Heteronymous H reflex in temporal muscle as sign of hyperexcitability in ALS patients. Issue 8 (August 2019)

• Record Type: Journal Article
• Authors: Libonati, Laura; Barone, Tommaso Francesco; Ceccanti, Marco; Cambieri, Chiara; Tartaglia, Giorgio; Onesti, Emanuela; Petrucci, Antonio; Frasca, Vittorio; Inghilleri, Maurizio
• Is Part Of: Clinical neurophysiology. Volume 130:Issue 8(2019:Aug.)
• Page Start: 1455
• Page End: 1459
• Publication Date: 2019-08
• Subjects: ALS -- Amyotrophic lateral sclerosis -- H reflex -- Hyperexcitability -- Masseteric reflex; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2019.05.010
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Masseteric H reflex is used as an electrophysiological equivalent of mandibular jerk. Heteronymous H reflex is used as a sign of UMN involvement in suspected ALS patients. Heteronymous H reflex can be used to evaluate motor neuron pool excitability. Abstract: Objective: The stimulation of the masseteric nerve elicits a homonymous and a heteronymous H reflex in the masseter muscle and in the temporalis one. The presence of the H reflex may be considered a sign of upper motor neuron (UMN) involvement in amyotrophic lateral sclerosis (ALS) patients. The aim of this study was to evaluate the presence of the heteronymous H reflex in patients with ALS and compare it with normal subjects. Methods: We enrolled 36 ALS patients and 52 healthy subjects. We stimulated the masseteric nerve in the infratemporal fossa and recorded the muscle responses ipsilaterally to the stimulation. Results: The heteronymous temporalis H reflex was elicitable in 88.9% of ALS patients and in none of the controls. Conclusion: The heteronymous H reflex does not disappear when the stimulation intensity is increased. It can be used as sign of UMN involvement and may prove useful in patients with suspected MND/ALS with purely lower motor neurons (LMN) signs and no signs of UMN involvement. Significance: The heteronymous H reflex is present far more often in ALS patients than in healthy people. It is a simple test that may be used to detect UMN involvement in patients in whom the only evident signs are LMN impairment, improving diagnosis of ALS.