Background and Objectives: To characterize the impact of pregabalin on sleep in patients with generalized anxiety disorder (GAD) and to determine whether the impact is a direct or an indirect effect, mediated through the reduction of anxiety symptoms. Methods: A post-hoc analysis of data from a randomized, double-blind, placebo- and active-controlled study in patients with GAD was conducted. Patients received pregabalin 300 mg/day, venlafaxine XR 75 mg/day or placebo for a week, followed by pregabalin 300-600 mg/day, venlafaxine XR 75-225 mg/day, or placebo for 7 weeks. Treatment effect on sleep was evaluated using the Medical Outcomes Study Sleep Scale. Anxiety symptoms were assessed with the Hamilton Anxiety Rating Scale. A mediation model was used to estimate separately for both treatment arms the direct and indirect treatment effects on sleep disturbance. Results: Compared with placebo (n = 128), treatment with pregabalin (n = 121) significantly reduced scores on the sleep disturbance subscale and Sleep Problems Index II at both week 4 and week 8, and the sleep adequacy subscale at week 8. Venlafaxine XR (n = 125) had no significant effect on these measures. The mediation model indicated that 53% of the total pregabalin effect on sleep disturbance was direct (p < 0.01) and 47% indirect, mediated through anxiety symptoms (p < 0.05). Conclusions: Pregabalin decreased sleep disturbance in patients with GAD both directly, and indirectly by reducing anxiety symptoms. Given the drug specificity of the results, this study provides evidence of an additional important pathway of action for pregabalin and its efficacy in GAD.

A Fibromialgia (FM) é uma síndrome que se caracteriza por dor crônica difusa, fadiga, transtornos do sono e alterações de humor. Embora sua fisiopatologia não esteja totalmente elucidada, o processo neurobiológico parece envolver alterações do córtex sensitivo e motor e de suas conexões com estruturas subcorticais que constituem a neuromatriz da dor, assim como alterações neuropáticas periféricas. Sabe-se que o aumento do cálcio intracelular acima de certo limiar, pode ser parte do processo dependente de atividade que leva à sensibilização central, por aumento do influxo de cálcio por meio de canais NMDA, AMPA, canais dependentes de voltagem, e por liberação de reservas intracelular microssomais. A sensibilização central pode ser também interpretada como um processo de plasticidade mal-adaptativa que sustenta circuitos da dor e de seus correlatos. Por tanto, o córtex sensitivo e motor tem sido alvo diagnóstico e terapêutico para o estudo e tratamento da dor crônica. Dentre as múltiplas estratégias farmacológicas tem sido preconizado o uso da pregabalina, aprovado pela Food and Drug Administration (FDA) dos EUA para uso no tratamento de fibromialgia em 2007. A pregabalina age inibindo os canais de cálcio pré sinápticos dependentes de voltagem por se ligar à proteína auxiliar alfa-2-delta. In vitro, este fármaco reduz a liberação de neurotransmissores cálcio-dependentes incluindo glutamato, norepinefrina, calcitonina e substância P, estes neurotransmissores têm sido associados à sensibilização do sistema nervoso. Portanto, considerando o potencial neuromodulador da pregabalina baseado no seu mecanismo de ação, é um fármaco atrativo para avaliar o papel da modulação do córtex sensitivo e motor na fisiopatolgia da FM. No entanto, para que se avance no conhecimento do efeito dos fármacos na função encefálica, necessitamos utilizar recursos de neuroimagem que sejam exequíveis em contextos diversos, e que permitam mensurar o efeito dos fármacos dinamicamente. Dentre os recursos de imagem existe a Functional Near Infrared Spectroscopy (fNIRS) que permite avaliar ativação cortical por meio da mudança no consumo local de oxigênio que acompanha o disparo neuronal regional, mensurado pelas mudanças na concetração da oxi- e desoxi-hemoglobina. Com estas considerações, hipotetizamos que a modulação farmacológica induzida pela pregabalina poderia ser mensurada, clinicamente por meio de testes psicofísicos da dor (que avaliam vias nociceptivas associadas a termoreceptores e barorreceptores) e à nível de neuroimagem por meio do fNIRS. Por se tratar de um mesmo sistema com potencial de ser avaliado de forma virtualmente simultânea, hipotetizamos também que existirá uma associação entre as modulações clínicas (testes psicofísicos) e neurológicas (fNIRS do córtex sensitivo e motor primários). Desta forma, neste estudo avaliou-se o efeito de pregabalina (150 mg) em dose única em fibromiálgicas e controles saudáveis. Em ambos os grupos a pregabalina foi comparada ao placebo, num desenho de estudo randomizado, duplo-cego, cruzado. Avaliou-se o efeito das intervenções, intra e inter-grupos, na ativação cortical de maneira indireta, pela concetração da