Embryological considerations and evaluation of congenital anomalies of craniovertebral junction: A single-center experience.

Objectives: Craniovertebral junction (CVJ) abnormalities constitute a group of treatable neurological disorders, especially in the Indian subcontinent. Thus, it is essential that clinicians should be able to make a precise diagnosis of abnormalities and rule out important mimickers on multidetector computed tomography (MDCT) as this information ultimately helps determine the management, prognosis, and quality of life of patients. CVJ is the most complex part of the cervical region. Congenital malformations of this region can cause serious neurological deficit and require a surgical intervention. The present study was undertaken to know the embryological basis of the CVJ and to identify commonly observed congenital CVJ abnormalities, their frequency, and mode of presentation.

Materials And Methods: Diagnosed cases of CVJ anomalies on dynamic MDCT head were reviewed at a tertiary care center between January 2014 to December 2019. Type of anomaly, clinical presentation, and associated malformations were recorded. Different types of variations were expressed in terms of percentage.

Results: Congenital anomalies were seen in 42 cases. Fifteen types of anomalies were detected. Anomalies were either singly or in combination. The CVJ anomalies were more common in young adults (28%), almost equal in both sexes. The most common anomaly was basilar invagination (52.3%), followed by atlanto-occipital assimilation (33.3%), and Arnold-Chiari malformation is the most common soft tissue anomaly. In fourteen cases, additional anomalies of other vertebrae were present. The most common symptoms were weakness of extremities, neck pain, paresthesia, torticollis, and gait disturbances. About 28 patients got improved, 8 patients had residual deficit as that of preoperative status, and 4 patients got deteriorated after surgery, at 1-month follow-up. About 34 patients had improved, 5 remained static, and 3 patients got worsened at the end of 3-month follow-up. About 37 patients had improved, 4 patients remained static, and 2 patients got deteriorated at 6 months of follow-up. The patients with increased atlantodens interval 3-5 mm showed 77% improvement after surgery.

Conclusion: Congenital CVJ anomalies, though rare, are fatal. CVJ abnormalities constitute an important group of treatable neurological disorders with diagnostic dilemma. The atlantodental interval is the most important preoperative prognostic marker. Dynamic CT imaging can provide additional useful information to the diagnosis of CVJ instability. To prevent long-term neurological problems, early diagnosis and treatment of congenital bony CVJ anomalies is important.