AANEM Connect

While recording F waves on left APB, stimulating at wrist, I noticed the waveforms in question. I made the screen capture at two different sweeps, with increased F-wave gain for better visualization. The patient is a 69 year-old female that had a left carpal tunnel release aprox. 13 weeks prior. She did well after CTR for around 4-5 weeks when she developed worsening hand symptoms.

Good evening,

I recently encountered an unusual case of carpal tunnel syndrome (CTS) that I found quite challenging, and I am seeking some insights from this esteemed group.

A 77-year-old right-handed woman presented with various right hand symptoms, including paresthesias, stiffness, and coldness, which were sometimes worse at night. A cursory examination was normal, except for mild APB atrophy.

Her nerve conduction studies (NCS) showed the following:

• Median motor potential: Normal latency (3.8 ms), low amplitude (3.0 mV), and normal velocity (53 m/s)
• Right median SNAP: Borderline increased peak latency (3.60 ms), borderline low amplitude (19.5 μV), and normal velocity (53 m/s)
• Radial SNAPs were normal
• Palmar studies and studies to the fourth digits were entirely normal

I did not perform the ulnar motor potential or a needle EMG due to time constraints and the assumption that the low median motor potential was artefactual. I concluded with an essentially normal report, attributing her symptoms to musculoskeletal issues.

She was later evaluated at another institution, where her history was described as more typical of CTS. Their NCS results were also normal, but a restricted EMG examination revealed severe chronic neurogenic changes in the APB and a normal FDI. They diagnosed severe CTS and referred her for surgery.

I was surprised by this conclusion and would have considered a radicular or myeloradicular origin, likely imaging the cervical spine.

My questions are:

• Can CTS present solely with axonal motor findings, even with sensory symptoms?
• Is this potentially a case of isolated thenar motor branch involvement?
• How would you have proceeded with a case like this?

Thank you for your guidance.

Sincerely,
Repentant EMGer

Good morining everyone. I wanted to reach out to anyone interested in presenting at a small conference virtually. We are looking for someone who can speak about the growing need for EMG/NCS and challenges of availability in both urban and rural communities. Anyone intersted please reach out to me at

cory.hansen2@imail.org

I have posted on this before.  The AANEM office suggested I post this to the forum to see if there are other physicians experiencing this issue.

I am starting to see billing warnings from other insurance companies (besides Humana who flat out denies) saying a patient can’t have carpal tunnel syndrome and cervical radiculopathy at the same time.  This combination frequently occurs in patients. 

And now the software system is also saying/warning that patients can’t have lumbosacral plexopathy and radiculopathy, even though there are patients with symptoms and findings that could be possible plexus and possible radiculopathy clinically where the EMG doesn’t definitively rule out one or the other and additional anatomical imaging or other work up is needed. 

This is looking like a trend where the insurance company will deny if these diagnoses are submitted together but will also deny higher nerve conduction codes like 95913 saying it isn’t necessary for “just” carpal tunnel or “just” cervical radiculopathy or any other limited diagnosis codes submitted. 

Perhaps AANEM would have more clout in going to insurance companies on this.  I have submitted position letters from AANEM with appeals, but many times it doesn’t work.  The insurance companies don’t give a s… about me as a solo practitioner and they have no incentive to do what is fair. 

 Thank you. 

Janet Balbierz, M.D.

I have a patient with a small fiber neuropathy who started with constant severe burning pain in his feet. After 2 or 3 infusions of Rituximab his pain intensity is now 20% of the original intensity and his pain is no longer constant with the pain lasting from 2 or 3 hours a day up to 11 hours (2 or 3 hours the most common duration.

He has a sustained response to the Rituximab but seems to be hitting a plateau in terms of response. Would switching him to another agent possibly produce additional benefit? If not how long should I continue the Rituximab. He has had 3 infusions so far?

We had a 40 years old male with no previous co-morbids in our edx lab for evaluation of non-specific generalized weakness since childhood which he noted has worsened recently with ho of neck pain. There was no radiation to arms, no reported sensory or motor weakness or bladder and bowel dysfunction.

OE: strength was good in all 4 limbs, relatively brisk reflexes (more in upper limb), hoffmans negative, plantars-down, no sensory level, was able to walk tandem, could walk few steps on toes and heels.

