Recent visit with my RLS Neurologist

[jinolke]

Hello RLS community,

I had a recent session with my neurologist who is part of the Oregon Health Science University here in Portland. This is my go to doctor for conditions related to RLS. In my most recent visit with him he said he wanted to confirm some thoughts he had about my condition and ordered a blood test for a genetic screening for Huntington's Chorea, symptoms which has a lot of similarities to RLS. The results came back and they indicated that I had a value of 35 CAG units. In looking at where it fell on the probability scale of whether I had developed symptoms of Huntington's Chorea or not I found this . The value of 35 is in units that measure how stable the gene segment is. Here is the table that I found on a British website dedicated to Huntington's Chorea:

hda.org.uk/professionals-an...

26 and below is normal range

27-35 is normal but unstable and has the potential for change that can result in HC symptoms.

36-39 Abnormal and unstable

40 and above is abnormal and individuals generally experience HC.

I have provided this information as a background to what my Neurologist gave me as a follow up to the testing which he texted to me:

"It is possible to have both conditions, it is uncommonly reported as an association with huntington's. Also you had a very low ferritin level which is another risk factor, and iron initially helped with symptoms.

The main difference to try and distinguish is if you feel like there are uneasy feelings or sensations in the limbs that then make you decide to move your legs (as if scratching an itch so somewhat compulsive) that happen more at night. Chorea happens automatically without thinking and continues to happen even if you are distracted and can be unnoticed if they don't interrupt what you are doing.

The typical treatment for chorea may worsen RLS symptoms. It might be that we have to try and treat both. If the main problem is an unbearable urge to move your body while you are trying to fall asleep, then continuing the increased gabapentin is probably a good idea.

Is there anyone in the RLS community that has experience with this while treating for RLS? I currently take 2700mg of gabapentin in three evening (starting at 5pm) doses. I do not have much if any relief from my symptoms except during the night when (on most nights) I get about 6 hours decent sleep.

Thanks very much.

[SueJohnson]

It sounds like you have an excellent doctor! I though you were having vision problems with gabapentin and were switching to horizant? As far as gabapentin as I mentioned before taking more than 600 mg at a time actually reduces the amount you absorb. Taking 900 mg at a time is equivalent to taking 540 mg.

[jinolke in reply to SueJohnson]

Yes I was surprised that he upped my dosage. I have seen your comment on dosage in the past. Do you have reference material that discusses dosage rate? I wasn't able to find anything online except that 600 is considered the typical dose.

[SueJohnson in reply to jinolke]

The Mayo Updated Algorithm on RLS discusses the doses. Https://mayoclinicproceedings.org/a...

[jinolke in reply to SueJohnson]

Sue, I stopped the Horizant because there was no noticeable improvement in symptoms and the cost of the drug compared to Enacarbil didn't make sense to continue. I tried to research the single dose limitations of gabapentin and found this NIH article that had a lot of discussion and data on maximum daily dose, but only indicates that participants took a maximum of 600mg at a time and did not look at higher single dose amounts. Here is the article:

ncbi.nlm.nih.gov/pmc/articl...

What is your reference for the the pharmacokinetics that shows that a single dose of 900mg has that level of blood absorption? I didn't see a discussion in the Mayo Clinic article.

[SueJohnson in reply to jinolke]

Unfortunately I didn't include in my notes the source for that.

[jinolke]

Thanks Desert Oasis for your insights. I really don't have the body movements that typically accompany HD and myoclonus. I can control my movements if I make a conscious effort. So the fine line between "voluntary" movement and "involuntary" movement is hard for me to distinguish. So far I don't see that my condition has progressed the way HD typically would.