Nocturnal seizures: Several important differential points help delineate the above three sleep behaviors from seizure activity. Seizures by their nature are very brief, often lasting only a few minutes. In addition, seizure events are likely to be confused with the above; and are characterized by a series of repeated, stereotypical, and frequent behaviors occurring in clusters. Moreover, seizures more commonly occur in the second half of the night's sleep. Patients often will have postictal (symptoms after the seizure) complications such as headache , extreme grogginess, hard to arouse, as well as incontinence of urine and stool. To assist in establishing a correct diagnosis a neurologist may perform a video- EEG study to help clarify the issue.