Spontaneous electromyographic activity of the tongue in amyotrophic lateral sclerosis

Introduction: Detection of denervation in muscles in the craniobulbar area is important to assure widespread lower motor neuron involvement in the diagnosis of amyotrophic lateral sclerosis (ALS). The value of spontaneous activity analysis in needle electromyography (EMG) of the tongue has been questioned in the recent literature. Methods: Spontaneous activity in the tongue and sternocleidomastoid (SCM) muscles was reviewed retrospectively in 17 ALS patients. Results: Needle EMG showed spontaneous activity in the tongue in 14 of 17 patients (82%) and in 6 patients of 17 (35%) in SCM. Spontaneous EMG activity in the tongue was found in patients with and without bulbar symptoms. Conclusions: Needle EMG is a valuable method for assessing clinical and subclinical involvement of the tongue in patients with bulbar and limb onset ALS. Adequate relaxation of the tongue is a prerequisite for proper spontaneous activity recording.