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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Interação dos fatores musculoesqueléticos com o equilíbrio de crianças e adolescentes com neuropatia sensorial e motora hereditária / Interaction of skeletal-muscle factors with balance in children and adolescents with hereditary sensory-motor neuropathy

Cyntia Rogean de Jesus Alves 04 May 2018 (has links)
O controle postural na doença de Charcot-Marie-Tooth (CMT) está subsidiado em estudos com adultos, nos quais deformidades distais, desequilíbrios musculares e aspectos maturacionais estão bem documentados. Para infância e adolescência, o controle postural permanece por ser explorado e pode contribuir para elucidar como um sistema neuromuscular imaturo lida com a doença em curso. Neste contexto, foi proposto um estudo de desenho transversal (Estudo 1) composto por crianças e adolescentes com CMT (encaminhados ao Ambulatório CMT-Infantil do Centro de Reabilitação do HCFMRP-USP; Grupo CMT) e seus pares saudáveis (Grupo Controle), e outro longitudinal (Estudo 2), composto exclusivamente de crianças e adolescentes com CMT. O Estudo 1 caracterizou a oscilação postural e explorou sua interação com variáveis musculoesqueléticas, a partir da comparação do Grupo CMT e Grupo Controle, sendo composto por 53 participantes de ambos os sexos, idade entre 6 e 18 anos, sendo 24 saudáveis e 29 com CMT. Foram coletados dados de massa, estatura, base de apoio, Índice Postural do Pé (IPP), amplitudes passivas de movimento, força muscular isométrica de membros inferiores, medidas de desempenho (teste de caminhada dos 6 min -T6, teste dos 10 m - T10, salto horizontal - SH) e de equilíbrio (estabilometria, Escala de Equilíbrio Pediátrica - EEP). A força muscular isométrica dos grupos musculares inversores, eversores, dorsiflexores, flexores plantares, flexores e extensores de joelho e extensores de quadril foi medida bilateralmente com um dinamômetro manual (Lafayette, modelo 01163). Para avaliação estabilométrica foi usada uma plataforma de força (Bertec, modelo FP 4060-08), com frequência de amostragem de 100 Hz, tempo de registro de 30 s por tentativa. As 4 condições de teste (olhos abertos/superfície rígida; olhos abertos/superfície deformável; olhos fechados/superfície rígida; olhos fechados/superfície deformável) foram repetidas aleatoriamente por 3 vezes, intervaladas por 30 s, perfazendo 12 tentativas. Foram extraídas a área da elipse de confiança, velocidade (total, mediolateral e anteroposterior), frequência (total, mediolateral e anteroposterior) e o Quociente de Romberg (QRv) por meio do programa MATLAB (R2014a), usando um filtro digital Butterworth passa-baixa de 4a ordem, com frequência de corte de 7 Hz. O programa SPSS (versão 17) foi usado para análise estatística (nível de significância de 5%). No aspecto musculoesquelético (amplitude de dorsiflexão, ângulo poplíteo e força muscular da maioria dos grupos testados) e nos testes de desempenho (T10, T6 e SH), os resultados mostraram que o grupo CMT exibiu valores inferiores ao Controle (p<0,05). Quanto ao controle postural, comparações intragrupo das condições de teste no grupo CMT evidenciaram incremento na área e velocidades do centro de pressão (CP), mas não nas frequências, conforme a complexidade da tarefa. Nas comparações intergrupos, tanto a EEP quanto a estabilometria evidenciaram menor equilíbrio no grupo CMT quando comparado ao Controle (aumento da área de confiança da elipse e das velocidades, associadas a um decréscimo da frequência do CP) (p<0,05). As interações mais relevantes entre fatores musculoesqueléticos e equilíbrio sugerem melhor controle postural para indivíduos com pés são planos e amplitudes de dorsiflexão reduzidas. O Estudo 2 buscou detectar alterações no controle postural nos participantes que foram seguidos por 6 e 12 meses consecutivos, sendo 22 com CMT de ambos os sexos, idade entre 6 e 18 anos. Registros da oscilação postural, das variáveis musculoesqueléticas e de desempenho foram analisados em intervalos de 6 meses (AV1, AV2 e AV3). Os programas SPSS (versão 17) e R Core Team (2016) foram usados para análise estatística. O teste de Wilcoxon foi usado para comparar variáveis estabilométricas do seguimento semestral e anual e para uma análise complementar, considerando os subgrupos de 6 a 9 anos (n=8) e de 10 a 17 anos (n=9). O comportamento das variáveis musculoesqueléticas foi analisado com o modelo linear de efeitos mistos. O teste t de Student para amostras pareadas foi usado para analisar T10, T6 e SH. O IPP e EEP foram analisados com o teste exato de Fisher. Os resultados mostraram que não houve mudanças significativas na estabilometria entre AV1 e AV2 ou AV1 e AV3. Nas comparações entre AV1 e AV2, houve aumento significativo no ângulo poplíteo, na força dos grupos musculares eversores de tornozelo e extensores de quadril, no SH e a força muscular dos extensores de joelho sofreu decréscimo (p<0,05). Nas comparações entre AV1 e AV3, houve aumento significativo da força muscular dos grupos inversores, eversores, dorsiflexores e extensores de joelho (p<0,05). A análise complementar do seguimento anual identificou reduções significativas na amplitude de dorsiflexão, velocidade mediolateral (condições olhos abertos/superfície rígida e olhos fechados/superfície rígida) e velocidade total (condições olhos abertos/superfície rígida e olhos fechados/superfície rígida) no subgrupo de crianças (n=8) (p<0,05). No subgrupo de adolescentes (n=9), houve aumento significativo da força muscular de inversores, dorsiflexores e extensores de joelho (p<0,05) enquanto a estabilometria permaneceu inalterada. Em suma, os resultados do Estudo 1 e 2 permitem concluir que o controle postural ii deficitário de crianças e adolescentes com CMT é mensurável com base nas variáveis estabilométricas extraídas da análise global; é expresso por grandes