OBJECTIVES: To study the utility of muscle ultrasound (US) for detection of 
fasciculations and its contribution to diagnosis in amyotrophic lateral 
sclerosis (ALS). Fasciculations are characteristic features of ALS, and US can 
detect them easily and reliably. New diagnostic criteria for ALS, the Awaji 
algorithm, reintroduced fasciculations as evidence of acute denervation 
equivalent to that of fibrillations and positive sharp waves.
METHODS: In 81 consecutive patients with sporadic ALS, we prospectively 
performed needle EMG and US in 6 muscles (tongue, biceps brachii, first dorsalis 
interosseous, paraspinalis, vastus lateralis, and tibialis anterior), and 
diagnostic category were determined by revised El Escorial criteria and Awaji 
criteria.
RESULTS: Fasciculations were much more frequently detected by US than by EMG in 
the tongue (60% vs 0%), biceps brachii (88% vs 60%), and tibialis anterior 
muscles (83% vs 45%). The proportion of the patients with definite or probable 
ALS was 48% by revised El Escorial criteria and 79% by Awaji criteria using US.
CONCLUSIONS: Muscle US is a practical and efficient tool to detect 
fasciculations, particularly in the tongue. A combination of US and EMG 
substantially increases the diagnostic sensitivity of ALS.