Sunday, April 13, 2014

What IS Optic Nerve Hypoplasia? - Everything I Know Part 2 -

Okay, we're back.  I hope from my last post you were able to come away with a general overview of what optic nerve hypoplasia is.  If you didn't catch that post, or if you've stumbled upon my blog because your child was just diagnosed with optic nerve hypoplasia, I'd recommend beginning here for information, or here for the beginning of our own story with ONH : )

In January I attended a conference put on by the Texas School for the Blind and Visually Impaired (TBSVI) specifically for parents of children with ONH.  At this particular meeting, we were able to hear information from an ophthalmologist who had become something of a specialist regarding ONH.  I loved what she said at the very beginning - ONH is a brain problem.  It's not an eye problem.  That's why vision isn't (always) the only thing affected by ONH.

The optic nerves exist in a part of the brain called the 'midline'.  Because kids with ONH obviously have malformations in this part of the brain, one of the first things that happens (or SHOULD, MUST, MAKE IT HAPPEN) after an ONH diagnosis is a referral to an endocrinologist and an order for an MRI of the brain.

Below are two pictures of different views of the brain and its regions/parts/whatever you call brain stuff.

The first is a side view - the midbrain that is usually checked for additional abnormalities after the diagnosis of ONH includes the corpus callosum, the hypothalamus, and the pituitary gland.  (Image courtesy of a Google search, which yielded this picture in a foreign language.  Good luck with the link.)

This picture (below) shows a view of the brain from above.  You can see how the optic nerves cross just in front of the pituitary gland in the middle of the brain.  (Image courtesy of some lecture notes from a community college.  Knock yourself out.)

Okay, so what does this all mean?  Why are these parts of the brain important?

First and foremost, let's discuss the pituitary gland, aka the reason you'll be referred to an endocrinologist (doctor specializing in glands/hormones).  The pituitary gland is responsible for secreting the hormones that keep the body functioning normally.  Because hormone abnormalities can have drastic consequences (loss of consciousness, mental retardation, even death), it is imperative that a child with an ONH diagnosis be monitored for pituitary function.  And because the hormone levels can fluctuate at any time or stage in life, people with ONH should continue to be monitored with regularity even if everything is functioning normally.  Sources vary, but it is reported that 75-80% of people with ONH have some degree of pituitary dysfunction.

The hormones secreted from the pituitary gland are responsible for the following things:

  • growth, temperature regulation, sex organs, thyroid gland function, metabolism, water balance/regulation in the body (related to kidney function as well), blood pressure, and pain relief 

Your endocrinologist will regularly monitor your child's hormone levels by ordering blood tests and, at each appointment, check to make sure she is growing normally.  This specialist will also review the results of your MRI.

Hayes' hormone tests have come back in the normal range after each screen.  He has always 'thrived', which is to say, grown and eaten normally.  He is tested every six months and will be until he is 2 (or 3, can't remember).  At that point, if he is still maintaining 'regularity' as far as his hormone levels, he will only be checked once a year.  Of course, if there are any changes in behavior or activity, we will contact his endocrinologist to run tests to make sure something hasn't gone awry, because hormone problems can manifest themselves at any time.  (For more information about the pituitary gland, talk to your endocrinologist and click here.)  And, for the record, I love our endocrinologist.  He is hilarious and looks like Dennis Hoffman, and he thinks I look like Brittany Murphy.  I was not as thrilled and am still confused about that.)

This is Hayes and me at his endocrinology appointment on my birthday in 2013.  As you can see, he's chunky thriving, and I look nothing like Ms. Murphy.  No offense to her, and may she rest in peace.)

Let's talk about the MRI.  An MRI is an image done by magnetic resonance imaging.  I have basically no idea how this works.  Okay, I have some idea, but I feel more comfortable explaining why a person with ONH is ordered an MRI than how exactly the MRI is done.  (For much, much more re: the MRI, please talk to your endocrinologist/neurologist/ophthalmologist and click here.)  The MRI for ONH will be focused on the brain, and will be specifically taken for review of the midline.  

We had a few issues as we went to have the MRI done in the spring of 2013.  Hayes was getting over RSV and had recurring colds, which led to us postponing the scan once before we finally got to do it.  I was a nervous wreck.  Because Hayes was only six months old when he had his MRI done, he had to be put under anesthesia in order to ensure his absolute stillness.  He also had to fast (which, at that time, meant no bottles) for a period of time before the MRI was done.  The whole thing took a whole morning - arriving at the hospital at its earliest opening (some tortuous time like 6 or 7 am, and my mom and I drove in from Jacksboro for the appointment), and after he went in around 8 or 9 I didn't see him until after lunch.  I tweeted a lot about it.  Here's a link to a tweet/picture of Hayes in his hospital gown, 10 hours since last bottle and pre-anesthesia.  You can find me on Twitter by my handle @christieandrews .)

