Table 1 Percentages of IEDs among non-epileptic ASD children
From: EEG changes associated with autistic spectrum disorders
Paper | N | % of subjects with IEDs | Location | Epilepsy excluded* | Comments |
|---|---|---|---|---|---|
Small, 1975 | 147 | 64 (included an unspecified low% of slow wave abnormalities) | Mainly focal and seen in all locations. | Yes | A single recording yielded 40% abnormalities, 2 studies 60% and 3 studies 80%. |
Gillberg et al., 1987 | 15 | 27 | Â | Yes | Five additional children with ASD and epilepsy all had abnormal EEGs. |
Rossi et al., 1995 | 81 | 25% | Focal and multifocal. 45% centro-temporal. | Yes | Photoparoxysmal response in some children. |
Tuchman & Rapin 1997 | 335 | 8% | 50% centro-temporal | Yes | 14% in non-epileptics but with history of deterioration. |
Kawasaki et al., 1997 | 96 | 31.3 | Frontal | Yes | A control group with intellectual development delay and exhibiting IEDs, had very significantly less frontal lobe discharges. |
Lewine 1999 | 18, EEG | 22 | Paroxysmal MEG activity mainly deep into sylvian plane. | Yes | All children with evidence of regression. Notice the progression in yield from standard EEG to 24Â hour EEGs to MEG. |
14, 24Â h EEGs | 64 | ||||
35 MEG | 97 | ||||
Hashimoto et al., 2001 | 68 | 54% | 76.6% frontal | Yes | Additional ASD 18 subjects with epilepsy had a rate of paroxysmal discharges of 72%. |
Hrdlicka et al. 2004 | 50 | 15% | Â | Yes | An additional 9% of non-epileptic ASD children had non-paroxysmal EEG abnormalities.nWhen subjects were classified into those with and without regression, rate of paroxysmal EEg abnormality rose to 44%. |
Reinhold et al., 2005 | 316 (overnight EEG monitoring) | 26.8% | Temporal (38%), frontal (28%), central (23%), occipital (8%). | Yes | EEG monitoring recommended for ASD work-up and more so if regression is seen. |
Gabis et al., 2005 | 40 | 3.6 | Â | Yes | Lowest rate reported. No obvious difference either in the study population or EEG procedure used. |
Canitano et al., 2005 | 40 | 25% | Mostly focal but few multifocal. | Yes | Â |
Hughes & Melyn, 2005 | 32 | 19% | 21% had bilateral spike discharges. | Yes | Â |
Chez et al., 2006 | 889 Overnight (at least 6Â hours) EEGs. | 60.7% | Right Frontal (21.5%), Bitemporal (20.2%). Gen sp& wave (16.2%), left temp (15.2%). | Yes and unmedicated at times of EEGs. | No difference in rate of EEG abnormality between those with and without regression. All paroxysmal activity were recorded only during sleep. Of 176 patients with paroxysmal activity and treated with valproic acid rate of EEG abnormalities decreased to 36% with follow-up EEGs. |
Hara, 2007 | 97 | 21% | Mainly temporal but also central/parietal. A minority had focal foci. | Yes | Epileptiform EEGs predicted subsequent seizures. |
Ošlejšková et al., 2008 | 57 | 42.5 | Abnormalities were mainly focal but specific locations not reported | Yes | Children with no evidence of regression |
Ošlejšková et al., 2008 | 41 | 57.8 | Children with history of regression | ||
Å°nal et al., 2009 | 81 | 27.2 | Mainly temporal regions | Yes | Only 8.3 % of children without evidence of impaired intellectual development had abnormal EEGs. |
Hartley-McAndrew and weinstock, 2010 | 15 | 33 | Focal spike and wave complexes, different locations. | Yes | Six additional ASD children had history of seizures and 83% abnormalities. The study suggest that in the absence of fraak epilepsy, signs like starring, automatism or shaking episodes are not good predictors of abnormal EEGs. |
Parmeggiani et al., 2010 | 259 | 31% | Temporal and central 31.4%. Much less frontal. | Yes | Seizures and EEG PA were not related to autistic regression. |
Ekinci et al., 2010 | 51 | 8% | Â | Yes | No relation between severity of intellectual dysfunction and presence of IEDs |
Kanemura et al., 2013 | 21 | 50% | Frontal, central and temporal. | Yes | The presence of frontal paroxysms was significantly associated with later development of epilepsy compared with centrotemporal paroxysmus |