Staring spells are common in children and may be epileptic (e.g., absence or complex partial seizures) or nonepileptic (e.g., inattention or daydreaming). The diagnosis is typically based on parental reports of the episode and results of electroencephalography (EEG). Other diagnostic information includes abnormal results on neuroimaging, focal findings on neurologic examination or the presence of other seizure types in addition to the staring spells. Confirming a diagnosis can be difficult when staring is the only symptom and the results of the EEG are within normal limits. Rosenow and associates sought to increase the diagnostic certainty of the parental interview by identifying questions specific and sensitive for nonepileptic and epileptic staring spells.
A 25-item questionnaire exploring the types and setting of symptoms for staring spells was given to the parents or guardians of 40 children who presented with staring spells. Questions focused on physical behaviors that characterized the staring episode, such as arrest of activity, unresponsiveness, eye blinking, upward eye rolling, myoclonic twitches, body stiffening, dropping of the head or jaw and body rocking. Other questions addressed patient age at onset, duration and frequency of the episodes, the presence of learning difficulties and the person who initially identified the episodes.
Of the 40 patients identified for the study, 17 had absence seizures with generalized seizure patterns seen on routine EEG, and 23 had nonepileptic staring spells diagnosed after a full clinical evaluation by a specialist. Children with nonepileptic staring spells had normal findings on routine EEG. Questions regarding the features of the staring episode were not useful, as both types of episodes were characterized by a dazed or vacant expression, sudden onset and abrupt cessation. Learning problems were identified with equal frequency in both groups. A family history of staring spells or epileptic seizures was more common among the children in the absence-seizure group, but the difference was not statistically significant.
Of the items on the questionnaire, only a few showed significant differences between the two groups. Children in the nonepileptic-staring group were more responsive to touch, did not interrupt play and were first identified as having a staring spell by a teacher or a health professional. Body rocking was reported exclusively in this group, but in only 13 percent of patients. Features that were highly specific for absence seizures included limb twitching, upward eye movements and urinary incontinence during staring episodes.
The authors conclude that in uncomplicated cases in which the physical behaviors suggest a nonepileptic-staring episode, asking parents or guardians the proper questions can help the physician confirm the diagnosis without the expense of an EEG. Compared with nonepileptic staring, staring spells of epileptic etiology occur much less frequently and can be confirmed by the presence of specific neurologic abnormalities on EEG. By asking parents about the presence of specific physical behaviors that characterize nonepileptic staring episodes and ascertaining the absence of behaviors that suggest epileptic staring episodes, physicians may defer ordering an EEG in selected cases.