Patient, Niu, male, 37 years old. He was admitted to the hospital mainly because of numbness of the right hemithorax with no sweating for 7 years. The patient had numbness and sweatlessness in the right half of the limb with no obvious cause 7 years ago, and had a sensation of stepping on the right lower limb when walking, as well as soreness in the right lumbar region and right hip. He had encephalitis when he was 7 years old and had a history of two head traumas in 1995 and 2005. The parents were alive and there was no family history of hereditary disease. Physical examination: clear consciousness, answers to questions, no cranial deformities, no hair loss. Both eyelids were not swollen, both eyes moved autonomously, bilateral pupils were equal in size and round, about 3 mm in diameter, and responsive to light. Nystagmus was not elicited. The nasolabial folds were symmetrical bilaterally, the extended tongue was centered, and the teeth were not crooked. There were no abnormal nasal and oral secretions bilaterally. The neck was soft and non-resistant. There was no scoliosis in the spine, hyperalgesia in the right hemithorax, a demarcation line above and below the 10th plane of the chest, dry palm of the right hand, movable, and normal grip strength in both hands. The dorsal surface of both feet was pigmented, the right foot could not be dorsiflexed, the limbs moved freely, and the muscle strength and tone of the limbs were normal. The right knee reflex and Achilles tendon reflex were not elicited, while the left physiological reflex existed and no pathological reflex was elicited bilaterally. External head and neck MRI: cervical spinal cord cavity manifestation, cerebellar tonsils did not show abnormalities. Our thoracic and lumbar MRI suggested that the whole thoracic spinal cord was cavernous and there were bead-like changes in the spinal cord. Physical examination: lumbar puncture, subarachnoid space inaccessible Diagnosis: spinal cord cavitation, arachnoid adhesions