Syringomyelia is a congenital developmental disease, but it usually occurs at the age of 20~30, occasionally occurs in children or adults, and is rarely born. According to the size, length and related lesions of syringomyelia, the clinical manifestations are different. The most typical clinical features are segmental and dissociative sensory disturbances in the neck, shoulders and upper limbs, that is, pain and temperature sense decline or absence, as well as tactile retention. After hand burns or stab wounds, patients often find pain and temperature sense's defects. The range of pain and temperature loss can be extended to the short hair distribution of upper limbs and chest and back. Insufficient joint pain can lead to joint wear and atrophy, joint deformity and swelling, increased activity, exercise friction without pain, joint in summer, late neurogenic bladder and urinary incontinence.
If syringomyelia invades the spinal nucleus of trigeminal nerve upward, it can cause facial pain, decrease or disappear the temperature sense, and the corneal reflex disappears. Spontaneous pain often occurs in the disappearance areas of pain sensation and temperature sensation. In the late stage, the posterior horn of spinal cord and lateral bundle of spinal thalamus are involved, which can cause various conduction sensory disorders below the lesion plane. Patients may suffer from unstable standing, tactile injury of upper limbs, joint position and vibration fatigue, and sensory ataxia. If the cavity expansion involves anterior horn cells, the small hand muscle and ulnar forearm atrophy and the muscle bundle vibrates. A few affect the scapular muscles and intercostal muscles of upper limbs, and the muscle tension and tendon reflex are reduced. If the cavity continues to expand, it can still invade the pyramidal tract, increase muscle tension and tendon hyperreflexia, and Babinsky sign is positive.
The exact cause and pathogenesis of syringomyelia are still unknown. At present, the common view is that syringomyelia is not caused by a single cause, but by many pathogenic factors, including congenital developmental abnormality and mechanical retardation. Syringomyelia is usually associated with other congenital developmental malformations. Many patients are accompanied by kyphosis, some with occipital deformity, short neck, low bun, congenital cervical fusion deformity, torticollis and so on. Deformation of the joint between skull base and cervical vertebra may lead to spinal canal obstruction, cerebrospinal fluid reflux obstruction and syringomyelia.