Cortical spreading depression

Animation of cortical spreading depression

Cortical spreading depression is a wave of electrophysiological hyperactivity followed by a wave of inhibition, usually in the visual cortex.^[1]

The term is used by neuroscientists to represent at least one of the following cortical processes:

• The spreading of a self-propagating wave of cellular depolarization in the cerebral cortex.
• The spreading of a wave of ischemia passing through an area of cortex.
• The spreading of a wave of vasoconstriction following vasodilation of contiguous cortical arterioles.^[2]

The scintillating scotoma of migraine in humans may be related to the neurophysiologic phenomenon termed the spreading depression of Leão.^[3]

The spreading depression wave progresses across the cortex at approximately 2 - 5 mm/minute.^[4]

Increased extracellular potassium ion concentration and excitatory glutamate contribute to the initiation and propagation of cortical spreading depression, which is the underlying cause of migraine aura.^[5]

See also

• Transient ischemic attack
• Scintillating scotoma
• Migraine

Notes

1. ^ Dodick DW & Gargus JJ (August 2008). "Why migraines strike". Scientific American.
2. ^ Brennan KC et al (2007) "Distinct vascular conduction with cortical spreading depression." J Neurophysiol. 97, 4143-4151.
3. ^ Leão AAP (1944). "Spreading depression of activity in the cerebral cortex". J Neurophysiol 7, 359-390.
4. ^ Porooshani H, Porooshani GH, Gannon L, & Kyle GM (2004). "Speed of progression of migrainous visual aura measured by sequential field assessment". Neuro-Ophthalmology 28(2), 101-105.
5. ^ Richter and Lehmenkühler (2008)

References

• "Cortical spreading depression causes and coincides with tissue hypoxia", Nat Neurosci. 29 April 2007, Takano T, Tian GF, Peng W, Lou N, Lovatt D, Hansen AJ, Kasischke KA, Nedergaard M., Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York.
• "A delayed class of BOLD waveforms associated with spreading depression in the feline cerebral cortex can be detected and characterised using independent component analysis (ICA)", Magn Reson Imaging. 21 November 2003, Netsiri C, Bradley DP, Takeda T, Smith MI, Papadakis N, Hall LD, Parsons AA, James MF, Huang CL., Physiological Laboratory, University of Cambridge, Cambridge, UK.
• "Cortical spreading depression (CSD): A neurophysiological correlate of migraine aura", Schmerz, May 17, 2008, Richter F, Lehmenkühler A.

Further reading

• MeSH Spreading+Cortical+Depression
• Dodick, David W.; J. Jay Gargus (August 2008). "Why Migraines Strike". Scientific American (Scientific American Inc.): pp. 56–63. ISSN 0036 8733. http://www.sciam.com/article.cfm?id=why-migraines-strike. Retrieved 2008-08-16.