EEG
Should EEG be obtained?
| Author, date, country, and industry of funding | Patient Group | Strength of Evidence (GRADE) | Research design | Significant results | Limitations | |||||||||||||||||||||||||||
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(Arthur et al., 2008) USA |
Children age 6-14 years N= 150 (349 were recruited) Single afebrile seizure followed up at 9, 11 and 27 months. Provider decided who got MRI
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Low |
Prospective cohort Followed for at least 27 months Children with absence, myoclonic or prior unrecognized seizure were excluded. |
There was a recurrence rate of 66.4% An abnormal EEG had no association with seizure recurrence at 9, 18, or 27 mo (p = 0.1806, p = 0.2792, and p =0.2379, respectively)
A “significant” MRI abnormality (16% of subjects) was associated with increased risk of recurrence at 9 mo (p = 0.0389), but not 18 or 27 months They do not recommend MRI after first seizure, because it is not predictive. |
Of the 349 recruited into the larger study, 189 subjects met the criteria for this study. 150 had EEG performed 125 subjects had MRI performed.
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(Chan et al., 2010) Singapore |
Children aged 1 month to 15 years with first afebrile seizure 108 with ≥ 2 afebrile seizure and 103 with first afebrile seizure |
Very Low |
Population Survey |
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Population based study that looked at the epidemiology of afebrile seizure. |
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(Anand et al., 2012) United Kingdom |
128 children mean age 6.5 years (range 1 month to 17 years. |
Very Low Appears to be an abstract only
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Retrospective observational cohort
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Video EEG (vEEG) was normal in 75 subjects (59%) Non-epileptic events were recorded in 8 subjects (6%) Idiopathic generalized epilepsy was diagnosed in 14 subjects (11%) Generalized epilepsy with febrile seizure was diagnosed in 2 subjects (2%) A focal epilepsy was diagnosed in 29 subjects (23%) Sensitivity= 100 Specificity = 10 (+) predictive value = 85% (-) predictive value= not estimable |
34 subjects had neurodevelopmental problem, 11 subjects had a family history of epilepsy, and 13 had a history of febrile seizure. |
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(Hamiwka, Singh, Niosi, & Wirrell, 2007) |
Children 1 month -17 years Mean age- 8 years, =/- 5 years N= 127 53% male Seen in clinic 52 +/- 18 days after first encounter Development delay present in 19 children (15%) Abnormal neurological exam was present in 14 (11%) |
Very Low |
Non randomized prospective cohort study of children seen at a First Seizure Follow-up Clinic |
24% events were felt to be non-epileptic (n= 31) Primary event was syncope 74% were felt to be epileptic (n=94) 2% (2) were unclassifiable
Results of follow up EEG All 94 children with an epileptic event had an EEG. 44 of these children (47%) had abnormalities present, 53% did not. Thirty children without an epileptic event had EEGs. 93% had normal studies. Over a one year follow up, 42 children (45%) were diagnosed with epilepsy.
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Many of the subjects (38%) in this study did indeed have a prior seizure event that was unreported by the referring provider, or unrecognized by the parent/caregiver at the time of the referral. |
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(Hsieh et al., 2010) USA |
317 infant subjects (range 1-24 months) urban population |
Low It is a cohort study based on a clinical guideline. |
Prospective cohort |
EEG (all subjects) abnormalities were found in half CT (298/317 obtained) abnormalities were found in a third MRI (182/ 317 obtained) abnormalities were found in 57% Of the 193 normal CTs, 97 underwent MRI of which 32 (33%) had an abnormal MRI |
The majority had more than one seizure upon presentation. The incidence of seizures lasting longer than 20 minutes was 8.5% 30 subjects had a history of prematurity. Increased likelihood of obtaining an MRI in younger infants.
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(Landau, Waisman, & Shuper, 2010) Israel |
85 subjects average age 7.5 y (range 0-18 y) who made 104 visits to the ED Excluded febrile seizure or other primary diagnosis |
Very Low- inconsistent includes subjects that do not apply to this guideline |
Retrospective chart review |
Laboratory tests were obtained in 84% of visits. Eight percent provided useful information and < 5% were helpful in diagnosis and management. Only one lumbar puncture was performed. Eight percent of visits had electrocardiography performed and all were normal Seven percent of visit had electroencephalography performed and was consistently useful and was always performed along with a neurology consultation |
Mix of children with first seizure and those already on medication for seizure. Only 30 (35% )subjects presented with first seizure |
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These guidelines do not establish a standard of care to be followed in every case. It is recognized that each case is different and those individuals involved in providing health care are expected to use their judgment in determining what is in the best interests of the patient based on the circumstances existing at the time. It is impossible to anticipate all possible situations that may exist and to prepare guidelines for each. Accordingly these guidelines should guide care with the understanding that departures from them may be required at times.