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. Author manuscript; available in PMC: 2016 Sep 20.
Published in final edited form as: Epilepsia. 2012 Nov 16;54(4):741–750. doi: 10.1111/epi.12039

Table 2.

Defining features of ESES and CSWS

Feature Options Number (percentage) CNS Number (percentage) AES Number (percentage) total Potential answers based on available literature

Are “ESES” and “CSWS” synonyms? Yes 75 (61) 42 (55.3) 117 (58.8) “ESES” and “CSWS” are considered essentially synonyms and interchangeable terms by some authors (Liukkonen, et al. 2010, Peltola, et al. 2011, Tassinari, et al. 2000).
No 32 (26) 29 (38.2) 61 (30.7)
Do not know 16 (13) 5 (6.6) 21 (10.6)
Skipped question 14 6 20
Other authors indicate that “ESES” refers to the electroencephalographic pattern present in several syndromes and “CSWS” is the most severe presentation of the electro-clinical syndromes with ESES (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Scholtes, et al. 2005)

Cut-off value for ESES Any amount 1 (0.8) 1 (1.3) 2 (1) Some authors consider at least 85% (Liukkonen, et al. 2010, Peltola, et al. 2011, Saltik, et al. 2005, Tassinari, et al. 2000), others a minimum threshold of 75% (Kevelam, et al. 2012), 60% (Inutsuka, et al. 2006), or 25% (Van Hirtum-Das, et al. 2006).
At least 50% 33 (26.8) 28 (37.3) 61 (30.8)
At least 85% 76 (61.8) 38 (50.7) 114 (57.6)
Not sure 13 (10.6) 8 (10.7) 21 (10.6)
Skipped question 13 6 19
Additionally, it has been noted that the cut-off value for ESES changes over time (Sánchez Fernández, et al. 2012c)

Cut-off value for CSWS Any amount 1 (0.8) 1 (1.3) 2 (1) If ESES and CSWS are considered synonyms (Liukkonen, et al. 2010, Peltola, et al. 2011, Tassinari, et al. 2000), then the threshold for CSWS would be the same as in ESES.
At least 50% 27 (22.3) 28 (36.8) 55 (27.9)
At least 85% 69 (57) 36 (47.4) 105 (53.3)
Not sure 24 (19.8) 11 (14.5) 35 (17.8)
Skipped question 13 6 19 If CSWS is considered an electro-clinical syndrome, not an EEG pattern (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Scholtes, et al. 2005), then the thresholds should be applied to the definition of ESES, not to the definition of CSWS.

Cut-off values in ESES are Mandatory 55 (44.7) 35 (46.1) 90 (45.2) The cut-off value could be considered mandatory (Tassinari, et al. 2000) or typical, but not required (Nieuwenhuis&Nicolai 2006).
Typical, not required 50 (40.7) 32 (42.1) 82 (41.2)
Not sure 18 (14.6) 9 (11.8) 27 (13.6)
Skipped question 13 6 19
The cut-off value for ESES may also change over time(Sánchez Fernández, et al. 2012c).

Cut-off values in CSWS are Mandatory 47 (38.5) 31 (40.8) 78 (39.4) If ESES and CSWS are considered synonyms (Liukkonen, et al. 2010, Peltola, et al. 2011, Tassinari, et al. 2000), then the threshold would be the same as in ESES.
Typical, not required 49 (40.2) 35 (46.1) 84 (42.4)
Not sure 26 (21.3) 10 (13.2) 36 (18.2)
Skipped question 13 6 19
If CSWS is considered an electro-clinical syndrome, not an EEG pattern (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Scholtes, et al. 2005), then the thresholds should be applied to the definition of ESES, not to the definition of CSWS.

For the diagnosis of ESES cognitive and/or language regression is Mandatory 24 (19.8) 14 (18.9) 38 (19.5) If ESES is considered an electro-clinical syndrome (Liukkonen, et al. 2010, Peltola, et al. 2011, Tassinari, et al. 2000), then the regression would be required.
Typical, not required 74 (61.2) 46 (62.2) 120 (61.5)
Not relevant for diagnosis 14 (11.6) 11 (14.9) 25 (12.8)
Not sure 9 (7.4) 3 (4.1) 12 (6.2)
Skipped question 14 8 22 If ESES is considered an electrical pattern (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Scholtes, et al. 2005), then the regression should be applied to the definition of CSWS, not to the definition of ESES

