Chiari malformation and odontoid panus causing craniovertebral stenosis in a child with Crouzon's syndrome

Chiari type I malformation in children

The diagnosis of Chiari type I malformation (CIM) is more and more frequent in clinical practice due to the wide diffusion of magnetic resonance imaging. In many cases, such a diagnosis is made incidentally in asymptomatic patients, as including children investigated for different reasons such as mental development delay or sequelae of brain injury. The large number of affected patients, the presence of asymptomatic subjects, the uncertainties surrounding the pathogenesis of the malformation, and the different options for its surgical treatment make the management of CIM particularly controversial.This paper reports on the state of the art and the recent achievements about CIM aiming at providing further information especially on the pathogenesis, the natural history, and the management of the malformation, which are the most controversial aspects. A historial review introduces and explains the current classification. Furthermore, the main clinical, radiological, and neurophysiological findings of CIM are described to complete the picture of this heterogeneous and complex disease.

C1-C2 arthrodesis after transoral odontoidectomy and suboccipital craniectomy for ventral brain stem compression in Chiari I patients

Chiari I malformations are often associated with congenital craniocervical anomalies such as platybasia, basilar invagination, and retroflexion of the odontoid process. Management of ventral brain stem compression associated with Chiari I malformations remains controversial, but several authors report a significant rate of failure with suboccipital decompression alone in the presence of pronounced ventral brain stem compression (VBSC). Treatment options described in the literature for these patients involve anterior, posterior, or combined decompressions with or without concurrent arthrodesis. A combined anterior and posterior approach provides a definitive circumferential decompression but also significantly disrupts the stability of the occipitocervical junction usually necessitating occipitocervical fixation. We describe an alternative surgical treatment for Chiari I patients with significant ventral brain stem compression where a combined anterior and posterior decompression was considered necessary. We report two patients who underwent transoral odontoidectomy with preservation of the anterior arch of the atlas and suboccipital craniectomy with C1 laminectomy followed by C1-C2 arthrodesis. Preservation of the anterior arch of the atlas in conjunction with C1-C2 arthrodesis stabilizes the occipito-atlanto-axial segments while conserving more cervical mobility as compared to an occipitocervical fusion.

Chiari type I malformation in four unrelated patients affected with Fabry disease

Fabry disease (FD) is an X-linked inborn error of metabolism resulting from the deficient activity of alpha-galactosidase A which leads to the widespread deposition of glycosphingolipids in lysosomes, and to ischemic complications involving kidneys, heart and brain. Among neurological symptoms, strokes and transient ischemic attacks (TIA) have been reported. A 30-year-old male patient, with FD, was referred to us for evaluation of a sudden episode of dizziness, with disequilibrium, and diplopia, in agreement with the diagnosis of a TIA. Head magnetic resonance imaging (MRI) showed no cerebrovascular involvement but revealed the presence of Chiari type I malformation (CMI). We subsequently performed head MRI in a cohort of 44 consecutive hemizygous male patients and seven heterozygous females affected with FD, and identified three additional cases (two males and one female) of CMI. Whether the association is coincidental or not will need further studies but our data suggest that CMI should be ruled out in all Fabry patients.