Spasmus nutans is described as a self-limited syndrome of unknown etiology characterized by nystagmus, head nodding, and torticollis. The onset of signs occurs between the ages of four months and one year, with head nodding usually preceding the nystagmus. Torticollis is the most variable component of this syndrome. Until recently, most authors have stressed the benign, self-limited course of this condition.1,2
In the patient described here, the course was neither benign nor self-limited. The "classic" signs of spasmus nutans were associated with a juvenile pilocytic astrocytoma involving the optic nerves and chiasm.
An eight-month-old black baby girl developed intermittent head nodding at age three months, followed by unusual bilateral vertical and horizontal eye movements at age four months. The baby was the 7-1b 11-oz product of a normal full-term gestation and an uncomplicated delivery whose growth and developmental milestones were normal, with height and length each in the 90th percentile for her age. Her head circumference was 46 cm (95th percentile). Examination revealed an alert, active, smiling baby who was able to fix and follow a small toy with each eye. The pupils were equal and reacted briskly to light, with no evidence of an afferent pupillary defect. A bilateral rapid pendular nystagmus of small amplitude and variable frequency was noted. The nystagmus was primarily horizontal, but intermittent episodes of vertical and rotary nystagmus were also present. Brief episodes of jerk nystagmus were noted in the extremes of lateral gaze to either side. The nystagmus appeared to diminish in frequency with convergence. The patient had a variable degree of right head tilt and left face turn. The head nodded from flexion to extension and from side to side. These head movements did not appear synchronous with the eye movements. The child appeared normocephahc with no evidence of proptosis. Ocular examination revealed no abnormalities otherthan thosedescribed above. The optic nerve heads were pink and flat with sharp margins. Results of the neurologic examination were otherwise unremarkable. A diagnosis of spasmus nutans was made by both the pediatric neurology service and the ophthalmology service. The mother was assured that this was a benign, self-limited condition requiring no further diagnostic investigation.
Two months later, the child presented with a two-week history of diminished head nodding and loss of vision. Examination revealed that the child was unable to fix or follow a small toy with either eye. but did blink to light bilaterally. The pupils reacted sluggishly to light; however, no relative afferent pupillary defect was present. The nystagmus was present, and was similar to that seen previously, but diminished in frequency. The child now appeared macrocephalic with a bulging anterior fontanelle. The head circumference had increased to 51 cm (48 cm = 98th percentile). No head nodding was noted. Both optic discs appeared pale with slight blurring of the superolateral margins in each eye.
Computerized tomography (CT) demonstrated a large isodense mass which filled the suprasellar cistern (Figure 1A). A cystic lesion thought to be part of this mass bulged superiorly into the third ventricle, splayed the foramina of Monro and fornices. and caused severe obstructive hydrocephalus (Figure 1B). Following administration of intravenous contrast agent (Renografin60, Squibb), the tumor exhibited intense, nearly homogeneous blush with bilateral extensions posteriorly along the optic tracts to the lateral geniculate bodies (Figure 2). ' These changes were interpreted as a probable chiasmal glioma with secondary obstructive hydrocephalus.
The child underwent insertion of bilateral, lateral ventriculo-peritoneal shunts (Codman, Raimondi UniShunt) to relieve the hydrocephalus. Although the patient developed transient hyponatremia postoperatively, no evidence of endocrinologie abnormalities was found. Subsequent bilateral, internal carotid angiography and left vertebral angiography demonstrated a large, bilateral anterior suprasellar and parasellarmass, which compressed and probably encased the pericallosal arteries as well as the right middle cerebral artery. The mass displaced posteriorly the basilar artery tip and the anterior pontomesencephalic vein, ltbowed the thalamoperforating arteries and posterior thalamic veins posterosuperiorly. Angiographically, the mass also appeared consistent with a chiasmal glioma or astrocytoma of the hypothalamus.
Subsequent craniotomy revealed a tumor measuring approximately 6 cm in diameter and 3 cm in height, which involved both optic nerves and occupied the entire region of the optic chiasm. The "tumor cyst" proved to be a trapped, encysted, suprachiasmatic cistern, which displaced the foramina of Monro upward. Tumor encasement of the right internal carotid, right middle cerebral, and right anterior cerebral arteries prevented complete resection.
Histopathologic examination of the biopsy specimen revealed scattered neoplastic foci randomly intertwined with collagen fibers (Figure 3). The neoplastic foci consisted of spindle cells or stellate cells, which demonstrated moderately hyperchromatic nuclei, slight pleomorphism, and fibrillary processes (seen on phosphotungstic acid-hematoxylin staining). The specimen was felt to be a low-grade pilocytic astrocytoma.
Residual tumor was treated with radiation using a 4 MeV Linear Accelerator; 5040 rads were delivered to the suprasellar region during 28 treatments extending over a period of 39 days, using opposing left and right lateral parallel ports measuring 8 cm × 9 cm.
Four weeks after completion of radiotherapy, the child maintained the ability to blink to bright light bilaterally.
