INTRODUCTION: The contribution of cranial and thoracic region electromyography 
(EMG) to diagnostic criteria for amyotrophic lateral sclerosis (ALS) has not 
been evaluated.
METHODS: Clinical and EMG data from each craniospinal region were 
retrospectively assessed in 470 patients; 214 had ALS. Changes to diagnostic 
classification in Awaji-Shima and revised El Escorial criteria after withdrawal 
of cranial/thoracic EMG data were ascertained.
RESULTS: Sensitivity for lower motor neuron involvement in ALS was highest in 
the cervical/lumbar regions; specificity was highest in cranial/thoracic 
regions. Cranial EMG contributed to definite/probable Awaji-Shima categorization 
in 1.4% of patients. Thoracic EMG made no contribution. For revised El Escorial 
criteria, cranial and thoracic data reclassified 1% and 5% of patients, 
respectively.
CONCLUSION: Cranial EMG data make small contributions to both criteria, whereas 
thoracic data contribute only to the revised El Escorial criteria. However, 
cranial and thoracic region abnormalities are specific in ALS. Consideration 
should be given to allowing greater diagnostic contribution from thoracic EMG. 
Muscle Nerve 54: 378-385, 2016.