title: Spreading depolarizations cycle around and enlarge focal ischaemic brain lesions.
abstract: How does infarction in victims of stroke and other types of acute brain injury expand to its definitive size in subsequent days? Spontaneous depolarizations that repeatedly spread across the cerebral cortex, sometimes at remarkably regular intervals, occur in patients with all types of injury. Here, we show experimentally with in vivo real-time imaging that similar, spontaneous depolarizations cycle repeatedly around ischaemic lesions in the cerebral cortex, and enlarge the lesion in step with each cycle. This behaviour results in regular periodicity of depolarization when monitored at a single point in the lesion periphery. We present evidence from clinical monitoring to suggest that depolarizations may cycle in the ischaemic human brain, perhaps explaining progressive growth of infarction. Despite their apparent detrimental role in infarct growth, we argue that cycling of depolarizations around lesions might also initiate upregulation of the neurobiological responses involved in repair and remodelling.
authors.affiliation: Max Planck Institute for Neurological Research, Gleueler Str. 50, 50931 Cologne, Germany.
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakamura
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Strong
authors.forename: Christian
authors.initials: C
authors.lastname: Dohmen
authors.forename: Oliver W
authors.initials: OW
authors.lastname: Sakowitz
authors.forename: Stefan
authors.initials: S
authors.lastname: Vollmar
authors.forename: Michael
authors.initials: M
authors.lastname: Sué
authors.forename: Lutz
authors.initials: L
authors.lastname: Kracht
authors.forename: Parastoo
authors.initials: P
authors.lastname: Hashemi
authors.forename: Robin
authors.initials: R
authors.lastname: Bhatia
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yoshimine
authors.forename: Jens P
authors.initials: JP
authors.lastname: Dreier
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Dunn
authors.forename: Rudolf
authors.initials: R
authors.lastname: Graf
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000473:pathology* / Q000503:physiopathology*; D002415:Cats; D002560:Cerebrovascular Circulation / Q000502:physiology; D013181:Cortical Spreading Depression / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010507:Periodicity; D051381:Rats; D017208:Rats, Wistar