Transient unilateral facial paralysis induced by perimesencephalic non-aneurysmal subarachnoid hemorrhage: A case report and review of the literature.

The present study is, to the best of our knowledge, the first report of a rare, transient form of unilateral facial paralysis induced by perimesencephalic non-aneurysmal subarachnoid hemorrhage. The paralysis may have resulted from the compression of a part of the facial nerve by the flow of the hemorrhage into the cavum subarachnoidale; alternatively, the paralysis may have been caused by disorder of the blood supply of the facial nucleus, with the hemorrhage leading to brainstem vasospasm. The patient underwent hemostatic therapy, administration of a symptomatic antiemetic and dehydration. The facial nerve compression was released due to the absorption of the hemorrhage or the rapid improvement of the facial nucleus blood supply following the resolution of the vasospasm. Consequently, the facial nerve function was fully recovered, and the facial paralysis disappeared.