Cervical and thoracic or lumbar intramedullary spinal cavernous malformations (ISCMs) may behave differently. We conducted this retrospective study by using data from adult ISCMs to compare their natural histories and explore prognostic factors for improved clinical outcomes. Neurological functions were assessed by using the Modified McCormick Scale (MMCS) and Aminoff-Logue Disability Scale. A total of 111 study-eligible adult patients were included in this study. Patients with cervical ISCMs mostly demonstrated a shorter duration of symptoms (P = 0.026), an acute onset pattern with some recovery (P = 0.026), and a larger lesion size (P = 0.033) than their thoracic or lumbar counterparts. Thoracic or lumbar lesions had a higher proportion of motor symptoms (P = 0.001) and sphincter problems (P = 0.005), and they were usually associated with an aggressive clinical course (P = 0.001, OR = 9.491, 95% CI = 2.555-35.262) in multivariate analysis. There was no difference in age, sex distribution, hemorrhage risk between the cervical and thoracic-lumbar groups. A better preoperative neurological status (P = 0.034, OR = 2.768, 95% CI = 1.081-7.177) and improvement immediately after surgery (P 0.001, OR = 8.756, 95% CI = 4.837-72.731) were identified as indicators for long-term improvement by multivariate analysis. Cervical lesions had a high proportion for long-term improvement, but it was not a predictor for improvement in multivariate analysis. ISCMs in the thoracic or lumbar location should be considered for surgical removal more aggressively than those in the cervical location. Surgical removal of symptomatic ISCMs can avoid further neurological deterioration and usually result in satisfactory long-term outcomes.
