Arnold-Chiari Malformation: Core Concepts

Arnold-Chiari malformation (ACM), a defect that involves downward displacement of the hindbrain and herniation of the cerebellar vermis, tonsils, pons, medulla, and fourth ventricle through the foramen magnum, is the most complex of the 4 types of Chiari malformations. Unique to the other types of Chiari malformations, approximately 95 percent of infants with ACM also present with an associated myelomeningocele (MMC), the most severe form of spina bifida. Among affected infants, those with symptomatic comorbidities incur a significantly higher morbidity and mortality risk. Prompt identification and diagnosis of ACM, as well as evidence-based postnatal and postsurgical nursing and medical care, is critical. Early surgical intervention can repair an existing MMC and restore proper cerebrospinal fluid circulation, which can dramatically improve patient outcomes and quality of life, and reduce disease and health care burden.

The “Three on a Stick” Incision—A Curvilinear Solution for the Occipital and Suboccipital Region

BACKGROUND Different conditions of the posterior fossa such as Chiari malformations, tumors, and arachnoid cysts require surgery through a suboccipital approach, for which a typical midline vertical linear incision is used. Curvilinear incisions have been carried in all other scalp regions other than the sub region for better cosmetic outcomes; a vertical curvilinear incision in the occipital and suboccipital region has not been reported. OBJECTIVE To evaluate the cosmetic value and safety of the “3 on a stick” vertical suboccipital curvilinear incision. METHODS We compared curvilinear to linear incisions, considering the scar's width, color, how conspicuous, and how well the scar could be covered by hair naturally. RESULTS Between 2010 and 2016, 68 children with Chiari I malformation were surgically intervened. The curvilinear incision was performed in 56 (82.4%) while a linear incision in 12 (17.6%) children. There were only 2 (2.9%) wound related complications (superficial dehiscences) in the curvilinear group and 1 additional dehiscence in a linear incision case. There were no neural or vascular complications. Scars were very similar among the 2 groups; both were equally conspicuous but curvilinear ones seemed to get covered better by hair. CONCLUSION The “3 on a stick” curvilinear incision of the suboccipital region is safe and allows for better hair coverage of the scar. It can be used for multiple conditions requiring a midline suboccipital or even occipital approach, such as Chiari malformations, tumors, and cysts.

Posterior midline cleft of the atlas – a crucial anatomical variation in vertebral fractures

The anatomy of the first vertebra, namely atlas, has significant clinical implications. Atlas is situated between the occipital bone and the second cervical vertebra (axis) and is one of the main points of head movement. Most congenital anomalies of the vertebra are diagnosed incidentally during imaging investigations and can be associated with cervical spine anomalies. The neurological symptoms may include weakness in the four limbs, acute neurologic deficits such as transient quadriparesis, paraparesis, Lhermitte's sign, chronic neck pain, and headache. This anomaly is also commonly seen in gonadal dysgenesis, Klippel-Feil syndrome, Arnold-Chiari malformations, and Turner and Down syndrome. Unlike other variations, which arise due to disturbances of ossification posterior midline clefts of the atlas, are different since they are a developmental failure of chondrogenesis. We therefore present an anatomical case and analysis of the literature about posterior arch clefts of atlas.