Cortical Spreading Depression¶
A depolarizing front traverses cerebral cortex while spontaneous electrical activity is newly suppressed in its wake at successive sites.
Core Idea¶
Cortical spreading depression is a slowly traveling event in cerebral cortex: a depolarizing front reaches successive sites, and spontaneous electrical activity that was present at those sites is newly suppressed as it passes. The traveling slow-potential change and the spreading fall in ECoG activity are the paired evidence. A front passing through cortex already electrically silent is a related spreading depolarization, but it cannot newly depress absent activity.[ref-c2552cd7389a][ref-713fc6c50f9f]
Recovery, lesion growth, a particular trigger, and one universal ion transmitter are not requirements for the event. Literature may use “CSD” more broadly; this entry uses the narrower activity-depression test.[ref-c2552cd7389a][ref-242de9a75e40]
Scope of Application¶
The literal setting is cerebral cortex with a recordable spontaneous background. It can be studied after an experimental cortical stimulus or directly monitored during human brain injury. The trigger and tissue condition differ between those settings; neither alone defines CSD.[ref-713fc6c50f9f][ref-c2552cd7389a]
A mouse familial-hemiplegic-migraine experiment found differences in DC-potential induction threshold and propagation speed by genotype, but its described methods did not directly record ECoG suppression. Human visual-aura fMRI provides an indirect, suggestive comparator rather than a direct electrical recording of a full event.[ref-242de9a75e40][ref-9e3393ddd42c]
Clarity¶
“Depression” means reduced ongoing activity, not that the tissue has necessarily been injured. Check whether activity existed immediately before the front reached each site. Then check that the depolarization and the fall in activity reached separated sites in order. An essentially synchronous ECoG decrease does not meet the spreading test; a slow-potential front in already silent cortex does not meet the new-depression test.[ref-c2552cd7389a][ref-ca0152c940ab]
Manages Complexity¶
Separating front, activity suppression, and later outcome keeps unlike observations from being counted as one event type. In an injured-human series, matched traveling slow-potential and ECoG changes were followed in some patients by recurrent slow potentials after the background failed to recover. Those later fronts remain worth describing, but they are not new observed activity depressions under this narrower definition.[^ref-c2552cd7389a]
Experimental focal-ischemia work links recurrent spreading depolarizations to stepwise lesion enlargement in that setting. That outcome does not follow from the definition of every CSD event.[^ref-3abbb4f95acc]
Abstract Reasoning¶
Map the recording sites in order. At each site, mark slow-potential onset, whether spontaneous activity was present beforehand, and whether it fell with the front. Ordered paired changes support CSD; a single-channel trace, simultaneous decrease, or depolarization after persistent silence does not supply the same evidence.[ref-c2552cd7389a][ref-ca0152c940ab]
Knowledge Transfer¶
The same classification question applies to a mouse cortical trace and a spontaneous injured-human recording, without importing a trigger, recovery course, or clinical prognosis from one to the other. The broader Prime Propagation describes their local source and travel through a medium. CSD adds the specific cortical depolarization and newly suppressed activity. A descriptive “wave” label by itself does not establish the fuller properties of the separate Wave Prime.[ref-713fc6c50f9f][ref-c2552cd7389a]
Examples¶
- Mouse, direct paired example: In Carlson and colleagues' simulated-neurosurgical experiment, the indexed Figure 2a caption describes a specific anterior-cautery event in which both a negative DC shift and ECoG suppression reached Channel 1 and then Channel 2. Ten of sixteen DC shifts had ECoG suppression in aggregate; the paper does not individually establish that all ten had this same ordered paired trace. A lateral example had near-simultaneous channel arrival because of electrode geometry, which is not proof of nonpropagating physiology.[^ref-713fc6c50f9f]
- Human, spontaneous direct observation: Fabricius and colleagues' original abstract reports 73 episodes in six of twelve acutely injured patients, with slow-potential changes accompanying spreading ECoG depression. Background activity recovered spontaneously in four of those six; later fronts in two occurred without its recovery. These counts and distinctions come from the original abstract, not independently inspected full traces.[^ref-c2552cd7389a]
- Human aura, indirect: An occipital BOLD progression during visual aura strongly suggested CSD-like activity in a small original study, but fMRI did not directly record the paired electrical signals required here.[^ref-9e3393ddd42c]
Relationships to Other Abstractions¶
Current abstraction Cortical Spreading Depression Domain-specific
Parents (1) — more general patterns this builds on
-
Cortical Spreading Depression is a kind of Propagation Prime
A cortical depolarization and activity-depression state spreads systematically from local onset through excitable tissue at a measurable, condition-dependent rate.
