In the first edition of this book, only a few lines mentioned this condition under the heading of Childhood Epilepsy With Occipital Spikes and Other Benign Localization-Related Epilepsies.³³ At present, early-onset benign childhood occipital epilepsy (Panayiotopoulos type) (EOCOE) is not only a clearly recognized syndrome, but it also represents the second-most-frequent benign focal epilepsy syndrome in childhood after benign childhood epilepsy with centrotemporal spikes (BCECTS). The characteristic clinical features of this syndrome should be known not only by epileptologists and neurologists, but also by pediatricians. An early diagnosis would avoid undue interventions and concerns on account of its really benign outcome.

In the International League Against Epilepsy (ILAE) classification of Epilepsy syndromes,¹¹ besides the well-known BCECTS, only childhood epilepsy with occipital paroxysms (CEOP), as described by Gastaut, is recognized.²⁹ In comparison with BCECTS, which has a prevalence of approximately 15% among children with epilepsy,^15,18,52 the Gastaut type of CEOP is rare, of uncertain boundaries, and often of unpredictable prognosis.⁸ This condition is characterized by brief seizures with mainly visual symptoms such as elementary visual hallucinations, illusions, or amaurosis, followed by hemiclonic convulsions. Postictal migraine headaches occur in half of the patients. Age at onset is approximately 8 to 9 years. The electroencephalogram (EEG) shows occipital spike-wave paroxysms that attenuate or disappear when the eyes are open.^11,29,30,47

In 1989, two significant papers of Panayiotopoulos based on an already long follow-up of his patients called attention to the particular cluster of symptoms present in what he called “benign nocturnal childhood occipital epilepsy.”^49,50 He had already emphasized vomiting as an ictal symptom in epileptic seizures in children 1 year earlier.⁴⁸ Another peculiar clinical feature of EOCOE was the “cerebral insult–like” partial status epilepticus including autonomic symptoms.^38,57,64 To stress the variable phenotypes of benign focal epileptic syndromes in childhood, Panayiotopoulos and coworkers used the term “benign childhood seizure susceptibility syndromes.”^51,52 After 1996, Fejerman and coworkers proposed naming this syndrome early-onset benign childhood occipital epilepsy (Panayiotopoulos type) as opposed to late-onset childhood occipital epilepsy (Gastaut type).^{7,8,19,20,21,22} Three important series of children with this syndrome were published about this time.^25,37,45 Retrospective analysis of the clinical histories allowed the authors to study the variants of childhood epilepsies with occipital paroxysms and to recognize this early-onset variant. In the same year, the first prospective study of 66 children with EOCOE was published.⁸ In 2001, the task force on Classification and Terminology of the ILAE published a proposed diagnostic scheme for people with epilepsy.¹⁷ It adopted the names proposed by Fejerman including eponymic designations to emphasize the differences between the Gastaut type and the Panayiotopoulos type of childhood epilepsy with occipital paroxysms, keeping intentionally the term “benign” only for this early-onset form.^19,20 Thereafter, several authors preferred the eponymic term “Panayiotopoulos syndrome” (PS) to include patients with and without occipital spikes or occipital ictal origins.^{3,8,13,14,16,26,27,28,36,42,54,56,59} Considering the emphasis given in recent years to the presence of autonomic seizures and autonomic status epilepticus in this condition, that occipital EEG abnormalities are not found in a certain proportion of the cases, and that there is no clear documentation of an occipital origin of seizures, we agree that the name PS might be more appropriate. As a practical measure, we will continue to refer to EOCOE as PS in this chapter.

Types of seizures, age of onset, normal neurologic status of patients, and spontaneous evolution allow us to define the PS as a benign, age-related focal epilepsy syndrome occurring in early and mid-childhood. The analysis of several large series of published cases and our own present series clearly demonstrates the significant frequency of PS, which is seen about one third as often as BCECTS.

