Christina Sjöstrand´s research group
Stroke is a disease with large consequences for disability and mortality in the whole world. Stroke is a common description that includes both stroke caused by a thrombus (clot), ischemic stroke, which accounts for approximately 85% of all stroke and intracerebral bleeding which accounts for about 15%. Today we have successful treatments in the emergency phase; thrombolysis and thrombectomy.
There are several well-known risk factors, such as cardio-embolic causes such as atrial fibrillation, as well as elevated blood lipids and high blood pressure, but there are still unknown underlying factors as well as unknown internal relationships between risk factors.
Cryptogenic stroke is a subset of ischemic stroke where various etiological factors have been ruled out and this group represents almost 25% of all ischemic stroke. PFO (patent foramen ovale) is a connection between the atria in the heart that is present in 20-25% of the population, ie a normal variant. About 50% of patients with cryptogenic stroke have a PFO.
Migraine, a so-called neurovascular headache, might in rare cases lead to a stroke, and migraineurs have for unknown reason more cardiovascular risk factors than others and there is a certain risk of stroke if you have migraines. There is also an unclear connection between PFO and migraines; About 50% of patients with migraine with aura also have a PFO, but it is unknown why it is more prevalent in migraine patients.
Migraine, stroke and PFO
We perform studies on the relationship between migraine and stroke, as well as the relationships between migraine, stroke and PFO. We have participated in a large multinational sponsored clinical trial regarding cryptogenic stroke and PFO and in parallel we have organized a multiprofessional team with cardiologists for the care of this patient group. We perform our own studies on this patient group focusing on vascular function, migraine incidence and outcomes after device closure of PFO. A comprehensive longitudinal study on migraine and stroke in the Swedish twin register has been performed and we observed a small risk increase for stroke in migraine, but not as great as previously described.
HISS - Hemorrhagic and Ischemic Stroke Study
We have a retrospective stroke database on stroke and TIA patients who have been treated and cared for at the stroke unit at Karolinska Huddinge during the years 2006-2016, a total of approximately 8000 patients. We conduct observation studies focusing on risk factors, cardiac embolism, treatment and PFO and more.
Cluster headache, also a neurovascular headache, is one of the most severe pain syndromes described. In addition to our focus on stroke and migraine, we also have an interest in cluster headache. In terms of cluster headache and genetics, we participate in a collaboration led by Associate Professor Andrea Carmine Belin, Dept of Neuroscience, KI. We also investigate the sickness pattern in cluster headache patients and collaborate with Professor Kristina Alexanderson at the Department of Insurance Medicine, Dept of Clinical Neuroscience, KI.
We are all clinically active in healthcare. We are involved in the development of healthcare in various ways and we participate in several research collaborations in the field of prehospital triage of stroke patients, the importance of health care and the physical environment in stroke, and more.
Sickness absence and disability pension days in patients with cluster headache and matched references.
Sjöstrand C, Alexanderson K, Josefsson P, Steinberg A
Neurology 2020 May;94(21):e2213-e2221
Cluster headache: Prevalence, sickness absence, and disability pension in working ages in Sweden.
Steinberg A, Josefsson P, Alexanderson K, Sjöstrand C
Neurology 2019 07;93(4):e404-e413
Migraine and risk of stroke: a national population-based twin study.
Lantz M, Sieurin J, Sjölander A, Waldenlind E, Sjöstrand C, Wirdefeldt K
Brain 2017 Oct;140(10):2653-2662
Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke.
Søndergaard L, Kasner SE, Rhodes JF, Andersen G, Iversen HK, Nielsen-Kudsk JE, et al
N. Engl. J. Med. 2017 09;377(11):1033-1042
Elevated plasma homocysteine upon ischemic stroke is associated with increased long-term mortality in women.
Markaki I, Klironomos S, Kostulas K, Sjostrand C
PLoS ONE 2017 ;12(8):e0183571
Impaired endothelial function in patients with cryptogenic stroke and patent foramen ovale is not affected by closure.
Lantz M, Kostulas K, Settergren M, Sjöstrand C
J Interv Cardiol 2017 Jun;30(3):242-248