1. The disease is more common in 20 to 40 years old, and there are more males than females. Clinical symptoms progress very slowly. Due to the different locations, sizes and ranges of the cavities, the symptoms are not consistent, and their preferred sites are mostly in the cervicothoracic junction of the spinal cord. Early symptoms are mostly spontaneous pain in the corresponding innervated area (the cavity begins at the bottom of the posterior horn of the dorsal gray matter of the central canal), and segmental dissociative sensory impairment, which gradually expands to the upper limbs and the back of the thorax, with a short jacket-like distribution of pain and temperature sensation loss or absence, and preservation of touch and deep sensation, which is often found by the patients who consult the doctor after the injury without any pain sensation. In the late stage, the cavities extended to the thalamic tracts of the spinal cord, and there were conductive bundle sensory deficits below the level of the cavities. Involvement of the anterior horn cells resulted in muscle atrophy of the corresponding segments, muscle fascicular tremor, decreased muscle tone and tendon reflexes, and muscle atrophy of both hands was obvious when the cavity was located in the cervical bulge. If the hollow is located in the cervical bulge, there is obvious muscle atrophy in both hands. Conic bundle sign appears below the level of the hollow, and Horner’s sign appears when the lesion invades the 8th cervical nerve to the 1st thoracic nerve lateral horn sympathetic nerve center. 3, joint pain loss can lead to neurogenic arthropathy, joint wear and tear, atrophy and deformity, joint enlargement, increased mobility, friction sound during movement without pain, i.e. Charcot (Charcot) joints. Skin trophic disorders are also more common, such as thickening and hyperkeratosis of the skin, persistent ulcers and scar formation caused by epidermal burns and cuts in areas of nociceptive deficits, and even painless necrosis and detachment of the ends of the knuckles of the fingers and toes (Morvan’s sign). Neurogenic bladder and urinary incontinence can occur in the late stage. 4, medullary cavernous disease rarely occurs alone, often for the extension of the spinal cord cavity, more asymmetric, symptoms and signs are mostly unilateral. Involvement of the spinal cord nucleus of the trigeminal nerve causes onion skin-like pain and temperature sensation in the face, which develops from the lateral side to the nasolabial area; involvement of the nucleus of the suspected cause of dysphagia and choking on drinking water; involvement of the nucleus of the hypoglossal nerve causes the tongue to be deflected to the side of the affected person, and atrophy of the lingual muscles on the same side as well as fibrillation of the muscle bundles; involvement of the nucleus of the facial nerve causes peripheral facial paralysis; involvement of the vestibulo-cerebellar pathway causes vertigo, nystagmus, and instability of the gait. Surgical treatment: Laminectomy and decompression of upper cervical segment is feasible for large cavities with spinal canal obstruction; suboccipital decompression is feasible for combined cervico-occipital deformity and subcerebellar tonsillar hernia, and surgical correction of cranial and neurological deformities is also possible. Tension cavities can be treated with myelotomy and cavity-subarachnoid shunt.