oxi-hemoglobina durante testes psicofísicos da dor por meio meio do Quantitative Sensory Testing (QST) e algometria de pressão, que foram comparados com a ativação cortical durante uma tarefa motora de percussão dos dedos da mão (left hand finger tapping). Foram estudadas mulheres com idade entre 18 e 65 anos, 17 fibromiálgicas e 10 controles saudáveis. Os parâmetros do QST foram avaliados uma hora após dose única de 150 mg de pregabalina. Resultados: Na linha de base, as fibromiálgicas apresentaram alterações no QST sugestivas de lesão de fibras finas: o limiar de detecção de calor (HDT, do inglês Heat Detection Threshold) foi maior que nas controles (35,53 ºC ± 3,22 vs. 33,33 ºC ± 0,85; p<0,05), enquanto o limiar de dor por pressão (PPT, do inglês Pain Pressure Threshold) foi menor (2,44 kg/cm2 ± 1,08 vs. 4,32 kg/cm2 ± 1,45; P<0,01). Não foram observadas diferenças nos outros componentes do QST, nem mudanças com a pregabalina. Quando comparados com as saudáveis, nas fibromiálgicas o HDT, limiar de dor por calor (HPT) e a tolerância ao calor (HT) evocaram activação nos giros frontal médio, precentral e póscentral, porém, de menor amplitude do que as controles. Depois da administração da pregabalina, aumentou a ativação em responsta ao HDT, mas não teve correlação com o valor do limiar. Já o HPT mostrou se correlacionar de forma inversa com a ativação nos giros frontal superior (rs=-0,552, p=0,033) e precentral (rs=-0,545, p=0,036) na linha de base e após pregabalina (rs=-0,52, p=0,047). A HT também apresentou uma correlação inversa com os giros frontal superior (rs=-0,645, p=0,032) e precentral (rs=-0,655, p=0,029), mas neste caso, esta correlação desapareceu após ter recebido pregabalina. A ativação cortical pelo PPT não detectou diferenças entre fibromiálgicas e controles. Conclusões: O perfil nos testes psicofísicos nas pacientes apresenta correlação com sua ativação cortical. As alterações nos testes sugerem alterações de fibras finas nociceptivas, o que é explicado por um componente de neuropatia periférica, que na fibromialgia é acompanhado por diminuição da ativação em áreas sensitivas e motoras, e aumento da ativação em áreas associadas com processamento cognitivo da dor, cuja atividade foi elevada com a pregabalina. Quando comparadas às controles, nas fibromiálgicas a HT recrutou mais áreas associada ao processamento cognitivo da dor, o que fortalece a hipótese a favor da existência do componente de sensibilização central na fibromialgia. Desta forma, estes achados reforçam a provável coexistência de alterações periféricas e centrais na fisiopatologia da fibromialgia. / Fibromyalgia is a syndrome characterized by presenting chronic diffuse pain, fatigue, mood and sleep disturbances. Although its pathophysiology has not been totally elucidated yet, the neurobiological processes seems to involve funciontal alterations of the sensorimotor cortex and its conections with subcortical structures (related to the pain neuronal matrix), and also, with quantitative and qualitative alterations in fine sensitive fibers from the peripheral nervous system. It is known that increased intracellular calcium above certain threshold might be part of a process activity-dependant that leads to central sensitization, due to elevated calcium influx through NMDA and AMPA channels, as well as voltage-dependent channels, and also due to relase of intracellular microsomal reserves. Central sensitization can also be interpreted as a maladaptive plasticity that sustains pain circuits and its correlated. Thus, the sensorimotor cortex has been a diagnostic and therapeutic target for the study and treatment of chronic pain. Among the multiple pharmacological strategies, the use of pregabalin has been recommended and approved by the Food and Drug Administration (FDA) of the United States of America for treatment of patients with fibromyalgia since 2007. Pregabalin acts by inhibiting voltage-dependant pre-synaptic calcium channels by binding to the auxiliary protein alfa-2-delta. In vitro, this drug reduces the liberation of neurottransmissors that depend on calcium, and that include glutamate, norepinephrine, calcitonin and P-substance. All the latter mentioned neurotransmitters are associated with the central nervou system sensitization. Thus, considering its potential as neuronal modulation, taking into accout tis mechanisms of action, the pregabalin is an appealing drug to study the role of the modulation fo the sensorimotor cortex in the pathophysiology of fibromyalgia. Nevertheless, to incrase the knowledge about the effect of drugs on the cortical function, we need to use feasible neuroimaging resources able to be applied in diverse contexts, and that allow to measure the effect of the drugs in real time. Among the neuroimaging resources, there is the Functional Near