Effects of the ketogenic diet on platelet counts and global coagulation tests in childhood epilepsy

Purpose: Several antiseizure drugs (ASD), especially Valproic acid (VPA), influence platelet counts and coagulation parameters. The ketogenic diet (KD), established in drug-resistant epilepsy, is combined with ASDs. Bruising and prolonged bleeding times during KD have been described, but whether hemostatic changes result from the KD or from concomitant ASDs, remains unclear. Aim of the present study was to evaluate bleeding, platelet counts and global coagulation tests prior to and during KD in childhood epilepsy. Method: Consecutive children treated with KD were systematically observed for bleeding. Serial measurements of platelet counts and global coagulation tests (APTT, PT and fibrinogen) were obtained at baseline and during KD (at 1, 3, 6 and 12 months). Children with KD monotherapy, concomitant VPA, or other ASDs were compared. Results: Among 162 children receiving KD, we observed neither bleeding in daily life nor perioperative bleeding in those undergoing surgery (n = 25). Most children had normal platelet counts and coagulation parameters. Only a few had transient mild thrombocytopenia and mildly prolonged APTT values, not indicative of a bleeding risk. Even KD combined with VPA did not cause relevant coagulopathy. Unexpectedly, we found mild thrombocytosis in 24 % of patients prior to KD, which was most pronounced in yet untreated epilepsy. Thrombocytosis steadily resolved during KD. Conclusions: During KD treatment of childhood epilepsy, we observed neither bleeding symptoms nor laboratory results indicating a bleeding risk. Unexpectedly, mild thrombocytosis was present in 24 % at baseline, normalising during KD. Thrombocytosis may reflect the underlying inflammatory process of untreated epilepsy and requires further study.