Incomplete SCI and delayed onset spasticity/flexor synergy in lower extremities

[Jerram]

I've been working with a 35 y/o lady for over a year now who suffered from a T-11 incomplete SCI due to spinal infection about 15 months ago. Briefly, she has progressed from w/c bound with trace bilateral LE activity and no sensation to approximately 2 to 2+/5 strength on right and 1to 2/5 strength on left, with spotty return of deep pressure and stretch sensation. Functionally, she can now walk about 300' with a RW and bilateral KAFOs. We have spent that last 4 months or so focusing on Body weight support treadmill training and she can walk about 1 to 1.4 mph with AFOs only and little to no use of UE support, with about 20 percent support for around 16 minutes or so.
I was really encouraged by this progress when in the last month, we really started to notice an increase
in muscle tone during ambulation. Most noticeably, the knee flexors would fire during mid/late swing, significantly limiting step length, often not even allowing heel strike. This is not seen as much in over ground walking with the KAFOs due to the knees being maintained in knee extension, but the patient reports significantly more effort to achieve swing (likely due to the cocontraction of knee extensors and flexors during swing. Slowing the gait speed seemed to be a first adjustment, due to spasticity being velocity dependent, but this did not work.
She is to meet with her MD about starting Baclofen but I'm wondering how best to proceed at this point.
In some ways I think its a good sign and could show ongoing plasticity in her cord but I don't know if I should expect this as a phase of healing on more of an endpoint. She is discouraged and feels like we've stepped backwards.
The nature of the cocontraction definitely is predominately active. In other words, traditional Modified Ashworth testing reveals little to no hip/knee spasticity, though there is some positive ankle clonus bilaterally. I sometimes have seen this in stroke patients, which I have much more experience treating. For them I usually hypothesize its a motor control issue, similar to an upper extremity synergy pattern seen in patients when actively reaching to a target who can't fully extend the elbow, despite little sign of spasticity on rapid passive ROM testing. (as opposed to the patient with more severe dysfunction that is nearly impossible to passively extend or already contracted).

She just can't inhibit that hamstring during swing, after using it (albeit limited) to assist preswing knee flexion !

Should I focus on submaximal exercises aimed at isolating the extensor groups or flexor groups? Try more NMES? I'd really hate to give up the BWSTT b/c she gets so many reps in with each session, but I'm also afraid it could be counterproductive by somehow reinforcing the response and/or wearing her out too quickly.

Thoughts on all this while I await a trial of Baclofen with her?

Jeremy, PT in ohio

GCoe replies

Hi jeremy

Thanks for your interesting and well described problem. My thoughts are:

If she really doesn't produce velocity-dependent resistance to passive knee extension then it really isn't spasticity. So...

is it really co contracting hamstrings or is she just having a real problem contracting her quads in the inner range to complete the movement? You say she is 2 - 2+ what about actually for quads against gravity in sitting? if this is the case I would then just go all out on strengthening the quads in the inner range and yes NMES would be a great way to proceed both in-task and out-of-task

However if you are right and she is firing her hamstrings, then my guess that is more of a motor control problem than spasticity - so inappropriate voluntary contraction of the hamstrings. She may be able to learn to control the contraction to surface electrode biofeedback EMG is situ while BWSTT - she may need to practice isolating the hamstrings group muscle contract and relax etc first before she practices in-task. Another treatment idea is get her standing in the paralell bars and practice pendulum swinging each leg with the goal of increasing the swing without flexing the knee. she can use a mirror for biofeedback - then see if she can put it into practice in parallel bar walking and BWSTT.

Another thing: is there a smooth transition from terminal stance to initial swing phase? If there is a slight pause that may indicate the lack of hip flexors used to get momentum up for the swing phase. if you can increase the momentum that could improve the knee extension later in swing. If that is the case you could work on improving power (ie force generated X velocity) of the hip flexors eg - getting holding in single stance holding the thigh extended with the lower leg flexed off the ground and get her to quickly contract the hip flexors to command. the see if she can carry this over to task.

If you are right about the lack of spasticity on ashworth testing then I suspect the Baclofen may be a waste of time. You can only try of course. and if it does improve things but it makes her weaker generally then botox injections might be a better option.

Hope this is of help

Gcoe,

Thanks for your quick reply to my incomplete SCI question. don't know why the thread is closed so I opted to reply private message.

