Abstracts

Rationale: Epileptic spasm is a peculiar type of epileptic seizure, entailing the clinical spasms and a characteristic electroencephalogram (EEG) abnormality often called hypsarrhythmia or its variants. The main goal of epileptic spasm treatment with standard therapy is to suppress clinical spasms and abolish the hypsarrhythmia and its variant EEG pattern. This interictal EEG pattern frequently heralds developmental regression. The elimination of hypsarrhythmia is a principal goal of therapy and a key outcome measure in clinical trials. There have been several studies in the interpretation or grading of hypsarrhythmia (Watanabe et al.1993 & Jeavons & Bower et al.1961). Still, there have been no studies in the grading of electrographic improvement with the standard treatment and its effects on the outcome, mainly in terms of remission vs. relapse. We aim to assess the electrographic improvement of hypsarrhythmia and its variants with standard hormonal (ACTH or prednisone) and Vigabatrin therapy based on the standard EEG scoring system (Kramer et al.1998). It is also generally accepted that outcome depends upon the underlying disease, so we selected patients with common etiologies (Cryptogenic, Down Syndrome, and Tuberous Sclerosis) and determined the EEG features predicting remission or relapse of epileptic spasms.

Methods: This is a retrospective chart review examining several EEGs before and after treatment using a standard scoring system (Kramer et al.1998) for a follow-up period of at least 1year. We analyzed different EEGs and graded them based on a standard scoring system on pretreatment EEG (at the time of diagnosis) and post-treatment EEG changes (1-2wks, 2-3 months, or 6-12 months) in patients with epileptic spasms who received standard treatment.

Results: Of 24 patients with epileptic spasms, 18 had EEG improvement of over 75% with resolution of spasms. Four had less than 50% improvement with refractory or recurrent spasms. Two patients had improvement between 50 and 75%. One had resolution of spasms, while the other had recurrent spasms. All the patients were treated with different treatment options as 10 received only ACTH, 9 received both ACTH & Vigabatrin, 4 received only Vigabatrin, and 1 received only prednisone and Vigabatrin.

Conclusions: Patients with sustained improvement in serial EEGs over 3-6 months of about >75% compared to pretreatment EEG were associated with spasms remission. Patients in whom the improvements were less than 50% continued to have ongoing spasms. These results highlight the need for the level of aggressiveness and close follow-up depending on the degree of EEG improvements with standard therapy.

Funding: Please list any funding that was received in support of this abstract.: None.