Infrared Spectroscopy (fNIRS), which allows to assess cortical activation estimating the uptake of regional oxygen, that accompanies local neuronal firing. The fNIRS measures changes in the concentration of oxy and desoxy hemoglobin. Given these considerations, we hypothezise that the pharmacological modulation induced by pregabalin could be measured, clinically through psychophysical pain testing, and at the neuroimaging level using fNIRS. Given that it is about the same system with the potential to be assessed in complementary and virtually simultaneous ways, we also hypothesize that there still could exist an association between the clinical modulation (psychophysical tests) and cortical sensorimotor activation (assessed by fNIRS). In this way, this study appraised the effect of a single dose of pregabalin (150 mg) in the cortical activation and psicophysical pain testing in fibromyalgic and in healthy subjects. In both groups, pregabalin was compared to placebo, in a randomized, double-blinded, cross-over trial design. We assessed the effect of pregabalin, within and between-groups, on the cortical activity in an indirect way via the changes in oxy-hemoglobin upon heat and pressure stimuliation inside a protocol of QST, and also compared the psychophysical pain tests results with the performance during a Left Hand Fingertapping Task. We studied women aging 18 to 65, 17 of them with fibromyalgia and 10 healthy controls. QST parameters were assessed one hour after a single dose of 150 mg of pregabalin. Results: At baseline, patients with fibromyalgia presented QST alterations suggestive of fine nerve fibers lesion: baseline HDT was higher in fibromyalgia (35.53±3.22 vs. 33.33±0.85, P<0.05), while PPT was lower (2.44±1.08 vs. 4.32±1.45, P<0.01) than healthy volunteers, but did not change with pregabalin. When compared to healthy subjects, HDT, HPT, and HT evoked smaller activation in the middle frontal, pre- and post-central gyri in fibromyalgia, that increased after pregabalin (only for HDT-induced activation), but that was not correlated to the HDT. HPT was inversely correlated to the activation in the superior frontal (rs=-0.552, p=0.033) and precentral gyri (rs=-0.545, p=0.036), remaining unchanged after pregabalin (rs=-0.52, p=0.047). HT was inversely correlated to the middle frontal (rs=-0.645, p=0.032) and precentral gyri activation (rs=-0.655, p=0.029), but was no longer correlated after pregabalin. PPT cortical activation did not differ between fibromyalgia and healthy volunteers. Conclusions: The psychophysical pain testing profile in fibromyalgia has a cortical correlate. Alterations in tests for small fibers support its probable peripheral neuropathic component, and was accompanied by decreased activation in sensorimotor areas but increased in pain-related cognitive processing cortexes, and whose activity is increased by pregabalin. Also, upon HT fibromyalgia patients recruited more areas related to pain cognitive processing, which could favor the hypothesis of a component of central sensitization in fibromyalgia, and which was poorly modulated by pregabalin. Taken together, these findings support the co-existence of both, peripheral and central alterations in fibromyalgia.

A Fibromialgia (FM) é uma síndrome que se caracteriza por dor crônica difusa, fadiga, transtornos do sono e alterações de humor. Embora sua fisiopatologia não esteja totalmente elucidada, o processo neurobiológico parece envolver alterações do córtex sensitivo e motor e de suas conexões com estruturas subcorticais que constituem a neuromatriz da dor, assim como alterações neuropáticas periféricas. Sabe-se que o aumento do cálcio intracelular acima de certo limiar, pode ser parte do processo dependente de atividade que leva à sensibilização central, por aumento do influxo de cálcio por meio de canais NMDA, AMPA, canais dependentes de voltagem, e por liberação de reservas intracelular microssomais. A sensibilização central pode ser também interpretada como um processo de plasticidade mal-adaptativa que sustenta circuitos da dor e de seus correlatos. Por tanto, o córtex sensitivo e motor tem sido alvo diagnóstico e terapêutico para o estudo e tratamento da dor crônica. Dentre as múltiplas estratégias farmacológicas tem sido preconizado o uso da pregabalina, aprovado pela Food and Drug Administration (FDA) dos EUA para uso no tratamento de fibromialgia em 2007. A pregabalina age inibindo os canais de cálcio pré sinápticos dependentes de voltagem por se ligar à proteína auxiliar alfa-2-delta. In vitro, este fármaco reduz a liberação de neurotransmissores cálcio-dependentes incluindo glutamato, norepinefrina, calcitonina e substância P, estes neurotransmissores têm sido associados à sensibilização do sistema nervoso. Portanto, considerando o potencial neuromodulador da