1. Monitoring of optic nerve function in Neurofibromatosis 2 children with optic nerve sheath meningiomas using multifocal visual evoked potentials
- Author
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Clare L. Fraser, Frank A. Billson, V. Jayanetti, John R. Grigg, Stuart L. Graham, M. Dexter, Meredith Wilson, Maree Flaherty, Alexander Klistorner, Kathryn N. North, and Kristi J. Jones
- Subjects
Adult ,Male ,Neurofibromatosis 2 ,Optic nerve sheath ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Vision Disorders ,Visual evoked potentials ,Optic nerve function ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,Ophthalmology ,Optic Nerve Diseases ,Meningeal Neoplasms ,Humans ,Medicine ,Neurofibromatosis type 2 ,Neurofibromatosis ,Child ,General anaesthetic ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,eye diseases ,Neurology ,030221 ophthalmology & optometry ,Optic nerve ,Evoked Potentials, Visual ,Female ,Surgery ,Neurology (clinical) ,Visual Fields ,medicine.symptom ,Meningioma ,business ,030217 neurology & neurosurgery - Abstract
Monitoring optic nerve sheath meningiomas (ONSM) in Neurofibromatosis type 2 (NF2) patients remains difficult. Other ocular manifestations of NF2 may obscure ophthalmic assessment of optic nerve function in these patients. Serial magnetic resonance imaging (MRI) used to assess the optic nerve is not without limitations, being expensive and often requiring general anaesthetic in children, with associated risks. This study was undertaken to describe the use of multifocal visual evoked potentials (multifocal VEP, mfVEP) in the regular monitoring of NF2 patients with ONSM. This study involved three NF2 patients with ONSM who undertook mfVEP testing at an academic ophthalmic centre. Same day mfVEP and routine ophthalmic testing were undertaken. Topographical function of the optic nerve was assessed, utilising tools such as asymmetry deviation and accumap severity index. Results were assessed alongside MRI and visual acuity (VA). From the three patients, five eyes had ONSMs, of which two caused unilateral blindness. The remaining three affected eyes had initial VAs 6/6, 6/24, and 6/18. Over follow up, ranging from 5 to 12 years, all tumours progressed, and VA declined for all patients. Multifocal VEP detected optic nerve functional loss corresponding with visual decline. This case series suggests mfVEP is effective in the objective topographic monitoring of optic nerve function in NF2 patients with ONSM. Due also to its safety in a paediatric population, the test may be considered in the routine monitoring of these patients, to be used to assist regular ophthalmic review and MRI scans.
- Published
- 2018