Chapters Ten through Thirteen Summary and Analysis

From medieval times there have been theories about contractions of arteries and their relationships to migraines, hence the "blood-letting" of those ancient times. At least one researcher equates the migraine with a release, similar to that of a sneeze, as a reaction to a specific situation. There are several theories as to the causes of migraines and Sacks notes that these occasionally become accepted as fact. These theories include that the intensity of the pain is directly proportional to the "dilation of extracranial arteries" and that the intensity could be reduced by "manual compression." Another is that there is a chemical explanation though Sacks discounts the possibility that histamines are a part of the equation. The possibility of an electrical correlation is also discounted by Sacks, largely due to studies that fail to produce indications...