Progressive hemiparesis due to spino-laminar anomaly of the axis-a case report and literature review.

Introduction: Some of the most common developmental malformations of the axis include anomalies of the odontoid, for example, hypoplasia or aplasia. Isolated anomalies of the posterior arch of the axis rarely occur. This study reports a unique case of congenital anomaly of the neural arch of the axis vertebra, which manifested clinically as progressive hemiparesis. Case presentation: A 33-year-old man presented with progressive weakness of the right upper and lower limbs that had lasted 18 months. The patient reported loss of right-hand dexterity in the 6 months period before he consulted us. Plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) revealed C5-C6 block vertebra, primary canal stenosis and spino-laminar anomaly of the axis, along with invagination of the lamina into the canal causing severe cord compression. Discussion: The anomalous posterior element of the axis was excised, and the cord was decompressed. The presence of congenital stenosis and block vertebrae at the C5-C6 level necessitated decompression and instrumentation between C2-C6. Simultaneous occurrence of a posterior arch anomaly, primary canal stenosis, and block vertebra has not been previously described. A cervical spine anomaly presenting as hemiparesis is uncommon in clinical practice. Information enabling clinicians to identify causative anomaly and determine the appropriate surgical intervention is useful, and can facilitate a good clinical outcome.

Congenital Osseous Anomalies of the Cervical Spine: Occurrence, Morphological Characteristics, Embryological Basis and Clinical Significance: A Computed Tomography Based Study.

Study Design: Observational retrospective computed tomography (CT) based study. Purpose: To analyze the congenital anomalies of the cervical spine, their morphological variations and their clinical significance. Overview of Literature: Studies published to date have focused mainly on upper cervical anomalies; no study has comprehensively reported on anomalies of both the occipitocervical and subaxial cervical spine. Methods: Nine hundred and thirty cervical spine CT scans performed in Ganga Hospital, Coimbatore, India between January 2014 and November 2017 were screened by two independent observers to document anomalies of both the upper and lower cervical spine. CT scans conducted for infection, tumor, and/or deformity were excluded. Different morphological variations, embryological basis, and clinical significance of the anomalies were discussed. Results: Of the 930 CT scans screened, 308 (33.1%) had congenital anomaly. Of these, 184 (59.7%) were males and 124 (40.2.7%) were females, with a mean age of 44.2 years (range, 14-78 years). A total of 377 anomalies were identified, with 69 cases (7.4%) having more than one anomaly. Two hundred and fifty (26.8%) anomalies of the upper cervical region (occiput to C2-C3 disk space) were identified, with the most common upper cervical anomalies being high-riding vertebral artery (108 cases, 11.6%) and ponticulus posticus (PP) (75 cases, 8%). One hundred and twenty seven (13.6%) anomalies of the lower cervical spine (C3-C7) were noted, of which double foramen transversarium was the most common anomaly observed in 46 cases (4.8%). Conclusions: We found that 33.1% of CT scans had at least one congenital anomaly. Some anomalies, such as abnormal facet complex and arch anomalies, have to be differentiated from fractures in a trauma patient. Other anomalies, like PP, have to be looked for during preoperative planning to avoid complications during surgery. Therefore, knowledge of these anomalies is important as different anomalies have different clinical courses and management.