pregabalina baseado no seu mecanismo de ação, é um fármaco atrativo para avaliar o papel da modulação do córtex sensitivo e motor na fisiopatolgia da FM. No entanto, para que se avance no conhecimento do efeito dos fármacos na função encefálica, necessitamos utilizar recursos de neuroimagem que sejam exequíveis em contextos diversos, e que permitam mensurar o efeito dos fármacos dinamicamente. Dentre os recursos de imagem existe a Functional Near Infrared Spectroscopy (fNIRS) que permite avaliar ativação cortical por meio da mudança no consumo local de oxigênio que acompanha o disparo neuronal regional, mensurado pelas mudanças na concetração da oxi- e desoxi-hemoglobina. Com estas considerações, hipotetizamos que a modulação farmacológica induzida pela pregabalina poderia ser mensurada, clinicamente por meio de testes psicofísicos da dor (que avaliam vias nociceptivas associadas a termoreceptores e barorreceptores) e à nível de neuroimagem por meio do fNIRS. Por se tratar de um mesmo sistema com potencial de ser avaliado de forma virtualmente simultânea, hipotetizamos também que existirá uma associação entre as modulações clínicas (testes psicofísicos) e neurológicas (fNIRS do córtex sensitivo e motor primários). Desta forma, neste estudo avaliou-se o efeito de pregabalina (150 mg) em dose única em fibromiálgicas e controles saudáveis. Em ambos os grupos a pregabalina foi comparada ao placebo, num desenho de estudo randomizado, duplo-cego, cruzado. Avaliou-se o efeito das intervenções, intra e inter-grupos, na ativação cortical de maneira indireta, pela concetração da oxi-hemoglobina durante testes psicofísicos da dor por meio meio do Quantitative Sensory Testing (QST) e algometria de pressão, que foram comparados com a ativação cortical durante uma tarefa motora de percussão dos dedos da mão (left hand finger tapping). Foram estudadas mulheres com idade entre 18 e 65 anos, 17 fibromiálgicas e 10 controles saudáveis. Os parâmetros do QST foram avaliados uma hora após dose única de 150 mg de pregabalina. Resultados: Na linha de base, as fibromiálgicas apresentaram alterações no QST sugestivas de lesão de fibras finas: o limiar de detecção de calor (HDT, do inglês Heat Detection Threshold) foi maior que nas controles (35,53 ºC ± 3,22 vs. 33,33 ºC ± 0,85; p<0,05), enquanto o limiar de dor por pressão (PPT, do inglês Pain Pressure Threshold) foi menor (2,44 kg/cm2 ± 1,08 vs. 4,32 kg/cm2 ± 1,45; P<0,01). Não foram observadas diferenças nos outros componentes do QST, nem mudanças com a pregabalina. Quando comparados com as saudáveis, nas fibromiálgicas o HDT, limiar de dor por calor (HPT) e a tolerância ao calor (HT) evocaram activação nos giros frontal médio, precentral e póscentral, porém, de menor amplitude do que as controles. Depois da administração da pregabalina, aumentou a ativação em responsta ao HDT, mas não teve correlação com o valor do limiar. Já o HPT mostrou se correlacionar de forma inversa com a ativação nos giros frontal superior (rs=-0,552, p=0,033) e precentral (rs=-0,545, p=0,036) na linha de base e após pregabalina (rs=-0,52, p=0,047). A HT também apresentou uma correlação inversa com os giros frontal superior (rs=-0,645, p=0,032) e precentral (rs=-0,655, p=0,029), mas neste caso, esta correlação desapareceu após ter recebido pregabalina. A ativação cortical pelo PPT não detectou diferenças entre fibromiálgicas e controles. Conclusões: O perfil nos testes psicofísicos nas pacientes apresenta correlação com sua ativação cortical. As alterações nos testes sugerem alterações de fibras finas nociceptivas, o que é explicado por um componente de neuropatia periférica, que na fibromialgia é acompanhado por diminuição da ativação em áreas sensitivas e motoras, e aumento da ativação em áreas associadas com processamento cognitivo da dor, cuja atividade foi elevada com a pregabalina. Quando comparadas às controles, nas fibromiálgicas a HT recrutou mais áreas associada ao processamento cognitivo da dor, o que fortalece a hipótese a favor da existência do componente de sensibilização central na fibromialgia. Desta forma, estes achados reforçam a provável coexistência de alterações periféricas e centrais na fisiopatologia da fibromialgia. / Fibromyalgia is a syndrome characterized by presenting chronic diffuse pain, fatigue, mood and sleep disturbances. Although its pathophysiology has not been totally elucidated yet, the neurobiological processes seems to involve funciontal alterations of the sensorimotor cortex and its conections with subcortical structures (related to the pain neuronal matrix), and also, with quantitative and qualitative alterations in fine sensitive fibers from the peripheral nervous system. It is known that increased intracellular calcium above certain threshold might be part of a process activity-dependant that leads to central