e rápidas oscilações do CP, nas quais a frequência não distingue as condições de teste quando comparadas aos seus pares saudáveis. A velocidade do CP parece refletir as mudanças na estabilidade postural quando crianças e adolescentes são analisados como subgrupos distintos. Além disso, seguimentos anuais parecem ser suficientes para detectar mudanças no controle postural, nas variáveis musculoesqueléticas e de desempenho. / Postural control in Charcot-Marie-Tooth disease (CMT) is supported in studies with adults, in which distal deformities, muscular imbalances and maturational aspects are well documented. For childhood and adolescence, standing balance remains to be explored and may contribute to elucidate how an immature neuromuscular system deals with the ongoing disease. In this context, a crosssectional study (Study 1) composed of children and adolescents with CMT (referred to the CMTInfantile Ambulatory of the HCFMRP-USP Rehabilitation Center, CMT Group) and their healthy peers (Control Group), and another longitudinal (Study 2), composed exclusively of children and adolescents with CMT were proposed. Study 1 characterized the postural oscillations and explored its interaction with musculoskeletal variables from the comparison of the CMT Group and Control Group, being composed of 53 participants of both sexes, age between 6 and 18 years, being 24 healthy and 29 with CMT. Mass, height, base of support, foot postural index (PPI), passive amplitudes of movement, isometric muscle strength of lower limbs, performance measures (6-min walk test -T6, 10- T10, horizontal jump - SH) and balance (stabilometry, Pediatric Balance Scale - EEP) were collected. The isometric muscle strength of the inversion, dorsiflexion, plantarflexion, knee extension, knee flexion and hip extension was measured bilaterally with a manual dynamometer (Lafayette, model 01163). Stabilometric evaluationused a force platform (Bertec, model FP 4060-08), with sampling frequency of 100 Hz, recording time of 30 s per trial. The 4 test conditions (open eyes / hard surface, open eyes / deformable surface, closed eyes / hard surface, closed eyes / deformable surface) were randomly repeated 3 times, intervals for 30 s, making 12 trials. The confidence ellipse area, velocity (total, mediolateral and anteroposterior), frequency (total, mediolateral and anteroposterior) and the Romberg Quotient (QRv) were extracted using MATLAB program (R2014a), adopting a 4th order Butterworth digital low-pass filter and a cut-off frequency of 7 Hz. Statistical analysis used the SPSS program (version 17) and it was adopted level of significance of 5%. In the musculoskeletal aspect (amplitude of dorsiflexion, popliteal angle and muscular strength of most of the groups tested) and performance tests (T10, T6 and SH), CMT group showed values lower than Control (p <0.05). For balance, intragroup comparisons of the test conditions in the CMT group evidenced an increased area and velocities of the pressure center (CP), but not the frequencies, according to the complexity of the task. In the intergroup comparisons, EEP and stabilometry showed less postural control in the CMT group when compared to the Control (increased confidence ellipse area and velocities associated with a decrease in CP frequency) (p <0.05). The most relevant interactions between musculoskeletal and oscillations of CP suggest better postural control for subjects the flat feet and reduced dorsiflexion amplitudes. Study 2 comprised 22 participants with CMT of both sexes, aged between 6 and 18 years and it sought to detect changes in postural oscillations in CMT with 6 and 12 consecutive months of follow-up. Postural oscillations, musculoskeletal and performance variables were analyzed at 6-month intervals (AV1, AV2 and AV3). SPSS (version 17) and R Core Team (2016) programs were used for statistical analysis. The Wilcoxon test was used to compare stabilometric variables of the bi-annual and annual follow-up and to a complementary analysis, considering the subgroups of 6 to 9 years (n = 8) and 10 to 17 years (n = 9). The linear mixed effects model analyzed the musculoskeletal variables. Student\'s t-test for paired samples was used to analyze T10, T6 and SH. The Fisher\'s exact test analyzed the IPP and EEP. The results showed no significant changes in the stabilometry between AV1 and AV2 or AV1 and AV3. Comparisons between AV1 and AV2 showed significant increase in the popliteal angle strength of the ankle evertors and hip extensors SH while the muscle strength of knee extensors decreased (p <0.05). Comparisons between AV1 and AV3, showed a significant increase in the muscular strength for inversion, eversion, dorsiflexion and knee extension groups (p <0.05). The complementary analysis of the annual follow-up identified significant reductions in dorsiflexion amplitude, mediolateral velocity (open eyes / rigid surface and closed eyes / rigid surface) and total velocity (open eyes / rigid surface and closed eyes / rigid surfaces) in the subgroup of children (n = 8) (p <0.05). Subgroup of adolescents (n = 9) showed a significant increase in the muscular strength of inverters, dorsiflexors and knee extensors (p <0.05) while the stabilometry remained unchanged. In summary, the results of Study 1 and 2 allow us to conclude that the poor postural control of children and adolescents with CMT is measurable based on the stabilometric variables extracted from the global analysis; is iv expressed by large and rapid CP oscillations, in which frequency does not distinguish the test conditions when compared to their healthy counterparts. The velocity of CP seems to reflect changes in postural stability when children and adolescents are analyzed as distinct subgroups. In addition, annual follow-up appears to be sufficient to detect changes in postural control, musculoskeletal and performance variables.
272

