I. What is spinal cavernous disease? Spinal cavernous disease is a chronic, progressive lesion of the spinal cord, characterized by the formation of tubular cavities in the spinal cord (mainly the gray matter) and glial (non-neural cell) proliferation, often in the cervical spinal cord. What is the cause of spinal cavernous disease? The cause is unknown, but there are theories such as the hydrodynamic force theory, the horizontal pressure gradient theory of the foramen magnum, the piston-like activity of the cerebellar tonsils in Chiari malformation, etc. In addition, chronic spinal arachnoiditis, spinal cord tumors, spinal cord infarction, spinal cord trauma, etc. can also cause spinal cord cavitation. What are the types of spinal cord cavitation? 1.Traffic spinal cord cavitation refers to the dilated central canal of the spinal cord communicating with the fourth ventricle, which is caused by the obstruction of cerebrospinal fluid at the exit of the fourth ventricle, and the ventricle is uniformly dilated. 2. Non-traffic spinal cord cavitation refers to dilated central spinal canal that does not communicate with the fourth ventricle, due to obstruction of cerebrospinal fluid circulation at or below the level of the foramen magnum. 3.Primary intra-parenchymal cavity refers to a cavity in the spinal cord parenchyma that does not communicate with either the central canal of the spinal cord or the fourth ventricle. 4.Atrophic spinal cord cavity occurs after spinal cord degeneration and softening, causing microcysts, fissures and limited central canal expansion in the spinal cord, which is caused by local tissue injury. 5.Neoplastic cavity is the necrotic change of intramedullary tumors such as astrocytoma, ventricular meningioma, and hemangioblastoma. What are the manifestations of spinal cavernous disease? 1, the age of onset is usually 20 to 30 years old, mostly in middle age, more women than men, the disease process is slow; the earliest symptoms are segmental distribution, first involving the upper extremities, when the cavity gradually expanded can involve the long conduction tracts in the white matter of the spinal cord and long tract dysfunction, the interval between the two can be several years. 2, sensory disorders are segmental distribution of pain and temperature loss, tactile and deep sensation intact or mildly diminished dissociative sensory disorders; the earliest involvement of the base of one or both posterior horns, the earliest unilateral pain and temperature disorders, the involvement of the anterior joint can have both hands, the ulnar side of the arm or part of the neck, loss of pain and temperature sensation in the chest, the cavity expands to the chest and back after the horse coat-like distribution of sensory disorders, the involvement of the trigeminal thalamus The involvement of the trigeminal thalamus bundle can cause hyperalgesia or loss of facial nociceptive sensation and loss of corneal reflexes (the loss of left-sided nociceptive sensation is often accompanied by central spontaneous pain), and the involvement of the spinal thalamus bundle can cause various sensory disorders and sensory planes below the cavity. 3, motor disorders are lower motor neuron damage after the involvement of the anterior horn of the spinal cord, manifested as atrophy and weakness of small muscles of the hand (such as interosseous muscles, interphalangeal muscles) and ulnar muscles of the forearm with tremor of the muscle bundles, gradually spreading to the scapular girdle and some intercostal muscles, hypotonia or disappearance of tendon reflexes, hypotonia; cone bundle signs below the cavity, increased muscle tone and hyperactive tendon reflexes, disappearance of abdominal wall reflexes, raphe reflexes, and appearance of pathological reflexes; Those with cavities in the lumbosacral region may develop the above motor and sensory disorders of the lower limbs. 4, autonomic and nutritional disorders lesioned segments may have skin dystrophy, ulcers that do not heal over time, excessive or excessive local sweating, neurogenic bladder, and urinary and fecal incontinence. 5, often accompanied by deformities such as scoliosis, spina bifida and bowed feet, joint sensory deficit causing joint wear and deformity, joint swelling forming Charcot joints, subcutaneous tissue thickening, swelling, abnormal tenderness with local ulcers and sensory deficit (Mervan syndrome). 6. Generally, abnormal gait or combined motor and sensory abnormalities are the most common complaints, and radicular pain or tenderness (different from Chiari type I pain in the neck or lower occipital region) is also more common, but Horner syndrome, Raynaud phenomenon and arthropathy have been rare. V. How can spinal cavitation be diagnosed? (1) Middle-age onset with other developmental defects in the atlanto-occipital region, segmental sensory deficits and sensory dissociation, and muscle atrophy of the hands and upper extremities. (2) Ortho-lateral and midline body X-ray of the craniocervical junction often shows bony deformities in the atlanto-occipital region, such as sunken skull base and flattened skull base. (3) CT can observe the size of the ventricles and the presence of hydrocephalus, and the injection of contrast agent can reveal the subungual herniation of the cerebellum and the presence of arachnoiditis at the skull base of the posterior cranial fossa. (4) MRI shows the size of the ventricles, the presence or absence of submicrocephalic herniation and its degree, the presence or absence of spinal cord cavity and its extent, the traffic between the cavity and the fourth ventricle and the central canal of the spinal cord, the thickness of the spinal cord and the size of the cavity and the presence or absence of separation, about 1/3 of the ventricles can be enlarged but only 7%-11% produce hydrocephalus. VI. How to treat spinal cord cavernous disease? At present, spinal cord cavity shunt and posterior cranial fossa decompression are most commonly used, especially posterior cranial fossa small bone window decompression + subchondral cerebellar tonsil electrocautery/partial resection + duralplasty is the main treatment means. VII. Can spinal cord cavitation be fully recovered? The preoperative neurological functional status is directly related to the later. Those with moderate to severe preoperative neurological dysfunction have a poor prognosis, so early surgical treatment is recommended.