Hierarchy path (1) — routes to 1 parentless root
- Cortical Spreading Depression → Propagation
Neighborhood in Abstraction Space¶
Cortical Spreading Depression sits in a sparse region of the domain-specific corpus (97th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.
Family — Unclustered & Miscellaneous (2551 abstractions)
Nearest neighbors
- Hyperpolarization (biology) — 0.78
- Place Field — 0.76
- Flux Limiter — 0.76
- Spike-Timing-Dependent Plasticity — 0.76
- Retinotopy — 0.76
Computed from structural-signature embeddings · 2026-10-08
Not to Be Confused With¶
- Spreading depolarization alone: a later front can pass through electrically silent cortex without a newly observed depression.[^ref-c2552cd7389a]
- Synchronous depression: activity falls without a demonstrated traveling front.[^ref-ca0152c940ab]
- Electrocorticography: the recording method that helps reveal activity loss, not the physiological event.
- Inevitable injury: lesion extension is a bounded experimental consequence, not a defining feature.[^ref-3abbb4f95acc]
References¶
[^ref-c2552cd7389a]: Fabricius M, Fuhr S, Bhatia R, et al., Cortical spreading depression and peri-infarct depolarization in acutely injured human cerebral cortex, Brain 129 (2006), 778–790, doi:10.1093/brain/awh716. Original paper abstract, Methods/Results/Conclusions; full text and electrode figures were not independently inspected. Supports the observed human spreading ECoG/slow-potential relation, episode count, speed, and variable recovery within the sampled patients.
[^ref-713fc6c50f9f]: Carlson AP, Carter RE, Shuttleworth CW, Vascular, electrophysiological, and metabolic consequences of cortical spreading depression in a mouse model of simulated neurosurgical conditions, Neurological Research 34 (2012), 223–231, doi:10.1179/1743132811Y.0000000077. Original abstract Results and indexed author-manuscript Results/Figure 2a–b caption; direct PMC page open was blocked. Supports the aggregate 10/16 ECoG-suppression observation and the individually described sequential paired Figure 2a event, not ten individually verified sequential paired traces or human-surgery incidence.
[^ref-ca0152c940ab]: Strong AJ, Fabricius M, Boutelle MG, et al., Spreading and synchronous depressions of cortical activity in acutely injured human brain, Stroke 33 (2002), 2738–2743, doi:10.1161/01.STR.0000043073.69602.09. Original abstract Methods/Results; full text was not independently inspected. Supports the spreading-versus-synchronous activity-depression contrast.
[^ref-242de9a75e40]: Leo L, Gherardini L, Barone V, et al., Increased Susceptibility to Cortical Spreading Depression in the Mouse Model of Familial Hemiplegic Migraine Type 2, PLOS Genetics 7 (2011), e1002129, Fig. 4 and CSD Methods/Discussion. Full original article. Supports electrically evoked DC-potential propagation and genotype threshold/speed effects; astrocytic glutamate clearance is a hypothesis. The described methods do not directly record ECoG suppression.
[^ref-9e3393ddd42c]: Hadjikhani, N., Sanchez del Rio, M., Wu, O., et al., Mechanisms of Migraine Aura Revealed by Functional MRI in Human Visual Cortex, PNAS 98 (2001), 4687–4692, Abstract and Results/Figs. 1–3. Full original article. Supports an occipital BOLD progression during visual aura and a qualified CSD-like interpretation, not direct electrophysiological proof.
[^ref-3abbb4f95acc]: Nakamura H, Strong AJ, Dohmen C, et al., Spreading depolarizations cycle around and enlarge focal ischaemic brain lesions, Brain 133 (2010), 1994–2006, Abstract and experimental Results. Full original article. Supports lesion-cycling and stepwise growth in its experimental focal-ischemia context, not inevitable injury in every CSD event.