sensitization, due to elevated calcium influx through NMDA and AMPA channels, as well as voltage-dependent channels, and also due to relase of intracellular microsomal reserves. Central sensitization can also be interpreted as a maladaptive plasticity that sustains pain circuits and its correlated. Thus, the sensorimotor cortex has been a diagnostic and therapeutic target for the study and treatment of chronic pain. Among the multiple pharmacological strategies, the use of pregabalin has been recommended and approved by the Food and Drug Administration (FDA) of the United States of America for treatment of patients with fibromyalgia since 2007. Pregabalin acts by inhibiting voltage-dependant pre-synaptic calcium channels by binding to the auxiliary protein alfa-2-delta. In vitro, this drug reduces the liberation of neurottransmissors that depend on calcium, and that include glutamate, norepinephrine, calcitonin and P-substance. All the latter mentioned neurotransmitters are associated with the central nervou system sensitization. Thus, considering its potential as neuronal modulation, taking into accout tis mechanisms of action, the pregabalin is an appealing drug to study the role of the modulation fo the sensorimotor cortex in the pathophysiology of fibromyalgia. Nevertheless, to incrase the knowledge about the effect of drugs on the cortical function, we need to use feasible neuroimaging resources able to be applied in diverse contexts, and that allow to measure the effect of the drugs in real time. Among the neuroimaging resources, there is the Functional Near Infrared Spectroscopy (fNIRS), which allows to assess cortical activation estimating the uptake of regional oxygen, that accompanies local neuronal firing. The fNIRS measures changes in the concentration of oxy and desoxy hemoglobin. Given these considerations, we hypothezise that the pharmacological modulation induced by pregabalin could be measured, clinically through psychophysical pain testing, and at the neuroimaging level using fNIRS. Given that it is about the same system with the potential to be assessed in complementary and virtually simultaneous ways, we also hypothesize that there still could exist an association between the clinical modulation (psychophysical tests) and cortical sensorimotor activation (assessed by fNIRS). In this way, this study appraised the effect of a single dose of pregabalin (150 mg) in the cortical activation and psicophysical pain testing in fibromyalgic and in healthy subjects. In both groups, pregabalin was compared to placebo, in a randomized, double-blinded, cross-over trial design. We assessed the effect of pregabalin, within and between-groups, on the cortical activity in an indirect way via the changes in oxy-hemoglobin upon heat and pressure stimuliation inside a protocol of QST, and also compared the psychophysical pain tests results with the performance during a Left Hand Fingertapping Task. We studied women aging 18 to 65, 17 of them with fibromyalgia and 10 healthy controls. QST parameters were assessed one hour after a single dose of 150 mg of pregabalin. Results: At baseline, patients with fibromyalgia presented QST alterations suggestive of fine nerve fibers lesion: baseline HDT was higher in fibromyalgia (35.53±3.22 vs. 33.33±0.85, P<0.05), while PPT was lower (2.44±1.08 vs. 4.32±1.45, P<0.01) than healthy volunteers, but did not change with pregabalin. When compared to healthy subjects, HDT, HPT, and HT evoked smaller activation in the middle frontal, pre- and post-central gyri in fibromyalgia, that increased after pregabalin (only for HDT-induced activation), but that was not correlated to the HDT. HPT was inversely correlated to the activation in the superior frontal (rs=-0.552, p=0.033) and precentral gyri (rs=-0.545, p=0.036), remaining unchanged after pregabalin (rs=-0.52, p=0.047). HT was inversely correlated to the middle frontal (rs=-0.645, p=0.032) and precentral gyri activation (rs=-0.655, p=0.029), but was no longer correlated after pregabalin. PPT cortical activation did not differ between fibromyalgia and healthy volunteers. Conclusions: The psychophysical pain testing profile in fibromyalgia has a cortical correlate. Alterations in tests for small fibers support its probable peripheral neuropathic component, and was accompanied by decreased activation in sensorimotor areas but increased in pain-related cognitive processing cortexes, and whose activity is increased by pregabalin. Also, upon HT fibromyalgia patients recruited more areas related to pain cognitive processing, which could favor the hypothesis of a component of central sensitization in fibromyalgia, and which was poorly modulated by pregabalin. Taken together, these findings support the co-existence of both, peripheral and central alterations in fibromyalgia.

