On 26 May 1999 13:17:35 GMT, didier at Glue.umd.edu (Didier A. Depireux)
wrote:
>Dave L (dave at lud-low.freeserve.co.uk) wrote:
>: There is a sensori-neural hearing loss - severe at high frequencies,
>: slight to moderate elsewhere. Wears hearing aids but is intolerant of
>: them outside school.
>>That I find curious. The cochlea can get damaged because of infections, and
>some antibiotics selectively destroy the outer hair cells for the high
>frequencies. But if her damage is only thalamic, how could that arise? The
>only part of the auditory thalamus (the medial geniculate body) that is
>tonotopic is the ventral part; if her hearing loss is due to thalamic
>damage, it would have to be a very localized damage! But then her hearing
>aids would help only through recruitment, which I doubt would be that
>helpful if her lower frequency hearing is OK... So she had some cochlear
>damage among all her misfortunes? Was it medication or anoxia induced?
>> Didier
I am back online again after my soccer break.
Here is the addditional information:
... The motor deficits were attributed to thalamic damage caused
by acute birth aspyxia (Apgars 0,1,3 at 1,5,10 mins) compounded by
inadequately treated hypoglycaemia (~20 to 40 mg/dl for 12 hours).
Three seizures ocurred, at 20 hours and on the second day...
The radiologist's report said the entire thalamus had (bilaterally) a
subtle but definite abnormal signal which was "most conspicuous
ventrally with faint extension into the midbrain in the area of the
aqueduct"
An investigating neurologist and an audiologist quoted literature
which identified birth asphyxia as a risk factor for "sensorineural"
or "cochlear" hearing loss.
I wonder if the midbrain extension of abnormal MRI signal might
indicate an asphyxial and/or hypoglycaemic injury to the auditory
pathway in that area of the brain. But this is pure speculation on my
part.
The only unusual (to me) medication given was phenobarbital, to
control the seizures. The unusual aspect is its abrupt withdrawal when
she was sent home from hospital at 14 days. She was miserable and
extremely upset at times for several days until the doctor diagnosed
withdrawal symptoms from the phenobarbital, which was prescribed again
and gradually tapered off. The problem did not recur.
Dave L