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AIM: We present an electronic tool for collecting data on the patterns of migraine headache onset and progression. METHODS: A digitized map consisting of 44 color-coded segments was defined based on previous reports of migraine pain and the distribution of nerves in the face, head and neck. The map was overlaid on a schematic map of the face, head and neck nerves. Thirty-six patients (N = 36, 28 female/eight male), who met ICDH-II criteria for episodic migraine and had headaches for at least three years, identified all regions where pain typically started and how pain spread and subsequently progressed. RESULTS: Consistent with previous findings, throbbing was the most prevalent quality of migraine pain, always present in 70% of patients surveyed. For the 70% of the patients with throbbing pain, the temple was the onset site of throbbing pain, with no significant difference in the laterality of onset site (58.3% on the right vs. 55.6% on the left hemisphere). The tool was able to capture patterns of pain distribution for throbbing and pressure headache pain and also may be used to assess the change in the pattern of the pain distribution as the disease progresses. DISCUSSION: The pain map survey may be a useful tool for recording and tracking the temporal pattern of migraine onset both for clinical and research purposes. The tool could be used to create maps of pain locations on a large population scale and thus will be a very useful tool in correlating the temporal nature of headache symptoms with potential mechanisms of disease evolution.
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Anatomía Artística , Internet , Registros Médicos , Trastornos Migrañosos/diagnóstico , Dimensión del Dolor/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Chronic pelvic pain (CPP) is a significant public health problem with 1 million affected women in the UK. Although many pathologies are associated with CPP, the pain experienced is often disproportionate to the extent of disease identified and frequently no pathology is found (chronic pelvic pain syndrome). The central nervous system (CNS) is central to the experience of pain and chronic pain conditions in general are associated with alterations in both the structure and function of the CNS. This review describes the available evidence for central changes in association with conditions presenting with CPP. METHODS: A detailed literature search was performed to identify relevant papers, however, this is not a systematic review. RESULTS: CPP is associated with central changes similar to those identified in other pain conditions. Specifically these include, alterations in the behavioural and central response to noxious stimulation, changes in brain structure (both increases and decreases in the volume of specific brain regions), altered activity of both the hypothalamic-pituitary-adrenal axis and the autonomic nervous system (ANS) and psychological distress. CONCLUSIONS: The evidence reviewed in this paper demonstrates that CPP is associated with significant central changes when compared with healthy pain-free women. Moreover, the presence of these changes has the potential to both exacerbate symptoms and to predispose these women to the development of additional chronic conditions. These findings support the use of adjunctive medication targeting the CNS in these women.
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Dolor Crónico/etiología , Endometriosis/complicaciones , Dolor Pélvico/etiología , Encéfalo/patología , Encéfalo/fisiopatología , Dolor Crónico/patología , Dolor Crónico/fisiopatología , Dolor Crónico/psicología , Endometriosis/fisiopatología , Femenino , Humanos , Sistema Hipotálamo-Hipofisario/fisiopatología , Dolor Pélvico/patología , Dolor Pélvico/fisiopatología , Dolor Pélvico/psicología , Sistema Hipófiso-Suprarrenal/fisiopatología , Estrés Psicológico/etiologíaRESUMEN
BACKGROUND: Pain remains the cardinal symptom of endometriosis. However, to date, the underlying mechanisms are still only poorly understood. Increasing evidence points towards a close interaction between peripheral nerves, the peritoneal environment and the central nervous system in pain generation and processing. Recently, studies demonstrating nerve fibres and neurotrophic and angiogenic factors in endometriotic lesions and their vicinity have led to increased interest in peripheral changes in endometriosis-associated pain. This review focuses on the origin and function of these nerves and factors as well as possible peripheral mechanisms that may contribute to the generation and modulation of pain in women with endometriosis. METHODS: We conducted a systematic search using several databases (PubMed, MEDLINE, EMBASE and CINAHL) of publications from January 1977 to October 2013 to evaluate the possible roles of the peripheral nervous system in endometriosis pathophysiology and how it can contribute to endometriosis-associated pain. RESULTS: Endometriotic lesions and peritoneal fluid from women with endometriosis had pronounced neuroangiogenic properties with increased expression of new nerve fibres, a shift in the distribution of sensory and autonomic fibres in some locations, and up-regulation of several neurotrophins. In women suffering from deep infiltrating endometriosis and bowel endometriosis, in which the anatomical distribution of lesions is generally more closely related to pelvic pain symptoms, endometriotic lesions and surrounding tissues present higher nerve fibre densities compared with peritoneal lesions and endometriomas. More data are needed to fully confirm a direct correlation between fibre density in these locations and the amount of perceived pain. A better correlation between the presence of nerve fibres and pain symptoms seems to exist for eutopic endometrium. However, this appears not to be exclusive to endometriosis. No correlation between elevated neurotrophin levels and pain severity appears to exist, suggesting the involvement of other mediators in the modulation of pain. CONCLUSIONS: The increased expression of neurotrophic factors and nerve fibres in endometriotic lesions, eutopic endometrium and the peritoneum imply a role of such peripheral changes in the pathogenesis of endometriosis-associated pain. However, a clear link between these findings and pain in patients with endometriosis has so far not been demonstrated.
