BellaOnline Forums Health and Fitness Thyroid Health Low Cortisol - Low dose ACTH test

Question for my son -

Son suffered a traumatic brain injury. He is doing very well but since his injury we are having some endocrine issues. He has been diagnoised with Central hypothyrodism. They feel his hypothylmaus or pituitary is not working correctly.

Recent blood work had his morning cortisol coming back at "3" - they wanted him to come back in and have a low dose ACTH stim test. The results of that we were told were above 20.

My question is does this test show them if the pituitary gland is communicating to the adrenal glands? Or does this test just tell them that the adrenal glands are working? I had read somewhere that if you have a low morning cortisol level and respond the the ACTH stim test it tells them that there is pituitary issues - but now I can't find that article.

Also are there difference in the different ACTH test - low dose versus full test?

He is on 125mcg of levothryoixe for the central hypothyroidism but he still seems to be suffering. The problem is with him it is difficult to separate brain injury issues versus endocrine. For example is his fatigue coming from the lesions seen on his brain from his injury or is it from endocrine issues caused by his brain injury. I think they are both are involved.

Any thoughts would be appreciated.

Cybercat, welcome to the forum, were glad to have you joining in here, and hope you enjoy your stay
"Rosie"

cybercat,

I'm so sorry to hear about your son's traumatic brain injury and the problems it is causing. His Dr.s will over time determine what dysfunctions in the brain glands it is causing and give him the treatments needed.
With it already being determined that he has Central Hypothyroidism, this lends strongly toward the possibility that the low cortisol is also centrally caused.
Most Dr.s order the ACTH Stim test to rule out the adrenal glands them selves as being the cause of adrenal insufficiency. If secondary adrenal insifficiency (lack of ACTH) is suspected as the cause, they usually give the patient both an ACTH Stim Test and test their level of the ACTH hormone as well (comes from pituitary to stimulate cortisol production). Or some may simply test the cortisol level and ACTH level at the same time.
In your son's case they did test cortisol first, then administered an ACTH Stim Test but I wonder if they have tested his ACTH hormone level?
You might ask if this was done and request a copy of that result or inquire with his Dr. as to whether they plan to test his ACTH level. It could be they plan to do so but wanted to wait until the ACTH they injected him with for the stimulation test has had time to diminish from his natural blood level, in order to get the most accurate reading possible.

Thanks Jim for the info and thanks to Rosie for the welcome.

Still trying to get a hold of the drs. to see what test they actually ran on him.

Will post back when I get them.

We look forward to an update!

OK here are the numbers they sent me

Cortisol - 2 (3-21)
Peak ACTH - 29 (>20)
Free T4 - 1.3 (1.0-2.4)
TSH- 1.16 (0.43-4)
IGF-1 - 657.2
IGF-BP3 - 4.7 (3.5-10)

Repeat TSH Surge - 8% (50-200%)

They told me to just followup with them in 5 months. Any thoughts on these numbers.

cybercat,

That cortisol level was flagged low but my suspicion is they will pronounce your adrenal function as normal because your Rapid ACTH peak response was above 20. The result of 29 however would seem to also be lowish normal but I would be curious what the average expected result range would be. In other words for males 18 and older, they might expect an average reading of 40 and for females a 35 but this is purely an example and they should have a factual average result they like to see.
That test is the same as what is referred to as ACTH Stimulation Test, just a different name. It helps rule out full blown adrenal insufficiency but doesn't rule out secondary adrenal insufficiency (ACTH hormone deficiency) and doesn't rule out subclinical adrenal insufficiency (adrenal fatigue), which many Dr.s do not recognize.
Your baseline cortisol of "2" was below what they like to see before beginning the test. If I remember correctly, they like to see a 5 or above as the baseline because below 5 may already point to adrenal insufficiency.
I'll get back online tomorrow and see if I can find links that refer to this and will add them to this thread below. I try to be very careful about the information I post and usually will not post anything I'm not totally sure of.

We just got back from another dr. visit and after going through son's recent blood test these doctors feel that he is suffering from adrenal insufficiency. They are going to call the endocrinologist and discuss it further with them. They said he might just need to take some medication to help him get through this "rough" time.

They basically said the same thing as you Jim - that the rapid test just proves that his adrenal glands are working but it doesn't tell them if the brain is telling the glands to release enough cortisol for him.

They also ordered a stress test just to get a clear idea where he is physically plus they want to make sure they are not missing something.

I felt good after this visit. These are sports doctors so I was surprised by what they told me.

Before this visit we had gotten a letter stating that they are diagnosis is that he has isolated central hyperthyroidism - can't find much on it. Will keep looking though.

cybercat,

It sounds like those Dr.s are staying on top of your son's situation and are fine tuning the diagnosis, to provide best possible treatment. I also like seeing Dr.s confer with other Dr.s to get the best input in putting together the full picture for what is needed.
They may see the possibility that there is still some recovery from the injuries taking place and is why some of the treatments may not need to be permanent but follow up retesting will reveal this if it's the case. Even if they are permanent, he can live a full, normal life with ongoing treatment.
I've seen the "isolated" term reported by patients as being the wording used on their lab results revealing Central Hypothyroidism and I believe it is just a little more descriptive but means basically the same thing. Central hypothyroidism itself is rare, I believe affecting less than 1% of the population. Others may have more input on the Central Hypo subject, my search and research is limited in that area.
Keep updating us when you can and we continue to wish you the very best and know your son will see great days ahead.

Just a quick update and hope you can answer a question or two.

Since my last post they had increased his medicine to 150mcg - levothryoixe - his blood work in Oct was the same and he was still having symptoms. Recent blood work was done and his TSH was lower 0.62 and his free t4 was 1.2 - however this time they don't want to change his medicine and they just want a followup in Feb. Because of his fatigue they put him on a stimulant.

The problem is that he still has the same if not more symptoms. His eye brows are all dried out and look like they are thinning. He has no appetite (this was even before the stimulant)- he has sinus arrhythmia which they tell me is nothing to worry about. He is now complaining that he can't seem to get enough air to breath. Before he only complained about this when he would try to exercise but now he said it can happen when he is just sitting there.

The doctors don't think his shortness of breath has anything to do with his central hypothyroidism but they don't really know what is causing it. When asked why his numbers would be getting lower if they increase his medicine - no answer except followup in Feb. I was talking to the nurse and not the actual doctor. I asked about his cortisol and that he has to be put on a stimulant to get through the day - no answer. I was also told back in October that they wanted to see his TSH at 2 - so I asked why if his TSH was lower why are we not doing a medicine change. No answer. Do any of you have any thoughts are what direction I should go or should I just wait until Feb to see the doctor? Could he be taking to much?

Thanks