Hemifacial Spasm and Craniovertebral Anomaly

Abstract

ABSTRACT:Two patients with congenital anomaly of the craniovertebral junction causing disabling hemifacial spasm (HFS) are presented. In one patient, complete cessation of the HFS occurred for a period of two years following simple bony decompression of the craniovertebral junction raising unanswered questions as to the exact pathogenesis of HFS. Eventually both patients required microvascular decompression at the root entry zone of the facial nerve.

Neurovascular relationships in the posterior cranial fossa, with special reference to trigeminal neuralgia. 1. Review of the literature and development of a new method of vascular injection-filling in cadaveric controls

“…First described by Dandy (1934), in the context of trigeminal neuralgia, neurovascular compression has since been implicated in disorders as seemingly disparate as hemifacial spasm, vertigo, presbycusis, glossopharyngeal neuralgia, hypertension, torticollis and hemiglossal atrophy, when vascular compression of, respectively, the facial, vestibular, cochlear, glossopharyngeal, vagus, accessory and hypoglossal nerves has been implicated (Jannetta, 1982a;Wilkins, 1985;Jannetta, 1990;Moller, 1991aMoller, , 1991b. The compression is thought to arise at the point where the nerves are attached to the brain stem and to have its effect by altering axonal transmission (Haines et al, 1980;Jannetta, 1980;Richards et al, 1983;Wilkins, 1985;Maroun et al, 1990). Fragmentation of the myelin from sustained pressure is thought variously to allow for ''cross talk'' or ''reverberation'' and thus syndromes of hyperactivity, or interruption of transmission, and those of hypoactivity (Moller and Jannetta, 1986;Moller, 1987Moller, , 1991aMoller, , 1991bNielsen, 1985).…”

A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

“…Upon literature review, the most common causes of HFS, besides neurovascular compression, were cerebellopontine angle tumors (epidermoid, arachnoid cyst, lipoma, and vestibular schwannoma) 2 , 3 , 9 , 15 , 26 , 38) , and other unusual causes including cerebellopontine angle medullary venous malformations 15 , 24) , Paget's disease 16 , 25) , occipital falcine meningioma 5) , cerebellopontine angle meningioma 11) , acoustic schwannoma 11) , pontine glioma 45) , fourth ventricle ganglioglioma 6) , pontine infarction 43) , syringobulbia 4) , multiple sclerosis 42) , trauma 29) , hypothyroidism 13) , idiopathic intracranial hypertension 37) , vertebrobasilar ectasia 21) , craniovertebral anomalies 28) , glomus jugular tumor 23) , parotid gland 8 , 11 , 12 , 32) , and arterial hypertension 33) . A few cases of HFS alone or in combination with trigeminal neuralgia have been reported as a false localizing sign in patients who had a contralateral posterior fossa mass or acoustic neuroma 30 , 31) .…”

Unusual Causes of Hemifacial Spasm

“…Other cases of hemifacial spasm were ascribed to cerebellopontine angle medullary venous malformation, 23 Paget's disease, 24,25 occipital falcine meningioma, 26 pontine glioma, 27 fourth ventricle ganglioglioma, 28 pontine infarction, 29 syringobulbia, 30 multiple sclerosis, 31 trauma, 32 hypothyroidism, 33 idiopathic intracranial hypertension, 34 vertebrobasilar ectasia, 35 and craniovertebral anomalies. 36 A few cases of HFS alone or in combination with trigeminal neuralgia have been reported as a false localizing sign in patients who had a contralateral posterior fossa mass 37 or acoustic neuroma. 38 Parotid gland tumors resulting in HFS are rare as demonstrated by the paucity of cases reported in the medical literature.…”