Unusual course of spasmus nutans in infant with chiasmal glioma

The authors report the case of an 8-month-old with spasmus nutans with an unusual clinical course and chiasmal glioma, a known association.

Spasmus nutans is a benign condition characterized by nystagmus, head nodding and an abnormal head position. It usually begins between 4 and 12 months of age. Most cases are idiopathic, and its natural history is one of spontaneous resolution. However, the authors note that in some cases, it can signal the presence of chasmal glioma or underlying retinal disease.

The authors write that 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 swellings; 3) large head size; 4) café-au-lait spots; and 5) coexistent neurological dysfunction or emaciation.

In this case, an 8-month-old patient who had been previously diagnosed with spasmus nutans was referred for evaluation of nystagmus, which was first noted at two months of age.

MRI showed bilobed thickening of the optic chiasm extending anteriorly to involve both intracranial optic nerves. The tumor extended posteriorly to involve the optic tracts and showed additional extension into the right anterior midbrain and mesial temporal lobe.

Over the next two months, the nystagmus and head nodding gradually resolved, and spasmus nutans completely resolved on follow-up, although two subsequent neuroimaging studies over a 10-month period showed no change in tumor size.

They say this case highlights three critical points in the clinical management of spasmus nutans:

• The early onset of spasmus nutans should raise particular concern about chiasmal glioma;
• The absence of “red flag” systemic or neuro-ophthalmologic signs does not definitively rule out the possibility of chiasmal gliomal; and
• Even the spontaneous resolution of spasmus nutans does not rule out chiasmal glioma as the underlying cause.