Indifferent Babinski sign

[neurosciguy]

I was shadowing and watching a neuro exam from afar on a ~30 y.o. male patient yesterday. The left Babinski had a clearly normal response. The right side had absolutely no response after multiple tries (but the patient didn't appear to have any paralysis).

Does this difference between the two responses elicit any clinical significance by itself? I didn't have time to ask. Obviously you'd want more information for the full clinical picture.

I can't find anything in the literature, but maybe I'm not looking in the right places. Thanks.

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[typhoonegator]

Nah. Sometimes the arc doesn't activate, doesn't mean it's not there. That's also why there are multiple "moves" with different names to elicit the same reflex. Chaddock, Bing, and Oppenheim are my favorites. Sometimes I combine Babinski with Oppenheim.

 

[neglect]

To add to an already great answer, one of my many mentors told us that he does not consider a toe to be a pathologic Babinski unless it is accompanied by other subjective/objective motor/sensory features. I'd also add that the Babinski without triple flexion should be thought of as a babinski with a little b.

Personal story time: I was demonstrating the Hoffman's reflex on a medical student, an otherwise entirely normal person destined to go into surgery (I mention this because he had fine hand-eye coordination). He clearly had a positive response on the left, so I said it is only pathologic if it is asymmetric. Sure enough... None on the right. Repeated and it was clearly reproducible. But he was asymptomatic. We did nothing and he graduated the next year without blooming into MS or GBM.

So I guess the question is: if a patient comes in with migraine, has no other neuro complaints, normal mentation, cranial nerves, motor, sensory, reflexes, why do we bother checking? It's like a vestigial organ, it stays around even though it has no function.

 

[typhoonegator]

Exactly. I try not to check unless I'm looking for something. Also, clinic feet are pretty gross.

 

[neurosciguy]

Thanks for the replies. It's so interesting that these tidbits can't be found written down elsewhere (I've come across this often). Well, it is the nuanced art of physical examination.

 

[RenegadeSynapse]

The inter-rater reliability of the plantar response can be pretty atrocious as well. Which is likely where the adage, "Whoever has the most grey hair gets to decide if it's a positive Babinksi or not." And as neglect said, a true Babinski sign should have triple flexion, and the vast majority of the time, no one really looks for that. Some sources would count the plantar response as a neurologic "soft sign" for these reasons.

I try to remember that every historical element and physical sign has some theoretical sensitivity and specificity and it's never 100%.

 

[dilaudid plz]

Made the diagnosis of MS in one of my patients who in addition to optic neuritis had a "silent" T-spine lesion - no other motor or sensory deficits. I think there's utility in using this sign routinely as part of a screening exam even if there are no other specific long tract signs.

 

[neglect]

Made the diagnosis of MS in one of my patients who in addition to optic neuritis had a "silent" T-spine lesion - no other motor or sensory deficits. I think there's utility in using this sign routinely as part of a screening exam even if there are no other specific long tract signs.

We can bicker about the use of the Babinski sign, but I think this makes rather than detracts from the thread's overall point. (It's an important point along a line.) An expert will weigh the historical context and setting appropriately and look hard for features that support or detract from the overall clinical impression. There's an important interplay between the history and the exam, with one informing the other. Getting a history of 6 months of cognitive problems in 70 yo who's screening cog test of 5/30 requires you getting a better history.

In this case you were astute: you looked for the toe, put it into context with the optic neuritis and perhaps other subjective and reflexive changes to arrive at a likely spinal lesion. I'm guessing "silent" T-spine lesion is MRI neg? Happens all the time, more on that later. It is important to note this is not diagnostic of MS, but supports a second lesion of uncertain timing (you got separation in space, but not time). I hope you're considering NMO in this patient as well.

The same gets applied to the tests we order. Young neurologists/doctors of all kinds/residents will order tests "to see," and "because I'm worried." Sadly many don't outgrow it. But an expert will order a test as nearly an extension of the exam, with a mind as to how this will support or detract from the overall clinical impression, and, importantly, change the diagnosis and really change management.

In the above case, an NMO antibody and highly cellular CSF will massively change management. You already know that she had ON, but a delay in the contralateral eye on VEP will also support NMO rather than MS.