[ExI] no brain, no pain

[David C. Harris]

Re: "normal pressure hydrocephalus"

This report is interesting because there is a condition called "normal 
pressure hydrocephalus".  The cause is a blockage of the normal flow of 
cerebrospinal fluid (CSF).  The brain spaces (ventricles) get blown up, 
pressing the neural tissue against the skull, causing damage.  The 
symptoms are a classic "triad" of (1) dementia, (2) an impaired gait 
like the feet are "stuck", and (3) incontinence of urine and sometimes 
feces.  (Yeah, gross).  My 89 year old father may have this condition, 
as he certainly has the "triad" of symptoms, otherwise unexplained in 
their relatively rapid onset.  The diagnosis is difficult (comparing 
brain scans taken over time, pressure measurement, lumbar puncture to 
temporarily lower CSF pressure), and the usual treatment is surgery to 
implant a shunt and tube that leads CSF one way out of the brain ventricles.

What's interesting here is that if the ventricle swells really slowly, 
the brain can compensate for the swelling.  With normal pressure 
hydrocephalus, the elderly are not known to be able to compensate for 
the pressure.  I guess it's possible that some of the waxing and waning 
of the symptoms could include a few of the elderly who partially or 
completely recover by this man's mechanism.  With surgical implanting of 
shunts into elderly brains, about half stabilize, a quarter recover 
"completely", and a quarter don't benefit.

   - David Harris

Damien Broderick wrote:
> WASHINGTON: A man with an unusually tiny brain managed to live an 
> entirely normal life despite his condition, caused by a fluid 
> build-up in his skull, French researchers reported yesterday.
>
> Scans of the 44-year-old man's brain showed that a huge fluid-filled 
> chamber called a ventricle took up most of the room in his skull, 
> leaving little more than a thin sheet of actual brain tissue.
>
> "He was a married father of two children, and worked as a civil 
> servant," Lionel Feuillet and colleagues at the Universite de la 
> Mediterranee in Marseille wrote in a letter to the Lancet medical 
> journal. The man went to a hospital after he had mild weakness in his 
> left leg.
>
> When Dr Feuillet's staff took his medical history, they learned he 
> had had a shunt inserted into his head to drain away hydrocephalus -- 
> water on the brain -- as an infant. The shunt was removed when he was 14.
>
> So the researchers did brain scans and were astonished to see 
> "massive enlargement" of the lateral ventricles -- usually tiny 
> chambers that hold the cerebrospinal fluid that cushions the brain. 
> Intelligence tests showed the man had an IQ of 75, below the average 
> score of 100 but not considered mentally retarded or disabled.
>
> "What I find amazing ... is how the brain can deal with something 
> which you think should not be compatible with life," said Max Muenke, 
> a pediatric brain defect specialist.
>
> "If something happens very slowly over quite some time, maybe over 
> decades, the different parts of the brain take up functions that 
> would normally be done by the part that is pushed to the side," said 
> Dr Muenke, who was not involved in the case.
>
> Reuters
>