[Semilobar holoprosencephaly associated with central diabetes insipidus].

The clinical and neuroradiological findings in a case of semilobar holoprosencephaly associated to hypernatremia behaving like diabetes insipidus are described. The differential diagnosis with a neurogenic hypernatremia is discussed. The advantages of ultrasounds in the diagnosis of this malformation are pointed out. So are the characteristics which differentiate it from other neurological malformations and the importance of a dorsal sac to delimitate the more serous clinical forms.