Not sure why I labled it "spasticity", given that I was the one who
pointed out that there isn't much in terms of resistance to quick
stretch! I guess it was just a good way to describe what I was seeing during gait b/c it does mimic what I see sometimes when there is spasticity. Anyway, I appreciate your suggestions and will try what I can. I'm seeing her today after a 2 week break due to holiday/weather conflicts.

We don't have surface EMG, but I am aware of the technology.

You'd asked about quads in sitting...she can do a partial knee extension on the right and minimal on the left. She really gets best quads in closed chain situations. One thing that is great is that she had //bars built at home and has a Total Gym. So she has been doing low incline squats and standing weight shifts with emphasis on quad strength/timing. They are slow to respond, (especially left) but have improved.

As far as pendulum swing, its interesting, because for for so many weeks, it was clear that she was using hip flexors and abdominals to advance the limb while I tried to facilitate knee
flexion for better clearance. Now she's getting more but
can't seem to deactivate during mid/late swing. We did try something similar in the // bars with me asking her to advance the limb with a smaller step than before. It seemed to be all or nothing with step to pattern at best. I just hate to inhibit those hamstrings now that they are trying to fire (arghhh!!) I feel like that is the essence of my dilemma, because I want them to fire briefly for clearance during swing. I'm also hoping to see the DF kick in now too (natural part of that flexion
synergy) but it seems to be the slowest to respond. I have had ther use some stim with 1/2 second ramp times to try to faciliate
rapid fire...fair success but its been awhile.

On a powder board or prone, she definitely gets better knee flexion in synergy with hip flexion, so I could try to isolate the hamstrings off/on.

Terminal stance to initial swing phase:
there is some pause here, partially b/c of what I described above about contraction time in general being delayed throughout. On the PBWSTT, she benefited from the speed to get prestretch
on the hip flexor (and lower abs) which helped get adequate swing, albeit with excess trunk extension. Are you suggesting I get her in right hip extension, support her left knee in flexion and faciliate rapid left hip flexion? This would be different than the
pendulum swing idea... Please clarify based on the additional info I've provided.

As far as the baclofen goes, it might be helpful to have the script in case things progress to a more clear spasticity.



I'd like to post a video of her too (with her permission of course)
which might help everyone provide feedback.
Thanks again.

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[gcoe]

Hi Jeremy

Sorry that this thread has got a bit mixed up but have put the posts in your initial message - best I could do. Just a couple of further comments:

We did try something similar in the // bars with me asking her to advance the limb with a smaller step than before. It seemed to be all or nothing with step to pattern at best. I just hate to inhibit those hamstrings now that they are trying to fire (arghhh!!) I feel like that is the essence of my dilemma, because I want them to fire briefly for clearance during swing.

It is hard to know if it really is the hamstrings firing inappropriately without sticking an EMG on during swing phase. As you haven't got one it might be difficult to find out. Just one ting about knee flexion in swing phase - my understanding is that the hamstrings aren't normally very active particularly at normal walking speed. The knee flexion required to clear the ground is created by an inertial moment by a short sharp burst of the hip flexors at the very beginning of swing phase. That is: the hip flexors firing causing the thigh to flex but because of inertia the lower leg is left behind causing the leg to flex. I know this sounds counterintuitive but if you look at EMGs or normal gait the hamstrings are relatively quiet during early swing phase. It does make sense though when you think that most of the hamstrings are also hip extensors - why would nature get you to fire hip extensors when hip flexion is needed.

Therefore if you concentrate on getting the hip flexors to fire more briskly and relaxing the hamstrings, the increased power should also increase the overall hip excursion in swing phase. Getting to take smaller steps would be counterproductive because without the momentum she will have to contract her hamstrings. The problem with these patients is they walk so slow that it is hard to use energy saving momentum

You'd asked about quads in sitting...she can do a partial knee extension on the right and minimal on the left. She really gets best quads in closed chain situations. One thing that is great is that she had //bars built at home and has a Total Gym. So she has been doing low incline squats and standing weight shifts with emphasis on quad strength/timing. They are slow to respond, (especially left) but have improved.

Well at least she is getting a contraction there so you have something to work on. If she is better at closed chain but in this case she needs open chain contraction you will really have to work on open chain contractions and yes terminal extension is what needs to be worked on. it may be also that you will need to work on unilateral contractions as she may be better at bilateral but that is no use for gait.

Perhaps someone else may have some comments?