Caracterização da dor, da sensibilidade discriminativa e dos achados neuropatológicos na biópsia cutânea em hanseníase em doentes após término do tratamento poliquimioterápico / Characterization of pain, discriminative sensitivity and neuropathological findings in cutaneous biopsy of leprosy patients after finishing polychemotherapy treatment

Irina Raicher 17 January 2018 (has links)
A dor neuropática decorre do acometimento das vias somatossensitivas por lesão ou doença e afeta 7% da população geral. No entanto, apenas uma proporção dos doentes com neuropatia desenvolve este tipo de dor. Diversos estudos tentaram comparar doentes acometidos por lesões aparentemente semelhantes do sistema somatossensitivo em busca dos fatores determinantes para a ocorrência e características da dor neuropática, com resultados conflitantes. Parte deste insucesso deriva do fato de que indivíduos diferentes podem ter lesões de nervo semelhantes, mas diferem quanto ao perfil psicológico, epigenético, de polimorfismos de receptores de neurotransmissores, e de catastrofismo. Estas características e uma série de outros fatores interindividuais podem enviesar a interpretação dos achados locais sobre a área de neuropatia e dor. Assim, o estudo de um mesmo indivíduo que possua áreas diferentes de neuropatia com e sem dor neuropática concomitantes serviria para reduzir os vieses interindividuais nas suas avaliações, e poderia revelar alterações locais que se relacionem com a ocorrência de dor neuropática. A hanseníase é uma doença que afeta o sistema nervoso periférico com o padrão de mononeuropatia múltipla frequente. Uma grande proporção de doentes apresenta dor neuropática crônica que ocorre, na maior parte das vezes, após o fim do tratamento farmacológico antibioticoterápico, e que representa intenso impacto negativo na qualidade de vida. Assim, a hanseníase é um modelo de estudo em que um mesmo doente apresenta neuropatia periférica com dor neuropática (D+) em uma área do corpo (n+d+) e em outra parte do corpo (contralateral homóloga) pode apresentar neuropatia sem dor neuropática (n+d-). Ainda, há indivíduos que podem compor um grupo controle de doentes acometidos pela hanseníase, mas que não tem dor neuropática (D-), apresentando áreas de neuropatia sem dor neuropática (n+d-) e áreas corpóreas sem neuropatia (n-d-). O objetivo do presente estudo foi investigar fatores periféricos que poderiam implicar na ocorrência de dor neuropática avaliando doentes com antecedente de hanseníase e mononeuropatia múltipla como modelo. Foram avaliados 37 doentes com hanseníase e dor crônica (D+) e 22 doentes com hanseníase sem dor crônica (D-), grupo-controle. Realizou-se a caracterização sociodemográfica e clínica, exame neurológico padronizado e utilizou-se escalas de avaliação da dor padronizadas e validadas (Inventário Breve de Dor - IBD, Questionário de dor neuropática 4 (DN4), Questionário Breve de Dor McGill e Inventário de Sintomas de Dor Neuropática - ISDN). Sobre cada uma das quatro áreas presentes possíveis (n+d+; n+d-; n+d-; n-d-), realizou-se aferição da sensibilidade exteroceptiva e proprioceptiva por meio de limiares de sensibilidade dolorosa e não dolorosa pelo teste quantitativo de sensibilidade (TQS) e análise morfológico-quantitativa da densidade de fibras nervosas intraepidérmicas (DFNIE), associados à aferição da presença de fatores inflamatórios na neuropatologia cutânea. As formas paucibacilar e dimorfa da hanseníase apresentaram menor limiar de dor ao quente (LDoQ) em comparação com a forma multibacilar (-2,66?C e -4,25?C, p = 0,002, respectivamente). As áreas com dor neuropática apresentaram sinais de disfunção de fibras nervosas do tipo C e hiperestesia em comparação com áreas com neuropatia sem dor neuropática. O LDoQ foi maior em áreas com neuropatia e dor neuropática (47,5 ± 3,4) em comparação com áreas com neuropatia sem dor neuropática (45,9 ± 3,6), p = 0,010, enquanto o limiar de detecção mecânica (LDM) foi menor (1,5 ± 3,6) em áreas com neuropatia e dor neuropática em comparação com áreas com neuropatia sem dor neuropática (5,8 ± 29,6), p = 0,047. Os doentes hansênicos apresentaram diagnóstico de neuropatia de fibras finas grave em todas as áreas de pele amostradas, a média das densidades variaram entre 2,1 a 3,2 fibras por milímetro (abaixo do percentil 5%). Não houve diferença estatisticamente significativa entre as quatro diferentes áreas quanto à DFNIE e quanto a fatores inflamatórios como contagens de macrófagos, linfócitos, células de Langerhans e medida da citocina fator de necrose tumoral alfa. Na modelagem matemática das variáveis significativas, as áreas com neuropatia sem dor tiveram LDoQ 2,30?C mais altos do que as áreas sem neuropatia e sem dor (n-d-). As áreas com neuropatia com dor (n+d+) tiveram LDoQ 3,45 C mais altos do que as áreas sem neuropatia e sem dor (n-d-). Nas análises de modelagem da relação dos dados entre LDoQ e DFNIE, verificou-se que áreas totalmente desnervadas (DFNIE = 0/mm apresentaram aumento do LDoQ estimada de 4,03 C, enquanto as amostras parcialmente inervadas (DFNIE = 1-5fibras/mm) apresentaram um aumento estimado de LDoQ de 1,54 C em comparação às áreas de referência (DFNIE >- 5fibras/mm). Encontrou-se uma relação entre o tempo e o agravamento da neuropatia. A cada mês, decorrido entre o término do tratamento com antibióticos da hanseníase e a avaliação atual, o LDoQ aumentou em 0,03?C, reforçando teorias de que a presença de debris bacterianos podem estar relacionados à ocorrência de neuropatia ativa e vigente, assim como, um potencial papel das reações hansênicas na ocorrência de neuropatia e dor neuropática a longo prazo. As alterações do LDoQ e do LDM foram relacionadas à ocorrência da dor neuropática no presente estudo e podem ter valor prognóstico e de rastreio se esses achados forem replicados em coortes maiores no futuro / Neuropathic pain arises from a lesion or disease of the somatosensory system and affects 7% of the general population. However, only a proportion of patients with neuropathy develop this type of pain. Several studies have attempted to compare patients with apparently similar lesions to the somatosensory system in search of the factors determining the occurrence and characteristics of neuropathic pain, yielding conflicting results. Part of the challenge in such assessment stems from the fact that different individuals may have similar nerve lesions, but may differ in their psychological, epigenetic, neurotransmitter receptor polymorphisms and catastrophism profiles. These features and several other interindividual factors may bias the interpretation of local findings in the area of neuropathy and pain. Thus, the study of the same individual who presents with different areas of neuropathy with and without neuropathic pain concomitantly would reduce the interindividual bias of these assessments, and could reveal local changes related to the occurrence of neuropathic pain. Leprosy is a disease that affects the peripheral nervous system with the frequent pattern of multiple mononeuropathy distribution. A large proportion of patients present chronic neuropathic pain, which occurs most often after the end of the antibiotic therapy drug treatment, and which poses an intense negative impact on the quality of life. Thus, leprosy is a \"model\" in which the same patient presents peripheral neuropathy with neuropathic pain (P+) in one area of the body (n+p+) and in another part of the body (contralateral homologous) presents neuropathy without neuropathic pain (n+p-). In addition, there are individuals who may constitute a control group, who are affected by leprosy but who do not have neuropathic pain (P-), and have body areas with neuropathy without neuropathic pain (n+p-) and body areas without neuropathy (n-p-). The aim of the present study was to investigate peripheral factors that could be related to the occurrence of neuropathic pain by assessing patients with leprosy and multiple mononeuropathy. We evaluated 37 patients with leprosy and chronic pain (P+) and 22 patients with leprosy without chronic pain (P-) (control group). Sociodemographic and clinical characterization were performed, as well as, standardized neurological examination and assessment of pain and related symptoms with validated pain assessment scales (Brief Pain Inventory - BPI, Neuropathic Pain Questionnaire 4 - DN4, McGill Brief Pain Questionnaire and Neuropathic Pain Symptom Inventory - NPSI). On each of the four possible body areas (n+p+; n+p-; n+p-; n-p-), exteroceptive and proprioceptive sensitivity were assessed by means of thresholds of painful and non-painful sensory stimuli by quantitative sensitivity test (QST), as well as, morphological-quantitative analysis of intraepidermal nerve fiber density (IENFD), and assessment of inflammatory factors in cutaneous neuropathology. Paucibacillary and dimorphic forms of leprosy presented lower heat pain threshold (HPT) compared to the multibacillary form (-2.66?C and -4.25 C, p=0.002; respectively). Areas with neuropathic pain had signs of defective C nerve fiber dysfunction and hyperesthesia compared to areas with neuropathy without neuropathic pain. HPT was higher in areas with neuropathy and neuropathic pain (47.5 ± 3.4) compared to areas with neuropathy without neuropathic pain (45.9 ± 3.6), p=0.010), while mechanical detection threshold (MDT) was lower (1.5 ± 3.6) in areas with neuropathy and neuropathic pain compared to areas with neuropathy without neuropathic pain (5.8 ± 29.6), p=0.047. Leprosy patients had a diagnosis of severe small-fiber neuropathy in all areas of skin sampled, the mean densities ranged from 2.1 to 3.2 fibers per millimeter (below 5% percentile). There was no statistically significant difference between the four different areas concerning IEFND and for inflammatory factors such as presence of number of macrophages, lymphocytes, Langerhans cells and cytokine tumor necrosis factor alpha. In the mathematical modeling of significant variables, areas with painless neuropathy (n+p-) had a HPT 2.30?C higher than areas without neuropathy and without pain (n-p-). Areas with neuropathy with pain (n+p+) had a HPT 3.45 C higher than areas without neuropathy and without pain (n-p-). In the modeling analyses between the relationship of HPT and IEFND data, it was found that totally denervated areas (IEFND=0/mm) presented an increase in estimated HPT of 4.03 C, while scarcely innervated samples (IEFND=1-5fibers/mm) presented an estimated increase of HPT of 1.54?C compared to reference areas (IEFND >- 5fibers/mm). We found a relationship between time and worsening of neuropathy. Each month between the termination of the leprosy antibiotic treatment and the present assessment, HPT increased by 0.03°C, supporting theories relating the presence of bacterial debris and the occurrence of active and ongoing neuronal damage, as well as, a potential role of leprosy reactions in the occurrence of neuropathy and neuropathic pain in the long-term. HPT and MDT changes were related to the occurrence of neuropathic pain in the present study and may have prognostic and screening value should these findings be replicated in larger cohorts in the future
273

