Page 101 - ILAE_Lectures_2015

Differential diagnosis between seizures and syndromes of BCSSS

The differential diagnosis between the main phenotypes of BCSSS is easy in their typical
presentations (Table 1). Problems may arise in children with clinical symptoms that fall into
two (or more) phenotypes or from overemphasising on EEG localisation. As in any other
medical condition, a single symptom is of limited syndromic significance. The differential
diagnosis requires that symptoms are meaningfully synthesised in regard to quality and
quantity, chronological sequence, consistency, relation to other seizure manifestations, the
circumstances of their appearance and the overall clustering of clinical-EEG manifestations.

Rolandic epilepsy vs Panayiotopoulos syndrome
Their differential diagnosis is usually easy (Table 1). However, there are some cases with
overlapping features:

(a) One-tenth of children with PS often have typical and lengthy autonomic seizures with
concurrent rolandic features such as speech arrest, hemi-facial convulsions, hypersalivation and
OPS but these appear after the onset of autonomic symptoms and emesis4,74-77,80. Conversely,
these ictal symptoms occur at onset and usually without autonomic symptoms in rolandic
epilepsy.

(b) One-tenth of children with PS develop pure rolandic seizures, either in parallel with
autonomic seizures, or at a later age prior to final remission4,75,77,80.

(c) The topography of inter-ictal spikes may overlap. Covanis et al79 studied 24 otherwise
normal children with focal non-febrile seizures who had emetic manifestations in at least one
seizure and CTS in at least one EEG; 21 (83%) had ictal semiology typical of PS but five also
had concurrent rolandic symptoms and four later developed pure rolandic seizures. The other
four children (17%) had typical rolandic seizures with concurrent ictus emeticus. Ohtsu et al82
found that in early-onset rolandic epilepsy vomiting usually happened in the middle of the ictus,
seizures, neurocognitive and behavioural abnormalities were more frequent while focal status
epilepticus and prolonged seizures were less common that in PS.

(d) Of siblings one may have rolandic seizures and another PS and there is a high prevalence
of febrile seizures in both4,74,75,0.

Idiopathic childhood occipital epilepsy of Gastaut vs PS
The differentiation here is more straightforward (Table 1). The seizures of ICOE-G are purely
occipital and as such start and often end only with occipital lobe symptomatology. Further,
seizures are mainly brief, frequent and diurnal. Rarely, seizures may be longer and also occur
in sleep but these are also fundamentally different to the rolandic epilepsy or the autonomic
seizures and autonomic status epilepticus of PS.

Exceptionally ictal vomiting may occur in ICOE-G but this follows the appearance of visual
symptomatology as it happens with reflex photosensitive occipital seizures131,135 and the same
patient usually has frequent brief occipital seizures. Conversely, visual symptoms in PS, when
present, are not prominent or stereotypic and by rule occur concurrently with other salient
clinical manifestations after the seizure has started4,74,80,167,168. From the EEG standpoint,
occipital paroxysms or occipital spikes which characterise ICOE-G are also common in PS but
these often occur with extra-occipital spikes and with shifting locations in sequential EEG.
Further, ictal EEG is markedly different in these syndromes.

Reported difficulties in the differential diagnosis of ICOE-G and PS169 may arise when
assessing them on individual symptoms and features without considering quality, chronological
sequence from onset, stereotypical appearance or not that may be common even amongst