Orientador: Alexandre Leite Rodrigues de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-27T11:24:09Z (GMT). No. of bitstreams: 1 Silva_GleidyAnaAraujo_M.pdf: 28585855 bytes, checksum: aaac289d72ca956b0b61eb90ac8c228e (MD5) Previous issue date: 2013 / Resumo: A esclerose múltipla se caracteriza por gerar uma inflamação esmielinizantecrônica e de caráter autoimune no sistema nervoso central, gerando uma série desinais e sintomas clínicos. Um modelo experimental para estudo da esclerosemúltipla é a encefalomielite autoimune experimental (EAE). Durante o curso da EAE, observa-se no SNC, perda de contatos sinápticos, bem como aumento da gliose reativa, envolvendo tanto astrócitos quanto células microgliais. Assim, a amenização dessas alterações, por tratamentos farmacológicos, pode ser útil no tratamento dos sintomas da EM. Neste sentido, o emprego da pregabalina, um ligante da proteína ?2-? associada a canais de cálcio voltagem-dependentes em neurônios, pode se constituir numa estratégia para o controle dos sintomas da doença. Assim, o presente estudo investigou o efeito da pregabalina sobre o curso da EAE, através da análise clínica de ratos Lewis imunizados com MBP e avaliação imunoistoquímica da medula espinal, utilizando marcadores para sinapses, astrogliose e reação microglial. Adicionalmente, através de RT-PCR, avaliou-se a expressão gênica de interleucinas pró e anti-inflamatórias, bem como a recuperação motora nos grupos placebo e tratado, foi avaliada pelo walking track test (CatWalk System). Os resultados demonstraram que o tratamento com pregabalina foi capaz de atrasar e amenizar os sinais clínicos e morfológicos da EAE, bem como reduzir a perda sináptica e a reação astroglial na medula espinal. Ainda, o tratamento resultou numa regulação positiva de genes anti-inflamatórios. De forma similar, a administração desse fármaco permitiu um mais rápido restabelecimento de parâmetros de marcha. Os resultados do presente estudo indicam que a pregabalina apresenta características neuroprotetoras e antiinflamatórias que refletem positivamente na amenização da doença, mostrando potencial para o uso clínico, em associação aos imunomoduladores atualmente empregados / Abstract: The multiple sclerosis (MS) is an autoimmune disease and neurodegenerative that affects young adults. It is characterized by generating a chronic demyelinating autoimmune inflammation in the central nervous system. An experimental model for the study of multiple sclerosis is the experimental autoimmune encephalomyelitis (EAE), induced by immunization with antigenic proteins of myelin of the central nervous system, dissolved in adjuvants. The present study investigated the evolution of the disease in pregabalin treated animals up to the remission phase. The results demonstrated a delay on the onset of the disease with statistical differences at the 10th and the 16th day after immunization For the gait evaluation, the walking track test (CatWalk) was used to evaluate different parameters related to motor function. Although no difference between groups was obtained for the foot print pressure, the regularity index was improved post treatment, indicating a better motor coordination. The immunohistochemical analysis of synapse preservation and glial reactivity revealed that pregabalin treatment improved the overall morphology of the spinal cord. A preservation of circuits was depicted and astroglial reaction was downregulated during the course of the disease. RT-PCR data were in line with the immunolabeling observations and indicated a shift of the immune response towards an anti-inflammatory response. Overall, the present data indicate that pregabalin is efficient for reducing the seriousness of EAE, delaying its course as well as reducing synaptic loss and astroglial reaction / Mestrado / Clinica Medica / Mestra em Clínica Médica

Background Neuropathic pain (NP), defined as pain caused by a lesion or disease of the somatosensory system, affects 6.9 – 10 % of people worldwide. Pregabalin is currently recommended as a first line drug for NP in South Africa. Methods A cross-sectional retrospective descriptive medicines usage evaluation (MUE) of Pregabalin at Groote Schuur Chronic Pain clinic for the year 2017 was conducted. A MUE using a standardized data collection form was performed on 100 randomly selected folders. Data are summarized using descriptive statistics. Results The majority of cases were women (76) with a mean age of 55.9y (SD12.49). A diagnosis of NP was recorded in 58 folders and a “possible” diagnosis recorded in 7 folders. In 79 cases there was no mention of a tool/method used to diagnose NP. The most common condition diagnosed was chronic post-surgical pain with a neuropathic component (n=16), followed by NP (n=15). The most common initiating and current dose of Pregabalin was 75mg twice daily. In 56 patients, Pregabalin was prescribed in conjunction with a tricyclic antidepressant (TCA) or selective noradrenaline reuptake inhibitor (SNRI). Patient education was documented as having taken place in 76 of cases. Conclusions Based on this MUE we recommend the use of screening tools for the diagnosis of neuropathic pain, and a focus on the initiating dose of Pregabalin. The use of a standardized assessment document and the interdisciplinary team input at this clinic appears to optimize prescribing of Pregabalin in line with practice guidelines.