Adaptação transcultural e validação do instrumento Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (CIPNAT) para o Brasil / Adaptation transcultural and validation of the instrument Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (CIPNAT) to Brazil

Alexandra Paola Zandonai 19 October 2015 (has links)
Introdução: A Neuropatia Periférica Induzida pela Quimioterapia (NPIQ) é um efeito adverso comum e debilitante ocasionado pela infusão de agentes quimioterápicos neurotóxicos como os taxanos, as platinas, alcalóides da vinca, bortezomibe e talidomida. A administração destas medicações aumentam a sobrevida do paciente, porém, aproximadamente, 30% a 40% desenvolvem NPIQ, o que afeta negativamente o tratamento planejado e a qualidade de vida ao interferir nas atividades diárias do paciente. A NPIQ manifesta-se com sintomas sensitivos (parestesia, disestesia, dor entre outros), motores (fraqueza, alterações na marcha e no equilíbrio, dificuldade nas habilidades motoras finas e outros) e neurovegetativos (constipação, retenção urinária, disfunção sexual e alterações na pressão sanguínea). Até o momento não foi concebido um instrumento que avalie a dor neuropática na NPIQ e, além disso, não há instrumento validado com essa finalidade no Brasil. Objetivos: Realizar a tradução e adaptação transcultural do instrumento Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (CIPNAT) para a língua portuguesa do Brasil e testar as propriedades psicométricas da versão adaptada em uma amostra de pacientes oncológicos, que apresentavam NPIQ. Métodos: Trata-se de um estudo metodológico com coleta de dados transversal. Para o processo de tradução e adaptação do instrumento, adotou-se o referencial teórico metodológico proposto por Beaton e colaboradores (2000). A coleta de dados ocorreu em dois hospitais referência no tratamento oncológico da cidade de São Paulo. Resultados: Obteve-se uma amostra de 245 participantes, sendo que, 135 (55,1%) apresentavam neoplasia maligna de intestino, 162 (66,1%) usavam um quimioterápico da classe análogos da platina, 125 (51%) manifestavam dormência nas mãos com gravidade média de 6,71 e angústia média de 7,0 (numa escala de 0-10), impactou negativamente nas Atividades de Vida Diária (AVD) como a prática de exercícios, o trabalho e atividades de lazer. Para testar a validade de construto convergente fez-se uma correlação de Spearmam da versão adaptada do CIPNAT com os instrumento NPSI e DN4 e, obteve-se uma moderada correlação. Não foi possível atingir a validade discriminante. A análise fatorial exploratória com rotação varimax identificou dois fatores, sendo estes, sintomas sensitivos e sintomas motores. Em relação a confiabilidade, alcançou-se um alfa de Cronbach de 0,87, considerado satisfatório. O teste-reteste demonstrou uma forte correlação entre a primeira e segunda avaliação pelo CIPNAT, sendo considerado estável. Conclusão: A análise psicométrica do CIPNAT foi adequada. Desta forma, estará disponível um instrumento válido e confiável que rastreia, caracteriza, avalia e mensura a NPIQ e seu impacto nas AVDs para que a enfermagem oncológica promova uma assistência segura e com qualidade / Background: Chemotherapy Induced Peripheral Neuropathy (CIPN) is a common and debilitating adverse effects caused by the infusion of neurotoxic chemotherapeutics such as taxanes, platines, vinca alkaloids, bortezomib and thalidomide. The administration of these medications increase patient survival, however, approximately 30% to 40% develop CIPN, which negatively affects the planned treatment and the quality of life by interfering with daily activities of the patient. The CIPN manifests itself with sensory symptoms (paresthesia, dysesthesia, pain and others), motors (weakness, changes in gait and balance, difficulty with fine motor skills and others) and neurovegetative (constipation, urinary retention, sexual dysfunction and changes in blood pressure). So far, it has not been a tool designed to evaluate the neuropathic pain in CIPN and furthermore, there is no validated instrument for this purpose in Brazil. Aims: To perform the translation and cultural adaptation of Chemotherapy- Induced Peripheral Neuropathy Assessment Tool instrument (CIPNAT) into Portuguese of Brazil and test the psychometric properties of the adapted version in a sample of cancer patients with CIPN. Methods: This is a methodological study with cross data collection. For the process of translation and adaptation of the instrument, it was adopted the methodological theoretical framework proposed by Beaton et al (2000). Data collection occurred in two referral hospitals in the oncological treatment of São Paulo. Results: There was obtained a sample of 245 participants, and that 135 (55.1%) had colorectal neoplasm, 162 (66.1%) used a platinum chemotherapeutic agent, 125 (51%) manifested numbness in the hands with medium gravity of 6.71 and average distress of 7.0 (on a scale of 0-10), impacted negatively on the activities of Daily Living (ADLs) such as exercise, work and leisure activities. To test the convergent validity has made a Spearman\' correlation of the adapted version of CIPNAT with NPSI and DN4 instrument and, was obtained a moderate correlation. Could not achieve the discriminant validity. Exploratory factor analysis with varimax rotation identified two factors, which are, sensory symptoms and motor symptoms. Regarding reliability, it was reached a Cronbach\'s alpha of 0.87, satisfactory. The test-retest showed a strong correlation between the first and second evaluation by CIPNAT and is considered stable. Conclusion: The psychometric analysis of CIPNAT was adequate. Thus, it will be available a valid and reliable instrument that tracks, features, evaluates and measures the CIPN and its impact on ADL for the oncology nursing promotes safe and quality care
274

