Cranial Nerve Injury
March 29, 2006What is a Cranial Nerve Injury? It is where the unilateral branches of the facial nerve and vagus nerve, in the form of recurrent laryngeal nerve, are most commonly involved in cranial nerve injuries and result in temporary or permanent paralysis.
Compression by the forceps blade has been implicated in some facial nerve injury, but most facial nerve palsy is unrelated to trauma.
Physical findings for central nerve injuries are asymmetric facies with crying. The mouth is drawn towards the normal side, wrinkles are deeper on the normal side, and movement of the forehead and eyelid is unaffected. The paralyzed side is smooth with a swollen appearance; the nasolabial fold is absent; and the corner of the mouth droops. No evidence of trauma is present on the face.
Physical findings for peripheral nerve injuries are asymmetric facies with crying. Sometimes evidence of forceps marks is present. With peripheral nerve branch injury, the paralysis is limited to the forehead, eye, or mouth.
The differential diagnosis includes nuclear genesis (Möbius syndrome), congenital absence of the facial muscles, unilateral absence of the orbicularis oris muscle, and intracranial hemorrhage.