ESPE Abstracts

Background: In our bone unit, we were following since their younger age, two brothers with a severe osteogenesis imperfecta. We had no genetic confirmation but the severity of the disease combined with unaffected consanguine parents argues for a recessive autosomal transmission. Both present with highly severe form of osteogenesis imperfecta: repeated vertebral and peripheral fractures, long bone deformations, centromedullary nails on the lower limbs, major motor handicap and disability (wheelchair), cyphoscolisois and severe growth retardation below – 3 standard deviation score.

Our Case: The younger boy had received treatment with bisphosphonates since the first year of life, associated with vitamin D supplementation, and with intensive physical rehabilitation. At fourteen years old, bisphosphonates reached their limits: repeated untraumatic fractures, delayed fracture healing, osteosynthesis material loosening. We confirmed a growth hormone deficiency. The cerebral MRI showed pituitary hypoplasia and asymptomatic craniocervical junction abnormalities. Basilar impression was associated to clivus malposition and brainstem deformation. The medullar MRI showed known vertebral fractures and scoliosis. We stopped bisphosphonate and started nocturnal enteral nutrition and growth hormone treatment in order to improve bone mass and strength.

Evolution: During 2 years, no fracture occurred. Nutritional status was better. At the age of sixteen years old, he presented behavioral troubles: disinhibition, motor instability, stereotypies, sphincter dysfunctions. Neurological examination was normal, especially without headache, or visual impairment, no sign of cranial hypertension, or pyramidal syndrome. However ophthalmologic examination revealed papilledema.

TDM survey: The cerebral TDM showed an important triventricular hydrocephalia and basilar impression.

Treatment: We stopped growth hormone treatment. A ventriculostomy was performed. It was well tolerated and improved the frontal behavior.

Conclusion: In that family, the phenotype concerning the skull basis seems different. While treated earlier, the younger boy had a worst evolution curse and more complex abnormalities. Usually phenotype is the same in the same family. Early bisphosphonate treatment did not protect that child from such a complex and unusual cranial base abnormalities. Neurological examination and behavioral evaluation are essential in severe osteogenesis imperfecta. Ophtalmologic examination and cerebral imaging must be performed in frontal behavior dysfunction.