Cord compression, Chiari, or ALS?

[koopatroopa]

29 y/o male. Last Nov, woke up with acure neck pain, exacerbated by moving my head. Resolved within a week. Since mid-May: tingling, warm sensations, mild pain in both legs but greater in the left.  Pain is worse by standing and relieved by laying down/sleeping.  In last month, been having widespread fasciculations, which have me concerned for ALS. In last weeks, leg pain eased after taking NSAID's but legs feel week. I still do get bouts of tingling in both hands (little fingers) and some neck discomfort. In the last week, feel globus sensation in throat with hoarse voice that's been chalked up to heartburn and NSAID's...of course, this has me concerned for bulbar-onset ALS.  

Imaging studies:after right facial numbness/headaches in June, I went to ER, where a brain MRI was negative but found Chiari I malformation with no syrinx, and C3-4 kyphotic defect across left paracentral disc herniation with effacement of the subarachnoid space.  Posterior subarachnoid space is still present on axial views.  This deviates the spinal cord by 3 mm. or so.  Full spine MRI was negative for syrinx. All neuro exams normal. Neuro felt EMG's unnecessary.  2 neurosurgeons did not believe that the Chiari Malformation was culprit, since no headaches and symptoms are not aggravated by exercise or the Valsalva.  Both recommended ACDF surgery and are surprised by lack of significant neck and/or arm symptoms.  Currently awaiting ADF with Prestige disc with a ortho. surgeon who recommended 2nd neuro opinion, as he felt that leg pain was unusual with cervical cord compression.  

1. Are symptoms suggestive of ALS?  I'm seeing the 2nd neurologist tomorrow and will request EMG/NCV.
2. Can my C3-C4 herniation with cord compression explain my leg symptoms, including the fasciculations and the globus sensation?  
3. Would you recommend cervical artificial disc replacement over the fusion procedure in my case?

Thanks!

[koopatroopa]

Here are the final results of the latest SSEP:

Abnormal Study

Findings are notable for an abnormal left tibial nerve SEP, but otherwise normal responses including median nerves, pudental nerve (S2,3,4) and multiple dermatomal levels (left/right T12, Left L3, left L5)

Regarding the tibial portion: "cortical response present on the right, but the early responses are nearly absent on the left. Right waveform well-developed with normal latency and normal amplitude (1.5 sd below the normal mean).  Left waveform, early peaks, are poorly developed with normal latency and significantly decreased amplitude (more than 3 sd below the normal mean).  These waveforms were reproducible x3 with no artifact obscuring the response.  Peripheral responses normal bilaterally.  Interpeak latencies normal."

These findings are not particularly suggestive of cervical myelopathy affecting somatosensory pathways.  However, we cannot exclude a myelopathy affecting other than dorsal columns.

It is possible that a left S1 root impairment could explain these changes.

Note that a thoracic/lumbar MRI with contrast last week was normal.  If a LEFT S1 root impingement was indeed the cause, why am I having bilateral leg symptoms (even though my left leg is indeed worse and feels weaker)?  Also, if a nerve was impinged in the sacral area, wouldn't the EMG I had have detected that?  My EMG was normal.  What is your take on all this?

[koopatroopa]

Well, my repeat SSEP's preliminary results were just discussed with me.  They shocked both hands, waist above the iliac crest on both sides, tibial nerve at both ankles, stimulated the top of both feet, and even penis!  Everything is normal except for the left tibial spot on left foot, which came out strongly abnormal.  The technician (who has extensive experience in SSEP's) is baffled, as such results do not correlate with cervical myelopathy. My neurologist/neurosurgeon have yet to get a copy of the results, since they are not final.  The technician believes the bilateral leg weakness/pain is coming from the lower back/sacral area, not the neck, since one would expect systemic abnormal SSEP findings.  I relayed this info to my neurosurgeon, who ordered another round of thoracic and lumbar MRI's, this time with contrast.  These were absolutely normal, except for some mild neuroforaminal stenosis in the thoracic spine, unchanged from the previous MRI's.  

Is it possible that only certain spinal cord pathways are getting compressed by the C3-4 disc, resulting in only the left tibial foot nerve being affected?  What else could be causing my leg symptoms, given the testing I've undergone?  My doctors appear stumped.  