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Endometriosis/complicaciones , Dolor/etiología , Líquido Ascítico/fisiología , Endometriosis/patología , Endometriosis/fisiopatología , Endometrio/irrigación sanguínea , Endometrio/inervación , Femenino , Humanos , Neovascularización Patológica/complicaciones , Neovascularización Patológica/patología , Neovascularización Patológica/fisiopatología , Fibras Nerviosas/patología , Neurogénesis/fisiología , Dolor/patología , Dolor/fisiopatologíaRESUMEN
The majority of functional MRI studies of pain processing in the brain use the blood oxygenation level-dependent (BOLD) imaging approach. However, the BOLD signal is complex as it depends on simultaneous changes in blood flow, vascular volume and oxygen metabolism. Arterial spin labeling (ASL) perfusion imaging is another imaging approach in which the magnetically labeled arterial water is used as an endogenous tracer that allows for direct measurement of cerebral blood flow. In this study, we assessed the pain response in the brain using a pulsed-continuous arterial spin labeling (pCASL) approach and a thermal stimulation paradigm. Using pCASL, response to noxious stimulation was detected in somatosensory cortex, anterior cingulate cortex, anterior insula, hippocampus, amygdala, thalamus and precuneus, consistent with the pain response activation patterns detected using the BOLD imaging approach. We suggest that pCASL is a reliable alternative for functional MRI pain studies in conditions in which blood flow, volume or oxygen extraction are altered or compromised.
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Encéfalo/fisiopatología , Circulación Cerebrovascular , Imagen por Resonancia Magnética/métodos , Dolor/fisiopatología , Marcadores de Spin , Adulto , Arterias/fisiopatología , Femenino , Humanos , Masculino , Oxígeno/sangreRESUMEN
The hippocampus is classically involved in memory consolidation, spatial navigation and is involved in the stress response. Migraine is an episodic disorder characterized by intermittent attacks with a number of physiological and emotional stressors associated with or provoking each attack. Given that migraine attacks can be viewed as repeated stressors, alterations in hippocampal function and structure may play an important role in migraine pathophysiology. Using high-resolution magnetic resonance imaging, hippocampal morphometric and functional differences (in response to noxious heat stimulation) were compared in age and gender-matched acute episodic migraineurs with high (HF) versus low (LF) frequency of migraine attacks. Morphometric results were compared with age and gender-matched healthy control (HC) cohort. Significant larger bilateral hippocampal volume was found in LF group relative to the HF and HC groups suggestive of an initial adaptive plasticity that may then become dysfunctional with increased frequency. Functional correlates of greater deactivation (LF > HF) in the same hippocampal regions in response to noxious stimulation was also accompanied by overall reduction in functional connectivity of the hippocampus with other brain regions involved in pain processing in the HF group. The results implicate involvement of hippocampus in the pathophysiology of the migraine.
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Hipocampo/patología , Trastornos Migrañosos/patología , Trastornos Migrañosos/fisiopatología , Plasticidad Neuronal/fisiología , Umbral del Dolor/fisiología , Adulto , Factores de Edad , Pesos y Medidas Corporales , Estudios de Cohortes , Imagen Eco-Planar , Femenino , Calor , Humanos , Masculino , Persona de Mediana Edad , Estimulación FísicaRESUMEN
Migraine is twice as common in females as in males, but the mechanisms behind this difference are still poorly understood. We used high-field magnetic resonance imaging in male and female age-matched interictal (migraine free) migraineurs and matched healthy controls to determine alterations in brain structure. Female migraineurs had thicker posterior insula and precuneus cortices compared with male migraineurs and healthy controls of both sexes. Furthermore, evaluation of functional responses to heat within the migraine groups indicated concurrent functional differences in male and female migraineurs and a sex-specific pattern of functional connectivity of these two regions with the rest of the brain. The results support the notion of a 'sex phenotype' in migraine and indicate that brains are differentially affected by migraine in females compared with males. Furthermore, the results also support the notion that sex differences involve both brain structure as well as functional circuits, in that emotional circuitry compared with sensory processing appears involved to a greater degree in female than male migraineurs.
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Corteza Cerebral/patología , Imagen por Resonancia Magnética , Trastornos Migrañosos/diagnóstico , Dimensión del Dolor , Caracteres Sexuales , Adulto , Encéfalo/patología , Encéfalo/fisiología , Corteza Cerebral/fisiología , Estudios de Cohortes , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/fisiopatología , Dimensión del Dolor/métodosRESUMEN
AIM: Various animal and human studies have contributed to the idea of cortical structural-functional alterations in migraine. Defining concurrent cortical alterations may provide specific insights into the unfolding adaptive or maladaptive changes taking place in cortex in migraine. METHODS: From a group of 60 episodic migraineurs, 20 were recruited to the study. Using high-resolution magnetic resonance imaging, structural and functional cortical measures were compared in migraineurs who experienced increased frequency of attacks (HF; 8-14 days/month; n = 10), to those who experienced less frequent migraine attacks (LF; < 2 days/month; n = 10), and to healthy controls (HC; n = 20). RESULTS: Parallel structural and functional differences were found as follows: (i) HF patients showed higher thickness in the area representing the face in the post-central gyrus, which correlated with the observed stronger functional activation, suggesting adaptation to repeated sensory drive; (ii) smaller cortical volume was observed in the cingulate cortex that correlated with lower activation in the HF group; and (iii) similarly significant structural and functional differences (HF > LF) were observed in the insula that may reflect potential alteration in affective processing. CONCLUSION: These results suggest differential response patterns in the sensory vs. affective processing regions in the brain that may be an adaptive response to repeated migraine attacks.
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Corteza Cerebral/patología , Corteza Cerebral/fisiología , Trastornos Migrañosos/patología , Trastornos Migrañosos/fisiopatología , Adaptación Fisiológica/fisiología , Adulto , Estudios de Cohortes , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodosRESUMEN
BACKGROUND: With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month). The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human) brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF) to a matched (gender, age, age of onset and type of medication) group of patients whose migraine episodes progressed (HF). RESULTS: In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain. CONCLUSIONS: Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine.