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Pediatrics/Infantile spasms or mimic 3 days after DTaP vaccine


3 days after his dtap vaccine my 4 month old was a bit lower energy than usual but I thought it was the hot weather. He was afebrile. When I turned him from facing me to away from me he went into arm extension (t shape), rigidity, and leg flexion. I turned him back to me and it seemed to settle. This happened three times in a row. I got scared so stood up and went to put him in cradle hold and it happened again and I could see he has a strong facial involuntary contraction/grimace. They all resolved within seconds. I took him home immediately in the car and once home he had one more spell when I went to pick him up off the floor. He slept most of the next 24 hours. But in the last 48 hours has been more like himself.

He is scheduled for an EEG and peds neuro consult. But I am terrified that this is infantile spasms. The posture looks like the same when I watch videos about it. To this point he has been developmentally normal and meeting milestones.

My question is are you aware of cases of transient seizures/spasms mimicking IS after vaccines then being healthy and normal after? I'm hoping this has occasionally happened and my baby is not going to have the dreaded condition.

I really appreciate your time and expertise,


Hi, Ana,

Events happening 3 days after the 4 mo vaccines are hard to link to the vaccination.  We commonly feel that vaccination effects, if any, will occur in the first 48 hours after the shot. Generally infantile spasms will have a progressive course and will not wax and wane.  A very helpful thing you can do is, if one happens again, do a phone video for the neurologist.

The problem with the vaccines is to separate out causative events from those that are coincidental.  Infantile spasms happen in the time period we give a lot of vaccinations, so the cause/effect relationship is tough.  I know of no studies that have suggested a cause/effect relationship with vaccines and infantile spasms.

You use the medical vocabulary well.  Are you in the medical field?  

Hope all turns out well, Dr. Olson


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David Olson, MD


I would be happy to attempt to answer any questions about general pediatric topics, either medical issues or behavioral issues. This would include all the various questions one receives in a busy pediatric practice. I`m a board certified pediatrician in northern Michigan and have been in practice for over 15 years. I enjoy the teaching role I have in our practice and would enjoy the opportunity to help others with their pediatric problems.

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