@article {904,
	title = {Deep Phenotyping of Headache in Hospitalized COVID-19 Patients via Principal Component Analysis},
	journal = {Frontiers in Neurology},
	volume = {11},
	year = {2020},
	pages = {1751},
	abstract = {<p>Objectives: Headache is a common symptom in systemic infections, and one of the symptoms of the novel coronavirus disease 2019 (COVID-19). The objective of this study was to characterize the phenotype of COVID-19 headache via machine learning.Methods: We performed a cross-sectional study nested in a retrospective cohort. Hospitalized patients with COVID-19 confirmed diagnosis who described headache were included in the study. Generalized Linear Models and Principal Component Analysis were employed to detect associations between intensity and self-reported disability caused by headache, quality and topography of headache, migraine features, COVID-19 symptoms, and results from laboratory tests.Results: One hundred and six patients were included in the study, with a mean age of 56.6 {\textpm} 11.2, including 68 (64.2\%) females. Higher intensity and/or disability caused by headache were associated with female sex, fever, abnormal platelet count and leukocytosis, as well as migraine symptoms such as aggravation by physical activity, pulsating pain, and simultaneous photophobia and phonophobia. Pain in the frontal area (83.0\% of the sample), pulsating quality, higher intensity of pain, and presence of nausea were related to lymphopenia. Pressing pain and lack of aggravation by routine physical activity were linked to low C-reactive protein and procalcitonin levels.Conclusion: Intensity and disability caused by headache attributed to COVID-19 are associated with the disease state and symptoms. Two distinct headache phenotypes were observed in relation with COVID-19 status. One phenotype seems to associate migraine symptoms with hematologic and inflammatory biomarkers of severe COVID-19; while another phenotype would link tension-type headache symptoms to milder COVID-19.</p>
},
	issn = {1664-2295},
	doi = {10.3389/fneur.2020.583870},
	url = {https://www.frontiersin.org/article/10.3389/fneur.2020.583870},
	author = {{\'A}lvaro Planchuelo-G{\'o}mez and Trigo, Javier and Rodrigo de Luis-Garc{\'\i}a and {\'A}ngel L. Guerrero and Porta-Etessam, Jes{\'u}s and Garc{\'\i}a-Azor{\'\i}n, David}
}
@article {887,
	title = {Factors associated with the presence of headache in hospitalized COVID-19 patients and impact on prognosis: a retrospective cohort study},
	journal = {The Journal of Headache and Pain},
	volume = {21},
	year = {2020},
	month = {Jul},
	pages = {94},
	abstract = {Headache is one of the most frequent neurologic manifestations in COVID-19. We aimed to analyze which symptoms and laboratory abnormalities were associated with the presence of headache and to evaluate if patients with headache had a higher adjusted in-hospital risk of mortality.},
	issn = {1129-2377},
	doi = {10.1186/s10194-020-01165-8},
	url = {https://doi.org/10.1186/s10194-020-01165-8},
	author = {Trigo, Javier and Garc{\'\i}a-Azor{\'\i}n, David and {\'A}lvaro Planchuelo-G{\'o}mez and Mart{\'\i}nez-P{\'\i}as, Enrique and Talavera, Blanca and Hern{\'a}ndez-P{\'e}rez, Isabel and Valle-Pe{\~n}acoba, Gonzalo and Sim{\'o}n-Campo, Paula and de Lera, Mercedes and Chavarr{\'\i}a-Miranda, Alba and L{\'o}pez-Sanz, Cristina and Guti{\'e}rrez-S{\'a}nchez, Mar{\'\i}a and Mart{\'\i}nez-Velasco, Elena and Pedraza, Mar{\'\i}a and Sierra, {\'A}lvaro and G{\'o}mez-Vicente, Beatriz and Juan F Arenillas and {\'A}ngel L. Guerrero}
}
