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EMG Specificity

PostPosted: December 14th, 2015, 7:07 pm
by misterjuanperalta
According to NIH, the most important observation was that absent fibrillations in the first dorsal interosseus and deltoid muscles identified benign conditions with sensitivities of 66%-77% and a specificity of 93%. Further, greater spontaneous activity levels were observed in upper trapezius EMG measurements with excellent specificity (=>70%). In conclusion, deltoid and upper trapezius EMG recordings may provide valuable information for assessing lower motor neuron involvement in MND patients, particularly at early disease stages. Alternatively, according to ALSTDI, muscle ultrasonography (NMUS) is being utilized to identify fasciculations in at least four muscles, and increased fibrosis (muscle echogenicity) in two muscles. Ultrasonography differentiated between MND and mimics with 96% sensitivity and 84% specificity. In the 27 MND patients, ultrasonography detected 15 regions with lower motor neuron involvement that were negative using either clinical examination or needle EMG.

Source: http://www.ncbi.nlm.nih.gov/pubmed/26059445
Source: http://www.ncbi.nlm.nih.gov/pubmed/21554033
Source: http://www.ncbi.nlm.nih.gov/pubmed/19086078
Source: http://www.sciencedirect.com/science/ar ... 5711010959

Re: EMG Specificity

PostPosted: December 14th, 2015, 7:26 pm
by Little Lost
According to the extract " Spontaneous activity was more frequently detected in the first dorsal interosseus and deltoid muscles of ALS patients than in patients with the slowly progressive motor neuron diseases "........


Oophs. .......well looks like I am in for it. First dorsal interosseus was the area I showed the most spontaneous activity in on my emgs.......but then that was 4 years ago and hand still as strong as ever. Thanks for the info ...so kind of you

Hx
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Re: EMG Specificity

PostPosted: December 14th, 2015, 7:52 pm
by misterjuanperalta
The study points to correlation and not causation. Further, it does not state that only MND results from such activity.

Re: EMG Specificity

PostPosted: December 14th, 2015, 9:40 pm
by Little Lost
This aim of this study was to find emg parameters that could reliably identify aggressive ALS MND from more benign mimics at an early stage.

The observations involving the first dorsal interosseus data was taking from patients at a very early stage. So these patients didn't officially have a clear MND diagnosis when the spontaneous activity was recorded but went on to develop it in consecutive emgs. Those that didn't have first dorsal activity tended to go on to have one of the slower variants.

As the exact point of ALS onset is not known, and the "incubation period from preclinical to subclinical to clinical is not set" then distinguishing between causation / correlation in this case is not clear cut. For it to have been clear correlation these patients would have had to have defined end point ALS at point of recording. But even if it is correlation it is seen in very early stages of ALS, so it is still a correlation I could have done without.

I will live....stupid twitching first dorsal..

Hx

Re: EMG Specificity

PostPosted: December 14th, 2015, 10:15 pm
by misterjuanperalta
I'm sorry if the post offended you. I thought it was positive.

Re: EMG Specificity

PostPosted: December 14th, 2015, 11:07 pm
by Little Lost
Not in the least offended. You do a good service taking the time to post what you find and it is very appreciated. It is my stupid first dorsal interosseus that is offensive not you.

Hx