1.What is congenital craniocervical junctional area deformity? Congenital craniocervical junctional area deformity refers to the congenital bony deformity occurring in the craniocervical junctional area. Due to the congenital bony deformity and the complex pathological changes occurring gradually afterwards, it often leads to the compression of the medulla oblongata and the upper cervical medulla due to the final appearance of atlantoaxial dislocation, which manifests the disease symptoms with the impaired motor and sensory functions of the extremities as the main symptoms and onset. 2, then, what is the craniocervical junction area? It is the transition area between the skull and the cervical spine, specifically the occipital bone, atlantoaxial spine (first cervical spine) and the pivotal spine (second cervical spine). 3. “I seem to have this disease, but why was it not diagnosed at my previous visit, and why?” Your previous diagnosis may have been atlanto-occipital deformity, atlanto-axial subluxation, atlanto-occipital fusion, flattened skull base, fusion of 2-3 cervical vertebrae, chiari deformity, and subungual herniation deformity of the cerebellar tonsils. All of these disorders can be broadly classified as congenital craniocervical junctional anomalies, which share the same etiology, similar disease progression, and similar symptoms. However, due to the specific details of the differences, their treatment may be very different. 4.What kind of symptoms are there to suspect this disease? Patients can have no obvious signs or symptoms until they develop neurological dysfunction, however, short neck (short neck), low posterior hairline, and limited neck movement are common symptoms in such patients. The development of neurological dysfunction can have a variety of manifestations. Dissociative sensory deficits in the upper extremities, i.e., hyperalgesia and normal tactile sensation, are manifestations of spinal cord cavitation in the cervical medulla. The presence of progressive muscle weakness in the extremities further indicates that the ventral compression of the medulla oblongata and cervical medulla has led to damage to the pyramidal tracts that conduct motor functions.