Her Mind Was Normal, Though She Had Almost No Brain

 Neuroscientists are members of a belief community dedicated to preserving the dogma that the brain is the source of the human mind. So when neuroscientists discover case histories that seem to defy such a dogma, neuroscientists tend to write up the results with papers having a title not likely to be noticed. An example of this was when neuroscientists discovered that a French civil servant had almost no brain. The case was written up in the British medical journal The Lancet with a paper having the title "Brain of a White Collar Worker," as if the authors were trying to get as few readers as possible by creating the dullest-sounding title they could create.  The paper had the visual below:

The 2007 paper told us that the subject had an overall IQ of 75 and a verbal IQ of 84, and that he was a father employed as a civil servant (a government worker). Such occupational success with so little brain defies claims that the brain is the source of the human mind. 

But occasionally there will be an neuroscience paper by authors brave enough to give a paper a title that correctly describes some case history clashing with the "brains make minds" dogma. One such paper is the paper "Asymptomatic Hydrocephalus" by neurosurgeons Amit R. Persad, Victoria Bass and Kotoo Meguro, a paper you can read here. They report the case of a 72-year-old woman with a very severe case of hydrocephalus, a brain-robbing disease in which brain tissue is replaced by a watery fluid. Brain scans of the woman showed that she little brain tissue. But (as the title tells us) the woman was "asymptomatic," meaning she had no symptoms. Her mind was normal, even though almost all of her brain had been lost. 

Below  is Figure 1 from the paper. We see the "almost gone" brain of a woman who scored "normal" on a standard cognitive test (the MMSE). Photos B and C are closeups of particular brain portions. Photos A, D and E show the full brain from different angles. The black part are cavities filled with watery fluid, where the brain was hollowed out. 

The woman came to the doctor not because of any mental difficulties she was having, but because she had a seizure.  The paper describes the woman's normal mental capabilities and cognition:

"The patient lived independently and had no previous history of seizures or diagnosis of hydrocephalus. Her developmental history was unremarkable; she had finished high school and had worked in various retail jobs. When our team examined her, she was alert and oriented, and did not report headache, visual disturbance or cognitive changes; her neurologic examination (including a Mini-Mental State Examination) was normal. The only pertinent physical finding was a long-standing gait disturbance related to hip dysplasia. An electroencephalogram showed epileptiform discharges, and we prescribed levetiracetam (500 mg administered orally twice daily) and stopped treatment with phenytoin. The patient also had an urinary tract infection (UTI), which was treated with trimethoprim/sulfamethoxazole. After 2 days in hospital, she was discharged with follow-up in the adult hydrocephalus clinic. She was well at 6-month follow-up, with no further seizures." 

The Mini-Mental State Examination referred to above is the most common test of cognitive performance used by doctors. The link here gives you some of the questions used on the test. An example question is that you are asked to count backwards from 100, going back 7 in each steps (for example, 93, 86, 79,  72, and 65). Another example question is that you are asked to identify where you are, giving the state, county, town, building name and floor number or room number (with each item correctly named scoring 1 point). Or you might also be asked to name the day of week and exact date (day, month and year), as well as the season of the year.  Another example question is that someone points to a watch and asks you to name what type of object it is, with a similar question being asked about a pencil. The MMSE test has a maximum score of 30. Adults with normal cognitive functions will tend to score about 29 on the test. The link here says that a score of 24 or higher is considered "normal."

To get a "normal" score on a Mini-Mental State Examination, a person needs to have almost all of these mental capabilities:

• The ability to understand instructions orally spoken by the person giving the examination;
• the ability to visually recognize common items and name what type of item they are;
• the ability to do simple mathematical operations such as backwards subtraction by 7; 
• the ability to remember details about your current position in time (such as date, month and year); 
• the ability to remember details about your current position in space (such as the current day, month and year, and the day of week); 
• the short-term memory ability to remember words you were asked to speak five minutes ago. 

But how if most of these things are required to get a "normal" score on the MMSE test, how could someone get a normal score when almost all of their brain had been replaced by watery fluid? It would seem that this could only happen if the brain is not the source of the mind. 

The paper discussed above has a citation of a similar type of case, a citation of a 2012 paper entitled "Asymptomatic Giant Arachnoid Cyst" which you can read here. In a brain cyst is a cavity filled with fluid. A giant cyst sounds like a very large cavity in the brain. But the 51-year-old man having the cyst is described as "asymptomatic" (a word meaning having no symptoms), and the man is described as a bricklayer (an occupation requiring procedural exactitude). 

Amazingly, this is not the only published paper with a title of  "Asymptomatic Giant Arachnoid Cyst." A 2003 paper (which you can read here) had the same title, and discusses an entirely different case. We read of a "39-year-old right-handed man, with a high-school education, good social and job functioning, and good command of three foreign languages (English, Spanish, and, in part, Arabic)."  We read that he had "a giant congenital supratentorial arachnoidal cyst occupying the anterior two thirds of the left hemisphere." Two-thirds of the left hemisphere of the man's brain was a mere fluid-filled cavity.  We are given this picture of the man's brain. The white area in the left photo and the black area in the right photo are the areas consisting of only a fluid-filled cavity. We read that "neurologic examination and standardized cognitive assessment revealed normal findings."  Apparently the man's mind was none the worse after such very heavy brain damage.