On NCS, right median sensory latencies and SNAP were normal, bilateral median motor were not-recordable bilaterally from APB. Ulnar motor and sensory were normal.

On needle examination few neurogenic units (polyphasic, broad) were found in right APB and bilateral ADM with no active denervation. Apart from these muscles, no EMG abnormalities found in bilateral upper limbs (including right EIP, PT, PQ, PL, FPL, biceps, triceps and left APB, FDI, FCU and EIP) and bilateral cervical paraspinals.

Since no significant abnormality was found in median SNAPs and EMG of median innervated muscles,

we did additional studies recording ulnar motor nerve from thenar (to rule out riche cannieu anastomosis) and median from hypothenar muscles (for MGA) which were inconclusive. Median nerve was then recorded from FPL which mostly showed ulnar motor wave form.

MRI cervical spine was reported multilevel disc degenerative disease most marked at C4-C5 level, resulting in mild compressive myelopathy (as reported )

Is this remote inactive cervical C8-T1 radiculopathy or proximal CB of bilateral median nerves but again EMG is normal in all median innervated muscles except minimally abnormal APB and, yes normal SNAPs?

Appreciate your input to understand this.

Thanks.

 

There is somewhat disputed different opinions about the ideal CMAP recording elctrode size, shape and type (metal vs. disposable) and relation to different muscle size. I appreciate experts discussion of this issue . 

Bassam A. Bassam, MD, FAAN

Hi all,

I am hoping for some input on the following case.

The patient is a 70F with no known medical history.

Left lower extremity weakness and pain for ~ 8 months. Progressed slowly; ~4 months ago the left lower extremity symptoms started to improve but patient developed weakness of the right lower extremity. Has had multiple falls. Some burning pain and numbness of right leg (not well characterized). No back pain. No upper extremity complaints.

Exam

LLE strength 2-3/5

RLE strength 1-2/5 proximally; 0/5 dorsiflexion, toe extension; trace plantarflexion

Sensation intact to pinprick and light touch, decreased to vibration on the right

Achilles/patellar reflexes absent

 

Patient has been seen by neurology. There was concern for CIDP.

Has not had extensive labs; ESR/CRP, CMP, CBC normal.

MRI lumbar spine and LP with CSF studies unremarkable

Electrodiagnostic results:(technically limited by lower extremity edema and obese body habitus)

NCS

Absent sural sensory responses bilaterally (there was moderate edema)

Left fibular CMAP: normal latency and CV; decreased amplitude 0.5 mV at EDB, 1.1 mV at TA

Right fibular CMAP: absent at EDB and TA

Left tibial CMAP: normal latency and CV; decreased amplitude (3.0mV)

Right tibial CMAP: normal latency; dec CV (28m/s); decreased amplitude (0.4mV)

Normal right radial SNAP and normal ulnar/median CMAPs

F waves-normal right median, normal left fibular, prolonged left tibial, absent right tibial

H reflex-borderline left tibial, absent right tibial

EMG: TA, FL, gastroc, VM, RF bilaterally: fibs/psws in all muscles; unable to activate the right TA or FL; there were mild-moderate neuropathic changes in all other muscles.

I'd like to call it an axonal polyneuropathy but am thrown by the relatively rapid onset, waxing/waning left lower extremity symptoms, and extent of proximal muscle involvement without any upper extremity involvement.

From reviewing Preston and Shapiro, the relapsing/remitting nature, stepwise progression, and asymmetry suggest mononeuritis multiplex or a CIDP variant. But would these present with findings isolated to the lower extremities and abnormal findings in all muscles tested?

Thank you and I appreciate any input!

 

67F Patient referred for right hand weakness and numbness/pain over the past year.  She reports it started in digit 5, now numb in digit 4 also. She is having progressive difficulty with gripping things, bending her fingers and thumb, but also weakness with extending her wrist and thumb. She has a histroy of stroke with right sided residual deficits a few years ago, but those were improving until the last year. Her exam is notable for 4/5 RUE  shoulder abduction, elbow flexion, elbow extension. 3/5 RUE wrist extension, finger extension, DIP flexion, thumb opposition, and 2nd/5th digit abduction. 5/5 throughout the LUE. Decreased sensation in right ring and pinky fingers. 3+ reflex throughout the RUE. Has a positive Tinel's at the elbow but also positive Spurling and Adson+Roos test (she really reported symptoms with any movement of that arm).

