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Description
See-saw nystagmus is a rare but a typical symptom, and has been reported with an array of pathologies which include suprasellar tumours,1 2 congenital achiasma,3 congenital anomalies of brainstem like Arnold Chiari malformation,4 multiple sclerosis5 and Wallenberg syndrome.6 But see saw nystagmus with giant craniopharyngioma and giant pituitary adenoma has been sparsely reported.7–9 We hereby report a case of a child who presented with see saw nystagmus and was eventually diagnosed with giant craniopharyngioma.
The parents of a 4-year-old child presented to us with symptoms that their child was not following light and objects which they noticed since last 6 months, they also noted that child had jerky eye movements along with this associated with outward deviation of eye. The child was then shown to a nearby primary centre and was later referred to our centre for further investigations. There was no history of fever, trauma and birth history was normal with normal milestones. On examination the child was not following light and objects in both eyes. Pupils in both eyes were sluggishly reacting. Ocular movements revealed a typical pattern of movements, wherein one eye was elevating and intorting and other eye depressing and extorting at the same time, suggestive of typical see saw nystagmus (video 1). Fundus examination revealed bilateral secondary optic atrophy.
Contrast enhanced MRI was advised which revealed the presence of a large supra sellar solid cystic mass compressing the third ventricles and causing dilatation of bilateral lateral ventricles suggestive of craniopharyngioma (figure 1).
Axial (A, C), sagittal (B) and coronal (D) view of contrast enhanced MRI showing a large suprasellar solid cystic mass, compressing the third ventricle. Note the dilated lateral ventricle.
The child was immediately referred to the neuro-surgery department of the institute. The child was lost to follow-up.
See saw nystagmus was first described by Maddox.10 The nystagmus has a unique characteristic feature, in the first phase of nystagmus one eye elevates and intorts and other eye depresses and extorts, while in the second phase this pattern of nystagmus is reversed. The exact pathogenesis of this peculiar nystagmus in cases of suprasellar lesions is still not known and has been hypothesised to be due to associated visual disturbances.11 See saw nystagmus has also been associated with brainstem pathologies and is believed to result from the dysfunction of intestinal nucleus of Cajal, medial longitudinal fasciculus or vestibular nucleus.12
In our case see saw nystagmus can be explained by the presence of the giant craniopharyngioma. Craniopharyngiomas are epithelial tumours arising from the residual cells of Rathke’s pouch, and account for 5.6%–13% of all intracranial childhood tumours.13 Trejos et al have defined giant craniopharyngiomas as the ones having suprasellar or frontal extension with a volume of >100 cm3. The classification system helps to determine the prognosis and recurrence of tumour after surgery.14
Learning points
See saw nystagmus can be associated with a large number of aetiologies in the chiasmal and brainstem region.
Presence of see saw nystagmus in a child must be considered as a red flag, and imaging must be advised in all cases.
Footnotes
Twitter @priyavratbhatia
Contributors GS and AS worked up the case. PB critically reviewed the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Parental/guardian consent obtained.
Provenance and peer review Not commissioned; externally peer reviewed.