INTRODUÇÃO: Dor facial crônica abrange várias condições que podem se apresentar isoladas ou concomitantes, cujas evidências têm apontado para o impacto local e na saúde como um todo. Morbidades odontológicas e sistêmicas podem estar presentes nesses indivíduos e afetar a sensibilidade álgica. Assim, o objetivo deste estudo foi investigar doentes com dor facial crônica quanto à prevalência e perfil de morbidades odontológicas e sistêmicas, em comparação com indivíduos sem dor facial. MÉTODOS: Cento e sessenta e quatro pacientes do ambulatório de Dor Neuropática Orofacial do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, com idade média de 57,7±15,75 anos, e 133 indivíduos-controles sem queixas de dor, com idade média de 49,83±22,55 anos, foram selecionados. Foram avaliadas as características clínicas e funcionais orofaciais e o histórico médico prévio, sendo utilizado um protocolo de avaliação sensitiva superficial que incluiu as seguintes modalidades: percepção mecânica (táctil e vibratória), percepção térmica (frio e calor), percepção álgica (superficial e profunda), percepção à estimulação elétrica, sensibilidade gustativa (doce, azedo, amargo e salgado) e limiar olfativo. Para a tabulação, os doentes foram divididos em dois subgrupos (dor facial neuropática e dor facial complexa). Os dados foram analisados estatisticamente considerando-se um nível de significância de 5%. RESULTADOS: Houve maior prevalência de doenças gastrointestinais, respiratórias e psiquiátricas no grupo de dor facial complexa quando comparado aos outros dois grupos estudados (dor facial neuropática e controle) (p < 0,033, p < 0,014 e p < 0,001, respectivamente). A prevalência de ausências dentárias foi maior nos indivíduos com dor neuropática (49,2%) quando comparados ao grupo de dor complexa (37,9%) e aos controles (30,1%). Estes últimos apresentaram mais cáries do que os doentes com dor, enquanto que alterações mandibulares foram mais comuns nos grupos de doentes (p < 0,050). Os doentes com dor neuropática apresentaram mais bruxismo (p=0,005), e os diversos tratamentos odontológicos, fisioterápicos e cirúrgicos se associaram a alterações nos limiares sensitivos. Quanto às morbidades sistêmicas, houve maior prevalência de doenças cardiovasculares na maioria dos grupos de doentes, sendo que tanto estas quanto os fármacos utilizados para seu tratamento também estavam relacionados principalmente a anormalidades sensitivas somestésicas e olfativas. CONCLUSÕES: A maior prevalência de morbidades em doentes com dor facial complexa parece relacionar-se com um caráter sindrômico e funcional dessas condições, sendo que a presença de morbidades se associou com a dor e com alterações sensitivas. O grupo de dor facial neuropática apresentou maior comprometimento funcional mandibular e perdas dentárias, sendo que estas se associaram a morbidades sistêmicas / INTRODUCTION: Chronic facial pain is a term that includes several conditions that might be present isolated or concomitant. The evidences have suggested an impact in general health and dental or systemic comorbidities can be found in these patients affecting their sensory pain perception. Thus, the objective of this study was to investigate patients with chronic facial pain about the prevalence and profile of general and local oral conditions in comparison to subjects with no facial pain complaint. METHODS: Hundred-sixty-four patients from the Neuropathic Facial Pain Clinic of Hospital das Clínicas of the Medical School of the University of São Paulo, with mean age of 57.7±15.75 years old, and 133 control subjects with no pain complaints, with mean age of 49.83±22.55 years old, were selected. The evaluation protocol included: clinical and functional orofacial characteristics, previous medical history and sensory evaluation of the following modalities: mechanical (tactile and vibratory), thermal (cold and warm), pain (superficial and deep), electric stimulation, gustative (sweet, sour, bitter and salty) and olfactory thresholds. The patients were divided into two subgroups (neuropathic facial pain and complex facial pain). Data were statistically analyzed considering a significance level of 5%. RESULTS: The prevalence of gastrointestinal, respiratory and psychiatric diseases was higher in the group of patients with complex facial pain compared to the other groups (p < 0.033, p < 0.014 e p < 0.001, respectively). The frequency of dental absences was higher in patients with neuropathic pain (49,2%) when compared to complex facial pain (37,9%) and controls (30,1%). The controls had more decays that the patients, while mandibular masticatory