Aetiological Factors

The aetiology of cerebral palsy (CP) is heterogeneous, multifactorial and only partially understood. The brain development begins with neurulation (3 weeks of gestation) and makes further important steps during the first 2 years of life, in particular in the first 12–15 months. CP can result from brain injury occurring during the prenatal, perinatal or postnatal periods. This chapter discusses the aetiological mechanisms that underpin the development of CP. For some, e.g. iodine, perinatal arterial ischaemic stroke (maternal, placental, fetal, neonatal), head injury, coagulation defects and haemorrhage, the relationship with the development of disability is clear. But for others, sometimes considered risk factors rather than aetiological factors, for example, premature birth, small for gestational age, and multiple pregnancies, despite strong evidence of an association, the aetiological mechanisms remain obscure. The potential mechanisms underlying the relationship between hypoxia and the role of neonatal encephalopathy in the development of CP are explored, and the role of genetic and familiar factors associated with CP is identified and discussed. In summary, the aetiological factors associated with CP are complex and diverse, and the precise causal mechanisms underpinning the development of CP for several of the associated risk factors are still unknown.