Duncan Memorial Lecture: Part 1. Dr Duncan's legacy in a remote New Guinea valley.

Dean, colleagues, I am very honoured by your invitation to give the Duncan lecture for 1997. In speaking of Dr Duncan’s legacy in a remote New Guinea valley, I would like to focus on the contribution made by research in cerebral palsy that has been carried out in Papua New Guinea and in Liverpool, dividing Duncan’s legacy into three time periods: Past—up to 1979; Present—1979 to 1997 and Future. The past, pre-1979: The Jimi Valley, endemic goitre and cretinism The Jimi valley is a remote area in the mountainous Western Highlands Province of Papua New Guinea with a population of about 24 000 comprising four language groups. In the early days of the research access to the valley was by light aircraft, there were no roads and all travelling in the valley was on foot. Numerous flimsy bridges made of bamboo and suspended over the river by vines had to be crossed (fig 1). Endemic goitre attributable to iodine deficiency, a worldwide public health problem, was common in many parts of Papua New Guinea. In the person with severe iodine deficiency, the thyroid can be very large indeed, the size of a football. It is particularly prevalent in women of childbearing age because their iodine requirements are greater than any other population group. Goitre is least prevalent in adult men. That iodine deficiency is the main cause of endemic goitre has been appreciated for over a century. In areas where goitre is endemic, the disease of endemic cretinism also is sometimes found. In contrast with what is written in most paediatric textbooks, the endemic variety of cretinism is a syndrome of neurological impairment comprising mental retardation, spastic diplegia/quadriplegia, deaf-mutism and occasionally, strabismus. In most countries where the disease is prevalent, clinical hypothyroidism is not a feature of the syndrome. There are two varieties of cretinism. The sporadic variety, which is congenital hypothyroidism, is well described in textbooks and may be found anywhere in the world with a birth prevalence of about 1:3500. Endemic cretinism is a variety of cerebral palsy usually accompanied by deaf-mutism, mental disability and strabismus. Because endemic goitre is attributable to iodine deficiency and endemic cretinism is found only in areas where there is endemic goitre, it was hypothesised that endemic cretinism was also attributable to iodine deficiency. However, there is conflicting evidence concerning the hypothesis whether or not iodine deficiency was the cause of both endemic cretinism and endemic goitre. For this reason we decided to undertake a controlled trial using intramuscular iodinated oil for the intervention group and physiological saline for the control group. The Figure 1 Suspension bridge over the Jimi river. J Epidemiol Community Health 1999;53:794–800 794