Clinical, aetiological and evolutive aspects of West syndrome in Yaoundé (Cameroon)

Background: West syndrome (WS) is an epileptic syndrome of the infant occurring between the 3 and 12 months of life and characterized by the triad: infantile spasms in flexion, extension or mixed; global developmental delay; and hypsarrythmia on the electroencephalogram (EEG). Its incidence varies between 2.9 and 4.5 per 10,000 live births. West syndrome is caused by a brain dysfunction whose origins can be prenatal, neonatal and postnatal. Sometimes the aetiology is genetic or unknown. Purpose: To determine the main clinical, aetiological and major evolutive aspects of West syndrome in child neurology unit in a university-affiliated hospital in Yaoundé. Materials and Methods: It was a retrospective descriptive study conducted from September 2011 to January 2012 in the child neurology unit of the Yaoundé gynaeco-obstetric and paediatric hospital. The medical records of 68 children followed for West syndrome (WS) in the service during the period from February 2008 to January 2012 (48 months) were used. All infants of 1to 16-month-old with the diagnosis of WS were included. The diagnosis of WS was based on clinical evidence of spasm in flexion and/or in extension with global development delay, and EEG evidence of hypsarythmia or focal/multifocal epileptic abnormalities when hypsarythmia is absent. For each included infant, relevant medical history and complete physical examination were performed. The following data were collected and reported on a standardized questionnaire: prenatal, perinatal and postnatal past histories, age at onset of spasms, age at diagnosis, semiology of spasms, psychomotor development, the EEG and CT aspects and the evolutive modes of WS under treatment. Psychomotor development was assessed using the Denver developmental screening test (DDST) which assesses the mental age compared to chronological age. Results: The age of onset of spasms varied between 1 and 16 months with a mean of 4.69 (±1.98) months. Males were highly represented with a sex ratio of 1.72. Flexion spasms were the most common clinical presentation (79.41%). 82.83% of the patients had a global developmental delay on the onset of spasms. Structural causes or symptomatic West syndrome was the most frequent presentation (77.94%). Perinatal aetiologies were highly represented (73.58%) with the main cause being neonatal asphyxia (55.88%). A hypsarrythmic tracing was found on the electroencephalogram (EEG) in 73.53% of cases. The most frequent CT abnormality was cortico-subcortical atrophy (38.24%). At the end of our study, global developmental delay persisted in 89.72%. Conclusion: The main aetiologies of West syndrome in our context are the sequelae of neonatal asphyxia and viral embryofoetopathies. There is a high incidence of associated global developmental delay. More prevention methods on risk factors for foetal distress and proper monitoring of deliveries to minimize severe neonatal asphyxia are indispensable.