A subclinical seizure is a seizure that, being , does not present any clinical signs or symptoms. Such seizures are often experienced by people with epilepsy, in which an electroencephalogram (EEG) trace will show abnormal brain activity, usually for a short time, but level of consciousness is normal. This is often manifest as a single spike on the EEG trace or a slowing of brain activity not correlating to what the person notices or experiences. Subclinical seizures can be useful to a neurologist in the diagnosis of epilepsy.