NCS notable for absent right ulnar SNAP with robust median, radial and contralateral ulnar signals. Very low amplitude right ulnar CMAP (0.2 mV) and slowing across the elbow (59 m/s to 48 m/s) without conduction block.  Also slowing of the right median SNAP at D2 (4.4 ms), with normal right median CMAP.

EMG with neuropathic changes in FDIH, OP, EIP (p waves, fibs, large polyphasic units with markedly reduced recruitment, with most spontaneous activity at FDIH). Normal biceps, triceps. 

The lesion seems to be post ganglionic, and with pattern of numbness and weakness, the most parsimonious location would be inferior trunk. No trauma, no cancer history. However, she also has slowing across the elbow, so considered seperate severe ulnar neuropathy and a cervical (C8?) radiculopathy. 

I sent for an MRI brachial plexus with contrast, which returned as essentially normal. Then got an MRI C-spine with findings of "Severe right foraminal zone stenosis C6-C7 due to uncinate osteoarthropathy and moderate degenerative disc disease.  Tiny right paramedian disc protrusion C5-C6. There is no central canal compromise at any level". Nothing notable at C7/T1.  I've referred her to both a hand surgeon to discuss her ulnar elbow, and a spine neurosurgeon for her neck. 

Any suggestions on interpretation of localization in this patient? Things that would have helped electrodiagnostically to point in the right direction for management? Looking back I probably should have done a MABC. 

Thanks!

In the evaluation of a person with LMN spina bifida (ie S1), who is referred for query S1 radiculopathy, can we be sure that if we see spontaneous activities on needle EMG that there is something acute going on? Or could that be a remnant of the underlying spina bifida? 

Hello colleagues,

I have a 16M patient with complicated history, presumed CIPD but also found to have MFN2 gene mutation. He came to me for PM&R consult, he has persistent distal weakness and atrophy requiring AFOs, hand splints and scoliosis. He has seen multiple neuromuscular specialists over the past few years, but now they are looking for referral to a neuromuscular specialist in CIDP who they can get another opinion regarding his medications (IVIG, rituximab). He likely needs a repeat EMG but I didn't want to do it if he was going to go to a new neuromuscular doctor who would probably want to repeat the study themselves anyway. He lives in central NJ. Any recommendations for a CIDP specialist in this area? Thank you

Hello All,

Looking for input/data for safety of NCSs in cardiac patients with external pacers/ defibrillators/ LVAD. there is plenty of literature on implanted devices, any insight for external devices.

Thanks.

I am requesting all of your help to better define both the audience and outreach for this forum via the AANEM Connect discussion venue.  Would you be so kind as to please give your thoughts on the following:

 

• Continue to keep the AANEM Connect forum open only to the AANEM membership as it currently exists as a benefit of a paid membership only.

Or

• Open up the AANEM Connect forum a bit for viewing purposes only, to Neurology/PM&R residents/neuromuscular fellows who are not members of the AANEM, but without the ability to ask questions or perform searches and free of charge.  A support letter from a program director would ensure the status of the resident/fellow.

 

Greetings EMGers,

 Do you have any old EMG or SSEP equipment or parts?  ASET--The Neurodiagnostic Society (Technologist society) is collecting old EMG and EP parts and equipment for the virtual museum of the  Smithsonian Institute Neurodiagnostic Museum. I'm on the ASET Historical committee for the Smithsonian Institute.  I'm working on the EMG/EP section.  If you have anything that looks like it should be thrown in the trash or old equipment you are trying to get rid of , please consider donating these old items to ASET for the virtual museum. 

I am posting this in part out of frustration, and also to generate discussion regarding training and philosophy on performing history/physical during EDx consult.

I recently saw a 63 y/o male, smoker, with pmxh from pcm note copd/chronic hep c with about 1 year of progressive subjective decreased balance, dropping items, shoulder weakness, numbness/tingling equal bilateral volar forearms into hands d1-3 (constant but improved with gabapentin) night cramps in thighs and calves.  He had seen local neurologist shortly before I saw him (fellowship trained neuromuscular) who did NCS but could not do needle study due to patient refusal.  NCS normal other then ulnar slowing across elbow, felt to be indicental given lack of ulnar symptoms.  This doctor did no history or physical exam, nor did he make any comments regarding potential diagnoses or workup.

