2 – Unexpected research results

Experiments with monkeys on asphyxia at birth were begun during the 1950s in an attempt to produce an animal model of cerebral palsy [1-3].  Asphyxia was inflicted by delivering the head of the infant monkey into a saline-filled sac and clamping the umbilical cord.  Thus the onset of breathing was blocked, as was continuing respiration from the placenta.

Damage found in the midbrain auditory pathway

The surprise result was that the monkeys displayed only transient delay in developing control of motor functions, and initially no damage in the brain could be found.  Damage was found only after members of the team of Landau et al (1955) suggested looking in the inferior colliculi (in the midbrain auditory pathway).  This was the site in the brain, where, to their great surprise, they had recently found the highest rate of blood flow [4].

The asphyxiated monkeys did not develop cerebral palsy, and eventually outgrew their initial developmental delays.  However, residual lack of manual dexterity remained in monkeys that survived for several months or years, and maturation of the cerebral cortex was disrupted [5].  Windle (1969) suggested the damage to the inferior colliculi and lesser degrees of injury in other brainstem nuclei might be the cause of what was then known as "minimal cerebral dysfunction" (MCD).  Pervasive developmental disorder (PDD) has now replaced the designation MCD; and, developmental language disorder is one of the most serious aspects of PDD.

The research on asphyxia at birth appears to be long forgotten, and these are experiments than cannot be repeated because of regulations on use of laboratory animals.  However, the data remain valid and merit reconsideration, particularly the prominent damage found in the inferior colliculi.

Loss of speech comprehension after midbrain auditory system damage

With the advent of magnetic resonance imaging (MRI) in the early 1990s, selective damage of the inferior colliculi has been reported in several case reports of people who lost the ability to comprehend spoken language after traumatic head injury or cancerous growth into the midbrain [6-13].  Deafness and “word deafness” was assumed to be a psychological reaction in some of these cases, until the small lesions in the inferior colliculi were found in MRI scans.

If impairment of function in the inferior colliculi can have such a catastrophic effect on people without previous language problems, what should we expect when an infant sustains damage to the inferior colliculi by asphyxia at birth?

http://placentalrespiration.net/

From:

Note: Check other open windows if this does not display in the foreground window