Cortical spreading depression

The term Streudepolarisierung ( spreading depression ) or Cortical Streudepolarisierung ( cortical spreading depression ) refers to a regularly occurring neurological phenomenon, which is characterized by a slowly spreading depolarization of the cerebral cortex (cortex ).

This phenomenon, which, inter alia, using functional magnetic resonance imaging ( fMRI) or by a Elektrokortikogramms ( ECoG ) can be registered, is associated with the pathogenesis of migraine and stroke. The spreading depression usually begins spontaneously at one point, and proceeds with a characteristic velocity of 3 to 5 millimeters per minute. In the migraine she walks a few inches as a localized wave segment through areas of the cerebral cortex wrinkled. When you stroke the spreading depression starts in the vicinity of the infarct tissue and circulates this several times if necessary. Here it is restricted to one hemisphere generally. In the affected areas depolarize the cell membranes of neurons and glial cells, and the electrically measurable activity breaks practically completely.

The formation and the propagation of the spreading depression is coupled to a release of potassium ions in the extracellular space. A malfunction of ion channels for calcium, sodium and potassium as well as a malfunction of ionotropic glutamate receptors may be involved. Potassium ions lead to a depolarization, which spreads over an area of the cortex. A slow spread of depolarization through the center of vision is considered to be electrophysiological correlate migratory scintillating scotoma, which can be frequently observed during a migraine aura. A spreading depression was first described in 1944 by the Brazilian Aristides Leão. Despite more than 5 decades of active research in various animal models, the occurrence of spreading depression in the human brain for a long time has been controversial. Initial clinical trials with elektrokortikographischen derivations in the area of brain injury in neurosurgical patients could provide a positive detection.