My exam notable for deltoid and scapular muscle atrophy and weakness with distal UE muscles and quad/hip flexors normal. Reflexes spastic with Hoffman, no clonus.

I orderd c-spine MRI:  Severe central stenosis C3-5 with cord signal changes.

• I was trained as PM&R to always do H&P; discuss findings with the patient; discuss clinical correlation, need for additional workup/treatment in my report. I will make the surgical referral or order additional workup within my scope of practice because that's how I learned and it's good for the patient and their referring provider.
• However, I have seen many studies over the years, all done by neurologists, where none of the above is done.  The patients have confirmed this as well.  Doctor told them to get on the table, no exam, test was done, no discussion, minimal or no discussion in the report, sent back to PCM so they can try to figure it out.
• I have had neurologists tell me this is how they were taught.
• I struggle with the concept that at least some neurologists don't practice EDx medicine per the guidelines from AANEM, especially considering that the AAN seems to use the AANEM guidelines.
• I'm frustrated:  how can a fellowship trained neuromuscular specialist miss what should be a pretty simple diagnosis?  
• Does anyone in this community also not do H&P as part of the test?  If so, why?
• Can we as a community do anything about this problem?

I've been looking for the ideal pen to use for studies -- a combination of visible, somewhat resistant to electrode gel, and washable.  I've used Zebra Clickart Water-Based Pen Calm Dark 12 Colors Set, Wyss22-12Cdk that has the advantage of being clicked open/closed but does smear a bit when patients sweat or when too much electrode gel is present.  Does anyone else have a product that they are happy with?

Hi all,

I'm interested in your opinion regarding relative sparing of the EDB muscle compared to an atrophic tibialis anterior. I have seen this occasionally in myopathy and dystrophy patients. 

I recently had a very complicated study for left foot drop and bilateral lower extremity numbness/burning in a 77 year old in which the left tibialis anterior muscle was visibly atrophic and bilaterally the TAs had low amplitude CMAPs [1.0;symmetric], yet the EDB were bulky with high normal CMAP amplitudes (left [foot drop side] was 3.6; the other was 8.7). There were not sensory or tibial abnormalities. A very comprehensive EMG Bilateral lower and some uppers) showed no myopathic findings at all. There were very significant, mostly chronic or sub-chronic reinnervation changes in all distal > proximal leg muscles bilaterally and in the left FDI with denervation (PSWs and fibs) in the left tibialis anterior only (the foot drop side).

The lumbar MRI doesn't show anything that would cause multilevel radiculopathy -- it's pretty normal. I feel that the time course (onset of foot drop 7 years ago) and relative paucity of active denervation would be atypical for ALS plus the robustly normal EDB muscles in the setting of ALS with foot drop would also be atypical.

Is this EDB sparing significant? What does it make you think of?

Thanks for your thoughts--

Hello! can anyone give guidance on how to approach a winging scapula case, on exam this appears to be long thoracic neuropathy. Needling Serratus Anterior muscle, is challenging, any suggestions, on the safest technique, I guess the diagnosis will mostly be based on the needle test. Appreciate any guidance!

-A patient who was referred to me for a deficit in the left hand with numbness of the inner side of the forearm….

Motor Amplitude of  median nerve with wrist stimulation was  3.5mV, at the palm stimulation amp 7.5mV (simultaneous recording of the first interosseous, there is no diffusion) a block at the wrist, palm stimulation in the other side was 14.

- Motor ulnar amplitude at the wrist was 10 and symmetrical to the contralateral without any conduction bloc (wrist, below and above elbow and axilla), the sensory D1, D3 and D5 are normal and symmetrical, the left cutaneous brachii medialis 20uV and hard to get it and on the other side at the first attempt I get 34, mixed cubital 45 and 65 on the other side….

The Needle electromyography: Was neuropathic: The abductor digiti minimi detection poor to intermediate recruitment (accelerated trace) same for the 1st interosseous, abductor policis brevis simple reduced recruitment too, only a single MUAP that was firing, the flexor carpi radialis and flexor carpi ulnaris were in good strength (5/5).