Innervation cutanée et neuropathies périphériques / Cutaneous innervation and peripheral neuropathies

Danigo, Aurore 07 November 2014 (has links)
L’existence de douleurs neuropathiques et/ou de perte de la sensibilité douloureuse sont souvent le reflet d’une neuropathie sensitive affectant plus particulièrement les fibres nerveuses sensitives amyélinique Aδ et C, dites neuropathie des petites fibres (NPF). Ces fibres innervent, notamment, le derme et l’épiderme de la peau. Elles communiquent la sensibilité thermique et algique au système nerveux central et contribuent à l’homéostasie cutanée, entre autres, par la libération de neuropeptides en périphérie. De nombreuses pathologies sont associées à une altération de ces petites fibres dans la peau. Deux pathologies impliquant une NPF ont été étudiées au cours de ce travail : les escarres et la maladie de Charcot-Marie-Tooth type 1A. Un travail expérimental a été réalisé chez la souris pour répondre à la question suivante ; est-ce qu’une seule atteinte des fibres nociceptives, responsables de la perte de sensibilité peut entraîner un déséquilibre de l’homéostasie cutanée, responsable de l’apparition des escarres ? La mise en place d’un modèle de neuropathie sensitive fonctionnelle réversible a permis de mettre en en évidence l’implication des neuropeptides, substance P (SP) et « calcitonin gene-related peptide » (CGRP), libérés par les fibres nerveuses cutanées, dans la formation d’ulcères de pression. Un traitement préventif à la rhEPO (Recombinant Human Erythropoietin) dans ce modèle associant une neuropathie et des plaies de pression, protège la peau contre une pression ischémiante induisant une escarre par son effet neuroprotecteur sur les petites fibres cutanées. L’association CMT1A et NPF a été étudiée à partir de biopsies cutanées humaines. La quantification des fibres intraépidermiques révèle que 48% des patients CMT1A sont atteints d’une NPF. L’analyse des biopsies cutanées révèle également une altération du nombre et de la morphologie de cellules de Langerhans dans la maladie de CMT1A. L'ensemble de ces résultats confirme l'intérêt de l'étude des petites fibres dans des pathologies variées et confirme le potentiel thérapeutique neuroprotecteur de l'EPO / The neuropathic pain and/or hypoalgesia often reflect a sensory neuropathy that affects particularly sensory, Aδ (thinly myelinated) and C (unmyelinated) nerve fibers. This kind of neuropathy is named "small fiber neuropathy" (SFN). These small fibers innervate the dermis and epidermis. C and Aδ free nerve endings respond to a variable range of stimuli including mechanical, thermal and pain stimuli. They conduct nociceptive signals to central nervous system and contribute to skin homeostasis, among others, by the release of neuropeptides in the periphery. Many diseases are associated with an alteration of these cutaneous small fibers. Two pathologies involving SFN were studied in this work: pressure ulcers and Charcot-Marie-Tooth disease Type 1A (CMT1A). Experimental studies on mice were performed to determine if impairment of nociceptive fibers could lead to an imbalance of skin homeostasis and could be involved in development of pressure ulcers, apart from its role in pain signal transduction. A functional reversible sensory neuropathy mouse model was set up and helped to demonstrate the involvement of the neuropeptides, substance P (SP) and "calcitonin gene-related peptide" (CGRP), released by cutaneous nerve fibers in the formation of pressure ulcers. By its neuroprotective effect on small nerve fibers, a preventive rhEPO (Recombinant Human Erythropoietin) treatment in this model protects the skin against an ischemic pressure-induced Stage 2 ulcer. The CMT1A and SFN association has been studied from human skin biopsies. Quantification of intraepidermal nerve fibers reveals that 48% of CMT1A patients have a SFN. The analysis of skin biopsies also revealed an alteration in the number and morphology of Langerhans cells in CMT1A disease. All these results confirm the interest of the study of small fibers in various pathologies and confirm the neuroprotective therapeutic potential of EPO.
275

Spinal cholinergic system and chronic pain / Douleur chronique et système cholinergique spinal