Spasmus nutans is an acquired clinical disorder of young children which in its complete form consists of nystagmus, head nodding, and torticollis. Spasmus nutans occurs most frequently before the age of one year, although it may appear as early as two weeks or as late as three years of age.1 Head nodding is usually the initial and most obvious sign, often preceding the nystagmus by months.1,4 The nodding movements are slow and intermittent, may occur in any direction, and appear unrelated to the nystagmus.5 The nystagmus is rapid and pendular with small amplitude excursions; it may have rotary, horizontal, or vertical components.5 Although characteristically bilateral and asymmetric, the nystagmus may be unilateral.1,6 Occasionally, it may be the last sign to disappear. : Torticollis is the most variable feature of this disorder and appears as a twisted or tilted head posture. Although the etiology and pathogenesis of spasmus nutans remain unknown, it has been regarded as a benign disorder.6 Recovery is usually complete within two years, although cases lasting as long as eight years have been reported.1,5
This patient presented with rapid pendular nystagmus, head nodding, and torticollis, the "classic" triad of signs that characterizes spasmus nutans. The initial examination revealed an otherwise normal child with no evidence of neurologic or visual deficits. However, two months later, the infant was found to have obstructive hydrocephalus, bilateral symmetric optic atrophy, and profound visual loss resulting from a pilocytic astrocytoma involving the optic nerves, chiasm, and anterior third ventricle.
FIGURE 3: Biopsy specimen of tumor demonstrates foci of neoplastic cells surrounded by intense desmoplastic reaction.
Diffuse gliomas involving the intracranial portions of the optic nerve or chiasm will most frequently present with optic atrophy, loss of vision, papilledema, headache, or strabismus.7.8 More unusual presenting signs include searching and unilateral rotary or vertical nystagmus.9 In contrast, tumors involving the hypothalamus may lead to the thencephalic syndrome, which is characterized by inanition, pale skin, hyperhydrosis, and neuroendocrine disturbances.10-12 Tumors in both locations may grow superiorly to obstruct the foramen of Monro or posteriorly to obstruct the aqueduct leading to severe hydrocephalus. Although this patient almost certainly harbored this tumor at the time of her initial examination, there was no evidence of diminished vision, optic atrophy, inanition, or other associated neurologic deficits. In retrospect, the child's large head circumference might have suggested the possibility of hydrocephalus.
Although optic gliomas may be associated with nystagmus, such tumors rarely present with the "classic" signs of spasmus nutans. Antony et al. described a case similar to our own, in which a 13-month-old girl with asymmetric pendular nystagmus, head nodding, and torticollis was found to have a glioma involving the optic nerve and chiasm.13 Kelly reported the case of a 3½year-old boy with a glioma of the optic nerves and chiasm who presented with nystagmus and head nodding, but no torticollis.14 Antony et al. also reported the case of an 8-month-old girl with thencephalic syndrome due to a glioma involving the optic chiasm and hypothalamus who presented with nystagmus, head nodding, and failure to thrive.13 White and Roes reported the case of a 14-month-old girl with thencephalic syndrome whose history revealed a brief episode of nystagmus and head nodding.10
This case, in conjunction with the cases noted above, suggests that gliomas arising from the region of the optic nerve, chiasm, or hypothalamus are capable of producing signs that imitate spasmus nutans. We feel, therefore, that patients with findings consistent with the diagnosis of spasmus nutans should be observed for changes in vision, optic disc pallor, and abnormalities in head circumference. It would appear reasonable to suggest that such patients be evaluated with computed tomography to rule out unsuspected optic nerve, chiasmal, and/or hypothalamic neoplasms before considering the diagnosis established and assuring the patient and family of the benign nature of the condition.
The authors would like to thank Carol Fabian for secretarial assistance in manuscript preparation.
1. Norton EWD, Cogan DG: Spasmus nutans: A clinical study of twenty cases followed two years or more since onset. Arch Ophthalmol 52:442-446, 1954.
2. Jayalakshmi P, Scott TFM, Tucker SH: Infantile nystagmus: A prospective study of spasmus nutans, congenital nystagmus, and unclassified nystagmus of infancy. J Pediatr 77:177-187, 1970.
3. Savoiardo M, Harwood-Nash DC. Tadmor R, et al: Gliomas of the intracranial anterior optic pathways in children. Radiology 138:601-610, 1981.
4. Cox RA: Congenital head nodding and nystagmus. Arch Ophthalmol 15:1032-1036, 1936.
5. Walsh FB, Hoyt WF: Clinical Neuro-Ophthalmology, ed 3. Baltimore, Williams & Wilkins Co, 1969, vol 1, pp 274-277.
6. Cogan DG: Neurology of the Ocular Muscles, ed 2. Springfield. IL. Charles C Thomas Publisher, 1956. ? 192.
7. Dodge HW Jr, Love JG, Craig WM, et al: Gliomas of the optic nerves. AMA Arch Neurol Psychiatry 79:607-621, 1958.
8. Cogan DG: Neurology of the Visual System. Springfield, IL, Charles C Thomas Publisher, 1966, pp 191-194.
9. Udvarhelyi GB, Khodadoust AA, Walsh FB: Gliomas of the optic nerve and chiasm in children: An unusual series of cases. Clin Neurosurg 13:204-237, 1965.
10. White PT, Ross AT: Inanition syndrome in infants with anterior hypothalamic neoplasms. Neurology 13:974-981, 1963.
11. Russell A: A thencephalic syndrome of emaciation in infancy and childhood. Arch Dis Child 26:274, 1951. (Collection of presentations at the British Paediatric Association Twenty-Second General Meeting, April 18-20, 1951.)
12. Dods L: A thencephalic syndrome of early infancy. Med J Aust 2:689-691, 1957.
13. Antony JH, Ouvrier RA, Wise G: Spasmus nutans: A mistaken identity. Arch Neurol 37:373-375, 1980.
14. Kelly TW: Optic glioma presenting as spasmus nutans. Pediatrics 45:295-296, 1970.