Abstracts

Rationale: To compare the prognosis after successful completion of the ketogenic diet (KD) between after a short-term for 8 months and a classic long-term trial for over 2 years in patients with refractory infantile spasms. Methods: Of 40 patients who had obtained seizure free and showed an improvement of hypsarrhythmic patterns within 6 months of the KD with a 3:1 ratio of fat to non-fat as an add-on treatment, 16 patients (boys, 11 and girls, 5) have been randomized into a short-term trial group and the diet has been tapered through additional two months. Twenty four patients randomized into a long-term trial group and finally 19 patients (boys, 12 and girls, 7) could successfully discontinue the diet after 2 years. Finally 35 patients could be followed up for at least more than 12 months after successful discontinuation of the diet. Primary outcome measures included seizure relapse and frequency after successful completion of the KD. Secondary outcome measures included electroencephalogram (EEG), developmental scale, complications and growth. Results: Of 16 patients in a short-term trial group, 2 patients showed relapse by clusters of spasms and additional 1 patient occurred occasional focal seizures. Of 19 patients in a long-term trial group, 2 patients showed evolving to Lennox-Gastaut syndrome and additional 1 patient occurred occasional focal seizures with secondary generalization. A dramatic, early response to the KD, evidenced by short latency till to seizure free and disapperance of hysarrythmia and cryptogenic etiology may also indicate the successful early discontinuation of the KD. Their developmental outcomes were well correlated to seizure outcomes and an accompanying improvement of EEG findings. In both groups, during an administration of the KD, various complications occurred but most of them are transient and can be managed easily by conservative treatments. However, osteopenia and renal stones could not be observed during a short term trial of the KD in contrary to during a long term trial of the diet. Conclusions: A short-term protocol of the KD has a comparable outcome and less frequent serious complications than the conventional long-term KD.