Dhanasobhon, Dhanasak 24 October 2017 (has links)
Chez les rongeurs et humains, un « tonus » cholinergique spinal endogène modulant les comportements nociceptifs (douloureux) a été décrit. Une source potentielle de cette acétylcholine sont les interneurones cholinergiques de la corne dorsale (CD) de la moelle épinière. Nos objectifs étaient les suivants : (1) caractériser le « tonus » cholinergique spinal responsable de l’établissement des seuils mécaniques nociceptifs et (2) élucider le rôle des neurones cholinergiques CD dans la modulation de l'information sensorielle chez des animaux naïfs et neuropathiques. Nous avons confirmé la présence d'un « tonus » cholinergique qui module les seuils mécaniques et démontré qu'il est encore présent, bien qu'il soit modifié, après une neuropathie. Les interneurones cholinergiques reçoivent des entrées excitatrices localisées sur des segments plus distants et reçoivent généralement une faible fréquence d’entrées inhibitrices. De plus, ils sont indirectement reliés par des afférences primaires nociceptives qui expriment TRPV1, ce qui démontre leur implication dans le circuit nociceptif. Dans les conditions neuropathiques, les entrées des neurones LIII / IV ne sont pas affectées après une lésion du nerf périphérique. Une meilleure compréhension du système cholinergique spinal peut ouvrir la voie à une thérapie alternative contre la douleur. / An endogenous spinal cholinergic tone modulating nociceptive (pain­like) behaviors has been demonstrated in rodents and humans. One potential source of this acetylcholine is the spinal Dorsal Horn (DH) cholinergic interneurons. Our objectives were to: (1) characterize the spinal cholinergic tone establishing mechanical nociceptive thresholds and (2) to elucidate the role of DH cholinergic neurons in the modulation of sensory information of naïve and neuropathic animals. We have confirmed the presence of a cholinergic tone modulating mechanical thresholds and demonstrated that it is still present, although altered, after neuropathy. The DH cholinergic interneurons receive excitatory inputs from distant spinal segments and generally receive lower inhibitory inputs. In addition, they are indirectly connected by a subset of nociceptive primary afferents expressing TRPV1, demonstrating their involvement in nociceptive processing. In neuropathic spinal circuits, the inputs to LIII/IV neurons appears to be unaffected after injury. Better understanding the spinal cholinergic system can pave way to alternative pain therapy.
276

Laser Doppler Assessment of Vasomotor Axon Reflex Responsiveness to Evaluate Neurovascular Function

Kubasch, Marie Luise, Kubasch, Anne Sophie, Torres Pacheco, Juliana, Buchmann, Sylvia J., Illigens, Ben Min-Woo, Barlinn, Kristian, Siepmann, Timo 26 October 2017 (has links) (PDF)
The vasomotor axon reflex can be evoked in peripheral epidermal nociceptive C-fibers to induce local vasodilation. This neurogenic flare response is a measure of C-fiber functional integrity and therefore shows impairment in patients with small fiber neuropathy. Laser Doppler flowmetry (LDF) and laser Doppler imaging (LDI) are both techniques to analyze vasomotor small fiber function by quantifying the integrity of the vasomotor-mediated axon reflex. While LDF assesses the flare response following acetylcholine iontophoresis with temporal resolution at a single defined skin point, LDI records flare responses with spatial and temporal resolution, generating a two-dimensional map of superficial blood flow. LDF is characterized by a high intra- and interindividual measurement variability, which is smaller in LDI due to its spatial resolution. Nevertheless, LDI still lacks standardized methods for image analysis. Consequently, use of the technique currently remains on an experimental level. Here, we sought to review the current literature on laser Doppler assessment of vasomotor function and discuss potential future applications of established techniques as well as those that are still experimental.
277

Mikrovaskulární a makrovaskulární komplikace diabetes mellitus 2. typu / Microvascular and macrovascular complication diabetes mellitus 2. type

Šnorová, Markéta January 2017 (has links)
In my thesis I dealt with the theme of very serious and widespread diseases of civilization posed by diabetes mellitus (diabetes), type 2. Incidence of the disease is considered a pandemic of the 21st century. I focused on macro- and microvascular complications of type 2 diabetes mellitus. The work is divided into two parts. The theoretical part deals with the description of type 2 diabetes in terms of its origin, course, diagnosis and treatment, including komplkací. In the practical part I am devoted to a survey of diabetic patients in the waiting rooms of several diabetics. Through the questionnaire, I investigated how respondents have access to their disease. Whether they know their blood glucose levels as they are treated, whether they realize the seriousness of their illness if they have already expressed complications of diabetes and how to approach the treatment, if observe regime measures. The respondents' answers, I analyzed and processed using graphs.
278

Nouvelle méthode d'exploration fonctionnelle du nerf auditif / A new approach to probe the activity of auditory nerve fibers

