Hemifacial spasm can be the presenting symptom of a fourth ventricle tumour. A short case-illustrated review and pathogenetic considerations

Hemifacial Spasm Associated with Compression of the Facial Colliculus by a Choroid Plexus Papilloma of the Fourth Ventricle

BACKGROUND

Hemifacial spasm is an involuntary condition that involves muscles innervated by the ipsilateral facial nerve. There are secondary causes of hemifacial spasm that can produce a typical presentation of symptoms. Extrinsic compression of the facial colliculus at the floor of the fourth ventricle is responsible for <0.6% of the causes of secondary hemifacial spasm, as the cases with this origin reported in the literature are rare.

CASE REPORTS

We present the case of a 43-year-old female with hemifacial spasm of typical characteristics 6 months after onset. Upon clinical examination, a severe contraction of the orbicularis oculi, orbicularis oris, and superficial muscles of the neck displaying 50 crisis per hour was revealed. Brain magnetic resonance imaging showed absence of the facial nerve vascular loop in the cisternal portion, with evidence of an intraventricular tumor in relation with the medial portion of the fourth ventricle at the facial colliculus level, indicating a secondary origin of hemifacial spasm. Preoperative electromyography demonstrated irritative electric activity in the muscular branches of the facial nerve. A telovelar approach was performed to the fourth ventricle with intraoperative electrophysiology monitoring, with immediate resolution of the irritative activity after complete tumor resection. The result of the histopathologic study was a choroid plexus papilloma.

CONCLUSION

Fourth ventricle tumors with extrinsic compression of the facial colliculus represent <0.6% of the causes of hemifacial spasm. Its relationship with choroid plexuses papilloma is being described as the first case reported in the literature. Clinical correlation, imaging, and intraoperative findings in conjunction with intraoperative electrophysiology recordings allow to predict the resolution of symptoms after resecting the lesion.

Management of symptomatic hemifacial spasm or trigeminal neuralgia

Hemifacial spasm (HFS) or trigeminal neuralgia (TN) is a kind of hyperactivity disorder of cranial nerves caused by vascular compression. However, sometimes, the disease may arise from nerve damage produced by tumors, which was called as symptomatic HFS/TN. Until now, little is known about the exact mechanism and the necessity of microvascular decompression (MVD) regarding the tumor-induced HFS/TN, which is necessary to be retrospectively analyzed in a considerable sample. Among the 4021 patients who underwent MVD in our department between 2006 and 2014, 44 were finally diagnosed as symptomatic HFS or TN. These patients were focused in this study and their clinical features as well as intraoperative findings and postoperative outcomes were retrospectively investigated. Data analysis exhibited the symptomatic HFS/TN cases accounted for 1.1 % in the study, which were caused by epidermoid in 18 (40.9 %) and meningioma in 15 (34.1 %) followed by neuroma in 7 (15.9 %) as well as aneurysm in 2 (4.5 %) and arteriovenous malformation in 2 (4.5 %). Compared to those with idiopathic HFS/TN, younger females were more susceptible (p < 0.05). After resection of the neoplasm, the offending vessel was identified in 26 (59.1 %), which were followed by MVD process. Postoperatively, the symptoms relief rate was 88.6 %. Our study showed that surgical management of patients with symptomatic HFS/TN may lead to a satisfactory result, yet those primary lesions should be removed firstly. In some cases, a microvascular decompression process might be unnecessary afterward, but the entire nerve root should be checked to exclude any vessel in contact with.

Immediate disappearance of hemifacial spasm after partial removal of ponto-medullary junction anaplastic astrocytoma: case report

Hemifacial spasm (HFS) is generally caused by a neurovascular conflict (NC) at the root exit zone (REZ) of the facial nerve at the brainstem. Although a direct compression to the seventh cranial nerve (CN) by the anterior inferior cerebellar artery (AICA) is generally the most frequent cause, secondary HFS may be related to other pathological conditions. HFS due to an intracranial mass lesion is exceptionally rare and it has been reported in very few cases. The online database was searched for English-language articles reporting cases of HFS due to brainstem mass lesions and the possible pathophysiological mechanisms involved in its genesis. A 47-year-old man affected by an anaplastic astrocytoma of the brainstem at the level of the ponto-medullary junction developed right HFS. He underwent a subtotal surgical removal of the tumor with complete resolution of the HFS. This is the ninth reported case of HFS caused by an intrinsic brainstem tumor. The exceptional rarity of the relationship between intra-axial tumors and peripheral HFS was analyzed.