PS is seen only in children, with a peak incidence between 4 and 5 years of age. Given that the official recognition of EOCOE or PS took place only in 2001, it is very difficult to find epidemiologic studies in a childhood population that include PS among the diagnoses. Additionally, most studies are based more on seizure types than syndromes. One study included a mix of seizures and syndromes for the recognition of epilepsies in 440 consecutive pediatric patients. Thirty-six (8%) of the cases were diagnosed as benign rolandic epilepsy of childhood and 8 cases (2%) as benign occipital epilepsy of childhood. We may assume that this last group was underevaluated, and we do not know how many of the cases corresponded to PS.³⁹ A cohort of 407 children with their first unprovoked seizure was followed for a mean of 9.4 years, and distribution of epilepsy syndromes was reported: Of 114 children with localization-related
epilepsy syndromes, 26 were idiopathic, 24 were rolandic, and only 2 were occipital.⁶⁰ Another study of a population-based, active-prevalence cohort in children <16 years of age was able to classify syndromes in 235 (96%) of the 245 patients followed for many years. However, no specific data about PS were included in any of these three studies because they were based on the 1989 ILAE Classification.⁶¹ Therefore, one has to credit the everyday experience of active epileptologists caring for children, who have become aware of this condition in the last few years:³

As an idiopathic epilepsy syndrome, PS is by definition not associated with remote symptomatic or acute symptomatic etiology. Most likely, it is genetically determined, although neither a gene nor a chromosomal locus has been found in PS. Linkage with chromosome 15 has been reported in BCECTS,⁴³ although in another study this locus was not found.⁵⁸ One affected sibling with PS was reported in one series,²⁵ and two pairs of affected siblings were seen in each of two other series.^8,42 Three siblings were reported in 1987 as having benign occipital epilepsy as described by Gastaut, although the paper indicates that the three siblings showed seizures starting at ages 4 and 5 years, and the clinical features were quite compatible with PS.⁴⁰

There is a high prevalence of febrile seizures in children with PS, ranging from 16% to 45%.^{8,13,14,25,45,64} A family history of epilepsy was found in 30.3% of the cases.⁸ The finding of several children with PS who at the same time or later had rolandic seizures and centrotemporal spikes typical of BCECTS as well as siblings who had either rolandic epilepsy or PS speaks in favor of a genetic linkage of these two syndromes, perhaps expressed as a reversible functional derangement of the brains cortical maturation.^{6,8,13,14,24,50,52,54,56} Basic mechanisms and pathophysiology of PS are largely unknown. Clinical findings indicate that there is a diffuse cortical hyperexcitability, which is related to maturation.^14,26,54 Even when the majority of cases show occipital spikes, a significant number of patients have spikes in other areas, and according to the mentioned reference of PS and BCECTS in the same children, spikes may appear in two areas at the same time or over the course of time.^6,13 In addition, the high frequency of ictal vomiting indicates that epileptic discharges are generated at various cortical locations. The same concept is valid for other autonomic manifestations. As we will see later, different cortical locations in patients with PS were also documented with magnetoencephalo-graphy.³⁶

Panayiotopoulos syndrome occurs in children who are otherwise normal; it is not associated with neurodevelopmental problems. Although it has been described as starting as early as 1 year of age and as late as 14 years of age, the large majority of patients have their first seizure around the age of 4 to 5 years. Three fourths of patients have their first seizure between the ages of 3 and 6 years. It affects boys and girls almost equally. Seizures occur predominantly during sleep, and only in sleep in two thirds of patients. In seizures occurring while the patient is awake, onset may be inconspicuous with pallor, agitation, feeling sick, and vomiting. At this stage, the epileptic nature of the event can hardly be suspected in the absence of motor convulsive symptoms that, if present, may be rightly considered as secondary to an ongoing serious brain insult. It is only the normal postictal state of the child that should be reassuring.

The duration of the seizures is usually long, commonly >5 minutes, and in approximately 40% of the cases, >30 minutes, constituting then a focal or secondarily generalized status epilepticus. Three groups of symptoms are recognized, as shown in Table 1.