abnormalities were more frequent among the patients (p < 0.50). Neuropathic facial patients had more bruxism (p=0.005) and the common dental, physiotherapic and surgical treatments were associated with abnormalities in sensory thresholds. Cardiovascular disease was the most common morbidity, and systemic conditions as well as the medication to treat them were associated with abnormalities in somatosensory and olfactory thresholds, mainly. CONCLUSIONS: The high prevalence of morbidities in patients with complex facial pain seems to be associated with a syndromic and functional aspect of these conditions; the frequency of systemic morbidities and pain were associated with sensory abnormalities. Patients with neuropathic facial pain had more mandibular function complications and teeth losses, which were associated with systemic morbidities

Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

Indiana University-Purdue University Indianapolis (IUPUI) / Voltage-gated sodium channels (VGSCs) are dynamic membrane-spanning proteins crucial for determining the electrical excitability in nerve and muscle. VGSCs transition, or gate, between opened, closed, and inactivated states, in response to changes in transmembrane potential. Altered VGSC gating can affect electrical communication and is implicated in numerous channelopathies. Nav1.7, a VGSC isoform highly expressed in the peripheral nervous system, plays a unique role in pain perception as evidenced by single point missense mutations causing a spectrum of pain syndromes (inherited erythromelalgia; IEM and paroxysmal extreme pain disorder; PEPD) and nonsense mutations resulting in human insensitivity to pain (CIP). These studies indicate Nav1.7 is critical in pain transduction and, as such, structural perturbations to Nav1.7 affecting conformational stability and response to changes in transmembrane potential have the potential to cause pain. Therefore, the aims of this dissertation were to (1) examine the effects of PEPD mutations on the voltage-dependent properties Nav1.7; (2) investigate the effects Nav1.7 alternative splicing has on the impact of IEM and PEPD mutations; (3) evaluate the effects channelopathies, resulting from slowed inactivation, have on modulating an unusual type of sodium current that flows during membrane repolarization; and (4) determine the structural components involved in stabilizing Nav1.7 inactivation. Standard patch-clamp electrophysiology was used to study changes in channel properties. Results from this dissertation demonstrate that (1) PEPD mutations significantly shift the voltage-dependent properties of Nav1.7 channels, destabilize an inactivated state in a residue specific manner, and render nociceptive neurons hyperexcitable; (2) alternative splicing can functionally impact PEPD; (3) channelopathies, resulting from slowed inactivation in neuronal and muscle VGSC isoforms, increase an unusual sodium conductance that flows during repolarization; and (4) specific residues located in distinct regions of Nav1.7 serve as docking sites to stabilize inactivation at different membrane potentials. Overall, this dissertation answers key questions regarding the molecular mechanics required during inactivation and the biophysical consequences of Nav1.7 mutations implicated in painful disorders. The results of this dissertation are important for a more detailed understanding of pain perception and validate the applicability of studying Nav1.7 for discovery of therapeutic targets for treatment of pain. – Theodore R. Cummins, Chair

Bakgrund Ett vanligt symptom som uppges när patienter söker vård är smärta. Sjukvårdspersonalen har ett ansvar att arbeta utifrån ett personcentrerat arbetssätt, där patienten ska känna sig inkluderad och involverad kring sin vård. Det kan innebära en enorm påfrestning för patienten att känna smärta, därav är det viktigt med en adekvat handläggning av tillståndet. Syfte Syftet var att belysa patienters upplevelser och erfarenheter av handläggning av smärta. Metod Arbetet är en icke-systematisk litteraturöversikt som är uppbyggd av 15 vetenskapliga artiklar med främst kvalitativ design, samt några av kvantitativ design. Databaserna CINAHL och PubMed har använts när de vetenskapliga artiklarna togs fram. Kvalitetssäkring av artiklarna har genomförts med hjälp av Sophiahemmets bedömningsunderlag. Datainsamlingen gjordes på så sätt att artiklarna genomgick en integrerad dataanalys. Resultat Resultatartiklarna delades in i två huvudkategorier, med tillhörandeunderkategorier. Resultatet från litteraturstudien beskriver patienters upplevelser och erfarenheter av vården rörande