ISNCSCI Practice 4

[Allison Dickie]

Hello,

I have a question regarding the motor level on the R side. I can’t figure out why that would be T1. I thought that S1 should be the correct answer.

Thanks for the clarification!

-Allison

[Allison Dickie]

I actually think I just got it after posting my question. Since the sensory level past that point is not fully intact, you have to use the sensory levels to determine the motor level. If sensation was intact (2s) the whole way down then the motor level would actually be S1. Is that correct? I was thrown off because the motor level on the L side is C8, but I think that is the case because T1 is rated 0/5.

[Abby McKeown]

Hi Allison,
I had the exact same question, thanks for posting! I think you’re right that even though the motor levels are intact all the way to S1, we can’t assume that they are intact in the areas that don’t have myotomes (T2-L1) because sensation is not intact there. So the lowest motor level we can say with confidence is intact is T1. BUT like you said, if sensory was intact all the way down, then the motor level would be S1. Or if sensory was intact to T3, for example, then the motor level would also be T3. Does this sound right?

Thanks!
Abby

[Abby McKeown]

I just noticed that ISNCSCI practice 3 has the same concept. Someone posted a question to the forum about the motor level in this case about a month ago, and Chrissy’s explanation is very helpful:

“even if motor scores are normal in all testable regions, if sensation is impaired between T2 and L1, the motor level is the lowest level with intact sensation.” The ASIA is purposefully designed to make conservative assumptions if there are unknowns.

Hope this helps!

Abby

[Chrissy Durrough Lugge]

Hi Allison and Abby,

Yes, I think you both figured it out! The motor level on the right is T1 because of sensory impairments between T1 and L2. The motor level on the left is C8 because that is the lowest level with at least 3/5 strength. Had T1 been scored as 5/5 strength on the left, the motor level would be determined based on sensory level.

Chrissy

[Liliana Jimenez]

Hello! I’m new here and I still don’t get why the motor level would be T1 if the sensory is not intact light touch/pin prick. Light touch is 2 but pin prick is 0. The level above (c8) has intact sensory level but not T1…..

[Chrissy Durrough Lugge]

Hi Lily,

I emailed you directly but will also post here in case anyone refers to this thread for clarification.

There is a motor test for T1 and it is normal. Therefore, T1 is the lowest level presumed to have normal motor function – because sensation is impaired at T2 (again, it’s a conservative assumption because we know motor function is normal in L2-S1).

Chrissy

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