Consideration of Acoustic Reflex Magnitude (ARM) in Cases of Idiopathic Facial Paralysis

Contralaterally elicited acoustic reflex growth functions were obtained from both ears of patients with unilateral idiopathic facial paralysis. Comparison was then made between the normal and impaired reflex arc by means of a simple calculation procedure. The resultant acoustic reflex magnitude (ARM) score was used to evaluate the symmetry of these responses, thereby providing an objective quantification of the functional status of the impaired reflex arc. These measures were found to be highly correlated with both the degree and rate of recovery of the facial motor impairment.