Hyperostosis cranialis interna

What it is

A rare primary bone dysplasia with increased bone density characterized by slowly progressive endosteal hyperostosis and osteosclerosis exclusively of the skull base and the calvaria, resulting in entrapment and dysfunction of cranial nerves I, II, V, VII, and VIII. First symptoms often appear during the second decade of life and include disturbances in smell, vision, facial sensation and expression, hearing, and balance, as well as headaches due to increased ocular and intracranial pressure. After the fourth decade, radiological progression is minimal, although decreased intracranial volume can lead to death in severe cases.

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Adolescent, Adult, Childhood

Inheritance

Autosomal dominant

Classified as

Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references