MRI for low muscle tone and macrocephaly.

[wiliaby]

At nine months of age our daughter was sent for an MRI in an attempt to figure out the cause of her low muscle tone (hypotonia) and macrocephaly.  She has undergone many tests and all have come back normal.  The MRI report is the only thing that wasn't completely normal, but we have been told that the finding were none specific. The following is an exact copy of the report:

The ventricles and sulci appear slightly larger than expected. There is moderate white matter signal abnormality in the periventricular regions bilaterally.  This could relate to non-myelination relating to age, however is non-specific.  There is also a focal area of signal abnormality within the deep white matter of the right frontal lobe measuring 6x8 mm in size.  Visible on T2 weighted imaging.  This has corresponding T1 signal hypointensity which would suggest a focus of encephalomalacia.  This is also non-specific.  There is no evidence of migrational anomaly.

What exactly does this mean?  Should another MRI be done now for comparison? (It has been ten months since the above MRI was done)  Should she be seen by a neurologist?  

Thank you for any and all information that you provide to us.

[CCF-Neuro-M.D.-SH]

First of all, keep in mind that I am unable to diagnose you because I am unable to examine you, this forum is for educational purposes.
   Yes, you should see a pediatric neurologist to help diagnose and manage your daughter.  The findings/story that you describe are indeed non-specific, but I can try to help you understand the different possibilities.  First, the MRI said there was no indication of a migrational abnormality. Neurons are 'born' on the inside of the brain (near the hollow center called the ventricles).  The newly born neurons then crawl along long cables (radial glial cells) to their final destination in the brain (many in the outer regions-called the cortex).  If an insult occurs to the brain during development (or a genetic defect in the migrational machinery) then some neurons may get stuck in the wrong place, which can then cause cogntive and motor delays, seizures, other brain problems.  Fortunately it sounds like the neurons migrated fine in your case.
  Hypotonia may have multiple causes in a newborn/young child.  The important thing to determine is that if the low muscle tone is caused by a brain problem, a spine problem or a muscle problem.  Some etiologies can affect multiple areas at once.  Some common causes of hypotonia include trisomy 21 (Downs syndrome), Prader-Willi syndrome, Hypoxic-ichemic injury (due to low oxygen/or blood pressure) and metabolic diseases (although many other possibilities also exist).
  Macrocephaly means 'large head' and can also have many possible causes.  Patients with macrocephaly may have increased skull size (as with hydrocephalus) or increased brain size in some genetic and metabolic disorders.  Hydrocephalus is caused by increased pressure in the brain that expands the skull and should be addressed early on to prevent any possible damage.  Causes of increased brain size are complex and often require advanced genetic/metabolic testing.  Another common cause of macrocephaly is familial macrocephaly ( Mom and Dad also have big heads-this is a benign condition).
  The white matter abnormalities that you describe on the MRI suggest the possiblity of hypoxic ischemic injury or a possible stroke.  I would suggest a repeat MRI to assess for any changes in this area and for the development of myelin.  Other possiblities given the white matter abnormalities that you describe would be a leukodystrophy (alexanders disease and canavans disease also have associated macrocephaly).
It is difficult to be confronted with all the different possilbilities that exist, but I would urge you to visit a pediatric neurologist to help diagnose and manage your daughter.
I hope this has been helpful.

[eschoening]

I realize your post is a few years old, but I was wondering how your daughter is doing today?  My daughter is 4 and has EXACTLY the same symptoms.  We still don't have a diagnosis for her.

[eschoening]

I realize your post is a few years old, but I was wondering how your daughter is doing today?  My daughter is 4 and has EXACTLY the same symptoms.  We still don't have a diagnosis for her.

[ctll2855]

A related discussion, Hypotonia, macrocephaly, all tests normal so far was started.

[rcs2]

Hi there,

I'm really sorry for your daughter problems... It's really painful when we (adults) have a health problem, I can only imagine how painful it is to see your own child suffering.

So she is not seeing a neurologist? Who asked for the exams? Did her symptoms improved? These exams sometimes drive us crazy, you know, there is something there but it might be nothing... My neuro says that if you do brain MRIs in several health patients you will find "normal" lesions in more than half of them...

If her symptoms didn't improve, I think it would be good to have these exams done every 6 months/year and have her checked by a neuro as well.

I'm sorry I can't help more. I really hope and pray that your little one gets better.

All the best.

[wiliaby]

In response to your questions posted above:

No, she has yet to see a neurologist - our family doctor and pediatricians didn't think that it was warranted. These are the doctors, along with three geneticists that ordered the tests and exams.  Since we were first told that something was "wrong" we have been attending physiotherapy and she has made progress, just very slowly. Our doctors have also stated "that if you do brain MRIs in several healthy patients that you will find "normal" lesions in more than half of them..."