Background and Objectives: To characterize the impact of pregabalin on sleep in patients with generalized anxiety disorder (GAD) and to determine whether the impact is a direct or an indirect effect, mediated through the reduction of anxiety symptoms. Methods: A post-hoc analysis of data from a randomized, double-blind, placebo- and active-controlled study in patients with GAD was conducted. Patients received pregabalin 300 mg/day, venlafaxine XR 75 mg/day or placebo for a week, followed by pregabalin 300-600 mg/day, venlafaxine XR 75-225 mg/day, or placebo for 7 weeks. Treatment effect on sleep was evaluated using the Medical Outcomes Study Sleep Scale. Anxiety symptoms were assessed with the Hamilton Anxiety Rating Scale. A mediation model was used to estimate separately for both treatment arms the direct and indirect treatment effects on sleep disturbance. Results: Compared with placebo (n = 128), treatment with pregabalin (n = 121) significantly reduced scores on the sleep disturbance subscale and Sleep Problems Index II at both week 4 and week 8, and the sleep adequacy subscale at week 8. Venlafaxine XR (n = 125) had no significant effect on these measures. The mediation model indicated that 53% of the total pregabalin effect on sleep disturbance was direct (p < 0.01) and 47% indirect, mediated through anxiety symptoms (p < 0.05). Conclusions: Pregabalin decreased sleep disturbance in patients with GAD both directly, and indirectly by reducing anxiety symptoms. Given the drug specificity of the results, this study provides evidence of an additional important pathway of action for pregabalin and its efficacy in GAD.

Background: There is a high incidence of moderate to severe postoperative pain in patients undergoing neurosurgery. Post-craniotomy headache (PCH) remains undertreated due to the cautious use of opioids in this surgical population. Various alternative analgesics such as acetaminophen and scalp blocks are widely utilized for the treatment of PCH, but this is often inadequate. Although a multimodal approach to the management of PCH may be effective in improved pain relief, only a limited number of randomized controlled trials have explored this. Aim: This study aims to investigate whether or not a multimodal analgesic regime, consisting of gabapentinoids and non-steroidal inflammatory drugs (NSAIDs) provides superior pain relief in patients undergoing elective craniotomy compared to the standard of care analgesia utilized at a local South African hospital. Methods: Twenty-seven patients, 18 years or older, scheduled for elective craniotomy for the management of their epilepsy were recruited into this clinical trial. Enrolled participants were randomized into one of two groups. The experimental group received oral 150mg pregabalin one hour before surgery, IV 40mg parecoxib at surgical closure, and oral 150mg pregabalin two hours after surgery. The control group received a matching placebo at these respective time points. Postoperatively, all patients received standard of care analgesia consisting of 24 hours IV paracetamol and additional analgesia as required (prn). Pain assessments using the numerical rating scale (NRS) and visual analogue scale (VAS) were performed at 1 hour, 8 hours, 24 hours, 48 hours and 72 hours postoperatively. Additional analgesia consumption, postoperative nausea and vomiting, as well as the incidence of any adverse events were captured. Results: Patients who received placebo showed an average trend of higher mean NRS pain scores compared to patients receiving pregabalin and parecoxib, although there was no significant difference (p = 0.218) in the maximum mean NRS pain scores between the experimental and control groups. However, patients who received pregabalin and parecoxib consumed significantly less dihydrocodeine than those who received placebo (p = 0.029). No significant differences were identified in use of other additional opioids and non-opioid analgesia during the first 24 postoperative hours. Conclusion: There is insufficient evidence to confirm that the perioperative use of pregabalin and parecoxib reduces PCH in patients undergoing elective craniotomy. The study medication did, however, result in a significant reduction in the use of postoperative dihydrocodeine, although it was also associated with higher rates of reported blurred vision and dizziness.

