Table 2.

Electro clinical features of r(20) syndrome

Series	Year of publication	No. of patients	Age at seizure onset	Clinical features	EEG characteristics
Inoue et al.[4]	1997	6	3 14 years	Brief and prolonged confusing state, eyelid myoclonia, GTCS, IQ 47 95	Interictal: Irregular high voltage, slow bilateral/unilateral synchronous and asynchronous spikes Ictal: Focal/diffuse onset with predominant bilateral or frontal evolution
Augustijn et al.[5]	2001	4	3 11.5 yrs	CPS, GTCS, NCSE, behavioral problems with learning disability	Interictal: Diffuse slow (maximal frontotemporal) generalized and frontotemporal spikes, no ictal data
Ville et al.[6]	2006	6	Neonatal; 5 8 years	Brief hypermotor and prolonged hypomotor CPS, Complex visual Hallucinations, IQ 60 80	Interictal: intermittent/continuous delta or slow spike wave discharges (frontally dominant) No ictal data
Jacobs et al.[7]	2008	1	4 years	NCSE, cognitive decline, died with prolonged SE	Interictal: Marked background changes, generalized rhythmic slow waves over frontal areas, very active widespread spike-and-slow wave activity over the right hemisphere. Ictal EEG: Generalized suppression, followed by 2 3 Hz rhythmic slow waves and then by a 1 Hz spike and slow wave activity over both hemispheres, but again more prominent on the right.
Vignoli et al.[8]	2009	3	7.5 10 years	Brief nocturnal hypermotor and prolonged hypomotor CPS with aphasia, night terrors	Interictal: Normal or frontal theta delta Ictal: Diffuse attenuation or generalized 3 Hz spike wave discharges (absence status)
Elens et al.[9]	2012	6	4 16 years	Nocturnal frontal seizures, atypical absence, drug resistance	Diffuse slow waves and deceleration, frontotemporal spikes, bifrontal high voltage spike waves
Avanzini et al.[10]	2014	12	26.3±16.7 years	NCSE, GTCS, nocturnal fear, dyscognitive symptoms, staring, fear expression	Interictal frontal and frontotemporal sharp and slow waves, ictal EEG prolonged burst of sub continuous paroxysms of sharp wave or fast activities over the bilateral frontal regions
Freire de Moura M, et al.[11]	2016	12	17 57 years	NCSE, CPS, GTCS	Frontopolar area bilaterally slow waves and spikes 11 pts, slow waves 7 pts, spike wave complexes 5 pts, spikes 5 pts, bursts duration 4 s to 60 min