Pial Circulation and Spreading Depression of Activity in the Cerebral Cortex

Leo, Aristides A. P.

doi:10.1152/jn.1944.7.6.391

Cited by 291 publications

(134 citation statements)

References 9 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…This decreased CBF has been found in models of subarachnoid hemorrhage (Dreier et al, 1998) and focal ischemia (Shin et al, 2006;Strong et al, 2007), and new evidence exists that they may cause secondary ischemic damage in human brains after subarachnoid hemorrhage Iadecola, 2009). In the normally perfused brain, in contrast, CBF increases in response to CSD as already shown by Leao (1944b) in the second of his two memorable articles.…”

Section: Introductionmentioning

confidence: 70%

Distinct Spatiotemporal Patterns of Spreading Depolarizations during Early Infarct Evolution: Evidence from Real-Time Imaging

Kumagai

Walberer

Nakamura

et al. 2010

J Cereb Blood Flow Metab

View full text Add to dashboard Cite

Experimental and clinical studies indicate that waves of cortical spreading depolarization (CSD) appearing in the ischemic penumbra contribute to secondary lesion growth. We used an embolic stroke model that enabled us to investigate inverse coupling of blood flow by laser speckle imaging (CBF LSF ) to CSD as a contributing factor to lesion growth already in the early phase after arterial occlusion. Embolization by macrospheres injected into the left carotid artery of anesthetized rats reduced CBF LSF in the territories of the middle cerebral artery (MCA) (8/14 animals), the posterior cerebral artery (PCA) (2/14) or in less clearly defined regions (4/14). Analysis of MCA occlusions (MCAOs) revealed a first CSD wave starting off during ischemic decline at the emerging core region, propagating concentrically over large portions of left cortex. Subsequent recurrent waves of CSD did not propagate concentrically but preferentially circled around the ischemic core. In the vicinity of the core region, CSDs were coupled to waves of predominantly vasoconstrictive CBF LSF responses, resulting in further decline of CBF in the entire inner penumbra and in expansion of the ischemic core. We conclude that CSDs and corresponding CBF responses follow a defined spatiotemporal order, and contribute to early evolution of ischemic territories.

show abstract

Section: Introductionmentioning

confidence: 70%

Distinct Spatiotemporal Patterns of Spreading Depolarizations during Early Infarct Evolution: Evidence from Real-Time Imaging

Kumagai

Walberer

Nakamura

et al. 2010

J Cereb Blood Flow Metab

View full text Add to dashboard Cite

show abstract

“…This, together with regular detection of transient (a) negativity of the cortical surface DC potential and (b) increase in extracellular potassium ion concentration, also features of CSD, led to the designation of such events as PIDs (Hossmann, 1996) when observed in the ischaemic penumbra. A first-and critical-difference between CSD and PID events is that whereas CSD is accompanied by marked, but transient hyperaemia (Leão, 1944a;Lauritzen et al, 1982), perfusion (as measured by laser Doppler probe) may fall transiently in association with a PID (Back et al, 1994). Secondly, CSD is not associated with histologic evidence of cytotoxicity (Nedergaard and Hansen, 1988), whereas there is a clear, direct relationship of infarct size with number of PIDs during a period of ischaemia (Mies et al, 1993), and infarct size is the dependent variable (Takano et al, 1996;Busch et al, 1996;Back et al, 1996).…”

Section: Rationale For Use Of the Laser Speckle Methods In Stroke Modementioning

confidence: 99%

Evaluation of Laser Speckle Flowmetry for Imaging Cortical Perfusion in Experimental Stroke Studies: Quantitation of Perfusion and Detection of Peri-Infarct Depolarisations