What else is the MRI looking at?  We already talked about the pituitary gland.  So next, the corpus callosum.  The corpus callosum is a group of fibers that connect the left and right sides of the brain.  These fibers allow the sides to 'talk' to each other.  Here's something completely mind-baffling about the corpus callosum: it can be completely missing and you might never know.  Some people with absent corpus callosums go on to college: some with partial loss of the same section of the brain have significant cognitive and motor impairments.  When the corpus callosum is thin, malformed, partially or completely missing, it is called agenesis of the corpus callosum.  (For more information about the corpus callosum, talk to your neurologist and visit this site.  A wonderful organization exists called the National Organization for Disorders of the Corpus Callosum, but unfortunately its website is temporarily down.)

Attached to the corpus callosum is the septum pellucidum, which is a thin membrane that runs to another part of the brain.  A condition often associated with ONH, called SOD (Septo-optic Dysplasia) involves diminished optic nerves, pituitary gland dysfunction (hormone problems), and a missing septum pellucidum.  For more information about SOD, talk to your ophthalmologist, endocrinologist, and/or neurologist and click here

I took the call regarding Hayes' MRI results on April 24, 2013.  As I'm writing this, that's only 11 days less than a year ago.  Hayes HAS a corpus callosum, but because he was six months old at the time of his MRI, his brain was six-months-old-tiny, as was his corpus callosum.  It's hard to tell, at that size, if a corpus callosum is malformed.  Hayes has not been diagnosed with SOD, as he doesn't seem to be 'missing' any brain parts and he has yet to have any endocrine issues.  Since his MRI, I've been wondering if his corpus callosum could be linked to some of the motor problems/delays he has, which you'll learn about later.  If your child has been diagnosed with SOD (or ONH), I would highly, highly recommend joining the Facebook group called 'Parents of Children with Optic Nerve Hypoplasia (ONH) / and Septo-Optic Dysplasia (SOD)'.)

Alright.  So.  We know that an ophthalmologist will refer a patient with ONH to an endocrinologist, and hopefully order an MRI (and it's not just to spend money; we understand why.).  Who do we discuss the MRI results with (aside from the endocrinologist... and the ophthalmologist.... and your family doctor/general practitioner/pediatrician...)?  We go to the neurologist.  A neurologist is doctor specializing in disorders of the nervous system, aka the brain.  And, obviously, ONH is a disorder of the brain.  The neurologist will (should) review the MRI results with you in detail.  She should show parents the MRI itself, discuss the findings in each targeted area, and explain what those findings mean.  A neurologist will be the doctor contacted in case of seizure activity, since that can be and is associated with ONH.  If the MRI results are inconclusive for any reason, the neurologist will refer you to other specialists.  (We'll discuss that later.)

I like our neurologist as a human and as a professional.  I really just haven't learned anything from our appointments with him.  He showed us Hayes' MRI results (pretty cool) and is willing to answer my ridiculous please-predict-the-future questions, but because Hayes has some other things going on that aren't explained by his MRI, he's referred us to other doctors.  We check in with our neurologist every six months to discuss any changes in behavior, monitor for signs of seizure activity, and keep track of his development.  The neurologist was the one who FINALLY said 'hypotonia' out loud for me, and is the one who is most concerned about his global developmental delays (which means delays in cognitive, speech, and gross/fine motor skills).

And from this point?  Rinse, lather, repeat.  And adjust as your preferred brand of shampoo is renamed, discontinued, or new and improved.  Because this is the medical community.

So, a recapitulation of post-ONH diagnosis and the 'D-team' assembly. (D is for Doctor, not performance.*  Hopefully.)

ONH diagnois (most likely via the ophthalmologistthen

  • Endocrinologist
    • hormone tests
  • Neurologist
    • MRI
Everything I Know Series
What IS Optic Nerve Hypoplasia - Part 2 (you are here)

  • Medical information / New Terms
  • Personal Andrews information
  • Medical specialists
  • Therapy / Government Programs
  • Really important information
  • and links I think you should visit always look like this

If all this helps just one person, I will feel incredibly accomplished.  It's a lot of typing if it doesn't.  :-)  I'm going to condition you to expect a really cute Hayes picture at the end of each installment, so here:

What?  Stop it, I know.  Hayes and Koby catching a snooze after a long weekend.  Hayes is smiling in his sleep.
* Remember, you can fire anybody who isn't up to snuff.  You can always question, challenge, and ask for clarification.  Above all, if you aren't satisfied, you can find another doctor (therapist/case manager/etc.)