Hemifacial Spasm Due to Cerebellopontine Angle Meningiomas. Two Case Reports.

Abstract

A 54-year-old female and a 49-year-old female presented with complaints of hemifacial spasm. Both patients underwent surgery to remove cerebellopontine angle meningiomas. In one case, no vascular compression was observed at the root exit zone. The tumor was removed subtotally leaving residual tumor adhered to the lower cranial nerves. The hemifacial spasm disappeared immediately after the operation. The residual tumor was treated using gamma knife radiosurgery. In the other case, the root exit zone of the facial nerve was compressed by both the tumor and anterior inferior cerebellar artery and the tumor was removed totally. Postoperatively, the hemifacial spasm disappeared, but the patient suffered facial nerve paresis and deafness that was probably due to intraoperative manipulation. However, the facial nerve paresis gradually improved. Cerebellopontine angle meningioma with hemifacial spasm must be treated by surgical resection limited to preserve cranial nerve function. Subtotal removal with subsequent radiosurgery to treat the remaining tumor tissue is one option for the treatment of cerebellopontine angle meningioma.

Gamma Knife surgery for hemifacial spasm related to cerebellopontine angle tumors

“…In patient groups treated with surgery for tumors, Chang et al 3 stated that 2 (3%) of 65 intracranial meningiomas presented with HFS, and Samii and Matthies 20 noted that 4 (0.4%) of 1000 patients with VSs presented with HFS. In groups of patients who underwent radiosurgery, Iwai et al 8 found that facial spasm occurred in 6% of the patients. There is another subgroup of patients with newly developed HFS after radiosurgery for VSs.…”

“…Nagata et al 16 noted excellent postoperative recovery after resection of benign tumors in the posterior fossa in their 4 patients (100%). Iwai et al 8 reported 2 cases, in which one patient had undergone microsurgery alone and the other patient had microsurgery followed by radiosurgery for residual tumor. Both patients obtained freedom from HFS.…”

Hemifacial Spasm Caused by a Huge Tentorial Meningioma

“…Hemifacial spasm commonly results from unilateral vascular compression 7,8) whereas it is rarely caused by ipsilateral pathology adjacent to the REZ of the facial nerve other than vascular compression 2,4,6,10,11,15) . This unilateral hyperac- tive dysfunction of facial nerve is manifested by spasm of the orbicularis oculi that slowly spreads to involve the orbicularis oris and all of the muscles of facial expression, including the platysma.…”

“…When the artery is located between the tumor and facial nerve, the artery may be trapped and begin to compress the nerve as the tumor grows. The standard surgical treatment for this tumor and the associated HFS is microsurgical removal of the tumor first, with MVD added selectively according to the anatomy around the CPA 6,11,19) . Tumors remote to the CPA causing HFS are rarely reported and the pathogenic mechanism is not clear.…”

“…In most cases, mechanical compression of the facial nerve at the root entry zone (REZ) by blood vessels is the main pathophysiological mechanism, and surgical treatment using microvascular decompression (MVD) is performed for the majority of patients. HFS can also develop as a result of other pathological conditions around the cerebellopontine angle (CPA), such as tumors, aneurysms, or arteriovenous malformations involving the REZ of the affected facial nerve 6,7,9,11,15,18,19) . Lesions distant to the CPA are very rare causes of HFS 1,3,5,14,17) .…”