Craniospinal Abnormalities and Neurologic Complications of Osteogenesis Imperfecta: Imaging Overview

Abstract

Osteogenesis imperfecta is a rare genetic disorder that leads to progressive skeletal deformities due to deficits in type I collagen, the main pathophysiologic effect of the disease. In addition, it may lead to a wide range of associated neurologic abnormalities: The central nervous system is usually involved because of softening of bone at the base of the skull, with resultant upward migration of the upper cervical spine and odontoid process into the skull base. Upward migration of the spine may cause compression of the brainstem, mechanical impingement of the spinal canal with restriction of cerebrospinal fluid circulation, and impingement of the cranial nerves. Osteogenesis imperfecta also may directly involve neurovascular structures, leading to cavernous fistulas of the carotid artery, dissection of the cervical arteries, and cerebral aneurysms. The brain parenchyma is frequently affected by the disease, with manifestations including cerebral atrophy, communicating hydrocephalus, and cerebellar hypoplasia. The imaging features of the disorder vary as widely as its clinical manifestations, depending on the severity of disease. Severe forms accompanied by debilitating skeletal fractures and progressive neurologic impairments may lead to perinatal death, whereas milder asymptomatic forms might cause only a modest reduction in life span. The most important advance in medical therapy for osteogenesis imperfecta has been the introduction of bisphosphonate therapy to slow the resorption of bone in patients with moderate to severe forms of the disease (ie, type III or IV). In some patients, neurosurgery may be necessary to correct the effects of severe basilar invagination by the odontoid process.

Imaging Findings and Evaluation of Metabolic Bone Disease

“…Cortical thinning results from abnormal bone structure, lack of lamellar bone, replacement of compact bone by spongiform bone, and defective endochondral and periosteal bone formation [71]. Cortical thinning can also misleadingly cause bones to appear wider in diameter on radiographs than in actuality.…”

Cranial base pathology in pediatric osteogenesis imperfecta patients treated with bisphosphonates

“…22 Neurosurgery with posterior occipitocervical fusion may be necessary to correct the effects of severe basilar invagination or impression. 21 The surgical treatment planning relies on radiographs and MR and CT images obtained with flexion and extension of the head. 24 Conventional lateral skull radiography is usually the first-line imaging modality in screening patients for further evaluation with MRI or CT. 21 The most significant progress in the treatment of OI has been the implementation of bisphosphonate therapy (since 1988) to increase bone mass and prevent fractures by reducing bone resorption.…”

“…21 The surgical treatment planning relies on radiographs and MR and CT images obtained with flexion and extension of the head. 24 Conventional lateral skull radiography is usually the first-line imaging modality in screening patients for further evaluation with MRI or CT. 21 The most significant progress in the treatment of OI has been the implementation of bisphosphonate therapy (since 1988) to increase bone mass and prevent fractures by reducing bone resorption. Reported benefits include increased bone mineral density and cortical bone thickness; reduction in fracture rate, deformity of long bones, and bone pain; normalization of vertebral morphology; and increased mobility.…”

Dissecting Aneurysm of the Recurrent Artery of Heubner in a Patient With Osteogenesis Imperfecta

“…However, up to one-third of cases may be sporadic. [7][8][9] Although diagnosis of OI is primarily clinical, genetic testing can help confirm the diagnosis in cases of uncertainty. In the present case, both the patient's brother and daughter had confirmed COL1A2 gene mutation.…”

“…Other manifestations may include fragile skin, easy bruising, muscle weakness, joint laxity, curved bones, short stature, scoliosis, brittle teeth (dentinogenesis imperfecta), hearing loss, and restrictive pulmonary disease. [7][8][9] OI and cerebrovascular pathology Compared with other connective tissue disorders, OI has been less commonly associated with cerebrovascular pathology. In fact, there is only a handful of case reports describing intracranial aneurysms in patients with OI, with the majority being saccular in nature, arising from typical locations, including the anterior communicating, basilar, or middle cerebral artery.…”