Sinus Hypoplasia and Intracranial Hypertension in Pycnodysostosis (SHIHP): A New Disease Process?

Abstract

Pycnodysostosis is a rare autosomal recessive skeletal dysplasia caused by absence of active cathepsin K. Intracranial hypertension represents a rarely reported, life threatening complication of pycnodysostosis. We describe, for the first time, two children with pycnodysostosis who presented with raised intracranial pressure and were found to have intracranial venous sinus hypoplasia. The combination of Sinus Hypoplasia and Intracranial Hypertension in Pycnodysostosis (SHIHP) has not been previously reported. In a patient with pycnodysostosis, neurological and ophthalmological assessment is necessary and MR Brain including venography should be considered. The management of such a patient is challenging in particular due to the uncertainty as to the mechanism of the raised intracranial pressure in the face of small ventricles and an open fontanelle. Multidisciplinary team management including the geneticist, ophthalmologist, neurologist, neurosurgeon, and the metabolic bone team is required. Surgical options include CSF diversion and cranial vault remodelling. The interplay of venous sinus hypoplasia, intracranial vault abnormalities, and raised intracranial pressure in a patient with pycnodysostosis shall be presented and discussed.

Cathepsin K osteoporosis trials, pycnodysostosis and mouse deficiency models: Commonalities and differences

“…In two other cases, sinus hypoplasia and intracranial hypertension were described resulting in visual deterioration, difficulties in motor tasks, and non-specific headaches. [152] Finally, Mujawar et al described an 11-year-old boy with pycnodysostosis who had vision and hearing impairments. [153] It should be noted that some of these cases have been diagnosed as pycnodysostosis based only on morphological features and not by genetic analysis.…”