<prompt> Which of the following tests is not required for the diagnosis of multiple sclerosis?Lumbar punctureGadolinium-enhanced MRIVisual evoked potentialElectronystagmogram  <response>: ElectronystagmogramENG Measures normal eye movement and involuntary rapid eye movements called nystagmus . Checks the muscles, that control eye movements. Checks how well the eyes, inner ears , and brain help you keep your balance and position Revised McDonald criteria for diagnosis of MS following investigation should be done: 1. MRI Gadolinium-enhanced: PlaquesDawson Fingers 2. Lumbar puncture-CSF electrophoresis shows Oligo-clonal IgG bands. 3. Visual evoked potentialVEP: shows reduced amplitude of voltage generated due to plaques in optic nerve. 