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Abstract(s)
Introdução: A enxaqueca é um distúrbio neurovascular que ocorre em indivíduos geneticamente suscetíveis, podendo ser desencadeada por diversos fatores, como alimentos, privação/excesso de sono, stress, entre outros. Carateriza-se por episódios de cefaleias com outros sintomas associados. Para a sua génese foram propostos diversos mecanismos, entre eles a participação do sistema dopaminérgico, estando a dopamina relacionada com alguns dos sintomas experimentados durante uma crise de enxaqueca.
A prolactina (PRL), como alvo principal da dopamina, tem sido também implicada na produção da enxaqueca, apoiado pelo facto de diversos fatores que podem afetar a secreção de prolactina também poderem intervir na enxaqueca, como os tumores hipofisários (prolactinomas, etc), stress, a dor, entre outros.
Objetivos: Este trabalho teve o propósito de analisar a possível relação entre a enxaqueca e os níveis da prolactina.
Métodos: Para a elaboração desta revisão da literatura, efetuou-se uma pesquisa bibliográfica na base de dados Medline (www.pubmed.com).
Resultados: Da pesquisa realizada, seis artigos foram analisados e resumidos, onde foram estudadas populações migranosas através da medição dos seus níveis séricos de prolactina, encontrando-se: a) aumento dos níveis de PRL em resposta ao TRH durante o período de crise de enxaqueca, b) diminuição do pico noturno da prolactina, c) redução dos níveis de PRL durante o período de crise de enxaqueca d) existência de uma hiperprolactinemia em alguns indivíduos com enxaqueca, e) níveis de PRL elevados durante o período de crise de enxaqueca.
Discussão: O processo de cronicidade da enxaqueca permanece desconhecido, contudo vários mecanismos têm sido postulados, entre eles, uma disfunção hipotalâmica. O papel da PRL na enxaqueca, pode ser apoiado por diminuição da dopamina (DA) resultante de uma hiperfunção serotoninérgica, devido aos efeitos inibitórios da serotonina sobre a DA e por conseguinte um aumento dos níveis de PRL. Uma outra teoria apontada é a presença de uma hipersensibilidade do recetor pós-sináptico dopaminérgico, uma vez que este neurotransmissor se encontra relacionado com algumas das manifestações sentidas numa crise de enxaqueca. A cefaleia destes pacientes pode ainda ser secundária à hiperprolactinemia que estes apresentam, como resultado de uma provável predisposição. Conclusão: Mais estudos serão necessários, com maior controlo das variáveis e com um maior número de doentes estudados, para esclarecer a eventual relação entre a enxaqueca e a prolactinemia.
Introduction: The migraine is a neurovascular disorder that occurs in genetically susceptible individuals and may be triggered by several factors like food, undersleeping / oversleeping or stress. It features a number of episodes of headache associated with other symptoms. For its genesis were proposed several mechanisms, including the involvement of the dopaminergic system because of the dopamine relation with some of the symptoms experienced before and during a migraine attack. The prolactin, which is dopamine’s main target, has also been implicated in the production of migraine. This is supported by the fact that several factors which can affect prolactin secretion, can also have a role in migraine, such as pituitary tumors (prolactinomas, etc.), stress or pain. Objectives: This study aims to examine the scientific evidence of a possible relationship between migraine and prolactin levels. Methods: In the preparation of this literature review, a bibliographic search in Medline database was carried out (www.pubmed.com). Results: Six articles were analyzed and summarized containing studies to migrane populations by measuring their prolactin serum levels, resulting in: a) increased PRL levels in response to TRH during the migraine attack; b) reduction of the nocturnal prolactin peak; c) reduction of PRL levels during the migraine attack; d) the existence of a hyperprolactinemia in some migrainous individuals; e) higher PRL levels during the migraine attack. Discussion: The process of chronic migraine remains unknown, however several mechanisms have been postulated, including a hypothalamic dysfunction. The role of prolactin in migraine can be supported by a decrease of the DA resulting from serotonergic hyperactivity, due to serotonin's inhibitory effects on DA and therefore an increase of PRL levels. Another theory is the presence of a hypersensitivity of the dopaminergic postsynaptic receptor, since this neurotransmitter is associated with some of the manifestations experienced in a migraine attack. The headache in these patients can still be secondary to the hyperprolactinemia they present, as a result of a possible predisposition. Conclusion: Further studies are needed, with a superior control of the variables and a larger study population, to clarify whether there is a possible cause-effect relationship between migraine and prolactin serum levels.
Introduction: The migraine is a neurovascular disorder that occurs in genetically susceptible individuals and may be triggered by several factors like food, undersleeping / oversleeping or stress. It features a number of episodes of headache associated with other symptoms. For its genesis were proposed several mechanisms, including the involvement of the dopaminergic system because of the dopamine relation with some of the symptoms experienced before and during a migraine attack. The prolactin, which is dopamine’s main target, has also been implicated in the production of migraine. This is supported by the fact that several factors which can affect prolactin secretion, can also have a role in migraine, such as pituitary tumors (prolactinomas, etc.), stress or pain. Objectives: This study aims to examine the scientific evidence of a possible relationship between migraine and prolactin levels. Methods: In the preparation of this literature review, a bibliographic search in Medline database was carried out (www.pubmed.com). Results: Six articles were analyzed and summarized containing studies to migrane populations by measuring their prolactin serum levels, resulting in: a) increased PRL levels in response to TRH during the migraine attack; b) reduction of the nocturnal prolactin peak; c) reduction of PRL levels during the migraine attack; d) the existence of a hyperprolactinemia in some migrainous individuals; e) higher PRL levels during the migraine attack. Discussion: The process of chronic migraine remains unknown, however several mechanisms have been postulated, including a hypothalamic dysfunction. The role of prolactin in migraine can be supported by a decrease of the DA resulting from serotonergic hyperactivity, due to serotonin's inhibitory effects on DA and therefore an increase of PRL levels. Another theory is the presence of a hypersensitivity of the dopaminergic postsynaptic receptor, since this neurotransmitter is associated with some of the manifestations experienced in a migraine attack. The headache in these patients can still be secondary to the hyperprolactinemia they present, as a result of a possible predisposition. Conclusion: Further studies are needed, with a superior control of the variables and a larger study population, to clarify whether there is a possible cause-effect relationship between migraine and prolactin serum levels.
Description
Keywords
Enxaqueca - Diagnóstico Enxaqueca - Prolactina Enxaqueca - Dopamina Cefaleia
Citation
Publisher
Universidade da Beira Interior