[Cerebral magnetic resonance in the study of West syndrome]

West's syndrome (WS) is an epileptic encephalopathy of the first year of life, associated with different aetiologies. MRI of the brain allows precise determination of the type and extent of the lesions. The aetiology must be recognised in order to establish the prognosis and a suitable therapeutic approach. The objective of this study is to analyse the aetiologies of a population of children with WS and compare the results of cases diagnosed before and after using MRI.

We analyzed the clinical histories of 448 patients fulfilling the diagnostic criteria for WS (infantile spasms and a EEG with a pattern of hypsarrhythmia), 217 in pre-MRI era (group 1) and 231 in the post-MRI era (group 2). The following parameters were analyzed: type of WS, sex, duration of follow-up, age of onset of infantile spasms and particularly the neuroradiological studies.

Group 1: symptomatic WS, 157 patients; cryptogenic WS, 60 patients. Group 2: symptomatic WS, 169 patients; cryptogenic WS, 62 patients. The aetiologies of symptomatic WS were: cortical dysplasias, neurocutaneous disorders, cerebral malformation and prenatal clastic lesions, hypoxic ischaemia, post-infection, metabolic, tumors, Down's syndrome, others and unknown cause.

It is known that cerebral MRI gives better definition of these types of cerebral lesions than cerebral CT does. We emphasize the importance of MRI in patients with symptomatic WS for precise determination of the aetiology, and speculate as to whether some of the 21 cases of unknown aetiology of group 1 could have been diagnosed if studied nowadays.