-History: Stress and important weight loss according to the patient, He is a smoker

-Cervical MRI: Degenerative changes, uncarthrosis C5 and C6

---> What are your opinions dear colleagues about this presentation? Are we allowed to consider it as postganglionic rather then preganglionic lesion because the cutaneous brachii of the affected limb is significantly reduced compared to the contralateral?

What about the distal bloc in the wrist? Could this be the onset of neuropathy with conduction bloc, proximal and distal?

I am looking for a black Neuromax, not a white one, 2 or 4 channel, to buy hopefully with a cart.

I plan to retire in a year or so. I have two EMG machines, one a Natus Quest, the other a Nicolet Viking, both working fine. I would like to give these away to a "worthy cause" at retirement, but do not know of any such that could use these machines. Please help me identify potential recipients. 

a 45 y.o. woman with a past medical history significant for hypothyroidism presented for evaluation of episodic muscle weakness. Patient reported 3 episodes of severe weakness of her legs. She describes this as feeling her legs like jello. Her 1st episode was in 2017 and lasted for 6 months. It usually starts in the legs then progresses all over. All her symptoms resolved and she was fine until 2019 when the same exact thing happened. All her symptoms resolved again after 3 days per her report. About a month ago, the same thing started again . She has difficulty getting upstairs. She has difficulty walking and is currently using a walker. She denies any weakness in the arms at the current time.

She had a muscle biopsy. It was read as showing myopathic changes including lipid accumulation consistent with lipid storage myopathy (That is all). She also had an EMG on 02/27/2019 that was read as diffuse myopathy with fibrillation potential.

On Exam: Normal exam except for hypertrophy of her calves. 

Her son is autistic and while he was having some medical treatment, he, his sister and mom (patient) had whole exome sequencing. All had mutation in the TMEM43 gene, heterozygous for arrhythmogenic right vent dysplasia-5 and Emery-Dreifus muscular dystrophy-7. 

EMG yesterday: Myotonia most prominant at TA, M Gastroch and thoracic paraspinals with other areas of denervation and myopathic units. Myotonic discharges were breif and fading. 

I sent the comprehensive NM panel to Invitae yesterday which has EDMD

The fact that it comes in spells (not exclusively in the winter), she is completely normal and able to exercise in between is buzzling to me. She has never had any physical restriction.. She denies any physical restriction in her children, or weakness. 

What do you think? We are in Greater Philladelphia area. She was seen before at U Penn. The initial EMG and muscle biopsy were done there. 

My future employer is designing a new EMG/EEG shared space and is asking me if a "chair bed" would work for EMG. My employer's goal is to have a single unit rather than having a separate recliner for EEG placement/sleep and a bed cart for EMG. The chair bed can convert from a flat bed to an upright chair and everything inbetween. Max pt weight is 385 lbs, length while flat is 74" (6' 2").

Have any of you done EMG on a motorized chair bed? Any advice/"lessons learned" on the patient surface for doing EMG?

My biggest worries are the lack of bed rails and thinking of a large patient lying in the fetal position for back muscles, but I'll be doing outpatient only for a community practice. I currently do EMG on patients in a Stryker hospital bed or a patient transport cart, which have been fine. 

Store link: https://www.source1beauty.com/Radi-Fully-Electric-Treatment-Table-2246B-Grey-p/2246b-g.htm

Youtube: https://www.youtube.com/watch?v=zHfLw6hFMOg&t=128s

What patterns/studies on EDX are helpful in differentiating between the two ?

There is suggestion of non length dependent non entrapment sensory neuronopathy could suggest a neuronopathy.

One study mentioned absent blink reflex in the setting of activated masseter reflex suggests a neuronopathy.

Can I request opinions re EDX findings to differentiate between the 2 or any recommended resources to differentiate between the two ? Also I'm not sure what an activated masseter reflex EDX testing involves, any leads ?

Thank you

I recently evaluated a 25 year old woman for a question of thoracic outlet syndrome, who was found to have a cervical rib on an X-ray. Her nerve conduction studies showed a median CMAP amplitude of 8 mV, ulnar CMAP amplitude of 7 mV, and normal median and ulnar SNAP amplitudes. However, her medial antebrachial sensory response was 7 uV but 18 uV on the other side. Is this consistent with true neurogenic TOS?