smärta. När ett bra partnerskap bildas upplever patienten det enklare att hantera smärttillståndet. Vid tidsbrist hos vårdpersonal uppkommer en känsla hos patienten att inte känna sig sedd eller hörd. Merparten patienter efterfrågar alternativa behandlingar, för en långsiktig och individanpassad lösning. En god kommunikation är en grund för personcentrerad vård. När vårdpersonal bidrar med kunskap till patienten ökar förståelsen, vilket leder till ett gott välmående. Detta förbättrar i sin tur patientens egenvård vilket ger en ökad förståelse för smärtans komplexitet och smärthantering. Slutsats Mötet har en stor betydelse i omvårdnaden av patienter med smärta. Handläggning av patienters smärta är komplex. Mötet mellan patient och vårdpersonal bör ske utifrån den enskilda individen. Detta för att handläggningen ska vara personcentrerad. En ökad kunskap och förståelse för patienter med smärta kan i praktiken leda till en bättre handläggning, där sjuksköterskan har verktyg för att vårda utefter patientens upplevelser och erfarenheter. Förhoppningen med denna belysning är ett minskat lidande hos patienten när handläggning av smärta sker. / Background A common symptom reported when patients seek care is pain. Healthcare professionals have a responsibility to work based on a person-centred approach, where the patient should feel included and involved in their care. It can put a huge strain on the patient to be in pain, hence the importance of adequately managing the condition. Aim The aim was to illuminate patients’ experiences of pain management. Method The work is a non-systematic literature review consisting of 15 scientific articles with mainly qualitative design, as well as some quantitative design. The databases CINAHL and PubMed have been used to find the scientific articles. Quality assurance of the articles has been conducted with help from Sophiahemmet University´s assessment form. The data collection was implemented by the articles undergoing an integrated data analysis. Results The result articles were divided into two main categories, with associated subcategories.The results from the literature study describe patients' experiences of care regarding pain. When a good partnership is formed, the patient finds it easier to manage the pain condition. In case of lack of time on the part of healthcare professionals, the patient feels that they are not seen or heard. The majority of patients request alternative treatments, for a long-term and individualised solution. Good communication is a foundation for person-centred care. When healthcare professionals contribute knowledge to the patient, understanding increases, which leads to good well-being. This in turn improves the patients´ self-care, which gives an increased understanding of the complexity of pain and pain management. Conclusions The meeting is significant in the care of patients with pain. Management of the pain experienced by patients is complex. The meeting between patient and healthcare staff should consider the individual. This is to ensure that the management is person-centred. An increased knowledge and understanding of patients dealing with pain may result in better management, where the nurse has tools to care according to the patients´ experiences. The ambition with this observation is a reduction of suffering among patients experiencing pain during pain management.

La vision joue un rôle très important dans la prévention du danger. La douleur a aussi pour fonction de prévenir les lésions corporelles. Nous avons donc testé l’hypothèse qu’une hypersensibilité à la douleur découlerait de la cécité en guise de compensation sensorielle. En effet, une littérature exhaustive indique qu’une plasticité intermodale s’opère chez les non-voyants, ce qui module à la hausse la sensibilité de leurs sens résiduels. De plus, plusieurs études montrent que la douleur peut être modulée par la vision et par une privation visuelle temporaire. Dans une première étude, nous avons mesuré les seuils de détection thermique et les seuils de douleur chez des aveugles de naissance et des voyants à l’aide d’une thermode qui permet de chauffer ou de refroidir la peau. Les participants ont aussi eu à quantifier la douleur perçue en réponse à des stimuli laser CO2 et à répondre à des questionnaires mesurant leur attitude face à des situations douloureuses de la vie quotidienne. Les résultats obtenus montrent que les aveugles congénitaux ont des seuils de douleur plus bas et des rapports de douleur plus élevés que leurs congénères voyants. De plus, les résultats psychométriques indiquent que les non-voyants sont plus attentifs