Introduction: Atypical febrile seizures (AFS) have been related with a higher incidence of severe pathologies of the central nervous system (CNS). Recent studies show a reduction in the prevalence of some of these diseases, a fact that could affect their management. AIMS. To determine the prevalence of severe pathologies of the CNS in patients treated for AFS in A and E departments and to detect any differences between these and patients suffering from AFS that is not associated to any severe pathology.
Patients and methods: A retrospective study was conducted by reviewing the medical records of patients diagnosed with AFS between November 2008 and November 2011.
Results: Altogether, the sample consisted of 231 episodes of AFS (223 patients), with an average age of 1.7 years (p25-75=1.2-2.3 years), 133 (57.6%) of whom were males. Twelve patients (5.2%; 95% CI=2.7-8.9) were diagnosed with a severe pathology of the CNS. In patients with a severe pathology of the CNS, AFS is on most occasions the first episode (91.7% versus 63%; p=0.036) and more than one diagnostic criterion is present (50% versus 15.1%; p=0.007). Moreover, focal seizures (50% versus 12.8%; p=0.003) or epileptic status (25% versus 5.9%; p=0.041) are more common, and patients present altered levels of awareness that persist after the episode (66.7% versus 31.5%; p=0.002).
Conclusions: Given the fact that the prevalence of severe pathology of the CNS in patients with AFS is low, carrying out complementary tests or admission to hospital on a routine basis are not recommended. Certain characteristics of the episode increase the likelihood of AFS being the manifestation of a severe pathology of the CNS (being a first episode, presenting more than one diagnostic criterion for AFS and being a focal seizure or epileptic status), and should therefore be taken into account in the management of the patient.