<p>Based on the concept that the tactile hypersensitivity and the central sensitization observed in animal models of peripheral neuropathy are maintained by peripheral drive from primary sensory neurons, the present project measured the changes in electrophysiological, immunohistochemical, and pharmacological properties of the dorsal root ganglia (DRG) neurons induced by a peripheral neuropathy. The aim of this study was to make a systematic survey and a unique understanding of changes that occur in primary sensory neurons that can sustain peripheral drive in this model. The data of this study indicate a prominent role of large diameter Aβ-fibers, including low threshold mechanoreceptors in peripheral neuropathy.</p> / Doctor of Philosophy (Medical Science)

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Submitted by MARCELO DE JESUS MARTINS null (celoufba@yahoo.com.br) on 2018-01-05T11:45:24Z No. of bitstreams: 1 Marcelo Martins (Tese de Doutorado).pdf: 3508982 bytes, checksum: ff73bd80060bf710ecc113d389df649e (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2018-01-05T17:19:45Z (GMT) No. of bitstreams: 1 martins_mj_dr_bot.pdf: 3508982 bytes, checksum: ff73bd80060bf710ecc113d389df649e (MD5) / Made available in DSpace on 2018-01-05T17:19:45Z (GMT). No. of bitstreams: 1 martins_mj_dr_bot.pdf: 3508982 bytes, checksum: ff73bd80060bf710ecc113d389df649e (MD5) Previous issue date: 2017-12-11 / Justificativa: a obesidade é uma doença crônica caracterizada por acúmulo excessivo de gordura corporal. Devido aos riscos associados, é considerada um grande problema de saúde pública nos países desenvolvidos. A cirurgia bariátrica (gastroplastia aberta) tem sido usada como uma estratégia importante para tratar esta condição nos países em desenvolvimento, especialmente quando associada a outras comorbidades. A qualidade de recuperação, no entanto, tem sido uma preocupação frequente no manejo pós-operatório desses pacientes. A pregabalina é um análogo estrutural do neurotransmissor ácido gama-aminobutírico (GABA) que se liga à subunidade alfa-2 do canal de cálcio voltagem dependente, bloqueando o desenvolvimento da hiperalgesia e a sensibilização central à dor. Objetivo: o objetivo principal da pesquisa foi avaliar o efeito da pregabalina perioperatória versus placebo na qualidade de recuperação pós-operatória em pacientes submetidos à cirurgia bariátrica. Métodos: trata-se de estudo prospectivo, randomizado, controlado com placebo, duplo cego. Após a aprovação do Comitê de Ética, setenta pacientes submetidos à gastroplastia abdominal foram randomizados para receber pregabalina, grupo 1 (75 mg por via oral 1 hora antes da cirurgia) ou uma pílula de placebo idêntica, grupo 2. O desfecho primário foi a avaliação da qualidade da recuperação (questionário QoR-40) em 24 horas. Os resultados secundários incluíram o consumo de opioides e os escores de dor pós-operatória. Um valor de P <0,05 foi usado para rejeitar erro de tipo I. Resultados: foram randomizados setenta pacientes e 60 indivíduos completaram o estudo. A mediana dos escores globais de recuperação (qualidade de recuperação QoR-40) às 24 horas após a cirurgia no grupo de pregabalina foi de 185 (176-191) x 184 (174-192) no grupo placebo (P = 0,95). O consumo total de opioides nas 24 horas não apresentou diferença estatisticamente significativa entre os grupos. Além disso, a incidência de náusea, o vômitos e o tempo de alta da unidade de cuidados pós-anestésicos não foram significativamente reduzidos no grupo pregabalina em comparação com o placebo. Conclusões: o uso pré-operatório de pregabalina não resulta em melhora na qualidade da recuperação pós-operatória, redução dos escores de dor, bem como redução do consumo de opioides em pacientes submetidos à cirurgia bariátrica. / Background: obesity is a chronic disease characterized by excessive accumulation of body fat. Due to the associated risks, it has been considered a major public health problem in developed countries. Bariatric surgery (open gastroplasty) has been used as an important strategy to treat this condition in developing countries, especially when associated with other comorbidities. The quality of recovery, however, has been a frequent concern in the postoperative management of these patients. Pregabalin is a structural analogue of the gamma-aminobutyric acid neurotransmitter (GABA) that binds to the alpha-2-subunit of the voltage-dependent calcium channel, blocking the development of hyperalgesia and central pain sensitization. Objective: the main objective of the current investigation was to evaluate the effect of perioperative pregabalin versus placebo on postoperative quality of recovery in patients undergoing bariatric surgery. Methods: the study was a prospective, randomized, placebo-controlled, double-blinded trial. After ethics committee approval, seventy patients undergoing abdominal gastroplasty were randomized to receive pregabalin, group 1 (75 mg orally 1 hour before surgery) or an identical placebo pill, group 2. The primary outcome was the quality of recovery-40 score at 24 hours. Secondary outcomes included opioid consumption and postoperative pain scores. A P value <0.05 was used to reject type I error. Results: seventy patients were randomized and 60 subjects completed the study. The median in global recovery scores (quality of recovery-40) at 24 hours after surgery in pregabalin group was 185 (176-191) x 184 (174-192) in placebo group (P = 0.95). Total opioid consumption in the 24 hours did not present a statistically significant difference between the groups. In addition, nausea, vomiting, and time to post-anesthesia care unit discharge were not significantly reduced in the pregabalin group compared with placebo. Conclusions: preoperative use of pregabalin showed no improve in quality of postoperative recovery, no better pain relief as well as reduction of opioid consumption in patients submitted to bariatric surgery.