[Prognostic value of classical electrodiagnosis in patients with peripheral facial nerve paralysis]

Electrodiagnostic tests are performed in order to obtain information on the severity of lesions and the possibility of functional recovery. Classic electrodiagnostics implies excitability testing by faradic and galvanic currents, and chronaximetry. This method has been pushed out by new diagnostic procedures, although it is a reliable method that can give data about the severity of lesions and precise data about the maximal possible function recovery and the time it takes. The aim of this study was to investigate the correlation between the results of classic electrodiagnosis and functional recovery in patients with facial paralysis.

The prospective study included 50 ambulatory patients treated at the Department of Physical Medicine and Rehabilitation. After the use of diagnostic procedures (otorhinolaryngological, neurological, radiological), all patients underwent physical therapy. Two weeks after the onset of paralysis, classic electrodiagnostics was performed. We compared the prognosed and achieved recovery in two ways: for each muscle separately and for gross function (the House-Brackmann scale).

32 patients (64%) had only changes in excitability, 7 patients (14%) showed partial electrodegenerative reactions, 4 patients (8%) had electrodegenerative reactions and preserved reactions to faradic currents, 4 patients (8%) showed electrodegenerative reactions and inexcitability to faradic currents, and 3 patients (6%) had disruption of conductivity. Comparison of prognosed and achieved marks for the frontal, orbicularis oris and mental muscle showed a highly significant agreement in 94%, 80% and 86% of patients, respectively. There is also a highly significant agreement between prognosed and achieved recovery, described according to the House-Brackmann scale.

In this study, classic electrodiagnostics showed a highly significant correlation between the predicted and the achieved outcome. Correlation was more significant when the "marking method for individual muscles" was used. The authors think that the classic test, unjustly pushed out in favor of new methods, (electroneurography - ENG, nerve excitability test - NET), certainly has advantages (insignificant intertrial and side-to-side variations as well as the possibility to test each muscle separately).

The classic electrodiagnostics is a century old technology that offers useful information on nerve lesions. In our opinion, it should be part of the physiatric examination of patients with peripheral facial nerve paralysis.