à la douleur. Dans une deuxième étude, nous avons mesuré l’impact de l'expérience visuelle sur la perception de la douleur en répliquant la première étude dans un échantillon d’aveugles tardifs. Les résultats montrent que ces derniers sont en tous points similaires aux voyants quant à leur sensibilité à la douleur. Dans une troisième étude, nous avons testé les capacités de discrimination de température des aveugles congénitaux, car la détection de changements rapides de température est cruciale pour éviter les brûlures. Il s’est avéré que les aveugles de naissance ont une discrimination de température plus fine et qu’ils sont plus sensibles à la sommation spatiale de la chaleur. Dans une quatrième étude, nous avons examiné la contribution des fibres A∂ et C au traitement nociceptif des non-voyants, car ces récepteurs signalent la première et la deuxième douleur, respectivement. Nous avons observé que les aveugles congénitaux détectent plus facilement et répondent plus rapidement aux sensations générées par l’activation des fibres C. Dans une cinquième et dernière étude, nous avons sondé les changements potentiels qu’entrainerait la perte de vision dans la modulation descendante des intrants nociceptifs en mesurant les effets de l’appréhension d’un stimulus nocif sur la perception de la douleur. Les résultats montrent que, contrairement aux voyants, les aveugles congénitaux voient leur douleur exacerbée par l’incertitude face au danger, suggérant ainsi que la modulation centrale de la douleur est facilitée chez ces derniers. En gros, ces travaux indiquent que l’absence d’expérience visuelle, plutôt que la cécité, entraine une hausse de la sensibilité nociceptive, ce qui apporte une autre dimension au modèle d’intégration multi-sensorielle de la vision et de la douleur. / Vision is important for avoiding encounters with objects in the environment that may imperil physical integrity. Since pain also plays a major role in preventing bodily injury, we tested whether, in the absence of vision, pain hypersensitivity would arise from an adaptive shift to other sensory channels. Indeed, a wealth of literature indicates that blindness leads to sensory compensation and crossmodal plasticity. Furthermore, studies have shown that pain perception can be modulated by vision and by temporary visual deprivation. In a first study, we measured innocuous and noxious thermal thresholds using a Peltier-based thermotester in congenitally blind and normal sighted participants. We also assessed their suprathreshold pain ratings using a CO2 laser device and evaluated their attitude towards daily pain encounters using questionnaires on attention and anxiety. Results show that congenitally participants have lower pain thresholds and higher suprathreshold pain ratings. The psychometric data further indicates that they are more attentive to pain compared to their sighted peers. In a second study, we investigated whether visual experience has an impact on pain perception by replicating the first study in late blind participants. Results indicate that individuals who lost sight later in life are similar to the sighted in every aspect of pain perception that we measured. In a third study, we tested whether blind individuals have supranormal skills in detecting small and quick increases in temperature, as these thermal cues of the environment might help identifying and avoiding potentially harmful objects. Results show that congenitally blind participants outperform their sighted peers and that they are more susceptible to spatial summation of heat. In a fourth study, we examined the contribution of A∂ and C-fibres to blind individuals’ nociceptive processing, as these fibres are thought to signal the first and second pain, respectively. Our findings indicate that congenital blindness leads to an enhanced detection to C-fibre mediated sensations and to faster reaction times to these nociceptive inputs. In a fifth and final study, we probed the potential changes in the descending modulation of nociceptive inputs following visual deprivation by measuring the effects of psychological factors like anticipation and anxiety on blind individuals’ pain perception. Results show that congenitally blind participants are more sensitive to pain in response to uncertainty about threat, suggesting that they are more susceptible to top-down modulation of pain. Overall, this work indicates that visual deprivation from birth, but not later in life, causes a leftward shift in the stimulus–response function to nociceptive stimuli and lends new support to a model of sensory integration of vision and pain processing.

