fijación Interna de las Fracturas), y electromiografía (EMG) para la evaluación de la lesión del nervio axilar. Resultados: De 105 casos consecutivos de fracturas de húmero proximal, 31 pacientes cumplían los criterios de inclusión. Muestra: 86% mujeres y 14% hombres con edad media de 71,8 años (30-96 años). De los pacientes incluidos en el estudio, 58% presentó una EMG normal o leve axonotmesis, 23% presentó neuropatía del nervio axilar sin denervación muscular y 19%, lesión con denervación del nervio axilar. Los pacientes que sufrieron fracturas complejas de húmero proximal (AO11B y AO11C) tuvieron más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG, siendo esta relación estadísticamente significativa (p < 0,001). Conclusiones: Los pacientes que sufren fracturas complejas de húmero proximal (AO11B y AO11C) tienen más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG (p < 0,001).(AU)

Objective: Description and analysis of the relation between the proximal humerus fracture patterns and the traumatic injury of the axillary nerve. Material and method: Prospective, observational study of a consecutive case series that analyzed proximal humerus fractures. Radiographic evaluation was performed, and AO (Arbeitsgemeinshaft für Osteosynsthesefragen) system was used to classify the fractures. Electromyography was used to diagnose the axillary nerve injury. Results: Thirty-one patients on 105 who had a proximal humerus fracture met inclusion criteria. Eighty-six percent of the patients included were women and 14% men. The mean age was 71.8 years (30–96 years). Of the patients included in the study, 58% had normal or mild axonotmesis EMG, 23% had axillary nerve neuropathy without muscle denervation and 19% had injury with axillary nerve denervation. Patients who suffered complex fractures of the proximal humerus (AO11B and AO11C) had a higher risk of presenting axillary neuropathy type lesions with muscle denervation in the EMG, this relationship being statistically significant (p<0.001). Conclusion: Patients who have more risk on presenting axillary nerve neuropathy with muscle denervation in electromyography are those who present complex proximal humerus fractures AO11B and AO11C (p<0.001).(AU)

[Translated article] Electromyographic axillary nerve injury in fractures of the proximal humerus: Prospective, observational study, analysing the fracture pattern / Lesión electromiográfica del nervio axilar en fracturas del extremo proximal del húmero. Estudio prospectivo, observacional, analizando el patrón de fractura

Objetivo: Descripción y análisis de la relación entre las fracturas de húmero proximal y la lesión traumática del nervio axilar circunflejo. Material y método: Estudio prospectivo, observacional, de una serie de casos consecutivos de fracturas de extremo proximal de húmero. Se realizó valoración radiográfica, clasificando las fracturas según el sistema AO (Arbeitsgemeinshaft für Osteosynsthesefragen, Asociación de Grupo de Trabajo para el Estudio de la Fijación Interna de las Fracturas), y electromiografía (EMG) para la evaluación de la lesión del nervio axilar. Resultados: De 105 casos consecutivos de fracturas de húmero proximal, 31 pacientes cumplían los criterios de inclusión. Muestra: 86% mujeres y 14% hombres con edad media de 71,8 años (30-96 años). De los pacientes incluidos en el estudio, 58% presentó una EMG normal o leve axonotmesis, 23% presentó neuropatía del nervio axilar sin denervación muscular y 19%, lesión con denervación del nervio axilar. Los pacientes que sufrieron fracturas complejas de húmero proximal (AO11B y AO11C) tuvieron más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG, siendo esta relación estadísticamente significativa (p < 0,001). Conclusiones: Los pacientes que sufren fracturas complejas de húmero proximal (AO11B y AO11C) tienen más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG (p < 0,001).(AU)

Objective: Description and analysis of the relation between the proximal humerus fracture patterns and the traumatic injury of the axillary nerve. Material and method: Prospective, observational study of a consecutive case series that analyzed proximal humerus fractures. Radiographic evaluation was performed, and AO (Arbeitsgemeinshaft für Osteosynsthesefragen) system was used to classify the fractures. Electromyography was used to diagnose the axillary nerve injury. Results: Thirty-one patients on 105 who had a proximal humerus fracture met inclusion criteria. Eighty-six percent of the patients included were women and 14% men. The mean age was 71.8 years (30–96 years). Of the patients included in the study, 58% had normal or mild axonotmesis EMG, 23% had axillary nerve neuropathy without muscle denervation and 19% had injury with axillary nerve denervation. Patients who suffered complex fractures of the proximal humerus (AO11B and AO11C) had a higher risk of presenting axillary neuropathy type lesions with muscle denervation in the EMG, this relationship being statistically significant (p<0.001). Conclusion: Patients who have more risk on presenting axillary nerve neuropathy with muscle denervation in electromyography are those who present complex proximal humerus fractures AO11B and AO11C (p<0.001).(AU)

Brain activity sustaining the modulation of pain by empathetic comments.

Empathetic verbal feedback from others has been shown to alleviate the intensity of experimental pain. To investigate the brain changes associated with this effect, we conducted 3T-fMRI measurements in 30 healthy subjects who received painful thermal stimuli on their left hand while overhearing empathetic, neutral or unempathetic comments, supposedly made by experimenters, via headsets. Only the empathetic comments significantly reduced pain intensity ratings. A whole-brain BOLD analysis revealed that both Empathetic and Unempathetic conditions significantly increased the activation of the right anterior insular and posterior parietal cortices to pain stimuli, while activations in the posterior cingulate cortex and precuneus (PCC/Prec) were significantly stronger during Empathetic compared to Unempathetic condition. BOLD activity increased in the DLPFC in the Empathetic condition and decreased in the PCC/Prec and vmPFC in the Unempathetic condition. In the Empathetic condition only, functional connectivity increased significantly between the vmPFC and the insular cortex. These results suggest that modulation of pain perception by empathetic feedback involves a set of high-order brain regions associated with autobiographical memories and self-awareness, and relies on interactions between such supra-modal structures and key nodes of the pain system.