It's ironic how I was to undergo cervical fusion surgery a month ago, when now that diagnosis is in doubt!

[Stephen Ryu, MD]

your neurologist is correct, in essence. Fasciculations by definition are a result of lower motor neuron disease. However, you can nab some of these with a cord compression. It is rare to see it with a disc.

However, people get muscle twitchies all the time - these are not pathologi fasciculations. Fasciculations coupled with muscle atropy is concerning. Having part of your body twitch, especially when you are tired or falling asleep, is very common.

[koopatroopa]

Hi Dr. Ryu,

Thanks for your prompt response.

My neurologist gave me an EMG/NCV today, which was normal.  I'm still awaiting the results of the tibial SSEP.  All blood tests are normal or negative: ANA panel, Sed. rate, CPK, Lyme, Compl. Metabolic Panel, Fasting Glucose, Hemoglobin A1C, B12, and a few others.

I will be undergoing a flexion/extension cervical MRI tomorrow to better assess the C3-C4 cord compression in relation to my leg symptoms.  

My follow-up question is this: My neurologist told me today that cervical cord compression CANNOT cause fasciculations anywhere, even below the level of the herniation, because fasciculations involve the lower motor neurons, whereas the herniated disc should only cause upper motor neuron dysfunction.  Based on your knowledge and the patients you've seen, is this an accurate statement?

Thanks.

[Stephen Ryu, MD]

Your story is very interesting and I can understand your concern. It's easy to start reading about things and start to say "Oh! That's what I have!" People have even been known to start having new symptoms after reading about things they think they might have. Often the symptoms were there, but now you have a newfound awareness of them.

Nothing obvious comes to mind in your case. I think you are doing the right thing getting lots of opinions on the matter. Let me address your questions.

1) ALS - it would be very unusual. A KEY factor in ALS is there is NO SENSORY component - you should not feel pain or numbness with ALS. Period. There are other neurological conditions that mimic ALS, though they tend to be very rare.

2) I don't know what your MRI looks like so I don't know how bad it is. It could cause your symptoms if you have cervical myelopathy because the cord is very compressed to the point of injury. On the other hand, it could be unrelated. It should not affect anything above the lesion - that is nothing in the throat, face, or head.

3) Good questions - I don't know unless I see the films. I do both operations and teach Prestige to other surgeons. There is clearly a role for both fusion and arthroplasty (disc) and picking the right patient it key. With the disc, you get the THEORETICAL benefit of preserved motion that MIGHT reduced degeneration in the long run. (None of this is proven) With the fusion, you get a very tried and true operation that works great but MIGHT cause limited movement and accelerated degeneration. I think the biggest thing for you is to get a clear understanding of the goal of surgery - do the surgeons think you will get better? I can't say without seeing you, the films, and doing an exam.

Good luck.

[koopatroopa]

Thanks for your comments.

I find it incredibly coincidental that my fasciculations started a month after my leg symptoms first appeared.  Given that one neurologist and two neurosurgeons believe the cervical cord compression is causing my lower limb symptoms and given that (based on your description above) fasciculations CANNOT be associated with the cord compression, is it fair to reason that my leg symptoms are most likely NOT caused by the cervical cord compression, due to the presence of fasciculations?

In addition to the lab work I described in my initial post, my 2nd neurologist has attempted to rule out additional systemic diseases that would cause leg pain/weakness/fasciculations.  However, those additional tests have turned out negative: Thyroid Panel (TSH, Free T3, Free T4), RA, CRP, and another random glucose.  This 2nd neurologist is doubting that my cervical cord compression is causal to my leg symptoms, because of the pain component, which he thought was rare (weakness is more typical).

Also, the recent flexion/extension cervical MRI showed no gross subluxation.  Findings were similar to what I stated in my first post.  My first tibial SSEP was inconclusive, so my neurologist is having me repeat it next week.  As for the globus sensation, my primary doc. has doubled my prilosec dose to 40 mg/day....hopefully, that'll do the trick to eliminate that problem.

Any additional thoughts?  I am baffled.