Book T of C
Chap T of C
Perhaps the most famous brain injury in history was a penetrating wound suffered by a railroad worker named Phineas Gage . Gage was setting up a black powder charge when the explosion went off prematurely, sending an iron bar a meter long and three centimeters thick shooting through Gage's skull. The iron bar left a clean exit wound and landed on the ground several meters away.
What is the story of Phineas Gage?
Gage was stunned but quickly regained full consciousness and was able to walk and talk. Although the iron bar penetrated his brain, Gage survived the accident. However, his personality was changed. "Gage was no longer Gage" as one observer put it. Previously he was an easy-going, friendly type of person. After the injury he grew irritable and suspicious and was unable to keep a steady job. He died twelve years later, and his skull remains on display at the Warren Museum of Harvard Medical School.
What area of Gage's brain was affected by the wound?
The research team of Damasio, Grabowski, Frank, Galaburda, & Damasio (1994) used imaging techniques to reconstruct the exact path of the iron bar. They were able to create a three-dimensional model of Gage's skull that showed that the iron bar went through prefrontal areas of the brain. The Damasio research team reported, "Gage fits a neuroanatomical pattern that we have identified to date in 12 patients," all of whom suffered similar psychological effects. "Their ability to make rational decisions in personal and social matters is invariably compromised and so is their processing of emotion" (Damasio, Grabowski, Frank, Galaburda, & Damasio, 1994).
The Gage case impressed doctors with the relationship between brain and personality...but it also suggested that the brain was an incredibly resilient organ that could suffer a massive injury and keep functioning. Gage was lucky; the iron bar missed the major arteries supplying blood to the brain. With the blood supply preserved, the brain was able to continue operating.
The case of Phineas Gage has become so well known that a web site is devoted to it. Malcolm Macmillan of Deakin University in Victoria, Australia maintains the "Phineas Gage Information Page". The URL is: http://www.deakin.edu.au/hbs/gagepage/. Interesting illustrations and links to articles and books about Gage are provided.
What are different ways the brain can be damaged?
Penetrating wounds are only one of the types of brain injury that provide information to neuropsychologists. Strokes, known to doctors as cerebrovascular accidents or CVAs, are also a common cause of brain injury. They can be caused by fatty deposits in the brain's arteries (atherosclerosis), by thickening and hardening of the artery walls (arteriosclerosis), by clots forming in a narrowed artery (thrombosis), or by a clot formed somewhere else in the body and carried to the brain in the bloodstream (embolism). Sometimes blood is cut off from portions of the brain when an artery wall balloons out (aneurysm) or bursts (hemorrhage).
What are TIAs?
Four out of five stroke victims suffer "temporary strokes" called transient ischemic attacks (TIAs) caused by a brief interruption in the blood supply. Symptoms include weakness or numbness of an arm, hand, leg, or facial muscle, difficulty speaking, blurry vision in one eye, deafness, loss of balance, sudden unexplained headache or abrupt personality change. A TIA usually lasts only a few minutes (almost always less than an hour) and the effects wear off quickly, so people tend to ignore them. However, it is important not to brush off the symptoms because about a third of TIA victims have a stroke within five years unless treated.
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