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I'm curious because I'm reading conflicting information in studies as to the likelihood of a clean EMG but still having ALS. One paper shows 10% of cases reveal no major EMG abnormalities for those already diagnosed with ALS...

Has anyone here who has been diagnosed, had a clean EMG only to find out they had ALS soon after? Or had a clean EMG and then a dirty EMG a few months later?
 
I'm not an expert, but from what I understand, it is possible to have a clean EMG if you have PLS, which is upper motor neuron only. The EMG picks up the damage caused by the lower motor neurons being damaged. So while it is possible, it's not probable, and I would guess that in most cases its when PLS is later determined to be ALS.

In my case, the EMG showed problems in my arms nearly 2 years before I started having a lot of issues with them (it started in my foot, so was already diagnosed).

Check trfogey's postings, he had a really good explanation a few weeks before he passed away explaining how it works.
 
Not me. I had 3 dirty ones.
 
I have a clean emg (emg showed fasciculations and no other signs) but I have signs of upper motor neuron problems so the doctors are saying I have an upper motor neuron dominant mnd. I don't have a final diagnosis yet but this is what they told me about the main possibility.
 
I have a clean EMG but have bulbar ALS. Take care.
 
Reading posts above...we can consider CLEAN EMG doesn't mean NO ALS.
A clinical exam is more important than EMG?

Best!
 
I had a clean EMG when symptoms first started. I had only bulbar symptoms for years affecting mainly speech.
Then years later, I have muscle weakness, and balance problems. My left hand cramps and is weaker and my legs are very stiff.
I am sure that if I had an EMG now that it would be dirty, but I am in no hurry to have another one of those.
 
I'm an up per mo tor kinda gal who still had 4 of the dir ty little buggers. Why 4 you might ask? I was trying to pro ve the doc tors wro ng!
 
My first EMG was mostly clean... just some decreased recruitment, fasciculations, and a few weird runs in my anteriright lower leg. The next EMG about 3 months later showed more of the same kind of stuff distally in my right arm and leg. The third EMG 3 months after that was just plain dirty and horrible, especially when the doctor decided to needle my tongue in an effort to confirm denervation and reinervation in 3 areas. I REFUSE to ever have another EMG again!
 
i had four emg's, all dirty. oct09, jan10, feb10 (als)' sep10 (satisfy va)
 
Doctor told me emg will pick lower motor neuron problems. Sometimes people have problems in upper motor neurons and this kind of problems cannot be picked up by an emg and are just diagnosed by a clinical exam. Other times people have problems in bulbar area and an emg done in other places (like limbs for example) can be clean or not since the disease that starts in bulbar area will spread to another places but not in the beginning . Als is a disease in which you have problems in both upper and lower motor neurons so after these explanations I think a clean emg means no als but could not rule out all kinds of mnd.
 
I HATED THE EMG. SO PAINFUL Can't imagine going through 3.
 
This is a dangerous thread for many reasons. First you must always keep in mind that the EMG is only as good as the person performing the test. Also it is not like an x - ray so if the test wasndings not done properly or thoroughly when they do the print out their is nothing for the next Dr. to interpert they can only go off of the printed results of the test but it is not a picture or an image. This is why so many Dr's want to perform their own emg.

Second we throw around terms like clean or dirty and act like it is that simple. It is possible to have UMN dominant or LMN dominant ALS but you have to have both involved to receive a diagnosis. However if you really want to understand how they determine if someone has ALS I suggest you research EL Escorial ALS criteria. Then if you want to understand some of the potential confusion with EMG findings read about awaji ALS criteria. Here is a brief synopsis of the differences.
"In addition, in the context of a suspected clinical diagnosis of ALS, fasciculation potentials should be taken as equivalent to fibrillation
potentials and positive sharp waves in recognising denervation. The importance of searching for instability in fasciculation potentials
and in motor unit potentials in ALS is stressed. These changes in the interpretation of electrophysiological data render obsolete the category
Probable Laboratory-Supported ALS in the modified El Escorial diagnostic criteria for ALS. Methods for detection of upper
motor neuron abnormality appear sensitive but require further study, particularly regarding their value when clinical signs of upper
motor neuron lesion are uncertain."

I am no expert but if you are showing all the other signs of ALS especially the clinical weakness and some abnormalaties in the EMG but not true denervation they can still diagnose you with ALS. Again though I am not a Dr, researcher, scientist medical expert. All of my research leads me to one conclusion, find I Dr. or two that you trust and believe what they tell you. We can all try and interpert and guess and explain but none of that will take the place of 7 + years of top notch medical training.

Some people will use this thread to convince themselves they have this disease and others will argue over the interpertation of EMG results but the bottom line is listen to your Dr, you can not be diagnosed on the computer.
 
Last post went to moderation. Hopefully this one will not. Anyway learn the difference between El escorial criteria vs awaji criteria.

Read # 3 below closely Patricia was Bulbar onset and one of the people who originally had a clean emg.

"3. Conclusions of the consensus conference
1. We reaffirm the general principles underlying the El
Escorial and Airlie House recommendations for the
diagnosis of ALS. These are set out in modified form
in Table 2. In particular, the importance of full nerve
conduction studies and conventional EMG in excluding
other diseases was recognised (Lambert, 1969; Behnia
and Kelly, 1991; Daube, 2000). It is important to keep
in mind that the clinical neurophysiological examination
is used in the diagnosis of ALS when the diagnosis is suspected
clinically – suggestive neurophysiological findings
are therefore not intended to stand alone, outside the
context of the clinical assessment.

2. We conclude that, since needle EMG is essentially an
extension of the clinical examination in detecting features
of denervation and reinnervation, the finding of
neurogenic EMG changes in a muscle should have the
same diagnostic significance as clinical features of neurogenic
change in an individual muscle. Thus, within a single
limb, we recommend that abnormalities required for
the diagnosis of ALS may be derived from either clinical
or neurophysiological study, thus constituting the
requirement for involved muscles as set out in the general
instructions (Table 2). This interpretation renders
redundant the category ‘‘Laboratory Supported Probable
ALS’’ (Table 2) and will facilitate earlier diagnosis since it will allow a limb to be classified as abnormal earlier
than if this decision is based on clinical or EMG criteria
alone. The essential change is thus to recognise a
neurogenic EMG abnormality (Table 1) as of equivalent
significance to the clinical abnormality. It is, nonetheless,
important to confirm that EMG evidence of neurogenic
abnormality is found in clinically weak muscles.

3. We recognise that muscles may show evidence of chronic
neurogenic change in the absence of fibs-sw. We therefore
propose that the presence of fasciculation potentials
(FPs) in a muscle identified as showing needle EMG features
of neurogenic change should serve as evidence of
ongoing denervation, equivalent in importance to fibssw.
This criterion would obviate the need for the often
difficult search for fibs-sw in patients with clinically evident
features of ALS; in particular, in cranial-innervated
muscles and muscles of normal bulk and strength. For
example, although Finsterer et al. (1998) recorded fibssw
in some patients in bulbar muscles, de Carvalho
et al. (1999) found no fibs-sw in bulbar muscles in 15
bulbar-onset patients; fibs-sw were found in limb muscle
in only 7 of these 15 patients. In addition, in 2 of 28
newly diagnosed upper limb onset ALS patients, fibssw
were absent in the weak upper limb."
 
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