Na tomada de decisão, o conteúdo afetivo dos possíveis resultados é determinante para escolha. Pessoas com diferentes tolerâncias a estes resultados têm distintas tolerâncias a risco. Decisões são moduladas minimizando-se resultados aversivos (emoção negativa e dor), e diferenças individuais relacionadas a aversão a risco poderiam ser preditoras de percepção de dor. Aqui, objetiva-se explorar se indivíduos com distintas aversões a risco financeiro teriam diferente percepção de dor física, social e imagética (contemplação de imagens de baixa valência/alto alerta). Em decisões financeiras, características pessoais de sensibilidade a preço ou produto seriam reveladas na maneira como o cenário de decisão é visualmente explorado. Outro objetivo é investigar como se dá a modulação da atenção visual em decisões financeiras de acordo com características individuais, manipulando-se diferentes formas de apresentação de preço. Espera-se colaborar para o entendimento dos processos de decisão em humanos, e contribuir para a construção de um modelo amplo de tomada de decisão. / The human behavior has its basis in dynamic coalitions of networks of brain areas underling emotion and cognition. It is believed that the decision is made through simulations of possible outcomes, and the affective content of these outcomes is crucial to the choice. Individuals experience different levels of tolerance to aversive results, these differences shape tolerance to risk, and it might also shape tolerance to pain. Therefore, pain perception could be an important component of decision-making. We explored the relationship between individual differences in pain perception (nociception, social exclusion and imagetic pain, the displeasure caused by low valence and high arousal images) and financial risk aversion. We also investigated how individual differences in economic decisions are reflected in visual attention, in different prices scenario. We hope to collaborate to a better understanding of the decision processes in humans, and to contribute to the conception of a more complete model of decision-making.

Der technische Fortschritt führte in jüngster Vergangenheit zur Neuentwicklung kleinerer Kamerasysteme und laparoskopischer Instrumente. So ist seit einiger Zeit die Durchführung der Cholezystektomie durch Inzisionen von 2-5 mm Größe (mikrolaparoskopische Cholezystektomie) anstatt der sonst üblichen 5-10 mm großen Hautschnitte (laparoskopische Cholezystektomie) möglich. Methoden: 25 Patienten wurden nach Randomisierung der laparoskopischen Gruppe und 25 der mikrolaparoskopischen Gruppe zugeordnet. Das Hauptzielkriterium der Studie war der postoperative Schmerzmittelverbrauch unter der patienten-kontrollierten Analgesie untersucht. Zusätzlich wurden die Häufigkeit von Konversionen, die Dauer des operativen Eingriffs, der postoperative Krankenhausaufenthalt, die perioperativen Schmerzen, die Fatigue, das kosmetische Resultat und die postoperative Arbeitsunfähigkeitsdauer untersucht. Ergebnisse: Alter, Body Mass Index und die Geschlechtsverteilung beider Gruppen waren vergleichbar. In jeder Gruppe erfolgte jeweils 1 Konversion (mikrolaparoskopische Cholezystektomie zur laparoskopischen Cholezystektomie; laparoskopische zu konventionellen Cholezystektomie). Der postoperative Krankenhausaufenthalt, die postoperative Arbeitsunfähigkeitsdauer, die Eingriffs- und die Narkosedauer zeigten für das mikrolaparoskopische und laparoskopische Verfahren keine wesentlichen Unterschiede. Die subjektive Schmerzwahrnehmung war beim Husten mit 340,5(204-410) in der mikrolaparoskopischen Gruppe niedriger als in der laparoskopischen Gruppe mit 406(357-514)(p / Background: Laparoscopic instruments have been minimised for abdominal videoendoscopic surgery. Whether micro-laparoscopic surgery will actually result in clinically relevant benefits for patients, has not yet been proven. Methods: Fifty patients were randomised to elective laparoscopic (MINI; n = 25) or micro-laparoscopic (MICRO; n = 25) cholecystectomy in a blinded fashion. Analgetic consumption during PCA, pain perception (visual analog score), and cosmetic result (patient's self-assessment) were evaluated postoperatively as clinically relevant endpoints. Results: Age, sex, BMI and operative time were not different between both groups. From surgery to the 3rd postoperative day, cumulative PCA morphine doses were comparable (MINI: 0,2(0,1-0,23) mg/kg bw; MICRO: 0,2(0,1-0,46) mg/kg bw; p>0,05) but overall VAS for pain while coughing was higher in the laparoscopic 406(357-514) compared to the micro-laparoscopic group 340,5(204-410) (p

