An approach to diagnosing ALS emphasizing Clinical Neurophysiology Sociedad Mexicana de Neurofisiología Clínica, A.C Dr. Andrew Eisen MD.,FRCPC Profesor Emérito Universidad de British Columbia
Electrodiagnostic criteria for diagnosis of ALS Clinical Neurophysiology 119 (2008) 497–503 Mamede de Carvalho, Reinhard Dengler, Andrew Eisen, John D. England, Ryuji Kaji, Jun Kimura, Kerry Mills, Hiroshi Mitsumoto, Hiroyuki Nodera, Jeremy Shefner, Michael Swash .
Edx and clinical data are of equal and interchangeable value in diagnosing ALS
In the presence of signs of partial denervation , Fasciculations (preferably of complex morphology) are equivalent to fibs-psw, indicating ongoing denervation.
Unstable MUPs & FPs are especially relevant
Seek these EMG abnormalities in clinically normal muscles Positive sharp waves Fibrillation CRD Large complex unstable MUPs
More diffuse and profuse
Clinically large excursions
EMG - potentials complex, unstable, components “come and go”
Origin - supra-spinal
May be glutamate dependent - reduced by riluzole and neurontin