Extramedullary subdural space is a lesion of the spinal cord that compresses the spinal cord and occupies its original position, thus it is called a space-occupying lesion. Extramedullary subdural occupations may be benign or malignant, and require further testing such as MRIs and blood tests to confirm. Even for benign lesions, such as nerve sheath tumors and chordoma, surgery is usually required. Conservative treatments such as medication, massage, and warm compresses are not effective in relieving the pain and numbness caused by spinal cord compression. In most cases, extramedullary subdural spaces are considered to be malignant tumors, such as subdural chordoma and nerve sheath tumor, and epidural metastases. Malignant tumors are more complicated to treat than benign tumors, and may metastasize over time, so it is more important to go to a professional hospital as soon as possible.