For the diagnosis of CSWS cognitive and/or language regression is Mandatory 32 (26.7) 21 (28.4) 53 (27.3) The literature suggests that cognitive and/or language regression is required for the diagnosis of the clinical encephalopathy (Loddenkemper, et al. 2011, Sánchez Fernández, et al. in press, Tassinari, et al. 2000)
Typical, not required 64 (53.3) 49 (66.2) 113 (58.3)
Not relevant for diagnosis 11 (9.2) 2 (2.7) 13 (6.7)
Not sure 13 (10.8) 2 (2.7) 15 (7.7)
Skipped question 14 8 22

How do you diagnose CSWS? Clinical assessment only 0 (0) 0 (0) 0 (0) If CSWS is considered an electroencephalographic pattern (Liukkonen, et al. 2010, Peltola, et al. 2011, Tassinari, et al. 2000), then the diagnosis of CSWS would be based on EEG assessment only.
EEG assessment only 41 (33.1) 21 (27.6) 62 (31)
MRI assessment only 0 (0) 0 (0) 0
Clinical and EEG assessment 77 (62.1) 50 (65.8) 127 (63.5)
All of the above 6 (4.8) 5 (6.6) 11 (5.5)
Skipped question 13 6 19
If CSWS is considered an electro-clinical syndrome (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Scholtes, et al. 2005), then it should be diagnosed with clinical and EEG assessments.

Segment of EEG used for calculation of the epileptiform activity Whole night (all phases) 35 (27.6) 17 (21.8) 52 (25.4) Some authors calculate epileptiform activity during the complete nocturnal sleep duration (Tassinari, et al. 2000), others during the first 30 minutes of non-REM sleep stages of the first and last sleep cycles (Aeby, et al. 2005), at least one sleep-wake cycle (Saltik, et al. 2005), the whole-night, first non-REM sleep cycle or nap EEG (Inutsuka, et al. 2006) or the first five minutes of non-REM sleep (Sánchez Fernández, et al. 2012c).
Whole night (non-REM) 51 (40.2) 34 (43.6) 85 (41.5)
Comparison wake/sleep 15 (11.8) 10 (12.8) 25 (12.2)
Variable 4 (3.2) 3 (3.9) 7 (3.4)
Unknown 15 (11.8) 4 (5.1) 19 (9.3)
Other selected samples 7 (5.5) 10 (12.8) 17 (8.3)
Skipped question 17 14 31

Quantification of spike-wave activity Bilateral and synchronous only 15 (12.2) 11 (14.5) 26 (13.1) There is currently insufficient evidence to support that unilateral discharges should be quantified differently from bilateral discharges (Bureau 1995, Kramer, et al. 2009, Liukkonen, et al. 2010, Saltik, et al. 2005, Sánchez Fernández, et al. 2012b, Van Hirtum-Das, et al. 2006).
Bilateral even if not synchronous 25 (20.3) 22 (29) 47 (23.6)
Unilateral equivalent to bilateral 50 (40.7) 32 (42.1) 82 (41.2)
Unknown 33 (26.8) 11 (14.5) 44 (22.1)
Skipped question 14 6 20

Method of quantification of epileptiform activity Percentage of one-second bins occupied by spike-waves 57 (48.3) 43 (58.9) 100 (52.4) Some authors do not specify the exact method of calculation (Caraballo, et al. 2008, Inutsuka, et al. 2006, Kramer, et al. 2009, Liukkonen, et al. 2010, Saltik, et al. 2005, Tassinari, et al. 2000).
Total number of spike-waves per unit of time 53 (44.9) 25 (34.3) 78 (40.8)
Other 8 (6.8) 5 (6.9) 13 (6.8)
Skipped question 27 14 41
Other authors used the percentage of one-second bins occupied by at least one spike-wave (Aeby, et al. 2005, Sánchez Fernández, et al. 2012c) or the total number of spike-waves per unit of time (Sánchez Fernández, et al. 2012c).

Time of occurrence of the neuropsychological regression in CSWS Infancy (0-2 years) 7 (5.7) 3 (4) 10 (5) Regression usually occurs in childhood (Loddenkemper, et al. 2011, Nickels&Wirrell 2008, Nieuwenhuis&Nicolai 2006, Sánchez Fernández, et al. in press, Tassinari, et al. 2000)
Childhood (3-12 years) 107 (86.3) 66 (86.8) 173 (86.5)
Adolescence (13-18 years) 0 (0) 1 (1.3) 1 (0.5)
Adulthood (19-59 years) 0 (0) 0 (0) 0
Elderly years (60 or more years) 0 (0) 0 (0) 0
Unknown 10 (8.1) 6 (7.9) 16 (8)
Skipped question 13 6 19

Legend: CSWS: Continuous spikes and waves during sleep. EEG: Electroencephalogram. ESES: Electrical status epilepticus in sleep. MRI: Magnetic resonance imaging. REM: Rapid eye movement.