Journal of Neuro-Ophthalmology, June 1990, Volume 10, Issue 2

Bilateral hemifacial spasm.

Journal of Clinical Neurcrophlhalmology 10( 2): 1S3-- 156, 1990. Letters to the Editor Bilateral Hemifacial Spasm To the Editor: Hemifacial spasm is a unilateral hyperactivity of the facial nerve characterized by progressively worsening spasms of the orbicularis oculi spread­ing to other muscles of facial nerve innervation. Most cases are associated with compression by vascular anomalies of the seventh cranial nerve ( CN VII) at the root entry zone in the brainstem, which may be seen on magnetic resonance imag­ing ( MRI) or computerized tomography ( CT scan) ( 1). We describe a case of bilateral hemifacial spasm documented by radiographic and surgical findings. CASE REPORT A 62- year- old woman gave a history of right hemifacial spasm which had begun in 1976. In 1978, she underwent a neurosurgical microvascu­lar decompression ( MVD) in Pittsburgh, at which time a teflon sponge was placed between an anom­alous vascular loop and the right CN VII at the root entry zone within the cerebellopontine angle. Hemifacial spasm recurred and she underwent a second MVD a year later. The right hemifacial spasm again recurred postoperatively, and CN VII and CN VIII were injured on the right during a third MVD procedure in 1980. Hemifacial spasm recurred on the right two years later. A unilateral myectomy procedure was performed in October 1984, with a marked improvement in the right or­bicularis spasm. During a follow- up visit in May 1987, she related the recent onset of an intermittent twitching on the left ( previously uninvolved) side. Examination showed fine intermittent involuntary muscle con­tractions in the temporal aspect of the upper and lower eyelids on the left. These were asynchro­nous with the residual muscle contractions on the right side. Examination was otherwise unremark­able except for complete hearing loss on the right side. The patient underwent an MRI scan of the head, 153 © 1990 Raven Press, Ltd., New York which revealed vertebrobasilar dolichoectasia on the left with intimate contact between the left bas­ilar artery and the left CN VII at the root entry zone ( Fig. 1). There has been minimal progression of her left- sided spasm since this time, and the patient has declined further treatment. DISCUSSION Hemifacial spasm is unilateral, and usually re­lated to a vascular cross- compression of CN VII at the root entry zone in the cerebellopontine angle, commonly by branches of the posterior or anterior inferior cerebellar arteries ( 2). Digre and co­workers showed a characteristic convexity and en­largement of the vertebral or basilar arteries, termed vertebrobasilar dolichoectasia, in 92% of con­trast CT scans of patients with hemifacial spasm ( 1). Hemifacial spasm must be distinguished from bilateral squeezing disorders such as essential blepharospasm or Meige syndrome, which are thought to be due to abnormalities in the basal ganglia and midbrain and have normal radio­graphic findings. Although rare, bilateral cases of hemifacial spasm can occur. In a review of 106 patients with hemifacial spasm, Ehni and Woltman ( 3) noted six patients believed to have bilateral hemifacial spasm on the basis of asynchronous onset and asymmetric involvement. However, radiographic, surgical, or electromyographic findings were not presented in this report. Janetta ( 2) noted one pa­tient with bilateral hemifacial spasm of 229 patients treated with MVD. Eckman and associates ( 4) re­ported a case of bilateral hemifacial spasm docu­mented by electromyography and cerebral angiog­raphy. Hemifacial spasm is typically unilateral, which distinguishes it from the bilateral facial dystonias. Bilateral hemifacial spasm is a condition that may be confused with essential blepharospasm and the facial dystonias. In a large series of facial dystonia patients seen by one author ( R. L. A.), three bleph­arospasm patients were initially misdiagnosed as having hemifacial spasm because of a difference of months to years in the noticeable onset of spasm between the two sides of the face and a marked 154 LETTERS TO THE EDITOR FIG. 1. MRI ( magnetic resonance image) revealing dolichoectatic vertebrobasilar artery compressing fa­cial nerve at root entry zone ( arrow). asymmetry in the facial spasm. Bilateral hemifacial spasm is characterized by the temporally separate onset of asynchronous, asymmetric spasms. It is important to be aware that bilateral hemifa­cial spasm can exist, and to distinguish it from es­sential blepharospasm and other facial dystonias in order to offer appropriate evaluation and treat­ment options to the patient. MRl or CT scan is not routinely indicated in the evaluation of blepharo­spasm, but the posterior fossa should be evaluated with one of these studies in cases of hemifacial spasm. While rare, bilateral hemifacial spasm must be included in the differential diagnosis of a bilat­eral facial squeezing disorder. John B. Holds, M. D. Richard L. Anderson, M. D. Department of Ophthalmology University of Utah School of Medicine Salt Lake City, Utah David R. Jordan, M. D. Department of Ophthalmology University of Ottawa Ottawa, Ontario, Canada James R. Patrinely, M. D. Cullen Eye Institute Baylor College of Medicine Houston, Texas REFERENCES 1. Digre KB, Corbett n, Smoker WRK, McKusker S. CT and hemifacial spasm. Neurology 1988; 38: 1111- 3. 2. Janetta PJ. Microvascular decompression for hemifacial spasm. In: May M, ed. The facial nerve. New York: Thieme Inc, 1986: 499- 508. 3. Ehni G, Woltman HW. Hemifacial spasm: review of one hundred and six cases. Arch Neurol Psychiatry 1945; 53: 205- 11. 4. Eckman PB, Kramer RA, Altrocchi PH. Hemifacial spasm. Arch NeuroI1971; 25: 81- 7. Angiography for IIIrd Nerve Palsy in Children To the Editor: Dr. Allan J. Fox recently published an interest­ing paper concerning angiography for IIIrd nerve palsy in children ( 1). Dr. Fox asked for reader re­sponses, so here is mine. I have included three pictures illustrating the case of a six- year- old girl presenting ophthal­moplegia in upward gaze and on adduction of her right eye, without lid ptosis or pupillary involvement Fig. 1. Patient in primary gaze- note that there is no ptosis of her right eye. The pupil was also not in­volved, although difficult to see with a- dark iris in this picture.