Isolated, monocular vertical nystagmus: single symptom of an extensive intracerebral tumor

Case report: We report the case of a six year old boy who showed a monocular vertical nystagmus as isolated symptom without a history of trauma, infection or any associated clinical symptoms. One year before initiation of the diagnostic workup, the nystagmus was observed for the first time. It did not impair the vision of the child. The neurological examination did not reveal any additional symptoms. The boy's mental and motor development was normal. The history was unremarkable except for a foramen ovale and a mild valvular pulmonary stenosis, which could be heard as heart murmur. The physical examination was normal. Diagnostic workup including visual evoked potentials and sonography of the optic nerves was normal. Magnetic resonance imaging revealed an extensive intracerebral mass, classified as pilocytic astrocytoma (WHO grade I) by biopsy.

Discusion: Vertical nystagmus may occur as a symptom of a lesion along the pathway of the oculomotor nerve and indicates cerebral imaging. In our case, the discrepancy between the huge size of the intracerebral mass and the unspectacular clinical pathology was striking. This may be due to the slow progression of the tumor.

Conclusion: A monocular vertical nystagmus may be the only symptom of an extensive intracerebral tumor.