Hydranencephaly and allied disorders: a study of cerebral defect in Chinese children.

It is proposed to present 11 cases of cerebral defect. Six of these can be classed as hydranencephaly, the others show varying degrees of cerebral mantle tissue loss. The diagnosis and aetiology of these defects will be discussed and pictorial evidence produced to show that hydranencephaly is probably the end result of a graduated series of cerebral cortical defects. Hydranencephaly is defined by Potter (1952) as 'an abnormality consisting of a complete or almost complete absence of the cerebral hemispheres. The leptomeninges and dura are completely formed occupying their normal positions in the skull'. Although Bettinger (1940) attributes the name of the condition to Cruveilhier (1835), and although the latter describes the anomaly and illustrates his case with an excellent colour plate, he does not in fact use the word, remarking, 'II y a deux especes d'anencephalies: l'anencephalie hydrocephalique et l'anencephalie avec l'absence de la votute cranienne, du plut6t avec dejettement et deformation des os de la vo'ute'. He continues, 'Dans l'un et l'autre cas l'absence du cerveau doit etre produite par la meme cause'. It seems that Spielmeyer (1905) was the first to use the word in the title of his paper, 'Ein hydranencephales Zwillingspaar'. The number of reported cases is probably about 70. Reliable figures are difficult to obtain as various authors have not hesitated to extend the definition to suit their own specimens. Others, e.g. Picaza, Cardelle and Martin Jimenez (1955) who would abolish the term altogether, hide within their term 'hydroencephalodysplasia' undoubted cases of the classical condition. Yet others, like Kiss (1951),