Batrel, Charlène 19 December 2014 (has links)
Contexte: La réponse synchrone des fibres auditives, évaluée à partir de l'onde I des potentiels d'action évoqués auditifs (PEA), ou à partir du potentiel d'action composite (PAC) du nerf auditif, est l'élément clé du dépistage des neuropathies auditives. De récentes études ont toutefois montré que le seuil et l'amplitude de cette réponse pouvaient être absolument normaux malgré une perte importante de fibres du nerf auditif. Dans ce travail de thèse, nous proposons une nouvelle méthode d'exploration fonctionnelle, potentiellement applicable à l'homme, rendant mieux compte du nombre et de l'intégrité des fibres du nerf auditif. Cette méthode a été évaluée à l'aide d'un modèle pharmacologique de neuropathie physiologiquement pertinent.Matériel et méthodes: Chez des gerbilles, une perte sélective de fibres auditives a été induite par application d'une faible concentration d'ouabaïne dans la niche de la fenêtre ronde de la cochlée. Cette neuropathie a ensuite été caractérisée par des comptages de synapses (immunohistochimie/imagerie confocale 3D) et l'enregistrement de l'activité unitaire de fibres du nerf auditif. Les PAC et l'activité soutenue du nerf ont été enregistrés 6 jours après l'application d'ouabaïne, à l'aide d'une électrode de recueil disposée dans la niche de la fenêtre ronde. Résultats: L'application d'ouabaïne induit une perte spécifique des fibres à basse activité spontanée (AS<0,5 potentiel d'action/sec) comme observé au cours du vieillissement et après une surexposition sonore. La disparition de cette population de fibres est indétectable à l'aide du PAC car leur réponse unitaire est à la fois retardée et désynchronisée. Par contre, l'amplitude de la réponse soutenue du nerf se révèle être un bien meilleur indicateur de la perte des fibres à basse activité spontanée. Pour aller plus loin, nous avons mis au point une méthode qui permet d'observer l'activité synchrone et soutenue du nerf auditif dans une même réponse. Cette approche rend compte des trois mécanismes de fusion vésiculaire (libération rapide, lente et soutenue) de la première synapse auditive.Conclusion: L'analyse de la réponse soutenue du nerf auditif est une approche fiable pour déterminer le nombre et le phénotype fonctionnel des fibres qui composent le nerf auditif. Cette méthode, applicable à l'homme, devrait améliorer le dépistage des neuropathies, avec une meilleure différenciation des atteintes d'origine synaptique et/ou neuronale.Mots clés: Cochlée, nerf auditif, potentiel d'action composite, activité soutenue du nerf auditif, enregistrement unitaires, ouabaïne, neuropathie / Background: The synchronous activation of the auditory nerve fibers (ANFs), is commonly studied through the compound action potential (CAP), or the auditory brainstem responses (ABR), to probe deafness in experimental and clinical settings. Recent studies have shown that substantial ANF loss can coexist with normal hearing threshold, and even unchanged CAP amplitude, making the detection of auditory neuropathies difficult. In this study, we took advantage of the round window neural noise (RWNN) to probe ANF loss in a physiologically-relevant model of neuropathy.Material and methods: ANF loss was induced by the application of ouabain onto the round window niche. CAP and RWNN of the gerbil's cochlea were recorded through an electrode placed onto the round window niche, 6 days after the ouabain application. Afferent synapse counts and single-unit recordings were carried-out to determine the degree and the nature of ANF loss, respectively. Results: Application of a low ouabain-dose into the gerbil RW niche elicits a specific degeneration of low spontaneous rate (SR) fibers, as shown by single-unit recordings. Simultaneous recordings (CAP/single-unit) demonstrate that low-SR fibers have a weak contribution to the CAP amplitude because of their delayed and broad first spike latency distribution. However, the RWNN amplitude decreases with the degree of synaptic loss. The RWNN method is therefore more sensitive than CAP to detect low-SR fiber loss, most probably because it reflects the sustained discharge rate of ANFs. Based on these data, we proposed a far-field method (Peri-stimulus time response-PSTR) to assess the fast, slow, and sustain vesicular release at the first auditory synapse.Conclusion: The round window neural noise is a faithful proxy to probe the degree and the SR-based nature of fiber loss. This method could be translated into the clinic to probe hidden hearing loss and orient the practitioner toward synaptopathy and/or neuropathy.Key words: Cochlea, auditory nerve, compound action potential, round window neural noise, single fiber recording, ouabain-induced neuropathy
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Influência da neuropatia diabética no comportamento de respostas biomecânicas e sensoriais no andar em esteira rolante / Influence of the diabetic neuropathy on the behavior of biomechanical and sensorial responses in treadmill gait

Isabel de Camargo Neves Sacco 28 August 2001 (has links)
A investigação de parâmetros biomecânicos no movimento humano tem trazido importantes discussões sobre a função do sistema músculo-esquelético e o controle deste movimento. O andar humano é um dos comportamentos motores mais investigados pela biomecânica e seus aspectos mecânicos contribuem de forma a caracterizar, identificar e intervir em situações patológicas. A investigação de parâmetros dinâmicos, cinemáticos e eletromiográficos na marcha patológica pode beneficiar de forma significativa a compreensão dos mecanismos de controle do andar e as alterações compensatórias geradas, assim como contribuir nas intervenções terapêuticas e preventivas em sujeitos portadores de alguma doença que acometa o sistema músculo-esquelético. No presente estudo, buscou-se descrever e interpretar, sob a perspectiva da biomecânica, o andar em cadência auto-selecionada de sujeitos diabéticos neuropatas em esteira rolante, considerando os parâmetros dinâmicos, temporais, espaciais e eletromiográficos durante a fase de apoio. Investigou-se também aspectos sensoriais plantares e motores a fim de caracterizar os sujeitos neuropatas e controles estudados. Valores da sensibilidade somatossensorial e limiares de tolerância à dor nos sujeitos diabéticos neuropatas apresentaram significativamente maiores em relação ao grupo de sujeitos controle estudado, valores considerados fora do padrão de normalidade esperado. A cadência autoselecionada e a velocidade obtida na esteira rolante foram significativamente menores durante o andar dos neuropatas em relação aos sujeitos controle. Os tempos de apoio simples, duplo, comprimento da passada e do passo durante a marcha nos sujeitos diabéticos neuropatas apresentaram-se significativamente maiores em relação ao grupo controle. Foram observados menores picos de força vertical nos sujeitos neuropatas e menores deflexões da força vertical, conseqüências secundárias da estratégia de redução da velocidade do andar em neuropatas que buscam um padrão mais conservativo e estável do seu andar. As respostas eletromiográficas dos músculos da perna e coxa apresentaram-se com menores magnitudes e com picos de ativação atrasados em relação ao padrão normal de recrutamento, especialmente o m. tibial anterior bilateralmente nos neuropatas. Interpreta-se tal fato como uma provável alteração no mecanismo de controle central e/ou periférico da marcha em sujeitos diabéticos neuropatas decorrente dos déficits sensoriais periféricos e motores conseqüentes da doença investigada. O mecanismo de redução de choques na marcha apresentou-se de forma ineficiente em função das respostas atrasadas eletromiográficas tanto de m. vasto lateral, quanto de m. tibial anterior. Conclui-se que a neuropatia diabética periférica acomete não só respostas somatossensoriais e motoras periféricas mas também mecanismos intrínsecos de controle modificando a eficiência do tornozelo em seu papel na marcha, comprometendo desta forma alguns dos principais requisitos para o andar que são a progressão e o equilíbrio / Biomechanical investigation of the human movement has been bringing important discussions about the musculoskeletal system functions and the control of movement. The human walking is one of the most studied motor behaviors and its mechanical aspects contribute to characterize, identify, and intervene in pathological conditions. Dynamic, kinematic, and electromyographic analyses of pathological gait can significantly help the comprehension of the control mechanism of gait and its compensatory alterations. These analyses can also contribute to therapeutic and preventive interventions in patients whose walking behavior is altered due to some disease that accomplish the neuromotor system. In the present study, we described and interpreted self-cadence walking in a treadmill of neuropathic diabetic subjects under biomechanical considerations, such as dynamic, temporal, spatial, and electromyographic analysis during stance phase. We also studied sensorial and motor aspects in order to characterize the neuropathic and control subjects. The somatossensorial responses and pain tolerance threshold in the neuropathic subjects were significantly higher and considered away from the normal patterns. The self-cadence and the treadmill velocity were significantly lower in neuropathic gait. Single and double stance time, stride and step length were significantly higher during neuropathic gait. The neuropathic subjects showed lower vertical force peaks and lower deflections of vertical force and those findings were secondary consequences of the conservative strategy of lowering the gait velocity adopted by the neuropathic in order to reach a more stable locomotor pattern. The electromyographic responses of the thigh and leg muscles in neuropathic subjects showed lower magnitudes and were delayed comparing to the normal recruitment pattern, specially the anterior tibialis muscle right and left. These findings lead us to conclude that probably central and/or peripheral control mechanisms of the gait of neuropathic diabetic patients are altered due to somatossensorial and motor deficits. The mechanism of load reduction during walking was considered inefficient because of the activation delay of the lateral vastus and anterior tibialis muscles. We conclude that the peripheral diabetic neuropathy damages not only somatossensorial and motor sources but also intrinsic mechanisms of motor control leading to alterations in the ankle efficiency in gait. This resulting distal inefficiency compromises some of the principal requirements to gait, which are progression and balance
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Towards Understanding Neuropathy from Cancer Chemotherapy and Pathophysiology of Pain Sensation: An Engineering Approach