Strong

Bezzina

Anderson

et al. 2005

J Cereb Blood Flow Metab

View full text Add to dashboard Cite

Laser speckle imaging of the exposed cerebral cortex allows detailed examination of the time course and topography of perfusion under different experimental conditions. Here we examine the quantitative capacity of the method and its sensitivity for the detection of peri-infarct depolarisations (PIDs). In four cats anaesthetised with chloralose, the right hemisphere was exposed and the right middle cerebral artery was occluded. The brain was illuminated with a laser diode, the speckle pattern was imaged, and images of inverse speckle correlation time (ICT) were derived from the calculated speckle contrast images. We examined the relationship of ICT with perfusion, as imaged quantitively using umbelliferone clearance (CBF umb ). Values of ICT and CBF umb were compared and regression parameters were calculated for each experiment. In eight cats, cortical surface direct current (DC) potential was monitored at two locations and detection of PIDs by DC potential and ICT change was compared. ICT-and CBF umb -derived values of perfusion were closely correlated, with a high degree of significance (P < 0.0001). Overall, monitoring of DC potential detected 90% of PIDs, whereas ICT detected 56%. We conclude that (1) laser speckle imaging provides an index of perfusion that has a linear relationship with the clearance rate of umbelliferone within the range of levels of perfusion examined; (2) this relationship is relatively stable between experiments; and (3) the method's ability to detect blood flow changes associated with PIDs likely depends on the noise level of the speckle measurements.

show abstract

“…This knowledge allowed to better understanding the pathophysiology of several acute brain disorders, offering references box. Leão's seminal papers on spreading depression 5,6,7,8 .…”

Section: Resultsmentioning

confidence: 99%

“…Here, the studies advanced in relation to Leão' s findings, by identifying the main electrophysiological occurrence, and its underpinnings, where SD continues as an important electrophysiological feature. Since Leão' s discovery, SD has been implicated by him, and soon by other authors, in migraine 6,8 . Although it has been known that ischemia could also trigger SD, as shown by Leão 7,8 , it was not until the 80' s that recurrent SD-like depolarization waves were demonstrated in focal brain ischemia, which occurred as peri-infarct depolarizations (injury depolarizations, spreading depolarization), at the edge between the ischemic core and the penumbra rim.…”

Section: The Discovery Of the "Spreading Depression"mentioning

confidence: 95%

“…Next year the study was published (1944), and soon the phenomenon was named after him ("Leão' s wave" or "Leao' s wave", or "spreading depression of Leão") 1,2,3,5 . In sequence he published another paper, in the same year, with focus on the vasodilatation accompanying SD 6 . Before leaving back to Brazil, he submitted, together with Robert S. Morison, the "Propagation of spreading cortical depression", published in 1945 7 .…”

Section: The Discovery Of the "Spreading Depression"mentioning

confidence: 99%

See 1 more Smart Citation

Aristides Leão: a birth centennial homage with comments on his spreading depression

Engelhardt

Gomes

2015

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

The year of 2014 is the birth centenary of Aristides Azevedo Pacheco Leão (1914-1993), and also marks seventy years of the publication of his discovery of the novel electrophysiological phenomenon, named by him “spreading depression” (SD), soon designated “Leão’s wave” or “Leão’s spreading depression”. This was a remarkable scientific milestone, and the author must be celebrated for this achievement, as the studies he triggered proceeded worldwide, with new concepts, as spreading depolarization, until the present days. Robust experimental and clinical evidence emerged to suggest that these and related electrophysiological phenomena are involved in the mechanisms of migraine aura, acute cerebrovascular diseases, traumatic brain injury, transient global amnesia, epileptic seizures, and their pathophysiological characteristics come to offer new therapeutic perspectives. He was a remarkable and complex personality, and the authors remit the readers to a paper where his personal life is contemplated.

show abstract

Pial Circulation and Spreading Depression of Activity in the Cerebral Cortex

Cited by 291 publications

References 9 publications

Distinct Spatiotemporal Patterns of Spreading Depolarizations during Early Infarct Evolution: Evidence from Real-Time Imaging

Distinct Spatiotemporal Patterns of Spreading Depolarizations during Early Infarct Evolution: Evidence from Real-Time Imaging

Evaluation of Laser Speckle Flowmetry for Imaging Cortical Perfusion in Experimental Stroke Studies: Quantitation of Perfusion and Detection of Peri-Infarct Depolarisations

Aristides Leão: a birth centennial homage with comments on his spreading depression

Contact Info

Product

Resources

About