Cortical spreading depression refers to a neurological phenomenon that is characterized by a wave-like decrease in brain activity that sweeps across the cortex. This is often linked to migraines and other neurological disorders. Some synonyms for cortical spreading depression include CSD, spreading depression, and Leão's phenomenon. Other terms that might be used to refer to this phenomenon include cortical depression, cortical wave, and cortical depolarization. Despite their differences, all these terms refer to an area of reduced cortical activity that spreads across the brain in a wave-like pattern. Understanding these synonyms can help medical professionals better communicate about this phenomenon and improve their ability to diagnose and treat related conditions.