Parul Verma (8766597) 26 April 2020 (has links)
This thesis addresses chemotherapy-induced peripheral neuropathy (CIPN)- a form of pain sensation and a prevalent dose-limiting side-effect of several chemotherapy agents such as vincristine, paclitaxel, and oxaliplatin. These agents are used for treating various cancers such as leukemia, brain tumor, lung cancer. Peripheral neuropathy is a numbing, tingling, and burning sensation felt in the palms and feet, which occurs due to damage to neurons (nerve cells). Prolonged CIPN can impact the quality of life of cancer patients. Occasionally, severe CIPN can result in termination of chemotherapy treatment altogether. Currently, there are no established strategies for treating CIPN due to a lack of understanding of its mechanisms. Moreover, different patients react differently to the same treatment; a subgroup of patient population may never experience CIPN, while another may experience severe CIPN for the same dose. In addition, there are no established strategies for predicting CIPN either. This thesis addresses both prediction and mechanisms of CIPN.<br><br>The following paragraphs reflect the organization of this thesis. Each paragraph introduces a research problem, the approaches taken to investigate it, and states the key results.<br><br>First, a metabolomics-based approach was used to investigate CIPN prediction. Blood samples of pediatric leukemic cancer patients who underwent treatment with a chemotherapy agent - vincristine were provided. These blood samples were analyzed at different treatment time points using mass spectrometry to obtain the metabolite profiles. Machine learning was then employed to identify specific metabolites that can predict overall susceptibility to peripheral neuropathy in those patients at specific treatment time points. Subsequently, selected metabolites were used to train machine learning models to predict neuropathy susceptibility. Finally, the models were deployed into an open-source interactive tool- <i>VIPNp</i>- that can be used by researchers to predict CIPN in new pediatric leukemic cancer patients.<br><br>Second, the focus was shifted to the pathophysiology of pain and the pain-sensing neuron; specifically: (i) investigating pain sensation mutations and the dynamics of the pain-sensing neuron, and (ii) exploring chemotherapy-induced peripheral neuropathy mechanisms. <br><br>While pain is a common experience, genetic mutations in individuals can alter their experience of pain, if any at all (certain mutations yield individuals insensitive to pain). Despite its ubiquity, we do not have a complete understanding of the onset and/or mechanisms of pain sensation. Pain sensation can be broadly classified into three types: (i) nociceptive, (ii) neuropathic, and (iii) inflammatory. Nociceptive pain arises due to a noxious external stimulus (e.g., upon touching a hot object). Neuropathic pain (which is felt as a side-effect of the aforementioned chemotherapy agents) is the numbing and tingling sensation due to nerve damage. Inflammatory pain occurs due to damage to internal tissues. Pain in any form can be characterized in terms of electrical signaling by the pain-sensing neuron. Signal transmission regarding pain occurs through generation of an electrical signal called the action potential- a peak in neuron membrane potential. Excessive firing of action potentials by a pain-sensing neuron indicates pain of a specific form and intensity. In order to investigate this electrical signaling, a mathematical modeling approach was employed. The neuron membrane was assumed to be an electrical circuit and the potential across the membrane was modeled in terms of the sodium and potassium ions flowing across it via voltage-gated sodium and potassium channels, respectively. Generation of a single action potential followed by a resting state corresponds to a normal state, whereas periodic firing of action potentials (an oscillatory state) corresponds to pain of some form and intensity <i>in vitro</i>. Therefore, an investigation into the switch from a resting state to an oscillatory state was proposed. A bifurcation theory approach (generally useful in exploring changes in qualitative behavior of a model) was used to explore possible bifurcations to explain this switch. Firstly, genetic mutations that can shift the pain sensation threshold in the pain-sensing neuron were explored. The detected bifurcation points were found to be sensitive to specific sodium channels’ model parameters, implying sodium channels’ sensitivity towards the pain sensation threshold. This was corroborated by experimental evidence in existing literature. Secondly, a theoretical analysis was performed to explore all possible bifurcations that can explain the dynamics of this pain-sensing neuron model. The mathematical modeling simulations revealed a mixture of small amplitude and large amplitude membrane potential oscillations (mixed-mode oscillations) for specific parameter values. The onset and disappearance of the oscillations were investigated. Model simulations further demonstrated that the mixed-mode oscillations solutions belonged to Farey sequences. Furthermore, regions of bistability- where stable steady state and periodic solutions coexisted- were explored. Additionally, chaotic behavior was observed for specific model parameters.<br><br>Finally, this thesis investigated the role of voltage-gated ion channels in inducing CIPN using the same mathematical model. Repetitive firing of action potentials in the absence of any external stimulus was used as an indicator of peripheral neuropathy. Bifurcation analysis revealed that specific sodium and potassium conductances can induce repetitive firing without any external stimulus. The findings were supplemented by recording the firing rate of a sensory neuron culture. Next, a chemotherapy agent - paclitaxel, was introduced in the model to investigate its potential effects on the firing behavior. It was seen that a medium dose of paclitaxel increased repetitive firing. This was supported by the firing rate recordings of the sensory neuron culture.<br><br>In summary, this thesis presents a prediction strategy for CIPN. Moreover, it presents a bifurcation theory-based framework that can be used to investigate pain sensation, in particular, genetic mutations related to pain sensation and chemotherapy-induced peripheral neuropathy. This framework can be used to find potential voltage-gated ion channels that can be targeted to control the pain sensation threshold in individuals, and can be extended to investigate various degeneracies in CIPN mechanisms to find therapeutic cures for it.

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