Chiari Malformations, Syringohydromyelia and Scoliosis
Section snippets
Key features
The key feature of Chiari I malformation (CMI) is downward hindbrain herniation through the foramen magnum. Herniation always includes the cerebellar tonsils, and, in more severe cases, it can include portions of the medulla and fourth ventricle. The presentation of CMI is influenced by the age of the patient and the specific site of compression. Syringohydromyelia and scoliosis are present in 10% to 20% of patients who have CMI and often contribute to the clinical findings. There is no
Key features
The Chiari II malformation (CMII) is more complex and generally more severe than CMI. CMII always is paired with myelomeningocele, which occurs in 0.6 of 1000 live births [47]. In neonatal patients, brain stem compression caused by CM II can cause rapid irreversible neurological deterioration; therefore these patients require a high degree of clinical vigilance. All patients born with Chiari II and myelomeningocele require closure of the myelomeningocele within 72 hours of birth (Fig. 4). Most
Key features
Syringohydromyelia is defined by the presence of a cystic cavity in the spinal cord. Although many etiologies exist (eg, trauma and neoplasia), the most common cause of syringohydromyelia is posterior fossa malformation. CMI and CMII are the most common congenital posterior fossa malformations. Syringohydromyelia is present in approximately 20% to 85% of children who have CMI [13], [14], [16], [18], [23], [27], [28], [30], [31] and is present in 48% to 88% of children who have CMII [34], [62].
Syringohydromyelia and scoliosis
Although the association between syringohydromyelia and the development of scoliosis was established in the 1940s, it was not until the widespread use of MRI in the early 1990s that it was revealed just how common a neurologic etiology existed for patients diagnosed as having idiopathic scoliosis [88], [89], [90]. The mechanism by which the syrinx causes scoliosis has not been determined, but some believe that the syrinx injures either the lower motor neurons or the dorsomedial and ventromedial
Summary
Chiari I and II are the most common hindbrain malformations in the pediatric population. Despite their prevalence, the complex nature of their presentation, often including hydrocephalus, syringohydromyelia, and scoliosis, has prevented clinicians from establishing universal treatment protocols.
The increased use of MRI has facilitated the early diagnosis of CMI and has helped clarify the relationship between pediatric scoliosis, syringohydromyelia, and the Chiari malformations.
The most common
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Cited by (40)
Congenital malformations of the brain and spine
2016, Handbook of Clinical NeurologyCitation Excerpt :This is a complex hindbrain anomaly that is always associated with a myelomeningocele and is presumably the result of chronic CSF leakage in utero leading to incomplete expansion of the posterior fossa. As a result, the posterior fossa is small and there is crowding of the neural structures with resultant herniation into the adjacent spaces (Hankinson et al., 2007). Hence, the major brain anomalies in Chiari II malformation include inferior displacement of the pons, medulla, fourth ventricle (which appears elongated), and cerebellar vermis into the foramen magnum and upper cervical canal and a heart-shaped (“towering”) cerebellum that herniates superiorly through an insufficient incisura.
Spine ultrasound imaging in the newborn
2014, Seminars in Ultrasound, CT and MRICitation Excerpt :In short axis, one would see the dorsal roots lateral and the ventral loops medial as they drop from the flat nontubulated placode. All patients diagnosed with an open spinal dysraphisms will require surgical closure of the defect within 72 hours,14 if not sooner. Preoperative sonographic evaluation in patients with an open neural defect is to evaluate the skin-covered portions of the spinal canal, to view the cord cephalad to the open defect looking for associated malformations such as syringohydromyelia, arachnoid cyst, diastematomyelia, and intradural lipoma2,5 (Fig. 9).
Scoliosis-associated cervical spine pathologies
2014, Spine DeformityCitation Excerpt :Incidences of neural axis abnormalities in patients with IS were between 2.9% and 37%. Indications for MRI in patients with scoliosis are considered to be early onset, atypical curve, double thoracic curve, fast progression, male gender, and abnormal neurological findings[3,4,14,15,22,23,29,35,40,52-56]. In a prospective trial, Evans et al. [37] performed MRI of the spine and hindbrain in 31 patients with scoliosis with an onset between the ages of 4 and 12 years.
Treatment of Chiari Malformation and Concomitant Paediatric Scoliosis Long-Term Follow-Up in One Major Referral Centre in the UK
2023, Journal of Clinical MedicineManagement of Chiari Malformation
2023, Pediatric Neurosurgery Board Review: a Comprehensive Guide