Monday, 16 September 2013

From the Finnish researcher

There was a small but relevant study I shared a while back, you can read the post here.

I wrote to the researcher and asked a few questions and she has kindly replied. SO it's my duty not to forget and share. I did tell her that I would share with others.

- Based on my discussion with dozens of parents, it appears that most children with HCH wouldn't have an MRI done unless indicated. We were wondering if any of the findings (temporal lobe dysgenesis, peritrigonal white matter reduction, and abnormally shaped lateral ventricles) would show up on a CT, which they seem to be more likely to have? I am thinking the abnormally shaped ventricles would, but I am not sure of the other two? You´re right, on a CT you can only note the shape and size of ventricles, but not temporal dysgenesis. 
- I presume it didn't make any statistical difference which of the 2 common mutations the children had? Right. Both common mutations (c.1620 C>A and c.1630 C>G result to the same amino acid substitution and consequences are similar. We did not have children with other rare mutations. 
- When you use the term mild intellectual disability, I presume the IQ range meant is 50-69, is that correct?  That is correct. 
- Is there a significant difference in the verbal/non-verbal IQ that would have been noted? In most cases verbal IQ was lower than non-verbal, but there were a few exceptions. 
- In terms of the expressive language issues, is there a diagnosis provided by the speech pathologists, such as specific language impairment or any particular pattern in which way their speech seems to be impacted. - Speech delay seems to be the most common problem, so any light you could shed on this, based on your research, would be most appreciated, I realize this is not about neurology. In children with language problems: both speech production and understanding language were impaired, but in most cases expression (speech production) was more delayed/impaired than understanding. These children had benefit from augmentative and alternative communication, like using pictures and signs to aid communication.  
- Do you know if any of the children had hearing problems? - Up to 75% of kids with HCH seem to have recurrent otitis media and need multiple sets of grommets, etc.  Only one child had hearing impairment, but that was not caused by recurrent otitis media (it was sensorineural).


  1. wow- you amaze me. These are questions I don't have the knowledge to even form, so the significance of the answers elude me. Can I try to summarize the second part to make sure I understand? Children have speech delays, but it is not clear why, since neurological reasons have been ruled out as well as hearing impairment? Why is it not about neurology? If it's not due to physical impairment, wouldn't it have to be neurological? Or is it a different type of physical impairment?

    Can you explain the significance of your first question? What do all of those different findings indicate? Are they (possibly) related to seizures and/or learning delays?

    Thanks for decoding all this :)

  2. I just asked the first question because most kids wouldn't have an MRI, but many would have a CT and I wanted to know which of the typical MRI findings would show up on a CT as well.

    Second part: The children in the study most likely have the speech delays because of the neurological problems: temporal lobe dysgenesis, peritrigonal white matter reduction, and/or abnormally shaped lateral ventricles.
    Now, the thing to remember is that this study is very small 13 kids. And bias in the sense that for some reason these kids have made it to neuro and 8 of them had an MRI. 6 or 7 of them had seizures.
    So I don't think it is representative of the total hypo population, but it is significant because it links the speech, seizures, cognitive together with the bran abnormalities and in this sense it is the first, previously only a few isolated cases of temporal lobe dysgenesis and seizures have been reported. Or loads of controversial reports about the cognitive side of things, but no explanation. Hope this makes sense.

  3. Interesting...even if I don't fully understand it all ;)