Electrophysiological monitoring in a patient with an optic nerve glioma.
OBJECTIVE
To report a case illustrating the value of pattern VEP and pattern ERG (PERG) in monitoring optic nerve gliomata (OG).


METHODS
A 15-year-old girl presented with a 3-year history of frontal headaches and a 5-month history of blurred vision in the right eye. MRI scanning revealed a thickened, right optic nerve extending to the cranial opening of the optic canal, consistent with an optic nerve glioma. Pattern VEP showed a mildly delayed major positive component consistent with optic nerve dysfunction. The PERG N95:P50 ratio was subnormal in keeping with retinal ganglion cell involvement. Visual acuity decreased over the following 2 years and repeat VEP objectively demonstrated marked deterioration in optic nerve function despite neuroradiology showing no significant change in the tumour.


CONCLUSIONS
Pattern VEPs and pattern ERGs can provide early objective evidence of optic nerve/retinal ganglion cell dysfunction in optic nerve gliomata. Serial recordings can objectively demonstrate worsening function in the absence of significant neuroradiological change.
Moradi
Phillip
P
Moorfields Eye Hospital, City Road, London, EC1V 2PD, UK.
Robson
Anthony G
AG
Rose
Geoffrey E
GE
Holder
Graham E
GE
D000293:Adolescent; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D020339:Optic Nerve Glioma / Q000503:physiopathology*; D019574:Optic Nerve Neoplasms / Q000503:physiopathology*; D012160:Retina / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000502:physiology