FACIAL NERVE PARALYSIS Facial nerve palsy is often idiopathic. Causes: acute otitis, trauma, HSV infections. It is sudden, unilateral peripheral facial nerve palsy. Symptoms: the ability to wrinkle the forehead, blink, and grimace is limited or absent. Diagnosis: eg, chest x-ray or CT, serum angiotensin-converting enzyme [ACE] level to check for sarcoidosis, MRI for other neurologic deficits, tests for Lyme disease. Treatment : protection of the cornea this may include lubrication of the eye, intermittent use of an eye patch, and for idiopathic facial nerve palsy, corticosteroids.