Schierhout et al (2001) | 6 controlled trials, 1218 randomised patients; includes studies with both adults and children, some studies used other antiepileptics than phenytoin | Systematic review (level 1a) | Early seizures (in 1st 7 days post-injury) Late seizures (after 1st 7 days post-injury) Mortality Neurologic disability, (Glasgow Outcome Score) | RR for early seizure prevention 0.34 (CI 0.21–0.54); NNT=10; No? mortality, RR=1.15 (CI 0.89–1.51); No ? in death and neurologic disability RR= 0.96 (CI 0.72–1.26); No ? in late seizures Pooled RR =1.28 (CI 0.90–1.81) | Early seizure prevention values represent 4 studies with phenytoin and 2 with other agents Studies very heterogeneous in relation to late seizure outcome |
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McQueen et al (1983) | 164 patients ages 5 to 65 with serious head injuries (pts with seizures 1st wk post injury excluded) | Double blind RCT (level 1b) | Late seizures, overall mortality, skin rashes | No significant differences Late seizure ARR = −0.77% (CI −9.59 to +8.04) Mortality ARR = −3.45% (CI −9.56 to +2.66) Rash ARR = −4.7% (CI −10.32 to +0.91) | Loss to follow up at 2 years 1.2% (5% if include deaths) Authors' note: based on low incidence of events, future trials will have to be ∼6× larger than theirs to detect an effect |
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Young et al (1983) | 41 head injured children; (total study 244 pts, adult data published separately with similar results) | Double blind RCT (level 2b) | (Early seizures; data not published in this study, was collected for total study) Late seizures Overall mortality | No significant differences Late seizures ARR = −5.75% (CI −23.16 to +11.66) Mortality = 4.55% (CI −14.88 to +23.88) | Loss to follow up at 2 years 26% for overall study For children (1 withdrawn, 4 deaths in first wk not included in analysis of final 41 pts), otherwise no loss to follow up |
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Temkin et al (1990) | 404 patients with serious head trauma, 16 years of age and older | Double blind RCT (level 1b for early seizure outcome, but for late seizure outcome large loss to follow up in both groups at 2 years, thus level 2b) | Early seizures (in 1st wk post-injury) | 3.6% in treatment arm, 14.2% placebo, RR=0.27 (CI 0.12–0.62) | 24% loss to follow up at 24 months (22.5% in treatment group, 25% in placebo group) |
| | | Late seizures (from day 8 to the end of the year) | No significant difference; 21.5% treatment, 15.7% placebo RR=1.2 (CI 0.71–2.02) | |
| | | Overall mortality, skin rashes | No significant difference Mortality ARR = −2.64% (CI −10.74 to +5.27) Rash ARR = −3.35% (CI −9.27% to 2.58) | |