temporal lobe atrophy

A N Nagy annagy at hsc.vcu.edu
Fri Jan 14 20:58:43 EST 2000


Is the atrophy contralateral or ipsilateral to the impairment?



I do not know of any pathways connecting the temporal lobes specifically with
lower extremity function, but perhaps the following explanation may suffice.

In temporal lobe atrophy it is feasible that adjacent structures may expand or
be slightly pulled over to fill the space that had been occupied by the
temporal lobe. In severe atrophy this may allow the brainstem to be
tugged/pushed over toward the atrophied side, compressing the cerebral crus
against the tentorial edge and causing weakness in a fashion similar to that
which generates Kernohan's notch and hemiplegia ipsilateral to large
supratentorial mass lesions. In the case of temporal lobe atrophy, the force
pressing/pulling the brainstem into the tentorium on the side of the atrophy is
much less than the force pushing the brainstem during uncal herniation,  but it
still may be enough to compress the more lateral  tracts in the crus, affecting
those providing motor innervation to the legs before the tracts providing motor
innervation to the arms. This could be verified by examining the CT scans of
patients with lower extremity weakness for compression of the cerbral crura.

One could also suppose that the nearby basal ganglia are forced to distort
their shape because of the atrophy as well, although this is less likely to
cause a lower limb specific injury.

I have not read this anywhere, nor have I ever heard of a correlation between
temporal atrophy and lower extremity weakness, but the phenomenon associated
with Kernahan's notch is well established. [Kernohan J W, Woltman H W: Incisura
of the Crus due to Contralateral Brain Tumor. Arch Neurol Psychiatr 21:274,
1929].

Hope that helps.


-----------------------------------------------------

Xinxin Guo wrote:

> hi, there,
>
> I need your help. In our population-based study, we found a strong
> correlation between temporal lobe atrophy and impaired lower limb mobility.
> Both cortical and central atrophy were rated on CT scan. The temporal,
> parietal, frontal and temporal atrophy were rated as normal, mild, moderate
> and severe. Central atrophy were measured as bifrontal ratio, bicaudate
> ratio, third ventricle width. The mobility of upper limbs and lower limbs
> were measured by optoelectronic technique.
>
> My question is (1) how to interprete the association between temporal
> atrophy and impaired mobility? (2)why did the correlation is only limit to
> lower limbs?
>
> It would be very grateful if you could offer me some tips, or suggest me
> some relevant reference.
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>
> ---
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