Trigeminal Dysfunction in Patients with Bell's Palsy

Abstract

The trigeminal function was investigated in 30 consecutive patients with acute unilateral peripheral facial palsy. The patients were tested with electrophysiological methods within 5 weeks after onset of the disease. Trigeminus-evoked potential test (TEP) disclosed trigeminal dysfunction in 47%, while the blink reflex test (BR) showed trigeminal pathology in 60% of the patients. A topographical analysis of the trigeminal system showed that 24% of the patients had BR patterns that were consistent with brainstem involvement. In 2 cases (7%), TEP was pathological though the BR test proved normal. These findings suggest a more central tngeminal affection and may demonstrate multifocal lesions. This was further underlined by the investigation of the auditory brainstem response (ABR) which indicated brainstem involvement in 28%. It is concluded that acute facial palsy is frequently a symptom of a central nervous affection.

Key Words:

• Bell's palsy
• idiopathic facial palsy
• trigeminus-evoked potentials
• blink reflex
• auditory brainstem response
• CNS involvement