West syndrome (WS) is an age dependent
epileptic syndrome caused by various
brain disorders. WS has been frequently classified in two groups, cryptogenic and symptomatic. As symptomatic WS consists of patients with numerous types of brain lesions, the prognosis and evolutional changes may be different among the types of brain lesions. WS is resistant to treatment to most conventional
antiepileptic drugs, and only
valproic acid,
benzodiazepines,
adrenocorticotropic hormone (
ACTH),
corticosteroids and
vigabatrin have been found efficacious.
Benzodiazepine, notably
nitrazepam, and less
clonazepam had been effective in bringing
spasms under control but emerging tolerance and significant side effects (
hypotonia and drowsiness) precluded its wider use.
ACTH has been the treatment of choice for
infantile spasms ever since Sorel and Dusaucy-Bouloye described its effectiveness in 1958. Despite the empirical approach
steroids were capable of controlling the
spasms and normalizing EEG in about 60% of cases.
Corticotropin (
ACTH) was used in doses from 5 to 180 I.U. daily, prednizolone 2-10 mg/kg daily,
hydrocortisone 5-10 mg/kg daily and dexamethason 0.3-0.5 mg/kg. However, poor consensus was defined regarding the best
steroid molecule to use, the dosage, and the
duration of treatment. Also frequent and sometimes serious side effects have occurred during
ACTH therapy, notably serious
infections and
hypertension that promoted continuous search for alternative and safer drugs tolerated outpatient treatment, good tolerance and minor side effects. Recently a specific visual field loss has been reported in treated adults that raised concern about safety of
vigabatrin. New reports in children claim that
vigabatrin treatment of children and adolescents has a lower risk for visual field defect than in adults, because of reported reversibility.
Vigabatrin paediatric advisory group recommend the trial of
vigabatrin for 12-14 days as first treatment for WS and in the case of good clinical response continuation of
therapy for six months. Other new
antiepileptic drugs (
lamotrigine,
topiramate,
felbamate and
zonisamide) have shown significant efficacy in the treatment of resistant WS to previous medication. The current task is to determine risk/benefit ratios of these two drugs (vigabatine,
ACTH) and to delineate the group of patients with WS where their use would be optimal.