The diagnosis of acephalgic migraine is complicated by the fact that other neurological conditions such as transient ischaemic attacks, demyelinating disease, simple partial epilepsy, and even glaucoma, can present with similar symptoms. Using both flash and pattern stimulation, visual evoked potentials (VEPs) were examined as a means of differentiating between acephalgic migraine, migraine with aura, migraine without aura, demyelinating disease and a control group. This study demonstrated that by analysing the amplitude of the background fast activity in the flash and pattern VEP, acephalgic migraine can be differentiated from demyelinating disease, migraine with aura, migraine without aura and absolute controls.