Visual Evoked Potentials and SPIR-FLAIR MRI in Acute Optic Neuropathies,HASSAN I. MEGALY, MOHAMED A. AHMED and TAREK A. MOHAMED
Abstract
The aim of the present study was to determine the role of the visual evoked potentials and SPIR-FLAIR (Selective partial inversion recovery-fluid attenuation inversion recovery) MRI technique in differentiating between non arteritic ischemic optic neuropathy (NAION) from acute isolated optic neuritis (ON).
Thirty patients with acute optic neuropathy and 20 normal volunteers matched for age and sex were included. Optic neuropathy was classified as NAION and acute isolated ON according to the characteristic symptoms and signs. Visual evoked potentials (VEPs) were performed for patients and control groups. Fat and water suppression MRI examination of the optic nerve and MRI brain were done.
P100 latency and amplitude of VEPs in studied patients were significantly affected compared to control group. The 22 patients diagnosed clinically as acute isolated ON had significantly delayed P100 latency and higher amplitude in comparison to those diagnosed clinically as NAION. MRI of the optic nerve with abnormal signal diagnosed as acute isolated ON. In the two patients with history of head trauma, one of them had kinked optic nerve and the second one had carotid cavernous fistula compressing the optic nerve and they diagnosed as NAION.
VEPs can differentiate acute isolated ON from NAION. Fat and water suppression MRI technique of the optic nerve was positive in all patients with acute isolated optic neuritis and posttraumatic optic neuritis.