Multihandicapped blind and partially sighted children in south Germany. II: Aetiology and pathogenesis.

The results of a classification of the aetiology of visual impairment and mental retardation in a series of 239 multihandicapped blind and partially sighted children are reported. These children had been born between 1981 and 1987 and were examined in a population-based study in South Germany. There was marked aetiological heterogeneity. Most prominent were causes related to the perinatal period and late gestation which were found in 41% of the children. Among these, lesions of the visual pathways in preterm children were especially frequent and could be explained by periventricular leukomalacia in a large proportion. The distribution of the major aetiologic groups is different from populations with isolated mental retardation and populations with isolated visual impairment but similar to a Swedish population with spastic quadriplegia. The implications for the prevention of severe multiple impairments in children are discussed.