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Show Chiasmal Glioma in Spasmus Nutans: A Cautionary Note Michael C. Brodsky, MD, Gesina F. Keating, MD Abstract: We diagnosed chiasmal glioma in an 8-month-old infant who had spasmus nutans that spontaneously resolved. Magnetic resonance imaging showed no interval change in tumor size over the next 8 months. Clinical resolution of spasmus nutans does not preclude chiasmal glioma as the underlying cause. Journal of Neuro-Ophthalmology 2014;34:274-275 doi: 10.1097/WNO.0000000000000121 © 2014 by North American Neuro-Ophthalmology Society Spasmus nutans is a benign clinical entity characterized by the triad of nystagmus, head nodding, and an abnormal head position (1). The nystagmus is of low amplitude and high frequency and is often asymmetrical in the two eyes. It generally begins between 4 and 12 months of age (1) and is more common in the African American and Hispanic pop-ulations (2). Most cases are idiopathic, and its natural history is one of the spontaneous resolutions. In some children, how-ever, it can signal the presence of chiasmal glioma or under-lying retinal disease. We examined an infant with spasmus nutans whose unusual clinical course provides a cautionary note for the clinical management of this condition. CASE REPORT A healthy 8-month-old Caucasian infant with spasmus nutans was referred for evaluation of nystagmus, which was first noted at 2 months of age. The nystagmus intensified, and he began bobbing and tilting his head at 3 months of age. His head movements became more pronounced when trying to focus on objects of interest. He was born 4 weeks prematurely weighing 6 lb 11 ounces at birth. The parents had noted no photophobia or difficulty seeing in dim illumination. He had no family history of nystagmus and was neurodevelopmentally normal. On examination, he followed optokinetic stimuli and maintained fixation with either eye, and had normal pupillary responses to light with no relative afferent pupillary defect. He had fine symmetrical shimmery nystagmus, which was asso-ciated with vertical head bobbing and a chin-down head when viewing objects at near. Retinoscopy showed a mildly hyperopic refractive error. Retinal examination disclosed no optic disc swelling or pallor, and a normal retina in both eyes. Magnetic resonance imaging showed bilobed thicken-ing of the optic chiasm extending anteriorly to involve both intracranial optic nerves (Fig. 1). The tumor extended posteriorly to involve the optic tracts and showed additional extension into the right anterior midbrain and mesial temporal lobe. Endocrinologic test-ing disclosed no abnormalities. Over the next 2 months, his nystagmus and head nodding gradually resolved. Neuro-oncology evaluation was performed, and it was elected to observe him given the absence of associated neurological findings. On follow-up examination at 16 months of age, all signs of spasmus nutans were com-pletely resolved, and repeat neuroimaging showed no change in the tumor size. DISCUSSION The rare association of chiasmal glioma with spasmus nutans is usually signaled by one or more of the following clinical findings: 1) a relative afferent pupillary defect; 2) optic atrophy or disc swelling; 3) large head size; 4) café-au- lait spots; and 5) coexistent neurological dysfunction or emaciation (3,4). Because these clinical findings were absent in this infant, the decision was almost made to forego neuroimaging. More surprising was the finding that the spasmus nutans completely resolved on follow-up examination, although 2 subsequent neuroimaging studies Departments of Ophthalmology (MCB) and Neurology (MCB, GFK), Mayo Clinic, Rochester, Minnesota. Supported by an unrestricted grant from Research to Prevent Blindness, New York, NY. The authors report no conflicts of interest. Address correspondence to Michael C. Brodsky, MD, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905; E-mail: brodsky.michael@ mayo.edu 274 Brodsky and Keating: J Neuro-Ophthalmol 2014; 34: 274-275 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. over a 10-month period showed no change in the tumor size. If we had seen the child after the spasmus nutans had resolved, neuroimaging would certainly have been deemed unnecessary. This case history highlights 3 critical points in the clinical management of spasmus nutans. First, the early onset of spasmus nutans should raise particular concern about chiasmal glioma. Second, the absence of "red flag" systemic or neuro-ophthalmologic signs in the infant with spasmus nutans does not definitively rule out the possibility of chiasmal glioma (5,6). Finally, even the spontaneous resolution of spasmus nutans does not rule out chiasmal glioma as the underlying cause. REFERENCES 1. Norton EW, Cogan DG. Spasmus nutans: a clinical study of twenty cases followed two years or more since onset. AMA Arch Ophthalmol. 1954;52:442-446. 2. Wizov SS, Reinecke RD, Bocarnea M, Gottlob I. A comparative demographicand socioeconomic study of spasmus nutans and infantile nystagmus. Am J Ophthalmol. 2002;133:256-262. 3. King RA, Nelson LB, Wagner RS. Spasmus nutans. A benign clinical entity? Arch Ophthalmol. 1986;104:1501-1504. 4. Brodsky MC. Pediatric Neuro-Ophthalmology, 2nd edition. New York, NY: Springer, 2010. 5. Antony JH, Ouvrier RA, Wise G. Spasmus nutans: a mistaken identity. Arch Neurol. 1980;37:373-375. 6. Koenig SB, Naidich TP, Zaparackas Z. Optic glioma masquerading as spasmus nutans. J Pediatr Ophthalmol Strabismus. 1982;19:20-24. FIG. 1. Brain magnetic resonance imaging (MRI). Contrasted T1 coronal MRI shows enlargement of the prechiasmatic optic nerves (A) (arrows) and optic chiasm (B) (arrow). Brodsky and Keating: J Neuro-Ophthalmol 2014; 34: 274-275 275 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
