Objective: To present and discuss the clinical presentation and treatment in patients with long-duration unilateral facial paralysis and normal magnetic resonance imaging (MRI) findings.
Design: Case series.
Setting: Ear, nose, and throat department of the University of Cologne, Cologne, Germany.
Patients: A total of 486 patients with unilateral facial paralysis who were treated from 1986 to 1998. Besides the usual diagnostic workup, a complete electrophysiological evaluation, including investigations such as needle electromyography and neuromyography (also known as electroneurography), of the facial nerve was performed at repeated intervals. In 19 patients, a malignant tumor was delineated with ultrasonography or MRI. In 8 of these patients, the initially performed MRI did not detect any parotid gland lesion causing the paralysis, whereas long duration of the paralysis and electroneurography indicated malignancy.
Results: Exploration surgery was performed as total parotidectomy in these 8 patients and malignant parotid gland tumors were proved in all 8 patients.
Conclusions: Individuals with facial nerve paralysis without any signs of regeneration 6 months after the onset of paralysis and/or persistent electrophysiological evidence of ongoing neuronal degeneration should undergo surgical exploration of the parotid gland and facial nerve, even if MRI studies show no tumoral lesion.