Commentary.

Hemifacial spasms (HS) is a hyperactive dysfunction of the VII cranial nerves because some factors just like vascular causes (the basilar arteries or its branches AICA), rarely suffered with cerebellopontine angle (CPA) mass lesions. Epidermoid tumor is one of the common tumors in the CPA after acoustic neurinoma and meningioma. Hyperactive dysfunction of the cranial nerves, especially TN, may be the initial and only symptom that patients with CPA epidermoids experience.[1] The incidence of the occurrence of HS in the CPA epidermoid tumor ranges from 0.07% to 2.5%.[12] There are isolated case reports of epidermoid tumors in the cerebellopontine angle. Therefore, readers can get a new knowledge from this article, which presented a checking and treating process of the rare disease.

In our hospital, epidermoid cyst in cerebellopontine angle with HS always be found by the neurologists and treated by neurosurgeons. However, patients of HS are found comparatively easier and sooner than the other hyperactive dysfunction of the cranial nerves, especially trigeminal neuralgia. Just like this article, a simple MRI scan can find the intracranial primary disease. Therefore, more clinical work should be concentrated into the treatment program. Today more and more new MR scans series just like three dimensional time of flight (3D-TOF)[3] or three-dimensional spoiled-gradient recalled (SPGR)[4] can be used to reveal the relationship between the cranial never and the intracranial vessels. Certainly, it is the most careful for a patient that how to cure this rare disease. The best method is the operational program. Careful resection of the tumor is firstly necessary and microvascular decompression to the neuraxis should be performed in some cases to achieve a complete, permanent cure of symptoms with a low rate of recurrence.[5]

However, HE is the secondary disease in most situation, whose factors just like compression from intracranial vessel and tumors lesion can be found to be explained and treated by decompression of any methods just like shifting vessels or dissecting lesions.[6] On the other hand, an epidermoid cyst rarely could not be resected totally by one neurosurgical operation.[7] Therefore, HS originated from the intracranial epidemoid cyst is a troublesome disease with my little experience except that HS is related to a very little epidemoid cyst. The cause of symptoms recurrent is always due to partial resection and arachnoid adhesion especially in young people who is younger than 30 year old at the time of microvascular decompression.[8] In the paper,[9] the patient is a very young man. I sincerely hope that the author should do pay more attention to follow-up the patient to the long-period therapeutic effect.