Chiari malformation and syringomyelia

Abstract

<jats:p>Chiari malformation was first described over a century ago, and consists of posterior fossa anomalies that generally share the feature of cerebellar tonsillar descent through the foramen magnum. Our understanding of this disorder was initially based on autopsy studies, and has been greatly enhanced by the advent of MRI. The surgical management of Chiari anomalies has also evolved in a parallel fashion. Although the exact surgical technique varies among individual surgeons, the goals of surgery remain constant and consist of relieving brainstem compression and cranial nerve distortion, restoring the normal flow of CSF across the foramen magnum, and reducing the size of any associated syrinx cavity. Syrinx cavities are most commonly associated with Chiari anomalies, yet primary spinal syringomyelia (PSS) can be caused by traumatic, infectious, degenerative, and other etiologies that cause at least a partial CSF flow obstruction in the spinal subarachnoid space. As with syringomyelia associated with Chiari anomalies, the main goal of PSS surgery is to reestablish CSF flow across the area of obstruction. In addition to MRI, myelography with CT can be very helpful in the evaluation and management of these patients by identifying focal regions of CSF obstruction that may be amenable to surgical intervention. Future directions for the treatment of Chiari anomalies and syringomyelia include the application of advanced imaging techniques, more widespread use of genetic evaluation, large-scale outcome studies, and the further refinement of surgical technique.</jats:p>

Type I Chiari Malformation Without Concomitant Bony Instability: Assessment of Different Surgical Procedures and Outcomes in 73 Patients

“…[1][2][3][4][5][17][18][29][30][31] When CM occurs without a bony instability, the condition can be termed as a "pure CM" and traditionally, PFD has remained their treatment of choice. 9,[26][27][28][29][30][31][32][33][34][35][36][37] We found that nearly 31% of the patients had some bony anomaly like basilar impression, platybasia, assimilation of atlas, and C2-3 congenital fusion. However, the incidence of these anomalies did not vary significantly among the 3 treatment groups.…”

Utility of True Fast Imaging with Steady-State Precession in Detecting Arachnoid Veils of the Posterior Fossa

“…Similarly, although a tetraventricular pattern of hydrocephalus is easy to diagnose on neuroimaging, it can be difficult to visualize the presence of a mobile obstructing membrane at the level of the foramen of Magendie. Other imaging techniques, such as cine MRI phase-contrast CSF flow studies, can be very helpful in detecting the presence of occult CSF blocks [19, 20], but have a low predictive value in cases of 4th ventricular outflow obstruction [21]. Karachi et al [21] explained that unlike the cerebral aqueduct, which is small in diameter, the 4th ventricle is larger and has 3 outlets, making it more susceptible to turbulence in flux and therefore more difficult to reliably visualize any obstruction to CSF flow using cine MRI [21].…”

Medical genomic approach to early-onset scoliosis

“…Scoliosis in Chiari malformation type I is reported in up to 20% of the patients and in up to 60% of the patients with syringo- myelia [35]. Hypotheses on the occurrence of scoliosis in Chiari malformation type I are cerebellar tonsillar compression of the cervicomedullary junction and uneven expansion of a syrinx in the horizontal plane of the spinal cord [36,37]. Therefore, Chiari malformation type I should be included in the differential diagnosis of the underlying conditions of EOS.…”