Myoclonic Jerks in 9 month old

[twin_88]

Hello, my nine month old daughter has been having myoclonic jerks for the past six weeks.  They started abruptly one evening while feeding her.  Some are as simple as an eye blink, but most involve her arms pulling in and her body thrusting slightly.  Sometimes they're single, other times two or three fire in a row.

Since they began she has had three EEGs and an MRI.  All have come back clean--the EEGs did not indicate there was any loss of consiousness as is typical of epilepsy, and the MRI without contrast didn't indicate any abnormalities.  The neurologist believes they are benign and hopes that they will go away over the next few months (so do we!).  However, over the last week she has been having more than she has in the past (she's having around 20-30 a day vs. 5-15 when it started).  Some seem to be triggered by eating, over-stimulation, or being over-tired, while others seem totally random.  The doctor's official diagnosis is benign myoclonis of infancy.  Have you had experience with anything similar?  Should we get a second opinion?  We really like our doctor, but the reality is that this is such a rare condition that even an experienced doctor likely can't have his/her instincts properly callibrated.  We're worried about it devolving into sever myoclonic epilepsy or something similarly scary.  And we're worried that it could be foreshadowing something like turrets syndrome.  Any help you could provide would be really appreciated.

[CCFNeuroMD JT, MD]

Thank you very much for your inquiry.  I understand your concern for your daughter and I will attempt to address your questions to the best of my ability.  Please be aware that the following information should be regarded solely for educational purposes as I am unable to diagnose your child without having examined her or reviewed her records.  

To start off, I am happy to hear that all 3 of her EEG’s and her MRI are unremarkable and it sounds like you and your pediatrician are doing all the right things in evaluating the scenario.  Based on your description, it sounds as though your pediatrician has likely correctly diagnosed your child with benign infantile myoclonus, a condition that may be mistaken for epileptic infantile spasms but carries a very different prognosis.  It is especially encouraging that your child’s EEG’s have all been normal.   Please allow me to elaborate a little bit on the difference between the two.  

In children with epileptic infantile spasms, the EEG, even when the child is not having spasms is characterized by an abnormal brain wave pattern.  In the vast majority, this pattern is hypsarrhythmia- a very chaotic looking EEG with high amplitude brain waves.  The pattern is so distinct that it is generally hard to mistake for something else.  In addition, as many as 70-80% of these toddlers will have abnormal MRI findings. Children with epileptic infantile spasms often have other neurologic problems and may have associated mental retardation.  

Benign infantile myoclonus is a condition which may clinically look very much the same as epileptic spasms, however the hallmark feature is a normal EEG.  Children tend to grow out of these by about 2-3 years of life and no medications are required as treatment.  If you are still concerned and your child is demonstrating developmental delay or evidence of other neurologic dysfunction, her case may warrant further evaluation at an epilepsy center.  Diagnostic testing may include 24 hour video EEG where the child can be hooked up to an EEG continuously and videotaped; this setup allows correlation between EEG and the spasms in order to determine if they are epileptic in origin.  Obviously, I encourage you to further discuss your concerns with your pediatrician who is familiar with your daughter's medical history and is in the best position to guide you.  Best of luck, and thanks for writing.

[toucan]

I'm eagerly awaiting the response to your post.  My 8.5 month old has been having  jerks with her left shoulder (kind of like shrugging) that sometimes occur in bunches and sometimes only once.  It occurs pretty much daily.  I just had her in for her checkup a few days ago and spoke with the doctor about it and he suggested we see if they continue.  It started a few weeks to a month ago.  I can't be for certain because at first I just thought it was one of those cute things babies will do.  After it kept occurring and it was always the same shoulder I realized   it was not something she was doing intentionally.  I wish I had noted when this started so I knew exactly how long this was going on.

Next step for us would be the testing that you have already gone through.  He also suggested we start tracking how often/when they occur.

Anyway, I hope it is as your doctor suggested and is nothing to worry about.  

[sweetfury]

You didn't mention whether or not the child was on any kind of medication.  Some medications like reglan (not sure of spelling there) can cause myoclonic types of reaction. Benadryl is the antidote in that case.  Most people do not think about a medication as being the culprit and it was something I thought I would pass along.  My grandaughters pediatric MD informed us that this could happen when he prescribed the reglan for her digestive problems and informed us of the cure. Hope this helps someone out there.

[samsauntrn]

also keep in mind metabolic diseases, can start this way

[skyrob]

A related discussion, benign myoclonus of infancy ? was started.