A percepção dolorosa envolve um processo ativo de interpretação de informações cujo principal objetivo é a subsequente seleção de comportamentos protetivos para um contexto ou conjunto de estímulos que foram associados por nosso cérebro a uma lesão ou a um risco potencial de lesão, sem que necessariamente existam alterações estruturais físicas que expliquem estes sintomas. Enquanto atualmente a dor relacionada a execução de movimentos e a manutenção de posturas é o principal motivo pelo qual pacientes com queixas musculoesqueléticas crônicas buscam auxílio médico, a maior parte dos instrumentos de mensuração específicos para esta população de pacientes não avaliam a dor no contexto em que ela é percebida e, os que o fazem, possuem acesso a níveis de mensuração pouco informativos e apresentam diversos erros de construção. Objetivo: Desenvolver e validar uma escala psicofísica de razão que seja capaz de avaliar o gradiente de generalização da dor relacionada a execução de movimentos em indivíduos com dor no ombro. Métodos: Um total de 180 indivíduos com dor no ombro, destros, sintomáticos, sedentários e com início da queixa há pelo menos 3 meses foram recrutados entre os pacientes em atendimento no Grupo do Ombro do IOTFMUSP para a realização de 3 experimentos. Nos primeiros 2 experimentos, foi realizada a validação interna da escala psicofísica de razão por meio do procedimento de emparelhamento inter-modalidades e foram selecionados os movimentos que comporiam a escala oficial, respectivamente. Durante o experimento 3, o desenvolvimento da Escala Psicofísica de Avaliação da Dor Relacionada ao Movimento para pacientes com dor no ombro (EPADRMO) foi finalizado e seu processo de validação psicométrica teve início. Resultados: A validação interna da escala com base na teoria psicofísica, realizada no experimento 1, comprovou que a dor relacionada ao movimento pode ser mensurada dentro de um nível escalar de razão. Por meio da análise dos valores obtidos através das estimativas de magnitude da dor percebida durante a execução de 10 movimentos, selecionadas durante o experimento 2, e do expoente da função de potência obtido a partir destes valores, fomos capazes de compreender como a dor de cada indivíduo se manifestou no contexto em que ela é vivenciada e de mensurar seu gradiente de generalização ao longo dos movimentos que compõe a escala. As análises psicométricas realizadas durante o experimento 3 demonstraram validade de conteúdo, consistência interna e validade de constructo positivas com ausência de efeitos teto e piso, apresentando uma confiabilidade inter-examinadores adequada. Conclusão: A EPADRMO demonstrou ser capaz de mensurar quantitativamente o gradiente de generalização e a magnitude de variação da dor funcional de um indivíduo com dor no ombro com uma capacidade informativa superior as outras escalas disponíveis que se prezam a avaliar a dor funcional nesta população de paciente / The pain perception involves an active process of information interpretation whose main goal is the subsequent selection of protective behaviors to contexts or a set of stimuli that were associated by our brain to an injury or a potential risk of injury, without a necessarily structural change that could explain these symptoms. While the pain related to the execution of movements and the maintenance of postures is currently the main reason why patients with chronic musculoskeletal complaints seek medical help, most of the measurement instruments specific to this patient population do not assess pain in the context in which it is perceived and those who do so, have access to inferior levels of measurement and exhibit various construction errors. Objective: To develop and validate a psychophysical ratio scale that is capable of evaluationg the movement related pain generalization gradient in individuals with shoulder pain. Methods: A total of 180 patients with shoulder pain, right-handed, symptomatic, sedentary and with complaint for at least 3 months were recruited from patients in care in the Shoulder Group of IOTFMUSP to perform three experiments. In the first two experiments, the internal validation of the psychophysical ratio scale were made by the cross-modality matching procedure and 10 movements have been selected to compose the official scale, respectively. During the experiment 3, the development of The Psychophysical Scale for Movement Related Shoulder Pain (PSMRSP) was completed and the psychometric validation process of the instrument was initiated. Results: The internal validation of the scale based on the psychophysical theory, held in experiment 1, demonstrated that the movement related pain can be measured in a ratio level of measurement. Through the analysis of the values obtained by the magnitude estimations of the perceived pain during the execution of 10 movements, selected during the experiment 2, and the power function exponent obtained from these values, we were able to understand how the pain of each individual manifests in the context in which it is felt and to measure the gradient of pain generalization along the movements selected for the scale. The psychometric analyzes performed during the experiment 3 demonstrated positive content validity, internal consistency and construct validity with no ceiling and floor effects, presenting an adequate inter-rater reliability. Conclusion: The findings of the present study demonstrated that the PSMRSP provide a quantitative measure of the generalization gradient and of the range of variation of the movement related pain in subjects with shoulder pain with a higher informativeness than the other scales available to evaluate the functional pain in this patient population

