[Electrodiagnostic criteria for early diagnosis of bulbar-onset ALS: a comparison of El Escorial, revised El Escorial and Awaji algorithm].

Introduction: Diagnosis of bulbar ALS is difficult at the early stage of the disease. According to guidelines, early diagnosis is better in view to optimize the management of affected patients. To improve the sensitivity without losing specificity of the prior criteria, the Board of Awaji has proposed modified electrodiagnostic criteria for ALS. The aim of this study was to evaluate the contribution of needle electromyography in early diagnosis of bulbar ALS by comparing the El Escorial criteria (EEC), Revised El Escorial Criteria (R-EEC) and Awaji algorithm (AA).

Methods: In a retrospective study, we analysed clinical and electrophysiological data of 46 patients followed in our center for a bulbar-onset ALS seen for the first time between January 2007 and February 2011. All these patients had bulbar-onset ALS probable or certain at the last follow-up. All data were collected during the first clinical examination and the first electrophysiological study.

Results: Mean age of the population was 69 (37-90years, sex ratio: 0.91). Using the EEC, 9 patients were diagnosed as definite or probable ALS at the first consultation. Applying the R-EEC, 13 patients were diagnosed as definite or probable ALS and using the AA, 23 patients were diagnosed as definite or probable ALS. The sensitivity of the EEC was 19.5%, the R-EEC was 28.2% and for AA was 49.98%.

Conclusion: AA are more sensitive in early diagnosis of bulbar ALS compared to R-EEC with the contribution of ENMG and when fasciculations are considered as evidence of spontaneous activity. Such an approach can contribute to accelerate an optimal management of the disease. AA are a breakthrough in the diagnosis of ALS especially in the bulbar-onset forms.