Clues to differentiate Dravet syndrome from febrile seizures plus at the first visit

ABSTRACT

Objective: To investigate the clinical clues to differentiate between Dravet syndrome (DS) and febrileseizures plus (FS+). Methods: From September 2001 to March 2014, 44 consecutive patients whowere diagnosed with DS or FS+, were recruited. We retrospectively analyzed the characteristics of thefirst seizure and findings of patients exhibiting seizures during hot water immersion at the first visit.Comparisons between the two groups were analyzed. Results: Thirty-two DS and 12 FS+ patientswere enrolled. The most prevalent body temperature classification in the DS group was afebrile(43.8% vs. 25%, p=0.001), followed by 37-37.9oC (31.3% vs. 8.3%, p=0.02), and that in the FS+group was at 39oC or above (33.3% vs. 9.4%, p=0.001). The most prevalent seizure type in the DSgroup was focal motor seizures (43.8% vs. 25%, p=0.001), followed by alternating hemiconvulsiveseizures (12.5% vs. 0%, p=0.005), and that in the FS+ group was generalized clonic and/or tonic-clonicseizures (83.3% vs. 37.5%, p=0.002). Compared with the FS+ group, there was a greater prevalenceof vaccination-related seizure as the first presenting feature among the DS patients (46.9% vs. 8.3%,p<0.001). During hot water immersion, myoclonic seizure was seen significantly in the DS group(46.4% vs. 25.5%, p=0.013).Conclusions: Afebrile and mild body temperature variation below 38oC, focal motor seizure oralternating hemiconvulsive seizure types, and vaccination-related first seizure were found to be cluesfor highly suspected DS.