Slaughter by ventral neck incision (VNI) is performed on some animals without prior stunning in New Zealand and other countries. A single incision with a razor sharp blade is made in the ventral aspect of the neck, sectioning both carotid arteries and jugular veins, though, not the vertebral arteries. There are a number of potential welfare concerns surrounding slaughter by VNI including pain due to the incision, which may lead to distress during the time before loss of consciousness. The aims of this thesis were to identify cortical responses indicative of noxious stimulation due to slaughter by VNI using analysis of the electroencephalogram (EEG) power spectrum and to investigate the effects of non-penetrative captive bolt (NPCB) stunning on these cortical responses. The studies utilised adaptations of a minimal anaesthesia model, which has been validated in a range of mammalian species. Surgical dehorning was used as a validation technique for this methodology in cattle and demonstrated a ‘typical’ EEG response to noxious stimulation. Cattle slaughtered by VNI without prior stunning produced specific responses in the EEG that strongly indicated responses to noxious stimulation. Causation was investigated in cattle where blood flow through the brain remained intact during neck tissue incision (NTI) or the major blood vessels of the neck were isolated and transected independently of other neck tissues (BVT). The response to neck incision in intact animals was principally due to the noxious sensory input due to incision of neck tissues and not mainly as a result of loss of blood flow through the brain. NPCB stunning produced states of cortical activity that were incompatible with the maintenance of sensibility and pain perception. Experimental examination of the time to onset of undoubted insensibility was attempted in cattle subsequent to a pilot study in sheep. The generation of somatosensory-evoked potentials was problematic in cattle. The conclusions of this thesis are that incision of neck tissues during slaughter without prior stunning constitutes a substantial noxious stimulus. Were an animal conscious, this stimulus would be perceived as painful until the onset of hypoxiainduced insensibility. This would represent a significant compromise to animal welfare.

Slaughter by ventral neck incision (VNI) is performed on some animals without prior stunning in New Zealand and other countries. A single incision with a razor sharp blade is made in the ventral aspect of the neck, sectioning both carotid arteries and jugular veins, though, not the vertebral arteries. There are a number of potential welfare concerns surrounding slaughter by VNI including pain due to the incision, which may lead to distress during the time before loss of consciousness. The aims of this thesis were to identify cortical responses indicative of noxious stimulation due to slaughter by VNI using analysis of the electroencephalogram (EEG) power spectrum and to investigate the effects of non-penetrative captive bolt (NPCB) stunning on these cortical responses. The studies utilised adaptations of a minimal anaesthesia model, which has been validated in a range of mammalian species. Surgical dehorning was used as a validation technique for this methodology in cattle and demonstrated a ‘typical’ EEG response to noxious stimulation. Cattle slaughtered by VNI without prior stunning produced specific responses in the EEG that strongly indicated responses to noxious stimulation. Causation was investigated in cattle where blood flow through the brain remained intact during neck tissue incision (NTI) or the major blood vessels of the neck were isolated and transected independently of other neck tissues (BVT). The response to neck incision in intact animals was principally due to the noxious sensory input due to incision of neck tissues and not mainly as a result of loss of blood flow through the brain. NPCB stunning produced states of cortical activity that were incompatible with the maintenance of sensibility and pain perception. Experimental examination of the time to onset of undoubted insensibility was attempted in cattle subsequent to a pilot study in sheep. The generation of somatosensory-evoked potentials was problematic in cattle. The conclusions of this thesis are that incision of neck tissues during slaughter without prior stunning constitutes a substantial noxious stimulus. Were an animal conscious, this stimulus would be perceived as painful until the onset of hypoxiainduced insensibility. This would represent a significant compromise to animal welfare.