The role of cranial and thoracic electromyography within diagnostic criteria for amyotrophic lateral sclerosis

Abstract

The contribution of cranial and thoracic region electromyography (EMG) to diagnostic criteria for amyotrophic lateral sclerosis (ALS) has not been evaluated. 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. 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. 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.