Page 102 - ILAE_Lectures_2015

different disorders including migraine with aura (visual hallucinations, lengthy durations,
vomiting and headache).

Further, the commonly quoted argument that PS is not essentially different from ICOE-G
considering that ‘the younger the children are, the less likely they are to describe visual
symptoms’138 is not tenable: a) more than two-thirds of children with PS are older than four
years and therefore able to describe their visual experiences; b) there is no difference in seizure
presentation between younger and older children with PS.

A few patients with either PS or rolandic epilepsy may later develop purely occipital seizures
as of ICOE-G4,70,171. These cases are easy to diagnose and indicate the intimate links of these
disorders within the framework of BCSSS.

BCSSS: a unified concept of benign childhood focal seizures

Rolandic epilepsy, PS, ICOE-G and other possible clinical phenotypes of benign childhood
focal seizures are likely to be linked together by a genetically determined, functional
derangement of the systemic brain maturation that is mild and age related (BCSSS)3,4. They
have distinctive characteristics but they also share common clinical and EEG features: seizures
are infrequent, usually nocturnal and remit within a few years from onset. Brief or prolonged
seizures, even focal status epilepticus, may occur only once in the patient’s lifetime. Despite
the distinctiveness of their core clinical and EEG features, the natural histories of these
syndromes may show significant reciprocity: some children with rolandic epilepsy may present
autonomic seizures referable to PS (and vice versa) before remittance, while other may have
alternate autonomic and rolandic seizures. Some seizures may be of mixed character, and
certainly ictal autonomic manifestations, such as hypersalivation, emesis, headache and
syncopal-like attacks that are unusual in other epileptic syndromes in children or adults, are
frequent in BCSSS, and may predominate. Affected siblings may have the same or another type
of benign childhood focal seizures, and febrile seizures are common. EEG spikes are regional
(bilateral and multifocal) than focal – and as a rule disproportionately abundant to the frequency
of seizures – and there is a significant overlap of inter-ictal topographies.

There is no reason to suggest that these syndromes differ merely because an ‘epileptogenic’
focus is slightly anterior or posterior, lateral or medial to the central regions. The relevant ictal
semiologies and EEG findings suggest that each one of these forms reflects constitutional
hyperexcitability of a particular functional brain area or system: the lower rolandic
(somatosensory) cortex that represents the face and the oropharynx bilaterally in benign
rolandic epilepsy, the occipital areas (cortical visual system) in ICOE-G and of the central
autonomic network bilaterally and diffusely in PS7. Therefore, all these conditions are linked
together by a genetically determined, functional derangement of the systemic brain maturation
that is mild and age related2,3. This derangement is often clinically silent and presents in more
than 90% of the susceptible children only with – also age-related – EEG sharp and slow waves;
the remaining tenth of these children have infrequent focal seizures. A small number of
susceptible children, with or without seizures, may also have minor and fully reversible
neuropsychological symptoms that are rarely clinically overt and can be detected only by formal
neuropsychological testing. Finally, in a very small number of patients (probably <1%) this
disturbance of brain maturation may further evolve into a more aggressive clinical state with
seizures, neuropsychological manifestations and EEG abnormalities of various combinations
and severity, such as atypical benign focal epilepsy of childhood, Landau–Kleffner syndrome
and epilepsy with CSWS.

This concept of BCSSS is in agreement with previously expressed views of ‘functional
epilepsies of maturation’172, ‘multifactorial pathogenesis of epilepsies with benign focal