Leg pain after SCS trial

[painquestions8989]

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85y F, history of L2-L5 fusion, continued back and leg pain, mild canal stenosis with many disc bulges on MRI. Two days ago SCS trial goes smoothly, 30 mins in and out without issue. Wide awake for testing and most of placement. An hour later get a call from PACU that she is having severe hip and groin pain. Go see her, no real radicular symptoms, strength & sensation intact. Discussed that it's likely from positioning and should get better.

Called her today, still having the same pain, and "electrical sensations" in the legs. Difficulty walking due to pain. No saddle anesthesia or bowel/bladder incontinence. Discussed that the stim settings likely need to be tweaked to stop the paresthesias. Discussed less likely causes (hematoma, cord compression). Discussed an early lead pull at day 5 if her symptoms continue, or go to E.R. if things suddenly worsen.

Given the recent thread about thoracic imaging prior to SCS (which she did not have) wondering if I am missing something and should be pulling these leads today?

Thank you.

 

[BobBarker]

It is probably a little more in the right gutter now. Pull them back under fluoro and take that curve out.

 

[PinchandBurn]

Was thoracic mri insignificant? I assume yes.

If no weakness and just pain. The. Either pull it back. Turn it off for a day. Give IM dex.. or medrol dosepak. Could be a neuritis...

If weskness or super intense. Take it out. Then possibly mri

 

[Laryngospasm]

Any new imaging?

 

[po_boy]

How many of you get thoracic MRIs approved before a trial? Which code do you use?

 

[mdo1738]

How many of you get thoracic MRIs approved before a trial? Which code do you use?

All of mine have been approved. I just use “encounter for Preop examination” as my diagnosis.

 

[lobelsteve]

Pull leads and stat mri.
appalling angle of entry. If straight needles could not get 30 degree angle of entry into epidural space, should have coude needles. Lateral films show mashing on dura.

 

[Asclepius186]

My guess is that loop going anterior and lateral one or two levels above needle entry point is irritating the nerve root there. I guess you could try pulling them back a bit under fluoro as suggested and seeing if it resolves. Probably just needs to be pulled. MRI probably overkill unless things get worse but I’d see how she does after they’re pulled

 

[bedrock]

Pull leads and stat mri.
appalling angle of entry. If straight needles could not get 30 degree angle of entry into epidural space, should have coude needles. Lateral films show mashing on dura.

Agree with all points.

 

[Espn123]

Pull leads and stat mri.
appalling angle of entry. If straight needles could not get 30 degree angle of entry into epidural space, should have coude needles. Lateral films show mashing on dura.

This is the problem. The angle of entry is steep, so even though the needle didn’t “ding a nerve” the lead passing out of the needle bumps into the conus and causes nerve irritation. It likely will resolve with time but something I am very aware of from my own experience

 

[Centurion38]

The left lead dinged the conus, and then bounced into the right gutter and was jammed up there. You can get away with steep angle of entry like that sometimes (?most of the time) but not if you drive the lead up and through the gutter and back to midline like that.

With that angle of entry, make sure you stay in the lateral view and watch the lead come out; you will see it dive anterior immediately. Go back to A/P and adjust your angle of entry appropriately. Stay dorsal.

Take the leads out. MRI might show edema around the conus but not much can be done about it at this point.

This should resolve over weeks-months.

 

[BobBarker]

MDT has curved tip needles in their trial kits that help with steep angle of attack. I don’t think he really dinged the conus. You have the dura, csf protecting the conus.

 

[gdub25]

The needle angle is way too steep as others have said. Need to ask yourself how asleep was the patient really when you were placing the leads? With that needle angle and seeing the path the lead took falling out laterally around T11/T12 in the AP image and then in the lateral you see how anterior it went...its very unlikely that wouldn't hurt during the lead placement unless the patient was sedated. For reference, I don't use any sedation on trials for this exact reason and patients are always able to tell me if something is hurting when I'm driving the lead.

What to do now...? If there really is weakness I would take them out, start steroid taper and get MRI. If it's just pain, I would leave them in and hope that stim provides some pain relief for a few days while the nerves calm down. Give big doses of gaba/Lyrica. In time it's highly likely it will get better. The weakness would worry me that there is more significant nerve damage and MRI would be a diagnostic tool to look for cord signal change and will be the expected next step if anyone is looking at this on the future with a critical eye but it won't change the outcome or management most likely.

 

[Centurion38]

MDT has curved tip needles in their trial kits that help with steep angle of attack. I don’t think he really dinged the conus. You have the dura, csf protecting the conus.

Pounding the lead against ventral epidural space can displace dura into the conus and theoretically cause bruising/edema, especially in an 80 + year old person with thoracic stenosis and not a lot of CSF.

Several case reports of conus medullaris syndrome with perc leads. Most common identified risk was lead entry site around T12/L1.

I've started getting pre-trial and implant MRI's on these types of patients: 80 + years old, with fusion hardware above L3

 

[bedrock]

I find it concerning that the OP hasn't commented on this thread again.

 

[Gnarvin]

I find it concerning that the OP hasn't commented on this thread again.

Agreed. I would be interested in getting an update. We all can learn from cases like this.

 

[buddababa]

Pull leads and stat mri.
appalling angle of entry. If straight needles could not get 30 degree angle of entry into epidural space, should have coude needles. Lateral films show mashing on dura.

agree with all of this, never should have even attempted to pass at that angle

 

[Orin]

85y F, history of L2-L5 fusion, continued back and leg pain, mild canal stenosis with many disc bulges on MRI. Two days ago SCS trial goes smoothly, 30 mins in and out without issue. Wide awake for testing and most of placement. An hour later get a call from PACU that she is having severe hip and groin pain. Go see her, no real radicular symptoms, strength & sensation intact. Discussed that it's likely from positioning and should get better.

Called her today, still having the same pain, and "electrical sensations" in the legs. Difficulty walking due to pain. No saddle anesthesia or bowel/bladder incontinence. Discussed that the stim settings likely need to be tweaked to stop the paresthesias. Discussed less likely causes (hematoma, cord compression). Discussed an early lead pull at day 5 if her symptoms continue, or go to E.R. if things suddenly worsen.

Given the recent thread about thoracic imaging prior to SCS (which she did not have) wondering if I am missing something and should be pulling these leads today?

Thank you.

Looking at the imaging, I don't think the angle is miserable but clearly suboptimal. Having seen NSGY place perc SCS leads, my range of acceptable has increased.

As above, your left lead just goes into the right T11/T12 foramen as you can see on the AP And lateral. It is likely causing a thoracic sensory radic when the patient isn't prone. Once the leads are removed, you should see some improvement but it can take a few days to week to resolve just like a fresh radic. I suspect if you pull the left lead back gently, it could take the slack out, but hard to say.

MRI after likely won't show anything but should be done so the patient feels like you're looking for things and listening to them.
Steroids are fine if you must.
Low dose AEDs or SNRIs are my preference.

 

[painquestions8989]

I pulled the leads early and she is feeling better.

 

[Orin]

I pulled the leads early and she is feeling better.

Thank you for closing the loop. It's good for everyone to see/hear about these things, as they happen more commonly than described and are stressful if you haven't seen/heard about it before.

 

[po_boy]

Pounding the lead against ventral epidural space can displace dura into the conus and theoretically cause bruising/edema, especially in an 80 + year old person with thoracic stenosis and not a lot of CSF.

Several case reports of conus medullaris syndrome with perc leads. Most common identified risk was lead entry site around T12/L1.

I've started getting pre-trial and implant MRI's on these types of patients: 80 + years old, with fusion hardware above L3

Where would you enter?