[Treatment of West syndrome].

PURPOSE

West syndrome (WS) is one of the catastrophic epileptic syndromes in infancy characterized by a triad of infantile spasms, psychomotor deterioration and hypsarrhythmic EEG pattern. WS is commonly associated with poor long-term outcome, especially in symptomatic cases, with development of other seizure types, impaired cognitive and psychosocial functioning. The aim of our study was to evaluate the efficacy of the control of infantile spasms using synthetic ACTH or vigabatrin in newly diagnosed cases and to correlate it with the underlyning causes, outcome and adverse effects.

PATIENTS AND METHODS

The database of children with WS seen at the Neuropediatric Unit and followed at outpatient clinics from January 1, 1994 until December 31, 2003 were reviewed. The diagnosis of WS following the criteria of ILAE was made in 32 patients.

RESULTS

Data were collected for 32 children (9 girls and 23 boys). According to the etiology, 5 (15.6%) were cryptogenic, and 1 (3.1%) was idiopathic. In 26 (81.2%) symptomatic cases, hypoxic-ischemic encephalopathy (69.2%) was the most common etiologic factor, followed by central nervous system anomaly including malformation of cortical development (11.5%), and Sturge Weber syndrome (3.8%), and chromosomal translocation with Down syndrome (11.5%). In 65.1% of symptomatic cases birth occurred prematurely. The mean age at spasm onset was 5.8 months, and mean age at diagnosis and treatment 7.2 months. Between 1994 and 1996 synthetic ACTH was used for treatment of WS in 7 patients (1 cryptogenic and 6 symptomatic), spasm control was achieved in 6, hypsarrhythmia disappeared in 5, and vigabatrin was added after synthetic ACTH in 3 patients. In one child synthetic ACTH was stopped because of arterial hypertension. All children had Cushing syndrome. After 1996, vigabatrin was administrated to 5 children with cryptogenic and 20 children with symptomatic WS. In 22/32 spasm control was achieved within 15 days. Synthetic ACTH was added in 3 children with spasms and hypsarrhythmia disappeared in 1 child. There was no recurrence of WS. The mean follow-up in 27 children was 4.6 (0.5 to 9.9 years) whereas 5 were lost from follow-up. Of 6/27 children with cryptogenic WS, 1 had idiopathic WS, 3 had normal psychomotor development and 2 had psychomotor retardation, without epileptic fits and still receiving AED. Of 21/27 children with symptomatic WS 76.2% had severe psychomotor retardation, 42.8% had epilepsy, 23.8% had intractable epileptic fits, and 2 children with Down syndrome were without epilepsy and without AED. Lennox-Gastaut syndrome developed in 14.2% (3/21 children); 1 of them died at the age of 3.5 years from acute gastric bleeding during the administration of synthetic ACTH, and an other child died at the age of 5.5 years from infection and respiratory insufficiency. The mortality rate was 7.4% (2/27 children).

DISCUSSION AND CONCLUSION

The cryptogenic etiology is associated with a very low risk of poor outcome in WS. In children with normal development and regular school performance an idiopathic etiology can be presumed. The children with Down syndrome had a relatively benign outcome with regard to seizure control compared with symptomatic infantile spasms in the general population. In symptomatic WS caused by hypoxic-ischemic encephalopathy the outcome was linked with coexistence of other forms of epilepsy and neurologic deficit. The poor prognosis concerning intractable nature of the seizures and serious neurologic deficit is recorded in children with malformation of cortical development and Sturge Weber syndrome. The outcome of these children is determined by the brain damage other than by epilepsy itself. Regarding the treatment with synthetic ACTH or vigabatrin, the control of WS was the same for cryptogenic and symptomatic forms, one drug may be effective if the other drug fails. Synthetic ACTH can have many side effects, even death. The visual field defect is associated with vigabatrin, but can be avoided with careful funduscopic follow-up. Vigabatrin can be suggested as the first drug for WS; if spasms persist after 15 days with a dose of 150 mg/kg, synthetic ACTH should be considered.